3/5/2014 Hydrocephalus Official reprint from UpToDate® www.uptodate.com ©2014 UpToDate® Hydrocephalus Authors Abilash Haridas, MD Tadanori Tomita, MD Section Editors Marc C Patterson, MD, FRACP Leonard E Weisman, MD Deputy Editor Alison G Hoppin, MD Disclosures All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Feb 2014. | This topic last updated: May 20, 2013. INTRODUCTION — Hydrocephalus is a disorder in which an excessive amount of cerebrospinal fluid (CSF) accumulates within the cerebral ventricles and/or subarachnoid spaces, which are dilated [1,2]. In children, hydrocephalus is almost always associated with increased intracranial pressure (ICP). In most cases, this is caused by excess CSF accumulating in the cerebral ventricles due to disturbances of CSF circulation (known as obstructive or non-communicating hydrocephalus). Less often, the CSF accumulates because of impaired absorption (known as communicating hydrocephalus). These types of hydrocephalus will be the focus of this topic review. By contrast, in normal pressure hydrocephalus, the cerebral ventricles are pathologically enlarged, but the ICP is within the normal range. This condition is usually caused by impaired CSF absorption. This type of hydrocephalus is more often seen in adults and is discussed separately. (See "Normal pressure hydrocephalus".) These forms of hydrocephalus are distinct from two radiographic findings that include the same word. The term “hydrocephalus ex-vacuo” refers to dilatation of the ventricles secondary to brain atrophy or loss of brain tissue secondary to an insult; hydrocephalus ex-vacuo is not accompanied by increased ICP. The term “external hydrocephalus” or “benign enlargement of the extra-axial spaces” refers to excessive fluid, usually CSF, in the subarachnoid spaces and is associated with familial macrocephaly [3,4]. EPIDEMIOLOGY — The prevalence of congenital and infantile hydrocephalus in the United States and Europe has been estimated as 0.5 to 0.8 per 1000 live and still births [5-7]. Approximately half of these cases are associated with myelomeningocele (spina bifida), but that proportion varies substantially across different populations. There is substantial familial aggregation for congenital hydrocephalus. In a population-based study of congenital hydrocephalus (not including cases associated with neural tube defects), the recurrence risk ratios for same-sex twins, first-degree relatives, and second-degree relatives were 34.8, 6.2, and 2.2, respectively [8]. PHYSIOLOGY — Cerebrospinal fluid (CSF) is produced primarily by the choroid plexus. It circulates through the ventricular system and then through subarachnoid space, in which it is absorbed into the systemic blood circulation. The flow of CSF is primarily cephalad. CSF production — CSF is produced primarily by the choroid plexus, which is responsible for 60 to 80 percent of CSF production. The choroid plexus tissue is located in each cerebral ventricle and consists of villous folds lined by epithelium with a central core of highly vascularized connective tissue. The choroidal epithelial cells produce CSF using active transport dependent upon carbonic anhydrase, which can be blocked by acetazolamide (Diamox®), a carbonic anhydrase inhibitor. In addition to the active secretion, there is a diffusion component that is not blocked by acetazolamide. The remainder of the CSF is produced by cerebral tissue, which secretes CSF directly into the extracellular space http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 1/29 3/5/2014 Hydrocephalus (there are no lymphatic channels in the central nervous system). This fluid flows through the ependymal layer into the cerebral ventricles or the spinal central canal. CSF production rates are constant in physiological conditions unless extremely high levels of intracranial pressure are reached. Thus, absorption of CSF generally matches the rate of production to accommodate the volume of CSF being formed each day. In adults, the production rate of CSF is approximately 20 mL/hour, which results in complete turnover of the CSF three or four times per day. In newborns and young children, the CSF production rate is proportional to the size of the brain. Estimates of CSF production rates in infants and children are derived from measurements of the hourly output of the CSF from external ventricular drains. These studies suggest that CSF output increases logarithmically with age and body weight, ranging from 0.1 to 26.5 mL/hour [9]. Output increases rapidly in infancy; by the age of two years, output is 64 percent of that at 15 years. The total volume of CSF in infants is approximately 50 mL, compared with 125 to 150 mL in normal adults. In adults, approximately 25 percent of the CSF is within the ventricular system. (See "Cerebrospinal fluid: Physiology and utility of an examination in disease states", section on 'Physiology of CSF formation and flow'.) CSF circulation — The CSF originating in the choroid plexus and in cerebral tissue circulates through the ventricular system into the subarachnoid space. The ventricular system is comprised of a pair of lateral ventricles, each of which connects to the midline third ventricle through an interventricular foramen (of Monro) (figure 1). There are no direct connections between two lateral ventricles because they are separated by a membrane (the septum pellucidum). The third ventricle is connected to a midline fourth ventricle by the cerebral aqueduct (of Sylvius). The CSF exits from the fourth ventricle into the subarachnoid space via three foramen: the paired lateral foramina of Luschka and a midline foramen of Magendie. Focally enlarged areas of subarachnoid spaces known as cisterns are present at the base of the brain. The cisterns in the posterior fossa connect to the subarachnoid spaces over the cerebral convexities through pathways that cross the tentorium. The basal cisterns connect the spinal and intracranial subarachnoid spaces. CSF absorption — CSF is absorbed into the systemic venous circulation primarily across the arachnoid villi into the venous channels of the major sinuses. The arachnoid villi consist of a cluster of cells that project from the subarachnoid space to the sinus lumen; these are covered by a layer of endothelium with tight junctions that are continuous with the inner layer of the sinuses. This assembly acts as a one-way valve, allowing passive absorption of CSF down a pressure gradient; if the CSF pressure is less than the venous pressure, the arachnoid villi close and do not allow blood to pass into the ventricular system. The rate of absorption is relatively linear over the physiological range. Some CSF absorption also occurs across the ependymal lining of the ventricles and the choroid plexus, as well as from the spinal subarachnoid space to the perineural spaces. Although the CSF absorption via a lymphatic system has been noted in animals, this mechanism has not been established in humans. PATHOGENESIS — Hydrocephalus results from an imbalance between the intracranial cerebrospinal fluid (CSF) inflow and outflow. It is caused by obstruction of CSF circulation, by inadequate absorption of CSF, or (rarely) by overproduction of the CSF. Regardless of the cause, the excessive volume of CSF causes increased ventricular pressure and leads to ventricular dilatation. It is increasingly recognized that many cases of hydrocephalus have both obstructive and absorptive components [10]. This accounts for the variable response to third ventriculostomy for cases of hydrocephalus previously presumed to be purely obstructive, as discussed below. Moreover, the absorptive component of the hydrocephalus and the response to treatment may change over time. (See 'Third ventriculostomy' below.) Obstruction — The most common mechanism of hydrocephalus is anatomic or functional obstruction to CSF flow (known as obstructive or non-communicating hydrocephalus). The obstruction occurs at the foramen of Monro, at the aqueduct of Sylvius, or at the fourth ventricle and its outlets. Dilatation of the ventricular system occurs proximal to the