Neuromuscular Flashcards
CMT
CMT1 (all AD) - CMT1A - duplication PMP22 (most common) - peripheral myelin protein 22-PMP22
(Vs HNPP -AD- PMP22 deletion)
-starts 10s-20s
peripheral N hypertrophy (palpable) hammertoes, high arched feet (pes cavus), ue late
NC: conduction velocity slowed no conduction block
-CMT1 and CMTX- demyelinating form
-Roussy-Levy like CMT1A+tremor+ataxia
-biopsy: onion-bulb appearance-Schwann cell proliferation (also in CIDP), not specific
CMT1B - mutation in myelin protein 0 gene
-more severe vs CMT1A
CMT demyelinating (1 and TX) - get CV and over time secondary axonal loss
axonal form - normal CV, decreased SNAP, CMAP
CMT2: axonal less severe, Sx later in life
-mitofusin2 MFM2
CMT2A2-optic atrophy
CMT2B - foot ulceration
CMT2C - diaphragm weak, VC paralysis
CMT 2D - HANDS more than feet involved
CMTX - 2nd most common-demyelinating, limited to CMT1 but X linked-males worse
-connexin 32 gene
CMT3 - Dejerine-Sottas - hypertrophic neuropathy of infancy - as infant, pain and dysesthesias, no reflexes, hypertrophy peripheral nerves
-AD or AR, multiple myeline gene mutations
CMT4 - demyelinating + axonal = RECESSIVE - rare, severe, young age, scoliosis, hearing loss + vision loss (only CMT4 AR; CMT1, FAP, HNPP, HSAN1 all AD)
CMT vs muscular dystrophy: nerve conduction different and hammertoes/high arches specific for CMT
Irregular firing pattern
Fasciculations
giant axonal neuropathy
intermediate filaments in axonal swellings
-CNS and PNS Sx
-curled hair
-walk on insides of feet
(vs metachromatic leukodystrophy-elevated urine sulfatides)
Refsum disease
AD peroxisome disorder, build up of intermediary phytanic acid build up
-retinitis pigmentosa (night blindness, VF constriction)
-hearing loss, anosmia, ataxia-cardiomyopathy
-large fiber sensorimotor neuropathy
-short 4th toe
Tx: reduce phytanic acid in diet
vs KSS - no neuropathy
Abetalipoproteinemia / Bassen-Kornzweig
AR-defect in TG transport
-DEAK deficiencies
-low serum Beta-lipoprotein + vit E
-acanthocytes
-retinitis pigmentosa, neuropathy, ataxia
-mutation in microsomal triglyceride transfer protein MTTP
Kearns Sayre syndrome
mitochondrial disease
ophthalmoplegia; oculobulbar weakness
cardiac conduction defects
retinitis, hearing loss, ataxia
NO neuropathy
Myotonic dystrophy
Autosomal dominant
DM1 DMPK (myotonic dystrophy protein kinase gene) CTG repeats on 19q; anticipation, Moderate-severe Sx age 20s-30s
“Cataracts-toupee-gonads”
-distal predominant weakness - hand and peroneal; atrophy masseters, temporalis (rare)
-laryngeal, pharyngeal muscles spared vs oculopharyngeal muscular dystrophy
-megacolon, esophageal dilation, lenticular opacities, cataracts, infertility, intellect disability
-CK slightly elevated (vs muscular dystrophy)
-EMG: myotonic discharge, early recruits MUAP, fibrillations
-histo: central nucleation, type I fiber atrophy, peripherally placed sarcoplasmic masses, ring fibers, pyknotic nuclear clumps
DM2 CNBP (cchc type nucleic acid binding protein); CCTG repeats on Zinc finger (PROMM-proximal myotonic myopathy)
protein 9 gene, no anticipation Mild-moderate Sx, average age 50
-PROXIMAL myopathy vs DM1
DM1, DM2: repeats cause sequester RNA binding proteins; causes mispliced transcripts
Sx: leg weakness, myalgia, myotonia; neck flexion weakness
Tx handgrip/oropharyngeal myotonia: mexilitine if ok for cards
Cardiac and GI muscle involved
sleep study
get lipid panel, TSH, screen for DM
-higher cancer risk
acid maltase deficiency =POMPE
ALS, MG, phrenic N injury
early respiratory muscle weakness
-orthopnea - gravity working against diaphragm
-hypoventilate daytime sleepiness, morning HA during to hypercarbia
spinobulbar muscular atrophy
gynecomastia 2/2 androgen insensitivity
central core disease
rhabdomyolysis, myoglobinuria
arsenic toxicity
red swollen feet with Mees lines (white horizontal lines on fingernails)
-hair loss
Lambert-eaton LEMS
P/Q type Ca channels Ab
Antibodies from patients with LEMS inhibit the function of the VGCCs
Autoimmune (SOX Ab negative) or paraneoplastic (SCLC) - SOX1 Ab positive
prox muscle weakness, ANS dysfxn, areflexia (vs MG)
-still need malignancy w/u; SOX antibody
-facilitation of reflexes after exercise
NC: LOW CMAP (vs MG) initally
RAPID rep stim (20-50 Hz vs MG-slow 2Hz rep stim) incremental response CMAP amplitudes
with postactivation facilitation. Decrement <10% on repetitive nerve stim increasing 100% after muscle contraction
