Wahba Notes Flashcards
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Differential dx unilateral foot drop?
Common peroneal n neuropathy
L5 radiculopathy
Lumbosacral plexopathy
Sciatic n lateral trunk
Differential chronic bilateral foot drop?
Hereditary peripheral neuropathy AKA myotonia atrophica, CMT
CMT1 vs. CMT2
1: slowly progressive, high arches, absent DTRs, palpable nerves, demyelinating problem
2: onset later, preserved velocity, axonal problem
Ankle inversion
Intact toe and plantarflexion
Intact ankle jerk
Peroneal mononeuropathy
Is ankle jerk preserved in L5 radiculopathy?
Usually not
Sciatic nerve roots
L4-S3
Common peroneal nerve roots made up
L5-S3
Course of common peroneal nerve
W tibial division in thigh, where it innervates short head biceps femoris and does sensation lateral knee; separates in popliteal fossa and goes around fibular head, thru fibular tunnel (fibrous arch + aponeurosis of soleus), then divides into superficial and deep peroneal
Compression of common peroneal at fibular head
Loss of dorsiflexion and eversion = dominant inversion
Loss of sensation at anterolateral leg and dorsum of foot
What muscles does deep peroneal innervate?
PEET is DEEP! Peroneus tertius, Extensor digitorum longus/brevis, Extensor hallucis longus, Tibialis anterior
Where is the deep peroneal nerve usually entrapped?
@ anterior tarsal tunnel
Deep peroneal nerve entrapment presentation
Weak toe dorsiflexion
First web space sensory loss
Intact eversion!
AKA foot only no eversion/inversion
What does superficial peroneal innervate?
PB. Peroneus longus and brevis
What does superficial peroneal sensate?
Dorsolateral foot and leg
Where does superficial peroneal become entrapped?
At fascial exit on anterolateral leg
Superficial peroneal entrapment presentation
Weak eversion
Sensory loss anterolateral plus dorsum foot
Intact dorsiflexion
L5 root entrapment sensory loss?
BIG TOE
Review: sensory loss common peroneal
Lateral knee, leg, foot, btw digits 1-2
Review: superficial peroneal sensory loss
lateral leg and foot, NOT knee and NOT toes
Lumbosacral cord - roots?
L4 and L5
Where do herniated discs actually impinge on the root?
Intervertebral foramina
Weak muscle in sciatica
Extensor hallucis longus
What does the straight leg raise test do?
Passive traction of lumbosacral roots
S1 root impingement pres
Weak gastroc/soleus plus absent AJ
L5 entrapment pres
Big toe sensory loss Weak dorsiflexion Weak inversion Intact plantarflexion and AJ Medial foot sensory loss
AJ root
S1! So L5 radic has ok AJ
The butt muscles are innervated by
L5-S1 (medius and maximus)
Tensor fascia lata innervated by root:
L5
Recent postpartum mom can’t move legs but no epidural?
Retroperitoneal hematoma of lumbosacral plexus
Tight casts can cause _ entrapment
Common peroneal
What 5 muscles are innervated by tibial nerve from L5 (NOT cmmon peroneal?)
Paraspinals gluteus medius TFL flexor digitorum longus tibialis posterior
MRI can miss this on disc herniation
very lateral - need CT myelogram
Why get EMG if can dx foot drop w MRI?
- Asymptomatic discs
- Miss lateral
- Don’t fit in MRI
what does a slow SNAP across the fibular head indicate?
Common peroneal head entrapment
Normal SNAP =
ROOT only
SNAP gone lesion location =
PLEXUS or PERIPHERAL n.
CIDP LP
high protein normal cell count
CIDP nerve conduction study
demyelination
CIDP sensory loss pattern
stocking glove (vibration sense loss)
CIDP progression
Stepwise w/ plateaus
Essential CDIP muscle to be weak
Proximal hip flexor weakness
What is F wave delay?
Average of several responses taken as reliable nerve subpopulation to anterior horn cells and moves back down w/o synapsing….????
Underlying diagnosis w/ CIPD?
CTD, CMV, Hodgkin’s, hepatitis, HIV, IBS, Lyme, MS, raduloplexopathy
What is the first test to do after diagnosing CIPD?
Heme issues - M protein spike
What do you look for on EMG for Lambert-Eaton?
CMAP - compound muscle action potential - low usually and is marker for disease severity
Treatment of E-L syndrome
Guanidine hydrochloride - inhibits mito Ca uptake
What roots does cauda equina affect?
Below T10
S/S of cauda equina
ASYMMETRIC LMN signs and sensory loss inc absent AJ, urine probs, dec anal tone
Myelopathy LP
Lymphocytes increased
DDX myelopathy
Vascular, infection, tumor, abscess, autoimmune, structural
S/S transverse myelitis
All sensory and motor lost below lesion - often from virus > bacteria
Brown-Sequard syndrome pres
Ipsi UMN and loss of tactile/vibration; CL pain and temp loss; flaccid paralysis at level of lesion; +Horner’s if above T1
These viruses cause exclusively LMN disease
WNV, enterovirus, poliovirus
Common acute polio s/s
Bladder dysfunction, assymetric leg weakness
What is Froin syndrome?
