1. health and fitness
2. disease

Name________________________________ Degree________ Date ______
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There is no fee for this 1 year AASEM approved certification by the AXON-II manufacturer. Instructions
on where to send the completed examination are found on the last page. During the year attend a 12
hour CME workshop where 5 years certification is available. Two or more workshops will be held in
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major U.S. cities, where staff members can also receive certification. This 1 year certification is at no
charge. The 5 year certification workshop is free. You only pay your 5 year AASEM membership dues.
Read the paragraphs and fill in the blanks
Large motor nerve fibers are protected by a generous layer of
fatty myelin and often surrounded by small “early warning” pain
fibers that immediately signal damage. Unless cut, crushed or
over 50% of their myelin is lost, large fiber pathology is
detectable by EMG. The U.S. Military funded the development of
EMG in the 1940s to help detect gross nerve injuries. In civilian
populations it is rare to see over a 50% loss of myelin, which has made measuring pain
fiber function the holy-grail of neuro-diagnostic technology. Of the two types of pain
fibers, the A-delta (Fast Pain) fibers are the “Early Warning” fibers. These first
responders react during the Epicritic Phase (Early Warning Phase) to move the body
away from injury by synapsing with motor neurons in the spinal cord. This is called the
“Withdrawal Reflex.”
The ________________ funded the development of ______ in the ______ to detect
________ nerve injuries. In civilian populations over a _____% loss of _________ is
_________, which has made measuring pain fiber __________________ the holy-grail
of neurodiagnostic technology. Of the two types of pain fibers, ______________ (Fast
Pain) fibers are the “________________ __________________” fibers. These first
responders react during the _________________ Phase (warning phase) to move the
_________ away from injury by synapsing with ______________ neurons in the spinal
cord. This is called the “_______________ ___________.” Large motor nerve fibers are
________________by a generous layer of fatty ____________ and often surrounded
by __________________________ that immediately signal damage. Unless large fibers
are _________________, ___________________ or ________________________ EMG
cannot detect large fiber pathology.
Motor fibers are efferent and not afferent sensory fibers, so they cannot help a
patient localize injury. A-delta fibers evolved with the sensory cortex, which makes
them excellent localizers of the source of pain. A serious localization problem occurs
within minutes to hours after injury when the Epicritic Phase ends. With the beginning
of the Protopathic Phase, A-delta fibers down-regulate and localization shifts to the
up-regulating C-Type fibers, which evolved before the sensory cortex had fully
developed. This means C-Type fibers are very poor localizers of the source of pain. In
spite of the fact that C-Type fibers up-regulate, their threshold remains stable. The
threshold of the down-regulated A-delta fiber, however, requires more voltage to
cause threshold summation. Neurosurgeon, Peter Carney, MD, reported in the June
2012 issue of Practical Pain Management that in 151 patients the pf-NCS changed
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treatment in 56% and the side of treatment in 8%. This supports a consensus held for
over a decade by AASEM pf-NCS certified members that over 50% of neck and back
pain patients incorrectly localize the source of pain, with a high percentage localizing
pain to the wrong side. With over 50% of patients incorrectly localizing the source of
pain, it explains why NIH data shows 43% of pain patients develop chronic symptoms,
and why up to 80% of spinal surgeries end in failure. In 2002 The Internet Journal Of
Pain Symptom Control & Palliative Care published a 3 year peer-reviewed study by
Randall Cork, MD, PhD, Director of Pain Management at Louisiana State University.
Dr. Cork and his team found pf-NCS to have statistical sensitivity approaching 100% in
localizing the most difficult type of nerve pathology to diagnose - radiculopathy. Based
on Dr. Cork’s study, pf-NCS is the gold-standard for diagnosing sensory pathology,
especially radiculopathy. (Radical = Root + Pathos = Pathology)
A-delta fibers evolved with the_________________________________ of the brain, so
they are _________________ localizers of the source of _________. However, after
the __________ Phase, during the ______________ phase A-delta fibers __________ ___________ . Localization shifts to the ______________ fibers, which are __________
localizers of the source of pain. In an injured nerve the A-delta fibers require more
______________ to reach threshold summation. Neurosurgeon, Peter Carney, MD,
reported in Practical Pain Management that in 151 patients the pf-NCS changed
treatment in ______% and the side of treatment in ______%. This supports a
consensus held for a decade by AASEM pf-NCS certified members that over _______%
of neck and back pain patients incorrectly localize the source of pain. NIH data shows
______% of pain patients develop ________________________ symptoms, and up to
______% of spinal surgeries end in failure. The Internet Journal Of Pain Symptom
Control & Palliative Care published a _____ year study showing pf-NCS to have
sensitivity approaching _______% meaning the pf-NCS is the _____________________
for diagnosing sensory pathology, and especially ______________________________.
