Symposium on Neurological Disorder–Advances in Management-II
Neurocysticercosis in Children
Pratibha Singhi and Sunit Singhi
Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
ABSTRACT
Neurocysticercosis (NCC) is a common cause of seizures and neurologic disease. Although there may be variable
presentations depending on the stage and location of cysts in the nervous system, most children (> 80%) present with
seizures particularly partial seizures. About a third of cases have headache and vomiting. Diagnosis is made by either CT
or MRI. Single enhancing lesions are the commonest visualization of a scolex confirms the diagnosis. Some cases have
multiple cysts with a characterstic starry-sky appearance. Management involves use of anticonvulsants for seizures and
steroids for cerebral edema. The use of cysticidal therapy continues to be debated. Controlled studies have shown that
cysticidal therapy helps in increased and faster resolution of CT lesions. Improvement in long - term seizure control has not
yet been proven. Children with single lesions have a good outcome and seizure recurrence rate is low. Children with
multiple lesions have recurrent seizures. Extraparenchymal NCC has a guarded prognosis but it is rare in children. In
endemic areas NCC must be considered in the differential diagnosis of seizures and various other neurological disorders.
[Indian J Pediatr 2009; 76 (5) : 537-545] Email: [email protected]
Key words : Neurocysticercosis (NCC); Seizures; Cysts; Diagnosis; Management
Neurocysticercosis (NCC) is a major cause of
neurological disease world-wide.1,2 It is an important
cause of epilepsy in the tropics3 and was found to be the
commonest cause of focal seizures in North Indian
children.4 Although predominantly seen in developing
countries, it is also seen in many developed countries
mainly because of increasing number of immigrants
from endemic areas. Inspite of its recognition for several
years, many aspects related to diagnosis and
management remain controversial.
contagious eggs in the stools.
Pigs are the intermediate hosts and get infected by
eating food contaminated with parasitic eggs passed
in human faeces. The eggs hatch into larvae in the pigs’
intestine and cross the mucosa, to reach tissues, where
they mature into cysticerci over a period of 3 weeks to 2
months. When humans consume undercooked pork
containing the cysts, the life cycle of the parasite is
completed.
Neurocysticercosis is caused by infestation of the CNS
with encysted larvae of Taenia solium. It must be
distinguished from taeniasis which represents
intestinal infection with T Solium that is acquired
from pigs by ingestion of undercooked pork infected
with cysticerci. The larvae from these cysticerci
evaginate and develop into adult worms which live in
the intestine and shed thousands of extremely
NCC on the other hand is acquired through the
faeco-oral route. Infection occurs when humans eat raw
vegetables contaminated with T Solium eggs or food
prepared by carriers of tapeworms. Very rarely infection
may occur due to autoingestion of ova in patients who
have intestinal tape worms. As in pigs, in the human
intestine the eggs hatch to release larvae that penetrate
the intestinal mucosa, and migrate throughout the body
to produce human cysticercosis. Although the cysts
may be found in any human tissue, most mature cysts
are found in the CNS, skeletal muscle, subcutaneous
tissue, and the eyes. Generally the cysts tend to locate in
areas with high blood flow especially the grey white
matter junction.
Correspondence and Reprint requests : Dr Pratibha Singhi,
Professor of Pediatrics, Chief, Pediatric Neurology and Neuro
Development, Department of Pediatrics, PGIMER, Chandigarh160 012, India. Fax: 91-172-2744401 & 2745078
[Received March 17, 2009; Accepted March 17, 2009]
(i)
Pathogenesis:
Cycsticerci
often
live
asymptomatically within host tissues for years as they
have developed various mechanisms for evading host
response. 5 Metacestodes secrete a serine protease
inhibitor- taeniaestatin which inhibits complement
activation and cytokine production and interferes with
ETIOLOGY
Life cycle of the parasite
Indian Journal of Pediatrics, Volume 76—May, 2009
537
Pratibha Singhi and Sunit Singhi
leukocyte chemotaxis. Parasite paramyosin also binds
to C1q and inhibits the classic pathway of complement
activation. The cellular immune response is also
suppressed.5
The cyst has 4 stages
1. Vesicular Stage (Metacestode)- The parasite lives in
tissues as a fluid- filled cyst with a thin
semitransparent wall. The scolex lies invaginated on
one side of the cyst and appears as an opaque 4-5 mm
nodule. These viable cysts are generally asymptomatic.
Once the cysts start degenerating, an inflammatory
response is elicited and the cyst goes through the
following stages2. Colloidal stage: The larva undergoes hyaline
degeneration and gelatinous material appears in cyst
fluid.
3. Granular nodular stage: The cyst contracts and the
walls are replaced by focal lymphoid nodules and
necrosis.
4. Nodular calcified stage: The granulation tissue is
replaced by collagenous structures and calcification (6).
CLINICAL MANIFESTATIONS
These are pleomorphic and are determined mainly by
the location, number and viability of the cysts as well as
by the host response. NCC is generally classified into
(a) parenchymal and (b) extra parenchymal which
includes ventricular, cisternal, ophthalmic or spinal.
Most children present with single degenerating
parenchymal cysts, some with multiple cysts. It is not
clearly understood as to why some cases have single
and others have multiple cysts. Immunological
differences may possibly account for this; defective
functions of neutrophils and T lymphocytes have been
reported in patients with multiple lesions only and not
in those with single lesions.7
Parenchymal NCC
Most cases of childhood NCC are seen after five years of
age although some cases are seen in preschoolers and
even in infants. The common clinical manifestations
include:
(i) Seizures. Sudden onset of seizures in otherwise
healthy children is the commonest presentation.
