Clinical Neurophysiology Flashcards
TEst that determines distribution of sweating?
Thermoregulatory sweat test
what is quantitative sudomotor axon reflex testing (QSART)
test postganglionic sympathetic failure seen in small fiber neuropathies AND
excessive sweating in reflex sympathetic dystrophy
2 signs of SNS dysfunction during valsalva test?
- exaggerated drop in BP in early phase 2 as venous return drops b/c lack of vasoconstrix
- no overshoot of BP after relaxation due to increased venous return
How do you test parasympathetic function during valsalva?
You should get a reflex bradycardia as BP increases in final overshoot BP due to vagal tone. Absent in PNS dysfunction.
What should HR do w/ breathing and what does it test?
should increase with inspiration due to cardiovagal reflex
autonomic neuropathy with orthostasis, bradycardia, megaesophagus, megacolon, and congestive cardiomyopathy found in South America/Central America patients
Chagas’ disease from trypanosomiasis
dopamine beta hydroxylase deficiency
- what does it cause in adults (2 sx)
- what NT pattern do you see
- what chromosome
- what tx?
Increased dopamine, lack of NE
chromosome 9q34
causes ptosis, orthostatic hypotension
tx: L-DOPS which can be decarboxylated into NE instead
Dopamine hydroxylase deficiency causes what in neonates?
3Hys: hypothermia, hypoglycemia, hypotension episodes
Disease with hypohidrosis, decreased tear/saliva, GI dysmotility, impotence, severe lancinating pain in extremities, renal disease
Cause
Genetics?
Fabry’s
alpha galactosidase def
X-linked recessive
What is familial amyloid polyneuropathy caused by and what is the disease path and sx?
small fiber neuropathy due to transthyretin defect FAP1
causes pain/temp sensation loss, autonomic sx and CHF
Disease causing lack of sensitivity to pain?
Hereditary sensory and autonomic neuropathies (HSAN) particularly
Riley-Day syndrome: HSAN III autosomal recessive in Ashkenazi jews (familial dysautonomia)
Genetic cause of Riley Day?
autosomal recessive mutation in kappaBkinase complex assoc protein on chrom 9q31
Distinctive feature of Riley day? (2 sx/si)
absence of fungiform papillae on tongue and no overflow emotional tears
EEG frequencies: the order from slow to fast
Delta, Theta, Alpha, Beta
*Dig that awesome beat
Alpha freq EEG?
8-13
Theta freq EEG
4-7
Beta freq EEG
> 13
Delta freq EEG
<4
negative deflection on EEG means what
That the first input is positive compared to second
pos to neg is down
What is the layout of bipolar montage?
inputs 1 and 2 are adjacent:
Channel 1: Fp1-F3
Channel 2: F3-C3
Channel 3: C3…
What is a referential montage?
There is a reference electrode that is presumably inactive
Channel 1: Fp1-Cz
Channel 2: F3-Cz
Channel 3: C3-Cz
Hyperventilation shouldn’t be performed w/ EEG on which 3 (non resp dz)
- cerebrovascular dz
- sickle cell trait/dz
- moymoya
Normal EEG response to hypervent?
generalized background slowing
photic response w/ epileptiform discharges seen in what major epilepsy? Actual photoconvulsive response seen with what?
JME (photoparoxysmal response)
primary generalized epilepsy - pts can have seizure w/ photic
Background rhythm norms at 3 mos and 5 mos?
3 mos: 3 HZ
5 mos: 5 Hz
background alpha rhythm of at least 8HZ by what age?
3 yr
What is a kappa wave in EEG and when does it occur?
low amplitude in temporal regions, either alpha or theta during THINKING (phi beta kappa)
what is lambda waves and when do you seen them?
positive sharp transients in occipital area during visual scanning (if you are looking around at a bunch of lambs)
What is the mu rhythm
where and when does it occur?
arciform 7-11 Hz in centroparietal regions, attenuated by moving or thinking about moving the contralat body
spikes seen 6-11 hz in temporal region, during drowsy/light sleep in adults?
wicket spikes/waves
delta activity in kids/adol w/ overriding alpha that attenuates with eye opening
posterior slow waves of youth
WHo gets 14 and 6 positive bursts of arciform activity over posterior temporal for < 3 sec and when?
adolescents in light sleep
What do you see in teens/adults with wakefulness and drowsiness that disapper with sleep?
bursts of diffuse 6hz very small spike and higher amplitude wave discharges for a couple of seconds (phantom spike/wave)
What are small sharp spikes of sleep in adults
brief low voltage (<50mv) spikes over temporal region in drowsy/light sleep: small sharp spikes of sleep
5-7 Hz sharp countoured theta in bursts over temporal region in drowsy young adults
rhythmic temporal theta bursts of drowsiness/psychomotor variant pattern
WHat are the two types of alpha coma?