Spinal block from high (low?) protein and cord swelling
Poliovirus CSF
Mild-mod lymphos plus high protein and normal/mild glucose
CMV treatment
ganciclovir
Timeline do mechanical embolectomy in stroke?
Up to 8 h anterior circulation or beyond 8 hrs for basilar artery stroke even
After 8 hours stroke therapy
ASA only
When to do IV vs. IA tPA?
> 4.5 hours = do arterial
tPA inclusion criteria
> 18 y/o, stroke is dx, h/o TIA, CT done,
Exclusion criteria tPA
Score 185/110, GI bleed last 3 weeks, heparin last 48h, INR 400, coma, suspected SAH, arterial puncture recently w bleed
Always give tPA if:
Aphasia or hemianopia
Avoid this drug in status epi
flumazenil
Order of drug therapy in status epi
Ativan stat, then fosphenytoin, then more Ativan at 10 minutes, then phenobarbital or midazolam or propofol; simultaneous glucose + thiamine and Keppra or Depakote load
Depakote CI when
bleed in brain
S/S of epidural hematoma
Contralateral hemiparesis
Dilated ->nonresp pupil ipsi
CN3 compression
Posterior fossa hematoma s/s
Cerebellar signs, nuchal rigidity, drowsiness
Suspect posterior fossa hematoma next step
INTUBATE don’t wait for cerebral dehydration
Subdural mechanism
Stretching of veins, usually lateral cerebral convexities
Subdural common in these populations
Elderly/alcoholic/cerebral atrophy
What is Tolosa-Hunt sydrome?
Granulomatous cavernous sinus infection that looks like thrombosis early - do steroids
Compressive vs. noncompressive CN III
Noncompressive DM2: reactive pupil bc interior fascicles, vs. nonreactive in compressive which is noncompressive
Multifocal motor neuropathy with conduction block?
Asymmetric predominantly motor neuropathy in middle age males usually very benign
Most common locations of brain aneurysms?
PCOM and ACOM
Studies to order if new-onset CIDP?
Nerve conduction, muscle, LP, MRI, paraneoplastic studies, serum IF and protein electrophoresis
Best tx for hIv-induced CIDP?
IV Ig
GBS/Miller Fischer suspected - workup
get MRA to r/o basilar artery thrombosis and always admit to ICU
What are the 5 Parkinson-plus synucleinopathies?
Lewy body dementia, corticobasal degeneration, striatal nigral, MSA, PSP
What are the classic symptoms of PSP?
Ocular + Cerebellar + EPS
Alien hand syndrome common in:
Corticobasal degeneration
Some drugs that cause status epi
Flumazenil, theophylline, INH, vigabatran
Empiric tx of meningitis
ACV + rocephin + Vanc + Ampicillin
Tx acute dystonia
Benadryl plus benztropine
Anti-HAM s/s
WARP: wt gain, inc liver enzymes, rash, photosensitivity
Tx of serotonin syndrome
Cyproheptadine (periactin)
How is the pupil in MG?
SPARED!
What are all the weird antibodies for MG?
MuSK, muscle protein titin, ryanodine in pts with thymoma
EMG to do for MG?
Single-fiber EMG bc checks time btween transmission in synapse. Will show low variability
Intubate MG crisis if FVC
1.2 L
Treatment of intubated MG patient
Beta agonist to minimize bronchospasm, Atropine to minimize secretions
Findings in optic neuritis
Pain around one eye, loss of color vision, blurry vision; exam shows swollen disc
High ICP vs. bilateral ON
No field defect in papilledema
Ddx APD
MS, NMO, Lyme, CTD, B12, sarcoid, syphilis
Acute MS tx
IV steroids, NOT oral
Cavernous sinus thrombosis affects these nerves
3, 4, 5i and 5ii, 6
Two etiologies of noncompressive CN3
Diurnal variation MG and diabetes
Where is giant cell arteritis
Branches of external carotid, esp the STA
Thyroid stuff
Hyperthyroidism is a definite risk factor for stroke
Think of hyperthyroidism with a fib in young person with embolic stroke
Hyperthyroidism is a/w these neuro things
MG
Pseudotumor cerebrii
Signs of superior sagittal sinus thrombosis
Seizure, papilledema, suspect w postpartum and severe HA
Who is hypercoagulable and gets superior sagittal sinus thrombosis
Pregnancy, cancer and cancer meds, sickle cell
Lateral sinus thrombosis, usually from?
Infection in mastoid-inner ear or clot
CPA tumors affect these nerves
5 7 8
Weber lateralizes to:
the healthy ear
EEG in HSV encephalitis
triphasic waves (slowing)
Work-up of HSV encephalitis
ABCs, then CT w/o to r/o stroke, start antibiotics, do MRI look for temporal activity, then get EEG, do not use steroids
Triad of Miller-Fischer
Ataxia, ophthalmoplegia, areflexia
Antibodies in miller fisher
antiganglioside (GQ1b)
Tumor often in 4th ventricle in young people
ependymoma