Seizures occur in 70-90% of cases; in a series of 500
children from India, seizures were reported in 94.8%
cases.8 Most children present with partial seizures (8487%)8,9,10 particularly complex partial seizures; about a
quarter have simple partial seizures.8 Most seizures are
of short duration, generally lasting for less than 5
minutes. Status epilepticus has been reported in 1.7% to
538
32% cases. 8,9,10 Seizures are generally single; in a
hospital based study, NCC was discovered on imaging
in 59.2% of cases with single seizures.11 Depending on
the stage of the disease, the seizures may be considered
provoked or unprovoked, and these may co-exist.
Although it is presumed that degeneration of the cysts
and the associated inflammatory response evoke
seizures, this has been questioned in a recent study
wherein 29% asymptomatic family members of
symptomatic cases were diagnosed to have NCC. A
large number of individuals harboring different stages
of cysticerci in their brain were asymptomatic.12 NCC
has been found to be associated with mesial temporal
lobe epilepsy due to hippocampal sclerosis –this may
provide new insights into epileptogenesis.13
(ii) Raised intracranial pressure: headache and
vomiting occur in almost a third of cases. 10
Papilloedema has been reported in 2.3 9 to 6.6% of
children.8 Signs of raised ICP and papilleodema are less
common in children as compared to adults.
(iii) Focal Neurodeficits: determined by the location of
the cysts. Transient hemiparesis, monoparesis, and
oculomotor abnormalities are common. Focal deficits
were seen in 4% of children, 8 as compared to 16% of
adults. 14
(iv) Cysticercal Encephalitis: rarely massive cyst
burden with diffuse cerebral edema may present with
severe acute raised intracranial pressure and an
encephalitic picture in some children and adolescents.
These cases are difficult to treat and have high
mortality and neuromorbidity.
Extraparenchymal NCC: This is rare in children as
compared to adults.
(i) Ventricular and Subarachnoid NCC: generally occur
together and present as basilar arachnoiditis,
obstructive hydrocephalous or chronic meningitis.
Some subarachnoid cysts may enlarge without scolices,
become racemose and cause mass effects .
Seizures may occur in cases with associated
parenchymal NCC.
(ii) Spinal cysticercosis: is rare (1-5%) in children.
Cysts are generally located in the leptomeningeal space
but may occasionally be found within the cord.
Radicular pain, paresthesias, and spinal cord
compression may occur. Intramedullary cysts may
present as transverse myelitis with paraplegia and
sphincteric disturbances.
(iii) Ophthalmic cysticercosis: cysts may lodge
anywhere in the eyes including the subretinal space,
vitreous humor, subconjuctiva or anterior chamber.
Symptoms occur accordingly and include visual
deficits, sudden blindness, limitation of eye movements
etc.
Indian Journal of Pediatrics, Volume 76—May, 2009
Neurocysticercosis in Children
Unusual presentations: These are variable and
include communicating hydrocephalous, vasculitis,
stroke,15 learning disability and behavioural changes,
dorsal midbrain syndrome, ptosis, papillitis, cerebral
hemorrhage, dystonia,. neurocognitive deficits and
psychiatric morbidity particularly depression
syndromes in adults.16
DIAGNOSIS
NCC should be considered in the differential diagnosis
of patients with seizures, headache, vomiting and other
neurological symptoms and signs. Since pathologic
confirmation of the parasite is hardly ever feasible,
diagnosis rests mainly on neuroimaging.
CT Scan
Fig. 1B. Single Small Enhancing CT Lesion- disc.
(a) Parenchymal NCC
The appearance of cysts on CT varies with the stage.
Vesicular cysts generally appear as small round lesions
with CSF density cystic fluid; the wall is isodense to the
brain parenchyma. They are non-enhancing or mildly
enhancing and are not surrounded by edema.
Degenerating (colloidal vesicular) cysts appear as small
low-density lesions with ring or disc enhancement (Fig
1A , B). The scolex appears as a bright high density
eccentric nodule in these cysts and is pathognomonic
of NCC. Perilesional edema of varying grades is seen in
over half the cases. In most cases the lesions are single
and <20mm in size- termed as single small enhancing
computed tomographic lesion (SSECTL).17 Fig 1(A and
B). Some children may have multiple lesions;
disseminated NCC with numerous cysts may give the
so called “starry –sky” appearance which is typical of
NCC (Fig. 2). Calcified cysts are few mm in size, single
or multiple and generally without any surrounding;
oedema. However in children with active seizures,
Fig. 2. CT scan showing Multiple Neurocysticercosis.
oedema may at times be seen around calcified lesions.18
(b) Extraparenchymal NCC
In subarachnoid NCC, the CT may show
hydrocephalous, enhancement of tentorium and basal
cisterns due to arachnoiditis and occasionally infarcts.
Very raely, racemose cysts may be seen as cystic
hypodense lesions in the sylvian fissure or
cerebellopontine angle. Rarely intraventricular cysts
may cause obstruction and hydrocephalous .
MRI
Fig. 1A. Single Small Enhancing CT Lesion- ring with scolex and
perilesional edema.