- posterior dominant alpha: poorly reactive: pontine strokes/brainstem lesions
- diffuse frontal alpha: poorly reactive: after anoxia
*Alpha coma: anoxia/arrest
what is bancaud’s phenomenon
when alpha activity over one hemisphere doesn’t attenuate w/ eye opening (non reactive hemisphere is abnormal)
What causes beta coma
Bzd, Barbs: better buzzed encephalopathy or brainstem lesion
high amplitude generalized beta
What rhythm on EEG with skull defect with higher amplitude spiky looking EEG activity?
Breach rhythm
What causes focal delta activity on EEG
continuous and polymorphic delta due to structural lesion
define spike on EEG?
< 70ms
define sharp wave on EEG
70-200msec
WHat is FIRDA? and what does it mean?
Frontal Intermittent Rhythmic Delta Activity
seen in encephalopathy, incr ICP. deep midline lesions
What is pattern do you see in kids with encephalopathy instead of FIRDA?
Occipital (OIRDA)
WHat are PLEDS and what causes them?
Sharp activity at regular intervals over a hemisphere
usually from stroke or Herpes encephalitis
What are triphasic waves?
frontal dominant waves with an anterior to posterior lag seen in hepatic encephalopathy and others
What EEG findings can Clozapine cause?
Clozapine: clonic activity:
Interictal discharges, GTCs, myoclonus
Two meds that can cause seizures in people w/o epilepsy?
Bupropion (Wellbutrin) and DEmorol (meperidine) OD
Two meds that can cause seizures in patients with epilepsy and one med that causes interictal discharges in patients w/ epilepsy?
Seizures: Ultram (tramadol) and Benadryl
Discharges: Lithium
Sharp or sharp/slow wave complexes every 1-3 sec and PLEDS?
What dz?
herpes encephalitis
EEG showing high amplitude periodic sharp wave complexes every 4-15 seconds generalized occurs in what stage of post-measles?
subacute sclerosing panencephalitis, stage 2.
Stages of SSPE (post measles)
I: personality change/lose academics
II: EEG findings, myoclonic jerks, cognitive decline
III: stupor, EPS, autonomic sx, hyperreflexia, rigidity
IV: chronic vegetative state
generalized periodic sharp wave complexes every 0.5-1.6 seconds in what disease
CJD NOT variant (mad cow)
EEG criteria for brain death? (7)
- 8 electrodes
- 2microvolt sensitivity
- electodes at least 10cm apart
- impedance 100-5000 ohms
- low freq filter set < 1Hz
- high freq filter set >30 Hz
- Duration 30 min
QUiet and active sleep in neonates is found when and what are the stages like?
between 30-36wk
active: like REM (go straight to it)
quiet: similar to nonREM, less synchrony than in younger babies
What is active moyenne in neonatal EEG?
appears at 36 wks and is a continuous pattern of mixed freq during awake and active sleep (REM sleep)
EEG development in quiet sleep in neonate?
TD (trace discontinu) –>TA (trace alternans) –>CSWS (continuous slow wave sleep) –>CSWS and spindles
Active sleep - awake - quiet sleep.
What is a CMAP represent?
the sum of all the individual muscle fiber action potentials
Draw the CMAP and label the parts
latency: time from stimulus to initial CMAP
amplitude: peak of wave
duration: length of time on x axis from when waves return to original start before overshoot
What does latency reflect?
fastest conducting motor fibers
What does amplitude reflect?
number of muscle fibers
what does duration reflect on EMG?
synchrony of muscle fiber firing
what would a significant drop in area comparing CMAPs with distal and proximal stimulation suggest?
a conduction block
Do you see a conduction block in acquired vs inherited demyelinating polyneuropathies
only in acquired.
what do you see in multifocal motor neuropathy with conduction block?
Marker?
you see conduction blocks in sites w/o compression, asymmetric weakness and atrophy beginning distally.
Marker is anti-GM1 antibodies
What is a martin gruber anastomosis? what does it look like?
when recording from abductor digiti minimi, shows apparent conduction block between wrist and below elbow during ulnar motor studies
-from fibers crossing median nerve to innervate some muscles usually innervated from ulnar nerve
How does low temp affect EMG?
increased latency, duration, amplitude, area of motor and sensory action potentials
What do you use to measure the conduction velocity with regards to latency
onset latency (not peak latency) / distance from stimulation point
what does EMG/NCS show in small fiber neuropathies
its normal
EMG findings in demyelinating neuropathy?
- prolonged distal latency
- normal/reduced amplitude
- reduced conduction velocity by about 50%
- conduction block
- increased temporal dispersion
EMG findings in axonal neuropathy
- decreased amplitude
2. only mild slowing
if you have loss of sensation but normal sensory nerve action potentials, where is the lesion?
proximal to the DRG
if you have loss of sensation and lost SNAP, where is lesion?
plexus
what is more sensitive test for picking up carpal tunnel on EMG?
median nerve palmar sensory response b/c routine NCS may be normal