obstruction. The ventricle just proximal to the obstruction usually dilates most prominently. As examples: Obstruction of the aqueduct of Sylvius (aqueductal stenosis) causes dilation of the lateral and third http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 2/29 3/5/2014 Hydrocephalus ventricles, while the size of the fourth ventricle remains relatively normal. This is a very common cause of hydrocephalus in infants and children. Obstruction at the body of the lateral ventricle causes dilation of the distal temporal horn and atrium. Obstruction of one foramen of Monro causes dilatation of the lateral ventricle on that side. Impaired absorption — Less commonly, hydrocephalus is caused by impaired absorption of CSF, known as communicating hydrocephalus. This is typically due to inflammation of the subarachnoid villi but also may be caused by impaired CSF absorption. The radiographic hallmark of communicating hydrocephalus is dilation of the entire ventricular system, including the fourth ventricle. Impaired CSF absorption also can occur when cranial venous sinus pressure is elevated. Excessive production — Excessive production of CSF is a rare cause of hydrocephalus. This condition may occur with a functional choroid plexus papilloma. It leads to enlargement of the entire ventricular system and of the subarachnoid spaces, with a radiographic appearance that is similar to communicating hydrocephalus from other causes. (See 'Choroid plexus papilloma or carcinoma' below.) PATHOPHYSIOLOGY — The pathophysiology of hydrocephalus depends upon the underlying cause, upon how quickly the condition develops, and upon the presence of compensatory mechanisms: Hydrocephalus that begins in infancy before fusion of the cranial sutures, if untreated, typically results in marked enlargement of the head and in less destruction of brain tissue, compared with hydrocephalus that develops acutely. This is because the skull expands, partially relieving the intracranial pressure. In addition, the force of the intracranial pressure is distributed over the greater surface area of an enlarged ventricular system, so there is less pressure on the brain parenchyma compared with hydrocephalus that develops in a ventricular system that is not previously enlarged. If hydrocephalus occurs acutely or occurs after fusion of the cranial sutures, the head does not enlarge. This results in significantly increased intracranial pressure and in more rapid destruction of brain tissue. The progression of ventricular dilatation is usually uneven. The frontal and occipital horns typically enlarge first and to the greatest extent. Their progressive enlargement disrupts the ependymal lining of the ventricles, allowing the cerebrospinal fluid (CSF) to move directly into the brain tissue. This reduces CSF pressure but also leads to edema of the subependymal areas and to progressive involvement of the white matter. As the hydrocephalus progresses, edema and ischemia develop in the periventricular brain tissue, leading to atrophy of the white matter. The gyri become flattened, and the sulci become compressed against the cranium, obliterating the subarachnoid space over the hemispheres. The width of the cerebral mantle may be substantially reduced; gray matter is better preserved than white matter, even in advanced stages. The vascular system is compressed, and the venous pressure in the dural sinuses increases. ETIOLOGY — Hydrocephalus can be congenital or acquired. Both categories include a diverse group of conditions. Congenital — Congenital hydrocephalus can result from central nervous system (CNS) malformations (which include nonsyndromic and syndromic disorders), infection, intraventricular hemorrhage, genetic defects, trauma, and teratogens [11]. A rare cause of hydrocephalus is obstruction caused by a congenital CNS tumor, especially if located near the midline. The disorders can be grouped according to the primary pathogenic mechanism (obstructive versus absorptive) (table 1). Neural tube defects — The majority of patients with myelomeningocele have hydrocephalus. The etiology is obstruction of fourth ventricular outflow or flow of CSF through the posterior fossa due to the Chiari II malformation or to an associated aqueductal stenosis. This type of hydrocephalus tends to have both an obstructive component and a communicating component [10]. (See "Pathophysiology and clinical manifestations of myelomeningocele (spina http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 3/29 3/5/2014 Hydrocephalus bifida)".) Encephalocele is another relatively common neural tube defect, in which the brain and/or meninges herniate through a defect in the skull. Up to 50 percent of individuals with occipital encephalocele have associated hydrocephalus. (See "Primary (congenital) encephalocele".) Isolated hydrocephalus — Isolated hydrocephalus is frequently caused by aqueductal stenosis (image 1). This can be due to congenital narrowing of the aqueduct or can result from inflammation due to intrauterine infection. (See 'Intrauterine infection' below.) X-linked hydrocephalus — The most common genetic form of congenital hydrocephalus is X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (aqueductal stenosis), which accounts for about 5 percent of cases of congenital hydrocephalus [11]. Approximately 50 percent of affected boys have adducted thumbs, which is helpful in making the diagnosis. Some have other CNS abnormalities such as agenesis (or dysgenesis) of the corpus callosum, small brainstem, pachygyria, polymicrogyria, or absence of the pyramidal tract [12]. This disorder is due to mutations in the gene encoding L1, a neuronal cell adhesion molecule that belongs to the immunoglobulin superfamily and that is essential in neurodevelopment [13]. The gene for L1 has been mapped to Xq28. Mutations in L1 also result in other conditions, known as the L1 spectrum, that are characterized by neurologic abnormalities and by mental retardation. These include MASA spectrum (Mental retardation, Aphasia, Shuffling gait, Adducted thumbs), X-linked spastic paraplegia type 1, and X-linked agenesis of the corpus callosum. CNS malformations — CNS malformations are frequently associated with hydrocephalus. In the Chiari malformations, which often accompany a neural tube defect, portions of the brainstem and cerebellum are displaced caudally into the cervical spinal canal. This obstructs the flow of CSF in the posterior fossa, leading to hydrocephalus. (See "Chiari malformations".) The Chiari II malformation seen in spina bifida is acquired and is accompanied by other features on a magnetic resonance imaging (MRI), such as agenesis of corpus callosum low lying torcular herophili, tectal breaking, medullary kinking, and heterotopias (image 2 and image 3). The Dandy-Walker malformation consists of a large posterior fossa cyst that is continuous with the fourth ventricle and defective development of the cerebellum, including partial or complete absence of the vermis (image 4). Hydrocephalus develops in 70 to 90 percent of patients with Dandy-Walker malformation and is caused by atresia of the foramina of Luschka and Magendie. Dandy-Walker malformation is a heterogeneous disorder. Some patients have a syndromic form with associated congenital anomalies including dysgenesis of the corpus callosum, orofacial deformities, and congenital abnormalities of the heart, genitourinary, and gastrointestinal systems [14]. There is a wide range in neurodevelopmental outcomes, which depend upon the effectiveness of management of hydrocephalus as well as the associated central nervous system abnormalities. (See "Prenatal diagnosis of CNS anomalies other than neural tube defects and ventriculomegaly", section on 'Dandy-Walker malformation'.) A vein of Galen malformation is a rare cause of hydrocephalus. Obstruction results from compression of the aqueduct of Sylvius by the markedly dilated and distorted vein of Galen (image 5). The hydrocephalus in these patients is primarily caused by arterial pressure in the venous system rather than by compression of the aqueduct. Presentation in the