Indian Journal of Pediatrics, Volume 76—May, 2009
Identification of scolex and visualization of
extraparenchymal cysts is better with MRI . Live cysts
are seen as round lesions either isointense or slightly
hyperintense to the CSF. The scolex is seen as a nodule
539
Pratibha Singhi and Sunit Singhi
that is isointense or hyperintense relative to white
matter. On T2 weighted images, the perilesional oedema
appears bright and because of the high intensity cystic
fluid, the scolex may not be seen. The scolex is better
seen on proton density –weighted images. Gadolinium
enhanced MRI shows ring enhancement of lesion.
Calcified lesions appear hypointense on all MR
imaging sequences and may at times be missed. The
issue about which MRI sequence is best suited for NCC
has been discussed.19
For usual cases of suspected NCC, getting a CT scan
is enough ; however MRI is more sensitive for detecting
scolex and extraparenchymal NCC.20
In cases where the scolex is not well seen, it may be
difficult to make the diagnosis of NCC with certainity;
other sophisticated imaging techniques are therefore
being researched.
Proton Magnetic Resonance Spectroscopy (MRS)
has been tried for evaluation of inflammatory
granulomas. 21 It has been suggested that presence of
lipid indicates a tuberculoma whereas low levels of
metabolites together with a poor signal/noise ratio
could indicate NCC.
3D constructive interference in Steady State
(3DCISS) - In a study, it was found to be more
sensitive and specific than routine SE sequences in the
diagnosis of intraventricular cysticercal cysts.-scolex
was seen in all 11 patients.22
DWI MRI
Higher apparent diffusion co-efficient (ADC) is seen in
core of cysticercus cysts compared to tuberculomas and
tubercular abscess.23 Most of these imaging techniques
are investigational and are not routinely used.
Serological Tests
None of the several immunologic tests that have been
developed, is very sensitive or specific for diagnosis of
NCC particularly for single lesions. Low positivity
from 17 to 25% has been reported in children with
NCC.8,9
The widely used Enzyme Linked Immunosorbent
Assay (ELISA) showed 50% sensitivity and 65%
specificity in the CSF. 24 The Enzymelinked
immunoelectro transfer blot (EITB) assay using purified
glycoprotein antigens from T. Solium cysticerci has
been reported to be highly specific and nearly 100%
sensitive for patients with either multiple active
parenchymal cysts or extraparenchymal NCC. 25
However, sensitivity is less for patients with either
single cysts or calcifications alone. In a comparative
study of ELISA and dot-blot assay, in children aged 512 yr, both assays were more sensitive in the detection
of the specific antibody response, in cases with multiple
540
brain lesions (100%) than in in those with single-lesion
(87%).26 The detection of antibodies to antigens of 26
Kda and 8 RDA by immunoblot using a crude
antigenic preparation of T. Solium cysticercci has been
shown to approach 100% specificity but is less sensitive
than the glycoprotein based EITB 27 and has been less
extensively assessed. Lower molecular mass (20-24
kDa) Taenia solium cysticercus antigen fraction by
ELISA and dot blot for the serodiagnosis of
neurocysticercosis in children has also been evaluated.
28
Other Tests
(i) X-Rays: Calcified cysts may be detected in skeletal
muscles –however X-rays are not routinely done in
children with NCC.
(ii) Stool examination for tapeworms is not helpful
in diagnosis of NCC.
(iii) Biopsy of subcutaneous nodules in a patient
with suspected NCC, can corroborate the diagnosis in
doubtful cases.
(iv) Blood: Peripheral eosinophilia is variably
reported in about one third of cases.
(v) CSF : Analysis is is not routinely indicated in
cases of parenchymal NCC; if done it is normal in most
cases. In patients with NCC meningitis, CSF may show
mild elevation of protein with some pleocytosis and
hypoglycorrhachia. The cellular response may be
lymphocytic, polymorphonuclear or monocytic.
Other laboratory tests are usually normal in NCC
To ensure uniformity in diagnosis, criteria for
human
cysticercosis
and
neurocysticercosis
incorporating clinical, radiological, immunologic and
epidemiologic data of patients were proposed in 199629
and revised in 200030 Four degrees of criteria- absolute,
major, minor and epidemiologic were selected to give a
definitive or a probable diagnosis. However, in view of
the pleomorphism of the disease, NCC should be kept
in the differential diagnosis of a wide variety of
neurologic disorders particularly seizures, and
appropriate neuroimaging studies should be
undertaken to confirm the diagnosis.
DIFFERENTIAL DIAGNOSES
Parenchymal NCC. When the scolex is not well seen, a
number of conditions need to be considered in the
differential diagnosis of SSECTL. These include
(i)
Tuberculoma this is the commonest differential
diagnosis in developing countries. Certain criteria
such as the presence of raised ICP, progressive
focal neurodeficit, size of CT lesion> 20 mm,
Indian Journal of Pediatrics, Volume 76—May, 2009
Neurocysticercosis in Children
lobulated irregular shape, and marked edema
causing midline shift favour the diagnosis of
tuberculoma,31 but are not absolute.Tuberculomas
are most often seen in the posterior fossa or base of
the brain whereas NCC lesions are seen near the
gray white junction of the cortex. Mantoux test, Xray chest and other tests for exclusion of
tuberculosis should be done in all cases of
enhancing lesions where the scolex is not seen.
(ii) Other differential diagnoses include microabscess,
low grade astrocytoma, cystic cerebral metastasis,
toxoplasmosis and fungal lesion.17
Extraparenchymal NCC. Hydrocephalous with
racemose NCC in the subarachnoid space may
simulate a low density tumor. Meningitis due to NCC
needs to be differentiated from other causes of chronic
meningitis.