EMG/NCV has not changed since the mid 1960s. A State-Of-The-Art-Review was
published in the June 1999 issue of Physical Medicine & Rehabilitation titled:
EVALUATING RADICULOPATHY: HOW USEFUL IS ELECTRODIAGNOSTIC TESTING?
“In
chronic cases, particularly in
individuals with predominantly sensory symptoms,
it is difficult or impossible to clinically estimate the type or severity of nerve injury.
Only if there is obvious muscle atrophy can one know for certain that
motor axon degeneration has occurred. The electrodiagnostic (EMG) study can be
normal in the face of known pathology.”
Page 255, H Wave: “H wave is named
after Hoffman (1918). Used with any
regularity in assessment of S1 fibers. Many would argue that the H wave is simply a
neurophysiologic ankle stretch reflex and therefore does not have added value in the
evaluation of radiculopathy.”
F Wave: “Despite the theoretical advantage of using the F response it is of
little practical application in the evaluation of radiculopathy, especially a
lesion of a single level. If even a few large myelinated motor fibers are preserved, the F wave
latency will remain normal. Severe nerve-root damage at multiple levels is necessary to prolong
the (F wave) latency. . . . . . sensitivities typically reported in the literature are
falsely elevated and tend to lull us into thinking that electrodiagnostic
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evaluation of radiculopathy is both sensitive and specific. Most reports . . . used
surgical confirmation as the gold standard, although some used imaging. The specificity of
imaging studies is low, with up to 50% of asymptomatic subjects having an anatomic
abnormality noted on random screening. . . . Using surgery as a gold standard will skew the
population tested because they are typically the most severe cases. If only sensory fibers
are involved or if the motor involvement is mild . . . the EMG will be
normal while the person actually has radiculopathy.”
EMG/NCV has not changed since the mid ________. In ______ Physical Medicine &
Rehabilitation published a State-Of-The-Art-Review: EVALUATING RADICULOPATHY:
HOW USEFUL IS ELECTRODIAGNOSTIC TESTING?
Page 251/252: “In chronic cases, particularly in individuals with predominantly
sensory symptoms, it is difficult or _______________to clinically estimate the type or
severity of nerve injury. Only if there is ____________________ atrophy can one know
for certain that ________ axon degeneration has occurred. H Wave: “H wave is
named after Hoffman (1918). Used with any regularity in assessment of____________
fibers. Many would argue that the H wave is simply a neurophysiologic ____________
_________________reflex.” “Despite the theoretical advantage of using the F response
it is of __________________ practical application in the evaluation of radiculopathy,
SENSITIVITY AND SPECIFICITY: “. . . . . . sensitivities typically reported in the
literature are _______________elevated and tend to __________ us into thinking that
electrodiagnostic evaluation of radiculopathy is both sensitive and specific. Using
surgery as a gold standard will ____________ population tested because they are
typically the most________________ cases.
. . . . . EMG will be ________________
while the person actually has radiculopathy.”
If pf-NCS were a smoke detector, by the same analogy, EMG only warns
of fire when over half the roof is burned away.
Down-regulation of the A-delta fibers can occur within less than an hour following
nerve injury. Using a neuroselective frequency, the injured nerve requires stronger
than average voltage to cause the A-delta fibers to reach threshold summation.
Within a few minutes the doctor or staff member can test all the major nerves in a
region. The patient is his own control so accuracy approaches 100%, as opposed to
population comparison which at best yields sensitivity of 67% on a bell-shaped curve.
The pf-NCS is quick and easy. A dripping wet ground sponge is placed at T4 (cervical),
S1 (lumbar). Following a chart of standardized sites, a gold electrode fitted with a
saline soaked Q-tip is placed on each site, and in about 30 seconds each nerve is
tested. Total time, including patient setup, is less than 20 minutes. To assure accuracy:
A) Remind the patient to close his eyes and focus on the site and to say NOW the
instant he first feels the slightest tickling sensation. B) Always, AFTER telling him you
are going to test again, WAIT at least 3 seconds before starting the stimulus dial up.