neonatal period typically includes intractable heart failure [15]. (See "Prenatal diagnosis of CNS anomalies other than neural tube defects and ventriculomegaly", section on 'Aneurysm of the vein of Galen'.) Syndromic forms — Hydrocephalus can be part of syndromes associated with dysmorphic features and with other congenital abnormalities [11]. The most frequent cytogenetic disorders associated with hydrocephalus are trisomies 13, 18, 9, and 9p, as well as triploidy [11]. Rare autosomal recessive disorders include Walker-Warburg syndrome, which is also characterized by ocular anomalies, and hydrolethalus syndrome, in which micrognathia and postaxial polydactyly of the hands and preaxial polydactyly of the feet are associated. (See "Oculopharyngeal, http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 4/29 3/5/2014 Hydrocephalus distal, and congenital muscular dystrophies", section on 'Walker-Warburg syndrome'.) Intrauterine infection — Intrauterine infections such as rubella, cytomegalovirus, toxoplasmosis, lymphocytic choriomeningitis (LCM), and syphilis can result in congenital hydrocephalus. The mechanism is inflammation of the ependymal lining of the ventricular system and the meninges in the subarachnoid space [11]. This may lead to impaired absorption of CSF and/or to obstruction of CSF flow through the aqueduct or basal cisterns [10]. Choroid plexus papilloma or carcinoma — A papilloma or carcinoma of the chorioid plexus causes communicating hydrocephalus because of increased CSF secretion. This disorder usually can be identified by MRI (image 6). Acquired hydrocephalus Infections and tumors — Common causes of acquired hydrocephalus are CNS infections, such as bacterial meningitis or viral infections including mumps, and tumors, especially posterior fossa medulloblastomas, astrocytomas, and ependymomas. These conditions are associated with obstructed flow of CSF through the ventricular system and with impaired CSF absorption [10]. Posthemorrhagic hydrocephalus — Another important cause is hemorrhage into the subarachnoid space or, less commonly, into the ventricular system, by ruptured aneurysms, arteriovenous malformations, trauma, or systemic bleeding disorders. The hemorrhage induces an inflammatory response followed by fibrosis (image 7A-B). The main mechanism for hydrocephalus is impaired absorption of CSF (communicating hydrocephalus), although some obstruction to CSF flow also may occur. (See "Management and complications of intraventricular hemorrhage in the newborn", section on 'Posthemorrhagic hydrocephalus (PHH)'.) Posthemorrhagic hydrocephalus occurs in approximately 35 percent of preterm infants with intraventricular hemorrhage (IVH). It can be obstructive, communicating, or both and can be transient or sustained, with slow or rapid progression. (See "Management and complications of intraventricular hemorrhage in the newborn".) Low pressure hydrocephalus — This is an uncommon entity and is extremely challenging to manage. It is diagnosed when neurological improvement is attained by external ventricular drainage. Patients usually have symptomatic ventriculomegaly and surprisingly low intracranial pressure. This condition may result from tumors, chronic hydrocephalus, subarachnoid hemorrhage, and infections. Management is with low pressure shunts [16]. CLINICAL FEATURES — The signs and symptoms of hydrocephalus result from increased intracranial pressure (ICP) and dilatation of the ventricles. The time of presentation depends upon the acuity of the process. If accumulation of excessive cerebrospinal fluid (CSF) is slow, allowing adjustments to occur, the patient may have a long period without symptoms. Rapid progression of ventricular dilatation typically results in early development of symptoms. (See 'Pathophysiology' above.) Symptoms of hydrocephalus are nonspecific and independent of the etiology [17]. Headache is a prominent symptom. It is caused by distortion of the meninges and blood vessels. The pain often varies in intensity and location and may be intermittent or persistent. Headaches due to increased ICP tend to occur in the early morning and may be associated with nausea and vomiting. They tend to occur in the morning because venous pressure is higher in the recumbent position; this reduces CSF absorption and increases ICP. (See "Approach to the child with headache", section on 'Worrisome findings'.) Affected patients often have changes in their personality and behavior. These include irritability, obstreperousness, indifference, and loss of interest. The mechanism of the behavior changes is uncertain but is related, in part, to increased ICP. As the hydrocephalus worsens, midbrain and brainstem dysfunction may result in lethargy and drowsiness. Increased ICP in the posterior fossa often leads to nausea, vomiting, and decreased appetite. Physical examination — Physical findings are due to the effects of increased ICP. The following signs are often present: http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 5/29 3/5/2014 Hydrocephalus Vital signs — Distortion of the brainstem may result in changes in vital signs such as bradycardia, systemic hypertension, and altered respiratory rate. Head — Effects of hydrocephalus on the head are most obvious in infants who develop hydrocephalus while the cranial sutures are still open. Hydrocephalus is an important cause of macrocephaly in infants. Excessive head growth may be noted on serial measurements of head circumference plotted on growth curves. However, significant dilatation of the ventricles can occur before head growth becomes abnormal. The anterior fontanelle may become full or distended. The sutures feel more widely split due to an enlarging head circumference. There is an abnormal percussion note to the head when the sutures are spread (the “cracked pot” sound or Macewen’s sign) [18]. (See "Macrocephaly in infants and children: Etiology and evaluation".) Young infants may develop frontal bossing, an abnormal skull contour in which the forehead becomes prominent. The scalp veins may appear dilated and prominent. This is sometimes noted by the parents and is mentioned in the history. Cranial nerves Compression of the third or sixth cranial nerve may result in extraocular muscle pareses leading to diplopia. Pressure on the midbrain may result in impairment of upward gaze. This is known as the setting-sun sign because of the appearance of the sclera visible above the iris (picture 1), and it may be part of a larger constellation of neuro-ophthalmologic signs known as Parinaud syndrome (table 2). (See "Supranuclear disorders of gaze in children", section on 'Parinaud syndrome'.) Fundus — Funduscopic examination may reveal papilledema. Spine — The spine of children should be carefully examined for stigmata suggestive of an acquired Chiari II malformation associated with spinal dysraphism, such as a pit located above the gluteal crease, a palpable lumbar mass (suggestive of lipoma), or skin stigmata of spinal dysraphism (table 3). However, if the pit is located between the upper buttocks in the intergluteal cleft and if the coccyx is palpable, the lesion usually is benign and does not require imaging unless neurological or urinary symptoms develop. (See "Pathogenesis and types of occult spinal dysraphism".) Motor function — Stretching of the fibers from the motor cortex around the dilated ventricles may result in spasticity of the extremities, especially the legs. Growth and pubertal development — Accelerated pubertal development and disturbed growth, ans well as fluid and electrolyte homeostasis, may result from pressure of the dilated third ventricle on the hypothalamus [19]. The neurological examination of infants and children is described in detail in separate topic reviews. (See "Detailed neurologic assessment of infants and children" and "Neurological examination of the newborn".) Infants and children with suspected hydrocephalus should also be examined for associated congenital anomalies, including bilateral adducted thumbs (suggestive of X-linked hydrocephalus), ocular anomalies (suggestive of WalkerWarburg