TREATMENT
Therapeutic measures for NCC may be considered as:
(i) Symptomatic/supportive
(ii) Definitive- medical/surgical treatment for cysts
Symptomatic
(a) Anticonvulsants: As most cases present with
seizures, antiepileptic drugs (AED) are required. The
seizures are usually controlled with a single
anticonvulsant.
Recurrence of seizures after
discontinuation of AEDs has been variably reported. In
children with SSECTL, seizure recurrence is low and
varies from 10 to 20% of cases.9,32 a higher recurrence
rate of 54.4% was reported in one study of 28 children
with NCC.33 The rate of recurrence is generally higher
(40- 50%) in adults.34
The duration of AED therapy has been debated. The
conventional practice has been to use AED for about
two years seizure free interval. However, shorter
durations of AED may be sufficient.35 A randomised
controlled prospective study found no difference in
seizure recurrence when AEDs were given for a one
year vs two years seizure free interval. 36 Seizure
recurrence correlated significantly with an abnormal
CT (persistence or calcification of lesion) and an
abnormal EEG at the time of withdrawal. Children
having both CT and EEG abnormalities were at a
significantly higher risk of seizure recurrence.36 Thus
anticonvulsant therapy may be withdrawn after oneyear seizure free interval in those children where the
lesion has disappeared and the EEG is normal prior to
withdrawal. Children with persistent or calcified
lesions may require longer therapy.
Shorter durations of AEDs for three months have
Indian Journal of Pediatrics, Volume 76—May, 2009
also been tried. However, in a study (personal
unpublished data) this was associated with a higher
seizure recurrence as compared to one year therapy.
Most cases have partial seizures hence
carbamazepine is the preferred drug: Other AEDs could
also be used, provided the efficacy and side effects are
carefully considered.
(b) Corticosteroids: A short course of corticosteroids is
generally used concomitantly with anticysticercal
therapy to prevent or ameliorate any adverse reactions
that may occur due to the host inflammatory response
during the active inflammatory phase. 37 Acute
symptomatic patients who have cerebral edema on
neuroimaging, may be given oral prednisolone 1-2 mg/
kg or I.V dexamethasone if there are features of raised
ICP. Rarely steroids may be required for several weeks
particularly in children with disseminated lesions and
extensive cerebral oedema.
Definitive Therapy
The debate whether medical treatment for NCC is
effective or ineffective has continued for long even
though praziquantel and albendazole have been found
effective against T. Solium cysticerci in several studies.
The two main outcome measures of cysticidal therapy
are (i) cyst destruction and (ii) seizure control.
Cyst Destruction
Both praziquantel and albendazole were found to be
effective in destroying viable cysts. 38,39,40,41 The main
controversy revolves around the use of these agents in
cases with enhancing lesions as these are considered to
represent degenerating cysts. In the first double-blind
placebo controlled trial in 63 children, in whom
albendazole (15mg/kg/dayx 4 weeks) was given
within 3 months of onset of seizures there was an
increased and faster resolution of SSECTL. 42
Disappearance of lesions was seen in 41% of
albendazole vs 16.2% of placebo treated patients after 1
month (p < 0.05) and 64.5% of albendazole vs 37.5% of
placebo treated patients after 3 months of follow up (p
<0.05). Subsequently other trials have also shown
increased
disappearance
of
lesions
with
albendazole. 43,44,45 However, in a placebo-controlled
study that included adults after variable times (1 day to
6 years) of onset of seizures, no beneficial effect of
albendazole therapy was observed.46
A meta- analysis 47 of all studies of anticysticercal
treatment of NCC from 1966- June 1999, could find only
4 trials in which albendazole or praziquantel was
compared with either placebo or no treatment, using
randomised or quasirandomised method. It revealed
lower risk of cyst persistence in CT at 6 months among
those who received anticysticercal therapy. The same
authors updated the meta-analysis in 2007 and
541
Pratibha Singhi and Sunit Singhi
concluded that there is insufficient evidence to assess
whether cysticidal therapy in neurocysticerosis is
associated with beneficial effects. 48 However, another
meta-analysis of studies between 1979 and 2005
included eleven studies -six trials randomly assigned
464 patients with cystic lesions (vesicular cysticerci),
and 5 trials randomly assigned 478 patients with
enhancing lesions (colloidal cysticerci). In trials of
vesicular lesions, cysticidal therapy was associated
with complete resolution of cystic lesions (44% vs 19%;
P = 0.025). Trials on enhancing lesions showed a trend
toward lesion resolution favoring the use of cysticidal
drugs (72% vs 63%; P = 0.38) that became statistically
significant when an outlier trial was excluded from the
analysis (69% vs 55%; P = 0.006). 49 On the basis of
evidence, cysticidal therapy is effective in increasing the
destruction of viable cysts as well as the resolution of
enhancing lesions.
CLINICAL OUTCOME
Improved seizure control after cysticidal therapy has
been reported in some studies. A strong correlation
between the use of anticysticercal drugs and the rate of
seizure control was found in adults with epilepsy due
to NCC.14,50,51 It was also found that focal neurodeficits
improved after treatment with anticysticercal drugs. An
improved outcome was reported in 80% of patients in
whom treatment was given soon after recognition of
SSECTL.52 In a double-blind, placebo-controlled trial in
which 120 patients who had living cysticerci in the
brain, cysticidal therapy was effective, at least in
reducing the number of seizures with generalization.53
However, other studies have not found any significant
improvement in seizure control both in patients with
live cysts and multiple or single enhancing lesions.32,45,54
In a meta analysis of randomised studies referred
above, 47 Salinas et al could find only two controlled
studies which had studied seizure control as an
outcome. The authors did not report decrease in seizure
recurrence; however, the numbers studied were small.