This gives him time to focus on the site. C) Once you start turning the dial DO NOT SAY
ANYTHING, because it will distract the patient. D) After he has repeatedly said NOW at
the same dial setting, the last time, as the dial nears that setting, watch
potentiometer for the microvoltage jump that signals firing. If you are using the realtime software, press the foot-peddle about 4 points below the setting where he is
saying NOW. Then press it again when he says NOW. This captures the real-time firing
of microvoltage on a graph.
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Down-regulation of the A-delta fibers can occur within less than an _____________
following nerve injury. Using a neuroselective frequency, the injured nerve requires
stronger than average __________________to cause A-delta fibers to reach threshold
summation. All the major nerves in a region are tested, which takes less than _______
minutes. The patient acts as his own ____________________, so accuracy approaches
_______%, as compared to comparisons with population averages that at best yield
sensitivity of only _______%, on a bell-shaped curve. Place the sponge at ___ (cervical)
and ___ (lumbar. A _________ tip electrode with a saline soaked _______ is placed
over the standardized site of each major nerve. In about __________seconds each
nerve is tested, so the total time involved, including patient setup is less than ____
minutes.
Always remind the patient to close his _______ and focus on the site and to say _____
the instant he first feels the slightest ____________ sensation. Then, always after
telling him you are going to test again, WAIT at least ______ seconds before starting
the stimulus dial up. This gives him time to _________ his ______________on the site.
Once you start turning the dial DO NOT _________________________. After he has
repeatedly said NOW at the same dial setting, the last time as the dial nears that
setting___________________ the __________________________ for the microvoltage
jump that signals ________________ or, if you have the real-time software_________
the foot-peddle about ___ points below the dial setting where he has been saying
NOW and then again when he says NOW.
Electromotive Force, Electrical Pressure and Potential are interchangeable terms
meaning Voltage. A nerve impulse (action potential) is literally voltage in action moving along the nerve fiber. One microvolt is 1/1,000,000th of a volt. Nerve
membranes have voltage-gated channels, which means that when sufficient voltage is
applied the voltage-gate opens and the sodium (Na) ion on the outside switched
places with the potassium (K) ion on the inside. This switch causes a burst of
microvoltage that opens the next gate, then the next, and the next, etc. Threshold
summation can be best understood by the following example: Let’s say at a stimulus
dial setting of 24 about 200 fibers begin firing. Then one point higher (dial at 25) firing
increases to 500, then at 26 to 1000. At a dial setting of 26.5 in a few milliseconds
firing jumps to 50,000 then to 200,000+ fibers. Within a second or two, the brain
processes the signal and the patient says NOW, he feels a slight tickling sensation. This
sudden jump in microvoltage is termed threshold summation. This large number of
fibers generates a microvoltage jump, which is picked up by the potentiometer. The
threshold summation, like the motor fiber NCV, has
speed (velocity) and latency (the time it takes from start
to the peak of summation) and configuration (the shape of
the summation from start to peak), and the amplitude
(height of the peak). This is different from NCV where these
are in reference to the signal passing along the nerve,
which is not measurable in small pain fibers, because they
are up to 100 times smaller than large motor fibers.
Unlike the EMG, which is based on the patient reporting
when he feels a muscle twitch, and the examiner judging
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the sound of a muscle’s electrical activity, the A-delta real-time recording does not in
and of themselves have any presently known diagnostic meaning. However, they do
objectively prove that at a specific voltage stimulus (dial setting) threshold summation
did occur, independent of the subjective judgment of the patient or his examiner.
Electromotive Force, Potential, Electrical Pressure are interchangeable terms meaning
______________. A __________________ is 1/1,000,000th of a volt. Nerve membranes
have _______________________________channels, which means that when sufficient
_____________is applied the ___________________________________ opens and the
________________ ion on the outside switched places with the ________________ ion
on the inside. This switch causes a burst of ____________________that opens the next
gate, then the next, and the next, etc. The nerve impulse (action potential) is literally
________________ in action - moving along the nerve fiber. A stimulus causes more
and more fibers to fire and suddenly a receivable firing occurs. This sudden jump in is
_______________________ summation. This large number of fibers generates a jump
in _________________________ that is picked up by the________________________.
The threshold event, like the motor fiber NCV, has speed (_____________), time form
start to peak of summation (__________________). The shape of the summation from
start to peak is ______________________________and the height of the peak is called
_______________________ of the peak. This is different from NCV where these are in
reference to the signal passing ___________________ the nerve. Also, unlike the EMG,
which is based on the __________________reporting when he feels a muscle twitch
and the __________________ judging the sound of the muscle’s __________________
activity, the A-delta real-time recording in and of themselves have no presently known
diagnostic meaning, but they do ___________________ that at a specific stimulus (dial
setting) ____________________ summation occurred, independent of the subjective
judgment of the _______________________or his _________________________.