syndrome), and other syndromic features. (See 'Syndromic forms' above.) DIAGNOSIS — Hydrocephalus should be suspected in an infant whose head circumference is enlarged at birth or in whom serial measurements cross percentiles in standard growth curves, indicating excessive head growth [20]. (See "The pediatric physical examination: General principles and standard measurements", section on 'Growth http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 6/29 3/5/2014 Hydrocephalus parameters'.) In some cases, the diagnosis is made by antenatal ultrasonography. (See "Ultrasound diagnosis of neural tube defects".) Hydrocephalus should be considered in children with severe headache and other features suggesting increased intracranial pressure (ICP). (See "Approach to the child with headache", section on 'Worrisome findings'.) Imaging — The diagnosis of hydrocephalus is confirmed by neuroimaging. In a newborn, ultrasonography is the preferred technique for the initial examination because it is portable and avoids ionizing radiation. Ultrasound is good for imaging the lateral ventricles but does not assess the posterior fossa well; the diagnostic accuracy of ultrasound also depends upon the expertise of the user. As the anterior fontanelle closes, the ultrasound is no longer a useful diagnostic modality. In older infants and children with suspected hydrocephalus, computerized tomography (CT) or magnetic resonance imaging (MRI) should be performed. These imaging studies will also detect associated central nervous system (CNS) malformations or tumors. CT is fast, is reliable, and does not interfere with implanted medical devices. Head CT scanning usually can be accomplished without sedation. Disadvantages of CT scanning include radiation exposure [21]. (See "Approach to neuroimaging in children", section on 'Computed tomography'.) MRI is generally the imaging modality of choice in patients with unexplained hydrocephalus, if it is readily available. MRI provides superior visualization of pathological processes in the cerebrospinal fluid (CSF) pathway, including CSF flow dynamics. There are numerous sequences, but few will provide useful information regarding hydrocephalus. T2-weighted imaging provides information regarding the CSF spaces and cisterns. Specific sequences such as Turbo-spin echo (TSE), three-dimensional constructive interference in the steady state (3DCISS), and cine phase contrast (cine PC) have gained wide acceptance in evaluating CSF flow and anatomy [22]. (See "Approach to neuroimaging in children", section on 'Magnetic resonance imaging'.) Obstructive versus communicating hydrocephalus — Brain imaging can help to distinguish obstructive (non-communicating) from absorptive (communicating) hydrocephalus. This distinction informs treatment decisions about shunting versus third ventriculostomy. (See 'Management' below.) The site of obstructed CSF flow may be suggested by the pattern of ventricular dilatation. Stenosis of the aqueduct (a common type of obstructive hydrocephalus) typically results in dilated lateral and third ventricles and in a fourth ventricle of normal size. In contrast, communicating hydrocephalus (eg, caused by either extraventricular obstruction or by impaired CSF absorption) in neonates and infants usually results in symmetric dilatation of all four ventricles. If extraventricular obstruction or impaired CSF absorption occurs in children and adults, it may cause benign intracranial hypertension (pseudotumor cerebri) without ventricular dilatation, because of reduced compliance of the brain tissue. Hydrocephalus versus atrophy — It may be difficult to differentiate hydrocephalus from ventriculomegaly due to cerebral atrophy (“hydrocephalus ex-vacuo”). The following characteristics are suggestive of hydrocephalus, rather than ventriculomegaly secondary to atrophic brain: Enlargement of the recesses of the third ventricle Dilation of the temporal horns of the lateral ventricle Interstitial edema of the periventricular tissues (seen on T2-weighted or FLAIR [fluid-attenuated inversion recovery] MRI sequences) Effacement of the cortical sulci Antenatal MRI — Antenatal MRI of the fetus is becoming a more common practice and is often used to further evaluate ventricular abnormalities detected by fetal ultrasonography. Ventriculomegaly is diagnosed if the ventricular atrium exceeds 10 mm at any gestational age [23]. The posterior portion of the lateral ventricles is normally larger than the anterior portion in the fetus, and the discrepancy becomes less marked as the fetus approaches term. This configuration is called colpocephaly and is often misinterpreted as hydrocephalus by clinicians lacking experience in fetal imaging. http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 7/29 3/5/2014 Hydrocephalus Lumbar puncture — If an infection causing adhesive arachnoiditis or ependymitis is suspected, a lumbar puncture (LP) should be performed, and the CSF should be examined. However, LP is contraindicated if the patient has evidence of a space-occupying lesion such as an intracranial tumor or a brain abscess, because of the risk of cerebral herniation. Thus, neuroimaging should be performed prior to LP in an infant or child with hydrocephalus. (See "Lumbar puncture: Indications, contraindications, technique, and complications in children".) MANAGEMENT — Most cases of hydrocephalus are progressive, meaning that neurological deterioration will occur if the hydrocephalus is not effectively and continuously treated. The most effective treatment is surgical drainage, using a shunt or third ventriculostomy. In cases of hydrocephalus caused by a vein of Galen malformation, embolization of the malformation may be more appropriate than surgical drainage [24,25]. Shunting can be effective for hydrocephalus caused either by obstruction or by impaired cerebrospinal fluid (CSF) absorption (communicating hydrocephalus). By contrast, third ventriculostomy is only effective for obstructive hydrocephalus; it may be the optimal procedure for obstructive hydrocephalus including aqueductal stenosis [26]. However, many types of hydrocephalus have both obstructive and absorptive components, so the selection of procedure is not always clear [10]. Rarely, hydrocephalus is not progressive because alternate pathways of CSF absorption develop or because normal mechanisms for CSF handling become reestablished. This is known as “arrested hydrocephalus.” In this case, shunt revision is unnecessary. Shunt — A mechanical shunt system is placed to prevent the excessive accumulation of CSF. The shunt allows CSF to flow from the ventricles into the systemic circulation or to the peritoneum where it is absorbed, bypassing the site of mechanical or functional obstruction to absorption. Shunts consist of the following components: A catheter is placed into one of the lateral ventricles (usually the right). The catheter is connected to a one-way valve system (usually placed beneath the scalp of the postauricular area) that opens when the pressure in the ventricle exceeds a certain value. The ventricular pressure decreases as fluid drains, resulting in closure of the valve until the pressure increases again. The distal end of the system is connected to a catheter that is placed in the right atrium of the heart (ventriculoatrial [VA]) or into the peritoneal cavity (ventriculoperitoneal [VP]). Complications — In general, complications of treated hydrocephalus are due to malfunction of the shunt. If the shunt malfunctions and if the mechanism causing the hydrocephalus is still active, symptoms of hydrocephalus recur, and a shunt revision or other drainage procedure is required. Malfunction may be caused by infection or mechanical failure. Approximately 40 percent of standard shunts malfunction within the first year after placement, and 5 percent per year malfunction in subsequent years [27-29]. Infection — Shunt infection is a common complication, occurring in approximately 5 to 15 percent of procedures [27,28,30]. This may lead to ventriculitis [31], may promote the development of loculated compartments of