On the other hand, in the meta-analysis of randomised
studies by del Brutto et al,49 risk for seizure recurrence
was lower after cysticidal treatment in patients with
enhancing lesions (14% vs 37%; P < 0.001). The single
trial evaluating the frequency of seizures in patients
with cystic lesions showed 67% reduction in the rate of
generalized seizures with treatment (P=0.006). On
balance, there is insufficient evidence to determine
whether cysticidal therapy improves long term seizure
control and larger studies are required to answer this
question.
Choice of Cysticidal Drug
Although both praziquantel and albendazole have been
found effective in NCC, Albendazole is better than
542
praziquantel,40,41 is less expensive and better tolerated.
It also has a greater penetration into the subarachnoid
space and is therefore better for treatment of
subarachnoid NCC. Also, bioavailability of
albendazole increases with co-administration of
steroids and is not affected by phenytoin and
carbamezepine, 55 whereas that of praziquantel
decreases with co-administration of steroids,56 and with
phenytoin and carbamezepine which are generally
used as first line anticonvulsants in patients with
seizures due to NCC.57 Albendazole is currently the
drug of choice for treatment of NCC .
Albendazole has been used in a dose of 15 mg/kg/
day in 2-3 divided doses for 28 days.35 Shorter durations
of 14 days to 8 days have also been used.35 In a placebocontrolled trial of one week vs four weeks albendazole
therapy in children with one to three enhancing lesions
both the regimens were found to be equally effective.58
Resolution of lesions on 3 months CT was seen in
68.3% and 68.8% in the one week and four weeks
treatment groups respectively. Seizure control at 1 year
was similar in both the groups.58
Albendazole has also been used successfully for the
treatment of spinal NCC, 59 and meningeal NCC. In
cases with subarachnoid giant cysts, 60,61 steroids are
recommended before, during and after albendazole
therapy to prevent cerebral infarction which may occur
secondary to occlusive endarteritis induced by the host
inflammatory response. Praziquantel has been
generally used in a dose of 50mg/kg/day for a period
of 15 days. A single day praziquantel therapy (25 mg/
kg/dose every 2 hours x 3 doses) has been reported to
be as effective as 7 days treatment with albendazole.62
optimisation of single day therapy with a high
carbohydrate diet and cimetidine reportedly induced
83% elimination of cysticerci.63 A combination therapy
of albensazole and praziqunatel was found to have no
significant difference in the outcome of single lesion
NCC as compared to albendazole alone (although it
was associated with a trend to higher resolution). 64
Cysticidal therapy should not be used in cases with (i)
markedly raised ICP particularly in disseminated NCC
as sudden elevations of ICP may occur secondary to the
host inflammatory response. and in (ii) ophthalmic
NCC -as the host response may cause damage to the
eye. Such cases should be treated with steroids alone.
Cysticidal therapy is not indicated for calcified lesion
(s) as the parasite is already dead and buried. In view of
the controversies involved, consensus guidelines for the
treatment of NCC were published.35 and rediscussed.65
As NCC is a pleomorphic disease, treatment
approaches differ among the forms or types of NCC
and need to be individualized.
Surgery
Some cases with hydrocephalous may need shunt
Indian Journal of Pediatrics, Volume 76—May, 2009
Neurocysticercosis in Children
placement; steroids and albendazole are used
concomitantly to reduce shunt failure. Successful
endoscopic removal of cysts from the lateral, third and
fourth ventricles may obviate the need for shunt66,67 and
may be safer, faster, and curative with better long-term
clinical outcomes. Rarely, surgical removal may be
required in some cases of ophthalmic NCC; almost all
of these studies are in adults as extraparenchymal NCC
is rare in children
Follow up
This needs to be individualized. For single enhancing
lesions, a repeat CT after 3-6 months is generally
indicated to determine whether the lesions have
resolved.68
Outcome
The outcome depends upon the type of NCC, cyst
location and numbers. In general parenchymal NCC
has a better prognosis than extraparenchymal NCC and
single lesions have a better outcome as compared to
multiple lesions. In most children with seizures and
single parenchymal cysts seizures are well controlled
and lesions disappear within 6 months in over 60%
cases. Risk of seizure recurrence is low. Cases with
multiple lesions particularly disseminated NCC and
calcifications have frequent seizure recurrences. A
genetic susceptibility to NCC has been suggested by a
reported positive association of HLA- DRBII 13 with
SSECTL(s).69
Prevention
NCC is a disease perpetuated by poor hygiene and
sanitation. Lack of proper animal husbandry and meat
inspection procedures in developing countries, wherein
pigs are left to scavenge for food from open sewage
systems, are responsible for ongoing transmission.
Preventive efforts have to be directed against these.
Mass treatment of population with praziquantel to
eradicate human taeniasis resulted in marked reduction
in intestinal tapeworm carriage and rate of porcine
cysticercosis in Equador 70 and in Mexico.71 However,
these programs were shown to be ineffective when reevaluated some years after their application.72 Public
awareness and insistence on hygiene and sanitation are
of utmost importance.