The pf-NCS sites are located over major nerves that originate
from specific nerve roots. The stimulus passes through less than
2 cm of tissue to reach the primary neurons, thus bypasses the
skin receptors. This means the pf-NCS is not a dermatome test,
wherein a zone of skin (receptors) is stimulated by a natural
stimulus. The pf-NCS is also different from the Quantitative
Sensory Test (QST), which also uses natural stimuli and requires
the patient to judge a change in intensity. The pf-NCS does not
use stimuli, such as hot, cold or pressure, but uses electricity,
which has no receptors. The pf-NCS objectively detects
threshold summation independent of the patient’s or the
examiner’s perception, therefore, the pf-NCS is an
electrodiagnostic examination (EDX) that detects the earliest
change in the early warning A-delta fibers.
The pf-NCS sites are located over __________________nerves that originate from
specific _______________________. The pf-NCS stimulus passes through less than ___
cm of tissue to reach the ______________neurons, thus bypasses the skin _________,
which means the pf-NCS is not a dermatome test, which stimulate a _____________of
skin receptors, and it is different from the Quantitative Sensory Test (QST), which
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requires the patient to ________________a _________________in a natural stimulus,
such as hot, cold and pressure, whereas the pf-NCS uses ___________________, which
has no receptors, and objectively detects ________________________________ firing
independent of the patient’s or the examiner’s ___________________. Therefore, by
definition the pf-NCS is an objective E __ X. that detects the earliest possible change in
the early warning ________________________fibers.
Graphic Interpretation Overview
Basic Interpretation Rules:
1. Highest measure suggests pathology (A-delta hypo-function).
2. If there is no rated dysfunction, right to left deviation may suggest pathology,
especially if the highest is the highest on the graph and its opposite is the
lowest on the graph.
3. Usually the nerve root below (distal to) a highest rated measure drops to near
normal, while the proximal nerve roots on the opposite and same side rise up
and may even move into a rating. This is caused by interconnections above the
primary injury.
4. Chronic pathology over years will cause disinhibition, which makes the highest
rating much lower and its opposite moves toward a hyper-function rating.
See the manual for graphic explanations of this process. Here is the basic idea:
The software program calculates the average of all the measures and places that
average in the center of the normal zone. A high or low measure pushes the average
up or down, so normal measures are not in center, which may cause a normal
measure to be falsely rated. By recognizing normal patterns, one soon sees how to
shift the graph to avoid false ratings.
Deviation Index ratings
Very Severe
Severe
Marked
Moderate
Mild
Normal Zone
Hyper - Irritation
Examples:
Right C6 Radial Nerve (lateral branch). Note the left C6 mirrors
right C6 pathology. If the opposite was closer than 1 rating space
it would suggest bilateral pathology.
No rated dysfunction. C6 right to left deviation is 61%. The limit
in the cervical region is 20%. Therefore, this graph suggests right
C6 - radial nerve (lateral branch) dysfunction.
Chronic Right C6 - Notice how the opposite, left C6, is towards
Hyper and not mirroring. This is how disinhibition looks, as
caused by the spinal cord passing more signals to compensate
for the chronic drop (down-regulation) of A-delta signals.
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Normal: No rated measures, hypo (high on the graph) or hyper
(low on the graph) and no significant right to left deviation
between at any level. All measures are within the normal zone.
Draw lines connecting find to its graph
Normal
Very Severe + Irritation
One level above
Severe Pathology
Mild Pathology
Chronic Pathology
One Hyper-Function
Circle A, B or C which line is the software average?
A
B
C
Draw a line through the normal
measures (not the software average)?
Would you shift the measures up or down?
Hint: The patient complains of bilateral leg numbness and
tingling. Low back pain constant, with difficult walking. Legs tire
quickly.
A. Leave it where it is. Moderate bilateral multiple level
radiculopathy L4-5-S1.
B. Move up so L1-2-3 & S2 are in center of normal zone. Spinal stenosis - L3.
C. Move down, because L1-2-3 & S2 are all Hyper.
Circle One
A. The left C4 very severe with moderate left C8.
B. Bilateral C4 with moderate left C8.
C. Left C8 major (chronic) and left C4 severe, more acute
pathology.
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The graphs on the right show:
A. Very severe right C5-6
B. Bilateral C5 and right C6 and hyper right T1.
C. Bilateral C5 and right C6 – graph needs to be shifted up
because very severe hypo-function measures are pushing
normal pattern measures down so far that right T1 is a false hyper.