CSF, and may contribute to impaired cognitive outcome and death [27]. The risk of shunt infections may be higher in newborns compared with shunts placed in older infants and children [32]. Most shunt infections occur in the first six months after shunt placement. This is important in the algorithm of deciding when to tap shunts to evaluate a fever, especially when there is no clinical or radiographic evidence of mechanical shunt failure. Infection must be considered in a child with a shunt who develops persistent fever. Antibiotics should be started, but this treatment alone is usually not effective. In most cases, an infected shunt must be removed, and an external ventricular drain must temporarily be placed. Perioperative antibiotic prophylaxis may reduce the risk of infection. In a meta-analysis of 17 trials in 2134 participants, prophylactic antibiotics in the perioperative period and antibiotic-impregnated catheters reduced http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 8/29 3/5/2014 Hydrocephalus the risk of shunt infection by approximately 50 percent [33]. Whether prophylactic antibiotics are beneficial after the perioperative period remains uncertain. Mechanical failure — Mechanical shunt failure is another important cause of shunt failure. Like shunt infection, it is most common during the first year after shunt placement [27]. More than half of first shunt failures result from obstruction at the ventricular catheter [27]. One mechanism is excessive drainage of CSF (overdrainage), which greatly reduces the size of the ventricles. This causes the catheter to lie against the ependyma and choroid plexus, and these tissues block the holes at the end of the catheter. Fractured tubing is the cause of shunt failure in approximately 15 percent of cases. Other causes include migration of part or all of the shunt (7.5 percent). Overdrainage — In addition to obstruction, overdrainage can cause functional shunt failure, which causes subnormal intracranial pressure (particularly in the upright position) and which is associated with characteristic neurological symptoms such as postural headache and nausea [27]. Overdrainage can also lead to slit-ventricle syndrome, which is characterized by small or slit-like ventricles, coupled with transient episodes of symptoms of raised ICP [34]. Changes in shunt design to address the problem of overdrainage include valves designed to open at different pressures and selected based upon the patient’s characteristics; anti-siphoning devices to minimize the siphon effect caused by changes in posture; and valves that regulate by flow rather than by pressure differences. Third ventriculostomy — Endoscopic third ventriculostomy (ETV) is a procedure in which a perforation is made to connect the third ventricle to the subarachnoid space. This has been used in the initial treatment of selected cases of obstructive hydrocephalus and as an alternative to shunt revision. Some experts consider it the treatment of choice for aqueductal stenosis, although about 20 percent of patients still require shunting [26]. ETV is not useful for patients with communicating hydrocephalus (due to impaired CSF absorption). The success of the procedure depends upon the cause of hydrocephalus and upon previous complications [35-37]. When successful, ETV provides a treatment for hydrocephalus that is relatively low-cost and durable. In an observational study, the quality of life one year after the procedure was similar for patients treated with ETV compared with those treated with VP shunting [38]. In an analysis of 618 ETV procedures performed at 12 international institutions, the overall success of ETV was 66 percent six months after the procedure [39]. Older age at the time of the procedure (eg, greater than one year of age) was by far the strongest predictor of success, and noninfectious etiologies (eg, myelomeningocele, intraventricular hemorrhage, aqueductal stenosis, or tectal tumor) and lack of previous shunt were also important predictors. Based upon these data, the investigators retrospectively developed and validated an ETV success score that predicts the likelihood of early success. For the patients with successful ETV at six months, more than 80 percent are still successful five years later. In a follow-up study, the same investigators found that the best ETV candidates (high ETV success score) had substantially better outcomes after ETV compared with shunt. By contrast, for those with a low ETV success score, the risk of ETV failure is initially higher than the risk of shunt failure but becomes lower than the risk of shunt failure six months after the intervention [40]. Criteria for selection of patients for ETV versus shunting are not fully established. In our practice, we use the following approach: We generally perform ETV for patients with fourth ventricular outlet obstruction or with clear aqueductal stenosis and for those with pineal region tumors and tectal tumors, because these respond well to ETV. We generally do not perform ETV in patients with a history of intraventricular hemorrhage, meningitis, or previous shunting, because the likelihood of success is low. However, if patients with these disorders also have acquired aqueductal stenosis, we generally attempt ETV prior to pursuing shunting, because we have had moderate success with this approach. We generally do not perform ETV in infants with obstructive hydrocephalus who are younger than three http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=h… 9/29 3/5/2014 Hydrocephalus months of age, because the likelihood of success is around 25 percent in this age group, as compared with a 45 percent success rate in infants between three and six months of age [41] and with a success rate of 64 percent in those between 6 and 12 months of age [39]. Complications of third ventriculostomy are mainly perioperative and include inability to complete the procedure, hemorrhage, hypothalamic dysfunction (diabetes insipidus, syndrome of inappropriate antidiuretic hormone secretion, or precocious puberty), meningitis, and cerebral infarction. In a systematic review, permanent morbidity after the procedure was 2.1 percent, and mortality was 0.22 percent [42]. If ETV is performed, it is important to monitor the patient postoperatively with serial clinical examinations and imaging to determine if the procedure was successful. If the hydrocephalus progresses, a shunting procedure generally is performed, because repeating the ETV acutely is not likely to be successful [10]. Medical therapy — Nonsurgical treatment for hydrocephalus includes the use of diuretics, fibrinolysis, and serial lumbar punctures. These procedures have significant complications and are less effective than surgical treatment. Diuretics and fibrinolytics — The diuretics furosemide and acetazolamide decrease CSF production. They have been used for short periods in slowly progressive hydrocephalus in patients too unstable for surgery. In newborn infants with posthemorrhagic hydrocephalus, treatment with diuretics is generally not effective and is associated with complications. Treatment with fibrinolytic agents has had mixed results in this group of patients and also is associated with significant complications. These issues are discussed in a separate topic review. (See "Management and complications of intraventricular hemorrhage in the newborn", section on 'Management of PHH'.) Serial lumbar punctures — Repeated lumbar punctures have been used as a temporizing measure in preterm infants with post-hemorrhagic hydrocephalus, although they do not appear to be effective. In a systematic review of four trials, the relative risks for shunt placement, death, disability, and multiple disability were similar for repeated lumbar puncture and for supportive measures alone [43]. However, drainage of CSF was considered a reasonable treatment when evidence of increased intracranial pressure exists. In cases of rapidly progressive hydrocephalus, a temporary ventricular drainage device (ventriculostomy) may be needed until a permanent shunt can be placed or until the