CONCLUSION
Neurocysticercosis is the commonest cause of acquired
seizures in children. As neurocysticercosis may have
variable neurological manifestations, it needs to be
considered in the differential diagnosis of a number of
neurological diseases. Treatment with cysticidal drugs
is associated with increased and faster resolution of
lesions and is usually well tolerated; however it needs
Indian Journal of Pediatrics, Volume 76—May, 2009
to be individualized. Children with single or few
lesions have a good outcome whereas those with
multiple lesions often have recurrent seizures. Public
sanitation and hygiene are of utmost importance in
prevention.
REFERENCES
1. White AC. Neurocysticercosis: A major cause of
neurological disease worldwide. Clin Infect Dis 1997; 24:
101-115.
2. Roman G, Sotelo J, Del Brutto O et al. A proposal to declare
neurocysticercosis an international reportable disease. Bull
World Health Organ 2000; 78: 399-406.
3. Commission on Tropical Diseases of the International
League Against Epilepsy. Relationship between Epilepsy
and tropical diseases. Epilepsia 1994; 35: 89-93.
4. Singhi S, Singhi P. Clinical profile and etiology of partial
seizures in North Indian Infants and children. J Epilepsy
1997; 10: 32-36.
5. Leid RW, Suquet CM, Tanigoshi L. Parasite defense
mechanisms for evasion of host attack: a review. Vet
Parasitol 1987; 25: 147-162.
6. Escobar A. The pathology of neurocysticercosis. In Palacios
E, Rodriguez- Carbajal KJ, Taveras J, eds. Cysticercosis of the
central nervous system. Illinois: Springfield, Charles C
Thomas, 1983; 27-54.
7. Thussu A, Sehgal S, Sharma M, Lal V, Sawhney IMS,
Prabhakar S. Comparison of cellular responses in single and
multiple lesions neurocysticercosis. Ann Trop Med Parasitol
1997; 91: 627-632.
8. Singhi P, Ray M, Singhi S, Khandelwal N. Clinical spectrum
of 500 children with neurocysticercosis and response to
albendazole therapy. J Child Neurol 2000; 15: 207-213.
9. Talukdar B, Saxena A, Popli VK, Choudhury V.
Neurocysticercosis in children: clinical characteristics and
outcome. Annals Trop Pediatr 2002; 22: 333-339.
10. Morales NM, Agapejev S, Morales RR, Padula NA, Lima
MM. Clinical aspects of neurocysticercosis in children.
Pediatr Neurol 2000; 22: 287-291.
11. Singh G, Singh P. Singh I, Rani A, Kaushal S, Avasthi G.
Epidemiologic classification of seizures associated with
neurocysticercosis: observations from a sample of seizures
disorders in neurologic care in India. Acta Neurol Scand 2006;
113: 233-240.
12. Prasad A, Gupta RK, Pradhan S, Tripathi M, Pandey CM,
Prasad KN. What triggers seizures in neurocysticercosis? A
MRI- based study in pig farming community from a district
of North India. Parasitol Int 2008; 57: 166-171.
13. Wichert-Ana L, Velasco TR, Terra-Bustamante VC et al.
Surgical treatment for mesial temporal lobe epilepsy in the
presence of massive calcified neurocysticercosis. Arch Neurol
2004; 61 : 1117–1119.
14. Del Brutto OH, Santibanez R, Noboa CA et al. Epilepsy due
to neurocysticercosis: Analysis of 203 patients. Neurology
1992; 42 : 389-392.
15. Del Brutto OH. Cysticercosis and cerebrovascular disease: a
review. J Neurol Neurosurg Psychiatry 1992; 55 : 252-254.
16. Forlenza OV, Filho AH, Nobrega JP et al. Psychiatry
manifestations of neurocysticercosis; a study of 38 patients
from a neurology clinic in Brazil. J Neurol Neurosurg
Psychiatry 1997; 85: 612-616.
17. Singhi PD., Baranwal AK. Single small enhancing computed
tomographic lesion in Indian children-I: Evolution of
current concepts. J Trop Pediatr 2001; 47: 204-207.
543
Pratibha Singhi and Sunit Singhi
18. Antoniuk SA, Bruck I, Dos Santos LH et al. Seizures
associated with calcifications and edema in neurocysticercosis. Pediatr Neurol 2001; 25: 309-311.
19. Sotelo J. Which MRI sequences are best suited to the
evaluation of patients with neurocysticercosis? Nat Clin
Pract Neurol 2008; 4: 72-73.
20. Garcia HH, Del Brutto OH. Imaging findings in
neurocysticercosis. Acta Trop 2003; 87 : 71-78.
21. Jayasundar R, Singh VP, RaghunathanP, Jain K, Banerji AK.
Inflammatory granulomas: evaluation with proton MRS.
NMR Biomed 1999; 12: 139-144.
22. Govindappa SS, Narayanan JP, Krishnamoorthy VM,
Shastry CH, Balasubramaniam A, Krishna SS. Improved
detection of intraventricular cysticercal cysts with the use
of three-dimensional constructive interference in steady
state MR sequences. Am J Neuroradiol 2000; 21 : 679-684.
23. Gupta RK, Prakash M, Mishra AM, Husain M, Prasad KN,
Husain N. Role of diffusion weighted imaging in
differentiation of intracranial tuberculoma and tuberculous
abscess from cysticercus granulomas-a report of more than
100 lesions. Eur J Radiol 2005; 55 : 384-392.
24. 24.Rosas N, Sotelo J, Neito D. ELISA in the diagnosis of
neurocysticercosis. Arch Neurol 1986; 43: 353-356.