These two graphs are the same patient. The top - cervical
graph - very severe (+5) left C8 ulnar nerve.
The bottom - upper extremity graph - ulnar branches (medial
ring finger and lateral little finger, with left palmar branch very
severe.
A. Left Guyon’s Canal entrapment and separate left C8 pathology.
B. C8 causing abnormal ulnar digital findings, because palmar
branch does not pass through Guyon’s Canal, therefore, this
shows the problem is C8 alone.
C. B is correct, except this could be double crush, i.e., Guyon’s
Canal entrapment and left C8 nerve root. History is needed
with an Extended Evaluation.
REIMBURSEMENT
Based on AASEM reports the 2013 consensus, after the history, rather than guessing a
specific diagnosis, it is best to use a presumptive diagnosis that is
broad enough to allow testing to discover less likely pathology. For
cervical and lumbar plexopathy is best. The fees for pf-NCS run from
$21 to $95 per nerve. A maximum of 12 nerves can be billed in a
cervical or a lumbar study. Medicare limits testing to 10 nerves per
year, so the lower range is 10 X $21 = $210.00. Regular, PI and WorkComp is usually 12 X $95 = $1140. If the test verifies the existence of
nerve pathology, it is appropriate to conduct an Extended Evaluation
(95914) $60 to $120. The Extended Evaluation consists of the patient
filling out body charts showing first symptoms and present symptoms, with
approximate dates and causes of any symptom changes. The doctor notes
recommendation on part of the form (see above form). Federal judges in 2 Medicare
Appeals have found pf-NCS to be “necessary” and “payable”. As a reminder, it is
provider’s responsibility to determine reporting and fees in her/his geographic region.
Do not __________ at a specific pathology. Pick a ____________diagnosis that is broad
enough to cover _________________ possibilities. For cervical and lumbar pf-NCS this
means that ___________________ is the best choice. If the test verifies pathology, it is
appropriate to conduct an_____________ Evaluation (95914). Two __________ found
pf-NCS to be ____________________ and __________________ for Medicare patients.
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Video Exam Check List
Steps: Perform a cervical test – at least 3 sites
1. Start to finish, show the test in 3 segments of less.
2. Show & tell:
a. How wet is the sponge?
b. Show ground sponge placement.
3. Show powering up the device - what lights come on?
4. Show anchoring the hand holding the test electrode.
5. Have the dial and patient in the same view.
a. Say instructions the 1st time and before every
time the dial is turned up.
b. Show catching the potentiometer jump.
6. Show moving the potentiometer electrode.
NEXT
Fax these pages with a copy of your license, Pledge, and a
blowup of your picture ID. to: (800) 875-0119
FINAL STEP:
Get the manual at www.paindx.net (upper right PHYSICIAN
SUPPORT password – pain25) Print the manual and following the
steps practice testing a couple of staff members. Then call and
review the steps with Dr. Hedgecock (800) 766-0884. If he finds
you ready, he will ask that you video the setup, instructions and
testing of 3 sites. Email the video to Dr. Hedgecock at
[email protected] . Include the spelling of your name as
you want it on your certificate and include the mailing address
where you want it sent.
Questions? (800) 766-0884
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American Association of Sensory Electrodiagnostic Medicine
Ethics Pledge
Sign and fax along with a) Copy of your medical provider license and, b) Photo ID
(800) 875-0119
The undersigned hereby pledges to abide by the ASEM rules and ethics set forth
herein:
1. I pledge that I will personally perform at least two pf-NCS examination each
month.
2. I pledge to support the AASEM in its efforts to advance the science of PF-NCS
and to freely share clinical experiences with my colleagues in a cooperative effort
and to endeavor to stay current and open to innovations in this branch of medical
science.
3. I pledge to avoid over utilization and keep the welfare of patients my goal.
4. I pledge to uphold my responsibility in supervising and training staff and to carry
out periodic assessments of the equipment and staff performance.
5. I endorse and support the AASEM Practice Guidelines.
6. I will endeavor to educate others concerning the diagnostic value of PF-NCS.
7. I pledge to avoid criticism of my PF-NCS colleagues and to work within the
AASEM to maintain standards and cooperation with those using other EDX
methods.
8. I pledge to maintain adequate records and to keep private my patient’s
information and to supervise my staff in this regard.
Name: ____________________________________________________________
PRINT FULL NAME
Signed ________________________________________________Date _____________
© AASEM 2011
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