hydrocephalus resolves spontaneously [44,45]. (See "Management and complications of intraventricular hemorrhage in the newborn", section on 'Management of PHH'.) OUTCOME — The outcome of hydrocephalus depends upon the etiology, the associated abnormalities, and the complications such as infection. Survival — Survival in untreated hydrocephalus is poor. Approximately 50 percent of affected patients die before three years of age, and 77 to 80 percent die before reaching adulthood [27]. Treatment markedly improves the outcome for hydrocephalus not associated with tumor, with 89 and 95 percent survival in two reports [32,46]. Epilepsy — Seizures occur frequently in children with shunted hydrocephalus [46-48]. In one report from France of 802 children treated with VP shunt and followed for a mean of eight years, 32 percent had epilepsy [48]. Seizures often started approximately at the time at which the diagnosis of hydrocephalus was made. However, shunt placement and complications also predisposed to epilepsy. The incidence of seizures varied according to the etiology of hydrocephalus. The risks in patients with infection, with cerebral malformations or intraventricular hemorrhage (IVH), and with spina bifida were approximately 50, 30, and 7 percent, respectively [48]. Seizures are associated with poor cognitive outcome. In the large French series, fewer children with seizures had normal cognition (intelligence quotient [IQ] >90) compared with those without seizures (24 versus 66 percent) [48]. Seizures in this setting can be subclinical or can occur exclusively at night [49]. Electroencephalogram (EEG) monitoring should be considered in patients with neurologic deterioration who do not appear to have shunt failure or infection. http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 10/29 3/5/2014 Hydrocephalus Functional outcome — Functional outcome depends upon factors including degree of prematurity, central nervous system (CNS) malformations, other congenital abnormalities, and epilepsy, as well as sensory and motor impairments [27]. A Hydrocephalus Outcome Questionnaire has proven to be a useful tool to measure the physical, emotional, cognitive, and social function of hydrocephalic children, aspects of health that are often overlooked [50,51]. Few studies of long-term outcome are available. In a report from France, outcome at 10 years was evaluated in 129 consecutive children with hydrocephalus without tumor who had shunt placement before two years of age [46]. Motor deficits, visual or auditory deficits, and epilepsy occurred in 60, 25, and 30 percent of patients, respectively. IQ was >90 in 32 percent and was <50 in 21 percent. Attendance at a normal school was possible for 60 percent, although one-half were one to two years behind for their age or were having difficulties. Of the remainder, 31 percent were in special classes or were institutionalized, and 9 percent were not considered educable. In a series from the United Kingdom, 155 children with shunted hydrocephalus were followed for 10 years or until death (which occurred in 11 percent) [32]. For survivors, until school age, 59 percent attended a normal school. Children with hydrocephalus caused by infection or by IVH were more likely to need special school than were those with congenital hydrocephalus (52 and 60 percent versus 29 percent). Cognitive outcome at 5 to 10 years of age was assessed in 73 children with hydrocephalus born in Sweden between 1989 and 1993 [52]. IQ was ≥85 in 33 percent, 70 to 84 in 30 percent, 50 to 69 in 21 percent, and <50 in 16 percent. Median IQ was decreased among those who were born preterm compared with term (median IQ score 68 versus 76); among those with isolated hydrocephalus at birth compared with those with hydrocephalus and myelomeningocele or with acquired hydrocephalus (median IQ score 60 versus 77); and among those with cerebral palsy and/or epilepsy compared with those without (median IQ score 66 versus 78). There was a discrepancy between median verbal and performance IQ (90 and 76, respectively), which has been noted in other studies [53]. In extremely low-birthweight infants, hydrocephalus associated with intraventricular hemorrhage and a shunt correlated with adverse neurodevelopmental outcomes at 18 to 22 months follow-up, compared with children with and without severe intraventricular hemorrhage and with no shunt [54]. INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and “Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon. Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on “patient info” and the keyword(s) of interest.) Basics topics (see "Patient information: Hydrocephalus (The Basics)") SUMMARY AND RECOMMENDATIONS Most cases of hydrocephalus in children are caused by excess CSF accumulating in the cerebral ventricles due to disturbances of CSF circulation (known as obstructive or non-communicating hydrocephalus). Less often, the CSF accumulates because of impaired absorption (known as communicating hydrocephalus) or because of excessive CSF production. (See 'Pathogenesis' above.) Untreated hydrocephalus that begins in infancy before fusion of the cranial sutures typically results in http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 11/29 3/5/2014 Hydrocephalus marked enlargement of the head and in less destruction of brain tissue compared with hydrocephalus that develops acutely. This is because the skull expands, partially relieving the intracranial pressure. As hydrocephalus progresses, edema and ischemia develop in the periventricular brain tissue, leading to atrophy of the white matter. (See 'Pathophysiology' above.) Common causes of congenital hydrocephalus include intraventricular hemorrhage and neural tube defects including myelomeningocele. Other causes include infection, genetic defects (X-linked hydrocephalus), trauma, tumors, and teratogens. These disorders can be grouped according to the primary pathogenic mechanism (obstructive versus absorptive) (table 1). The signs and symptoms of hydrocephalus result from increased intracranial pressure (ICP) and dilatation of the ventricles. The time of presentation depends upon the acuity of the process. Symptoms of hydrocephalus are nonspecific and independent of the etiology. Headache is a prominent symptom; it tends to occur in the early morning and may be associated with nausea and vomiting. Affected patients often have changes in their personality and behavior. (See 'Clinical features' above.) Hydrocephalus should be suspected in an infant whose head circumference is enlarged at birth or in whom serial measurements cross percentiles in standard growth curves, indicating excessive head growth. The diagnosis is confirmed by head ultrasonography in infants and by computerized tomography (CT) or magnetic resonance imaging (MRI) in older infants or children. Brain imaging can help to distinguish obstructive (non-communicating) from absorptive (communicating) hydrocephalus, and this information informs treatment decisions. (See 'Imaging' above.) Most cases of hydrocephalus are progressive, meaning that neurological deterioration will occur if the hydrocephalus is not effectively and continuously treated, using shunting or endoscopic third ventriculostomy (ETV). In general, ETV is the procedure of choice for pure obstructive hydrocephalus. Shunting is used for patients with communicating hydrocephalus or for those in whom ETV is not successful. However, many forms of hydrocephalus have both obstructive and absorptive components, so the outcome of ETV cannot be consistently predicted. (See 'Management' above.) Most complications of treated hydrocephalus are due to malfunction of the shunt. If the shunt malfunctions and if the mechanism causing the hydrocephalus is still active, symptoms of hydrocephalus recur, and a shunt revision or other drainage procedure is required. Shunt malfunction may be caused by infection or by mechanical failure. Approximately 40 percent of standard shunts malfunction within the first year after placement. (See 'Complications' above.) Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Fishman MA. Hydrocephalus. In: Neurological pathophysiology, Eliasson SG, Prensky AL, Hardin WB (Eds), Oxford, New York 1978. 2. Carey CM, Tullous MW, Walker ML. Hydrocephalus: Etiology, Pathologic Effects, Diagnosis, and Natural History. In: Pediatric Neurosurgery, 3 ed, Cheek WR (Ed), WB Saunders Company, Philadelphia 1994. 3. Hellbusch LC. Benign extracerebral fluid collections in infancy: clinical presentation and long-term follow-up. J Neurosurg 2007; 107:119. 4. Bateman GA, Napier BD. External hydrocephalus in infants: six cases with MR venogram and flow quantification correlation. Childs Nerv Syst 2011; 27:2087. 5. Fernell E, Hagberg G, Hagberg B. Infantile hydrocephalus epidemiology: an indicator of enhanced survival. Arch Dis Child Fetal Neonatal Ed 1994; 70:F123. 6. Jeng S, Gupta N, Wrensch M, et al. Prevalence of congenital hydrocephalus in California, 1991-2000. Pediatr http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 12/29 3/5/2014 Hydrocephalus Neurol 2011; 45:67. 7. Garne E, Loane M, Addor MC, et al. Congenital hydrocephalus--prevalence, prenatal diagnosis and outcome of pregnancy in four European regions. Eur J Paediatr Neurol 2010; 14:150. 8. Munch TN, Rostgaard K, Rasmussen ML, et al. Familial aggregation of congenital hydrocephalus in a nationwide cohort. Brain 2012; 135:2409. 9. Yasuda T, Tomita T, McLone DG, Donovan M. Measurement of cerebrospinal fluid output through external ventricular drainage in one hundred infants and children: correlation with cerebrospinal fluid production. Pediatr Neurosurg 2002; 36:22. 10. Beni-Adani L, Biani N, Ben-Sirah L, Constantini S. The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices. Childs Nerv Syst 2006; 22:1543. 11. Schrander-Stumpel C, Fryns JP. Congenital hydrocephalus: nosology and guidelines for clinical approach and genetic counselling. Eur J Pediatr 1998; 157:355. 12. Graf WD, Born DE, Sarnat HB. The pachygyria-polymicrogyria spectrum of cortical dysplasia in X-linked hydrocephalus. Eur J Pediatr Surg 1998; 8 Suppl 1:10. 13. Fransen E, Van Camp G, Vits L, Willems PJ. 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Accelerated pubertal development in patients with shunted hydrocephalus. Arch Dis Child 1996; 74:490. 20. Rekate HL. Treatment of Hydrocephalus. In: Pediatric Neurosurgery, 3, Cheek WR (Ed), WB Saunders Company, Philadelphia 1994. 21. Brunetti MA, Mahesh M, Nabaweesi R, et al. Diagnostic radiation exposure in pediatric trauma patients. J Trauma 2011; 70:E24. 22. Dinçer A, Özek MM. Radiologic evaluation of pediatric hydrocephalus. Childs Nerv Syst 2011; 27:1543. 23. Cavalheiro S, Moron AF, Almodin CG, et al. Fetal hydrocephalus. Childs Nerv Syst 2011; 27:1575. 24. Jea A, Bradshaw TJ, Whitehead WE, et al. The high risks of ventriculoperitoneal shunt procedures for hydrocephalus associated with vein of Galen malformations in childhood: case report and literature review. Pediatr Neurosurg 2010; 46:141. 25. Schneider SJ, Wisoff JS, Epstein FJ. Complications of ventriculoperitoneal shunt procedures or hydrocephalus associated with vein of Galen malformations in childhood. Neurosurgery 1992; 30:706. 26. Cinalli G, Spennato P, Nastro A, et al. Hydrocephalus in aqueductal stenosis. Childs Nerv Syst 2011; 27:1621. 27. Chumas P, Tyagi A, Livingston J. Hydrocephalus--what's new? Arch Dis Child Fetal Neonatal Ed 2001; 85:F149. 28. Drake JM, Kestle JR, Milner R, et al. Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus. Neurosurgery 1998; 43:294. 29. Stein SC, Guo W. Have we made progress in preventing shunt failure? A critical analysis. J Neurosurg Pediatr 2008; 1:40. 30. Langley JM, LeBlanc JC, Drake J, Milner R. Efficacy of antimicrobial prophylaxis in placement of http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 13/29 3/5/2014 Hydrocephalus cerebrospinal fluid shunts: meta-analysis. Clin Infect Dis 1993; 17:98. 31. Forward KR, Fewer HD, Stiver HG. Cerebrospinal fluid shunt infections. A review of 35 infections in 32 patients. J Neurosurg 1983; 59:389. 32. Casey AT, Kimmings EJ, Kleinlugtebeld AD, et al. The long-term outlook for hydrocephalus in childhood. A ten-year cohort study of 155 patients. Pediatr Neurosurg 1997; 27:63. 33. Ratilal B, Costa J, Sampaio C. Antibiotic prophylaxis for surgical introduction of intracranial ventricular shunts. Cochrane Database Syst Rev 2006; :CD005365. 34. Agarwal N, Vernier E, Ravenscroft S, et al. Slit ventricle syndrome: a case report of intermittent intracranial hypertension. J Child Neurol 2013; 28:784. 35. Siomin V, Cinalli G, Grotenhuis A, et al. Endoscopic third ventriculostomy in patients with cerebrospinal fluid infection and/or hemorrhage. J Neurosurg 2002; 97:519. 36. Scarrow AM, Levy EI, Pascucci L, Albright AL. Outcome analysis of endoscopic III ventriculostomy. Childs Nerv Syst 2000; 16:442. 37. Javadpour M, Mallucci C, Brodbelt A, et al. The impact of endoscopic third ventriculostomy on the management of newly diagnosed hydrocephalus in infants. Pediatr Neurosurg 2001; 35:131. 38. Drake JM, Kulkarni AV, Kestle J. Endoscopic third ventriculostomy versus ventriculoperitoneal shunt in pediatric patients: a decision analysis. Childs Nerv Syst 2009; 25:467. 39. Kulkarni AV, Drake JM, Mallucci CL, et al. Endoscopic third ventriculostomy in the treatment of childhood hydrocephalus. J Pediatr 2009; 155:254. 40. Kulkarni AV, Drake JM, Kestle JR, et al. Predicting who will benefit from endoscopic third ventriculostomy compared with shunt insertion in childhood hydrocephalus using the ETV Success Score. J Neurosurg Pediatr 2010; 6:310. 41. Ogiwara H, Dipatri AJ Jr, Alden TD, et al. Endoscopic third ventriculostomy for obstructive hydrocephalus in children younger than 6 months of age. Childs Nerv Syst 2010; 26:343. 42. Bouras T, Sgouros S. Complications of endoscopic third ventriculostomy: a systematic review. Acta Neurochir Suppl 2012; 113:149. 43. Whitelaw A. Repeated lumbar or ventricular punctures in newborns with intraventricular hemorrhage. Cochrane Database Syst Rev 2001; :CD000216. 44. Berger A, Weninger M, Reinprecht A, et al. Long-term experience with subcutaneously tunneled external ventricular drainage in preterm infants. Childs Nerv Syst 2000; 16:103. 45. Heep A, Engelskirchen R, Holschneider A, Groneck P. Primary intervention for posthemorrhagic hydrocephalus in very low birthweight infants by ventriculostomy. Childs Nerv Syst 2001; 17:47. 46. Hoppe-Hirsch E, Laroussinie F, Brunet L, et al. Late outcome of the surgical treatment of hydrocephalus. Childs Nerv Syst 1998; 14:97. 47. Klepper J, Büsse M, Strassburg HM, Sörensen N. Epilepsy in shunt-treated hydrocephalus. Dev Med Child Neurol 1998; 40:731. 48. Bourgeois M, Sainte-Rose C, Cinalli G, et al. Epilepsy in children with shunted hydrocephalus. J Neurosurg 1999; 90:274. 49. Caraballo RH, Bongiorni L, Cersósimo R, et al. Epileptic encephalopathy with continuous spikes and waves during sleep in children with shunted hydrocephalus: a study of nine cases. Epilepsia 2008; 49:1520. 50. Kulkarni AV, Donnelly R, Shams I. Comparison of Hydrocephalus Outcome Questionnaire scores to neuropsychological test performance in school-aged children. J Neurosurg Pediatr 2011; 8:396. 51. Kulkarni AV, Drake JM, Rabin D, et al. Measuring the health status of children with hydrocephalus by using a new outcome measure. J Neurosurg 2004; 101:141. 52. Lindquist B, Carlsson G, Persson EK, Uvebrant P. Learning disabilities in a population-based group of children with hydrocephalus. Acta Paediatr 2005; 94:878. 53. Brookshire BL, Fletcher JM, Bohan TP, et al. Verbal and nonverbal skill discrepancies in children with hydrocephalus: a five-year longitudinal follow-up. J Pediatr Psychol 1995; 20:785. http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 14/29 3/5/2014 Hydrocephalus 54. Adams-Chapman I, Hansen NI, Stoll BJ, et al. Neurodevelopmental outcome of extremely low birth weight infants with posthemorrhagic hydrocephalus requiring shunt insertion. Pediatrics 2008; 121:e1167. Topic 6174 Version 11.