25. Wilson M, Bryan RT, Fried JA et al. Clinical evaluation of
the cysticercosis enzyme linked immunoelectrotransfer blot
in patients with neurocysticercosis. J Infect Dis 1991; 164:
1007-1009.
26. Mandal J, Singhi PD, Khandelwal N, Malla N. Evaluation
of ELISA and dot blots for the serodiagnosis of
neurocysticercosis, in children found to have single or
multiple enhancing lesions in computerized tomographic
scans of the brain. Ann Trop Med Parasitol 2006; 100 : 39-48.
27. Rodriguez- Canul R, Allan JC, Fletes C et al. Comparative
evaluation of purified Taenia solium glycoproteins and
crude metacestode extracts by immunoblot for the
serodiagnosis of human Taenia Solium cysticercosis. J Clin
Diagnostic Lab Immunol.
28. Mandal J, Singhi PD, Khandelwal N, Malla N. Evaluation
of lower molecular mass (20-24 kDa) Taenia solium
cysticercus antigen fraction by ELISA and dot blot for the
serodiagnosis of neurocysticercosis in children. Parasitol Res
2008; 102 : 1097-1101. .
29. Del Brutto OH, Wadia NH, Dumas M et al. Proposal of
diagnostic criteria for human cysticercosis and
neurocysticercosis. J Neurol Sci 1996; 142: 1-6.
30. Del Brutto OH, Rajshekhar V, White AC et al. Proposed
diagnostic criteria for
neurocysticercosis. Neurology 2001;
57: 177-183.
31. Rajshekhar V, Haran RP, Prakash S, Chandy MJ.
Differentiating solitary small cysticercus grandulomas and
tuberculomas in patients with epilepsy- clinical and
computerized tomographic criteria. J Neurosurgery 1993; 78:
402-407.
32. Baranwal AK, Singhi P, Singhi S, Khandelwal N. Seizure
recurrence in children with focal seizures and single small
enhancing computed tomographic lesions. Prognostic
Factors on Long-Term follow-Up. J Child Neurol 2001;16:
443-445.
33. Ferreira LS, Zanardi VA, Scotoni AE, Li LM, Guerreiro MM.
Childhood epilepsy due to neurocysticercosis: a
comparative study. Epilepsia 2001, 42: 1438-1444.
34. Del Brutto AH. Prognostic factors for seizure recurrence
after withdrawal of antiepileptic drugs in patients with
neurocysticercosis. Neurology 1994; 44: 1706-1709.
35. Garcia H H, Carlton A, W Evans, Nash TE et al. Current
Consensus Guidelines for Treatment of neurocysticercosis.
Clinical Microbiology Reviews 2002; 15: 747-756.
544
36. Singhi P, Dinakaran, Khandelwal NK. One year versus two
years of antiepileptic therapy for SSECTL. J Trop. Pediatr
2003; 5 : 274-278.
37. Singhi PD. Concomitant steroid and albendazole for
treating neurocysticercosis. Indian Pediatr 1999; 36 : 1176.
38. Sotelo J, Torres B, Rubio-Donnadieu F, Escobedo F,
Rodriquez-Carbajal J. Praziquantel in the treatment of
neurocysticercosis: long term follow-up. Neurology 1985; 35:
752-754.
39. Escobedo F, Penagos P, Rodriquez J. Sotelo J. Albendazole
therapy for neurocysticercosis. Arch Intern Med 1987; 147:
738-741.
40. Cruz M, Cruz L, Horton J. Albendazole vs praziquantel in
the treatment of cerebral cysticercosis: clinical evaluation
Trans R Soc Trop Med Hyg 1991; 85: 244-247.
41. Takayanaqui OM, Jardim E.
Therapy for
neurocysticercosis: comparison between albendazole and
praziquantel. Arch Neurol 1992; 49 : 290-294.
42. Baranwal AK, Singhi PD, Khandelwal N, Singhi SC.
Albendazole therapy in children with focal seizures and
single small enhancing computerized tomographic lesions:
a randomized placebo- controlled, double blind trial.
Pediatr Infect Dis J 1998; 17: 696-700.
43. Kalra V, Dua T, Kumar V. Efficacy of albendazole and
short-course dexamethasone treatment in children with 1 or
2 ring-enhancing lesions of neurocysticercosis: a
randomized controlled trial. J Pediatr 2003; 143 : 111-114.
44. Thussu A, Chattopadhyay A, Sawhney IM, Khandelwal N.
Albendazole therapy for single small enhancing CT lesions
(SSECTL) in the brain in epilepsy. J Neurol Neurosurg
Psychiatry 2008; 79 : 238-239.
45. Carpio A, Kelvin EA, Bagiella E, Leslie D, Leon P, Andrews
H et al. Ecuadorian Neurocysticercosis Group. Effects of
albendazole treatment on neurocysticercosis: a randomised
controlled trial. J Neurol Neurosurg Psychiatry 2008; 79:10501055.
46. Padma MV, Behari M, Misra NK, Ahuja N. Albendazole in
single CT ring lesions in epilepsy. Neurology 1994; 44: 13441346.
47. Salinas R, Counsell C, Prasad K, Gelband H, Garner P.
Treating neurocysticercosis medically: a systematic review
of randomized, controlled trials. Trop Med Int Health 1999;
4: 713-718.
48. Salinas R, Prasad K. Drugs for treating neurocysticercosis
(tapeworm infection of the brain). Cochrane Database Syst
Rev 2007; CD000215.
49. Del Brutto OH, Roos KL, Coffey CS, García HH. Metaanalysis: Cysticidal drugs for neurocysticercosis:
albendazole and praziquantel. Ann Intern Med 2006
4;145:43-51.
50. Medina MT, Genton P, Montoya MC et al. Effect of
anticysticercal treatment on the prognosis of epilepsy in
neurocysticercosis: a pilot trial. Epilepsia 1993; 34: 10241027.
51. Vazquez V, Sotelo J. The course of seizures after treatment
for cerebral cysticercosis. N Engl J Med 1992; 327: 696-701.
52. Del Brutto OH. The use of albendazole in patients with
single lesions enhanced on contrast CT. N Engl J Med 1993;
328: 356-357.
53. Garcia HH, Gilman RH, Martinez SM, Moulton LH, Del
Brutto OH et al. Cysticercosis Working Group in Peru. A
trial of antiparasitic treatment to reduce the rate of seizures
due to cerebral cysticercosis. N Engl J Med 2004;
15;350:249-258.
54. Das K, Mondal GP, Banerjee M, Mukherjee BB, Singh
OP.Role of antiparasitic therapy for seizures and resolution
of lesions in neurocysticercosis patients: an 8 year
Indian Journal of Pediatrics, Volume 76—May, 2009
Neurocysticercosis in Children
randomised study. J Clin Neurosci 2007; 14 : 1172-1177.
55. Jung H, Hurtado M, Medina MT, Sanchez M, Sotelo J.
Dexamethasone increases plasma levels of albendazole. J
Neurol 1990; 237: 279-280.
56. Vazquez ML, Jung H, Sotelo J. Plasma levels of
praziquantel decrease when dexamethasone is given
simultaneously. Neurology 1987; 37: 1561-1562.
57. Bittencourt PR, Gracia CM, Martins R et al. Phenytoin and
carbamazepine decreased oral bioavailability of
praziquantel. Neurology 1992; 42: 492-496.
58. Singhi P, Dayal Devi, Khandelwal N. One week versus four
weeks of albendazole therapy for neurocysticercosis in
children: a randomized placebo controlled double blind
trial. Pediatr Infect Dis J 2003; 22: 268-272.
59. Corral I, Quereda C, Moreno A et al. Intramedullay
cysticercosis cured with drug treatment. A case report.
Spine 1996; 21 : 2284-2287.
60. Del Brutto OH, Sotelo J, Aquirre R, Diaz Calderon E,
Alarcon TA. Albendazole therapy for giant subarachnoid
cysticerci. Arch Neurol 1992; 49: 535-538.
61. Proano JV, Madrazo I, Avelar F et al. Medical treatment for
neurocysticercosis characterized by giant subarachnoid
cysts. N Engl J Med 2001; 345 : 879-885.
62. Pretell EJ, Garcia HH, Custodio N et al. Short regimen of
praziquantel in the treatment of single brain enhancing
lesions. Clin Neurol Neurosurg 2000, 102: 215-218.
63. Lopez-Gomez M, Castro N, Jung H, Sotelo J, Corona T.
Optimization of the single –day praziquantel therapy for
neurocysticercosis. Neurology 2001; 57: 1929-1930.
64. Kaur S, Singhi P, Singhi S, Khandelwal N. Combination
Therapy of Praziquantal and Albandazole worries
Albandazole alone in Children with single Lesion NCC-a
randomized placebo controlled double blind trial Ped Infect
Indian Journal of Pediatrics, Volume 76—May, 2009
Dis J 2008 – In Press .
65. Nash TE, Singh G, White AG et al. Treatment of
neurocysticercosis: current status and future research needs.
Neurology 2006; 67: 1120-1127
66. Suri A, Goel RK, Ahmad FU, Vellimana AK, Sharma BS,
Mahapatra AK. Transventricular, transaqueductal scopein-scope endoscopic excision of fourth ventricular
neurocysticercosis: a series of 13 cases and a review. L
Neurosurg Pedaitrics 2008;1:35-39.
67. Goel RK, Ahmad FU, Vellimana AK et al. Endoscopic
management of intraventricular neurocysticercosis. J Clin
Neurosci 2008 Jul 22. [Epub ahead of print]
68. Singhi PD, Baranwal AK. Single small enhancing computed
tomographic lesions in Indian children-II. Clinical features,
pathology, radiology and management. J Trop Pediatr 2001;
47: 266-270.
69. Jain S, Padma MV, Kanga U, Mehra NK, Maheshwari NC.
Family studies and human leukocyte antigen class II typing
in Indian probands with seizures in association with single
small enhancing computed tomography lesions. Epilepsia
1999; 40: 232-238.
70. Cruz ME, Davis A, Dixon H, Pawlowski ZS, Proano J.
Operational studies on the control of Taenia solium
taeniasis/cysticercosis in Ecuador. Bull WHO 1989; 67:
401-407.
71. Sarti E, Schantz PM, Avila G et al. Mass treatment against
human taeniasis for the control of cysticercosis: a
population-based intervention study. Trans R Soc Trop Med
Hyg 2000; 94: 85-89.
72. Gilman RH, Garcia HH. Gonzales AE et al. Metodos para
controllar la transmission de la cisticercosis. In Garcia HH,
Martinez S, eds. Teniasis/cisticercosis por t. Solium. Lima:
Editorial Universo SA, 1996; 327-339.
545