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 15/29 3/5/2014 Hydrocephalus GRAPHICS Subarachnoid spaces and cisterns as seen in a median section of the brain The superior cistern (located dorsal to the midbrain) together with the subarachnoid space at the sides of the midbrain are referred to clinically as the cisterna ambiens. The superior cistern is important because it contains internal cerebral veins which join caudally to form the great cerebral vein (of Galen). It also contains the posterior cerebral and superior cerebellar arteries. The choroid plexuxes in the roof of the third and fourth ventricles are shown in red. Graphic 74410 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 16/29 3/5/2014 Hydrocephalus Common causes of hydrocephalus in the infant and newborn: Classification of obstructive versus absorptive hydrocephalus Communicating hydrocephalus Permanent impaired absorption: Primary congenital hydrocephalus Malformed brain Developmental/genetic association Secondary prenatal hydrocephalus Posthemorrhagic Postinfectious Secondary postnatal hydrocephalus Prematurity-related Posthemorrhagic Postinfectious Venous congestion: craniosynostosis, achondroplasia Venous thrombosis: superior vena cava obstruction after cardiac surgery Increased secretion: Choroid plexus papilloma/carcinoma Communicating hydrocephalus, with an obstructive component Tumors Intraventricular hemorrhage resulting in a clot at aqueduct or fibrosis of aqueduct (acute phase)* Intraventricular hemorrhage resulting in intracranial cysts (acute phase)* Infection resulting in intracranial cysts Meningitis/encephalitis resulting in secondary obstruction* Chiari 2 malformation Dandy Walker malformation Holoprosencephaly: lobar, semilobar, alobar Encephalocele Lissencephaly Hydranencephaly Obstructive hydrocephalus, with a transient minor communicating component Same as group 2, subacute or late phase (at least several months from primary insult: infection, bleed)* Large arachnoid cysts Chromosomal abnormalities, syndromic, genetic: http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 17/29 3/5/2014 Hydrocephalus X-linked hydrocephalus (mostly aqueductal stenosis) Osteogenesis imperfecta C raniofacial syndromic disorders Part of metabolic inherited disease: Hurler's disease (MPS T1) Achondroplasia Obstructive hydrocephalus (pure) Intracranial cysts with no evidence of bleed at diagnosis Triventricular hydrocephalus due to radiologically apparent aqueductal stenosis Membranous obstruction of aqueduct Asymmetrical hydrocephalus, due to atresia of the foramen of Monro Obstruction of fourth ventricle outlets * In these disorders, the communicating component is initially prominent, but tends to decrease over time, so that the obstructive component predominates in the later phases. Reproduced from: Beni-Adani L, Biani N, Ben-Sirah L, Constantini S. The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices. Childs Nerv Syst 2006; 22:1543; with kind permission from Springer Science + Business Media B.V. Graphic 82965 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 18/29 3/5/2014 Hydrocephalus Aqueductal stenosis due to a tectal lesion Sagittal T1 weighted magnetic resonance imaging (MRI) showing aqueductal stenosis. The hydrocephalus was treated with a third ventriculostomy. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 78793 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 19/29 3/5/2014 Hydrocephalus Hydrocephalus due to a Chiari II malformation Sagittal T1 weighted magnetic resonance imaging (MRI) showing acquired hydrocephalus due to a Chiari II malformation in a child with spina bifida. Note the shallow posterior fossa and descent of cerebellar tonsils past the foramen magnum. Other findings include large massa intermedia, low lying torcula, and partial agenesis of the corpus callosum. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 57510 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 20/29 3/5/2014 Hydrocephalus Intracranial MRI findings of a child with a Chiari II malformation A sagittal T1-weighted MRI in a pediatric patient shows several characteristic intracranial findings of the Chiari II malformation, including downward displacement of cerebellar tissue through the foramen magnum (white arrow), a small fourth ventricle (yellow arrow), and tectal beaking (pink arrow). Courtesy of Eric D Schwartz, MD. Graphic 61496 Version 4.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 21/29 3/5/2014 Hydrocephalus Hydrocephalus associated with Dandy Walker malformation Four-month-old child with a Dandy Walker malformation, showing agenesis of the cerebellar vermis and a large posterior fossa cyst. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 69351 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 22/29 3/5/2014 Hydrocephalus Hydrocephalus due to a vein of Galen malformation Vein of Galen malformation, causing hydrocephalus. (Panels A-D) Axial T2 weighted magnetic resonance imaging (MRI). (Panels E, F) Cerebral angiogram. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 79131 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 23/29 3/5/2014 Hydrocephalus Hydrocephalus due to a choroid plexus papilloma Magnetic resonance imaging in a 10-month-old male infant, showing a papilloma of the choroid plexus in the right lateral ventricle. There is associated hydrocephalus, caused by overproduction of cerebrospinal fluid (CSF). Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 60156 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 24/29 3/5/2014 Hydrocephalus Hydrocephalus due to germinal matrix intraventricular hemorrhage (IVH) of prematurity Ultrasound in an infant with grade IV intraventricular hemorrhage. (Panel A) Coronal view. (Panel B) Sagittal view. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 71951 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 25/29 3/5/2014 Hydrocephalus Post hemorrhagic hydrocephalus sequelae Coronal T2 weighted MRI in a child with communicating hydrocephalus. Courtesy of Drs. Abilash Haridas and Tadanori Tomita. Graphic 82502 Version 1.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 26/29 3/5/2014 Hydrocephalus Parinaud syndrome (dorsal midbrain syndrome) The patient has (A) bilateral lid retraction, pupillary dilatation; (B) the inability to look upward. The pupils do not react to light but do constrict to near effort. Reproduced with permission from: Tasman W, Jaeger E. The Wills Eye Hospital Atlas of Clinical Ophthalmology, 2nd ed, Lippincott Williams & Wilkins, 2001. Copyright © 2001 Lippincott Williams & Wilkins. Graphic 58178 Version 2.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 27/29 3/5/2014 Hydrocephalus Ophthalmic findings in the Parinaud syndrome Vertical gaze abnormalities, especially upgaze Downward gaze preference or tonic downward deviation of the eyes ("setting-sun sign") Primary position upbeat or downbeat nystagmus Impaired convergence and divergence Excessive convergence tone Convergence-retraction nystagmus Skew deviation, often with the higher eye on the side of the lesion Alternating adduction hypertropia or alternating adduction hypotropia Bilateral upper eyelid retraction (Collier "tucked-lid" sign) Bilateral ptosis Pupillary abnormalities (large with light-near dissociation) Modified with permission from: Lee AG, Brazis PW. Clinical Pathways in Neuro-ophthalmology: An Evidence-based Approach, Thieme, New York 1998. Graphic 81227 Version 4.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 28/29 3/5/2014 Hydrocephalus The cutaneous syndrome in occult spinal dysraphism Patch of hyperkeratosis Patch of hypertrichosis Patch of hyperpigmentation Patch of epidermal atrophy (may be tender) Subcutaneous mass (lipoma or neurofibroma) Capillary hemangioma or cutaneous angioma Dorsal dermal sinus Sacrococcygeal pit Sacrococcygeal dimple Caudal cutaneous appendage (true tail or pseudotail) Isolated deviation of the intergluteal fold Courtesy of Chaouki Khoury, MD, MS. Graphic 76756 Version 3.0 http://www.uptodate.com.proxy2.lib.umanitoba.ca/contents/hydrocephalus?topicKey=PEDS%2F6174&elapsedTimeMs=0&source=search_result&searchTerm=… 29/29
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