Tx: Sx-3,4 diaminopyridine (3,4-DAP = amifampridine) blocks efflux K+ ions, prolonging depolarization, ACh exocytosis -> keep Ca channels open longer (ACHEI don’t work)
-, if severe IVIG, plasma exchange
-if autoimmune: steroids, IVIG, PLEX;
-if cancer Tx cancer and LEMS will improve
-PDE-5 inhibits for ED
botulinum
presynaptic cleavage SNARE proteins to prevent ACh release
Botulinum toxin A - SNAP-25 (snare protein)
botulinum toxin B - VAMP (snare protein)
NO sensory symptoms
2,3 HZ repetitive nerve stim - mild/moderate post-activation facilitation
neuromuscular blockers
general anesthesia
macrolide, quinolone ABx
checkpoint inhibitors
immune checkpoint inhibitor related myositis
myasthenia gravis, myositis, myocarditis, lymphopenia
-neck extensors affected, limb girdle, ocular muscle weakness
-CK not as high myositis
Tx: steroids, IVIG is refractory
antisynthetase syndrome
myositis, ILD, Anti-Jo-1, Raynaud, mechanic’s hands, arthralgias
path: perimysial fragmentation+ macrophages,
no lymphs; no capillary pathology vs dermatomyositis
immune mediated necrotizing myopathy
SRP: very high CK, evere rapid progression, rare cancer
cancer risk: if seronegative
-anti-HMG-CoA reductase IgG Ab
path: no inflammation but necrosis
dermatomyositis
anti-Mi2 nail abnormalities
highest cancer risk: TIF, NXP
anti-TIF1-gamma, anti-NXP-2 antibodies
path: capillary dropout , perifascicular atrophy (white lines around muscle fascicles) + perifascicular inflammation
-Tx: steroids, azathioprine, methotrexate (but contraindicated in ILD)
inclusion body myositis
Dx: flexors weak
early-flexor digitorum profundus weakness (forearm flexor muscle atrophy)
-quad muscle weakness
-anterior tibial muscle weakness (plantar flexion weakness)
-dysphagia
* +endomysial inflammation/rimmed vacuoles *
If histo unrevealing ->anti-NT5C1A Ab but not specific for only IBM
No Tx, does not respond to steroids
Dystrophinopathies
DMD gene mutation on X chr- largest gene, lots of spontaneous de novo mutations, deletion/duplication common
produces dystrophin protein that is dysfxnal
females rarely symptomatic - if Turner’s, uniparental disomy
female carriers - can get cardiac involvement even if no skeletal involvement, need surveillance
reading-frame rule:
in-frame mutations = milderBecker phenotype
out-of-frame predicts Duchenne
dystrophin: stabilizes membrane and protects from cell damage
Type 1 Duchenne, type 2 Becker muscular dystropy
XL recessive, most common muscle disease
1/3 caused 2/2 spontaneous mutations in dystrophin gene
Sx at young childhood, gross motor delay, toe walking
-gait: widened, equinus contracture, waddling
Limb girdle + pretibial muscles weak
Scapular winging
lumbar lordosis
cardiomyopathy
enlarged calves (+CK elevation specific to becker/duchenne) hhhghg
Duchenne - nonambulatory by 13
Becker nonambulatory by 16
CK: 5-10x elevated
path: absent dystrophin, endomysial fibrosis, fat, loss type I fibers
Tx: genetic or muscle biopsy showing no staining of dystrophin
Treat: steroids
limb girdle muscular dystrophy
AR - more common; younger onset, higher CK, more acute loss strength
AD - older, less aggressive
Facioscapulohumeral muscular dystrophy
Muscle cell death via misexpression double homeobox 4 (DUX4) - pathogenically turned on -
Fshd 1 and 2 clinically indistinguishable
-most AD
FSHD1 - 95% of pts - contraction of D4Z4 repeat array - the more contracted the worst - encodes pathologic variant - DUX4 gene turned on
-milder disease if longer repeats; short repeats have severe phenotype
facial weakness, orbicularis oculi, corners of mouth- zygomaticus major
-levator palpebrae, EOM spared
EMG - myopathic units
FSHD2 - SMCHD1 mutation - chromatin modifier genes
early Sx: signe de cils (can’t bury eyeliches), scapular winging
-Beevor sign - umbilicus moves upward with neck flexion
-dorsiflexion weakness (vs LGMD2B/R2), face is expressionless b/c weak
-CK normal or slight elevation (vs LGMDR1, scapular winging with elevated CK)
late Sx: LE weakness
EYES, EARS, LUNG (restrictive lung disease) problems
NO cardiomyopathy, no diplopia
Emery-Dreyfuss muscular dystrophy
Life threatening cardiac problems, early contractures, biceps and triceps weakness
-start adolescence
-mutation in EMD/LMNA genes
LMNA - AD
Emerin- X linked
Hypokalemia PP, hyperkalemic PP
Hyperkalemic PP - SCN4A - AD
-trigger: rest after exercise, fasting
Tx: snack, thiazide diuretic as maintenance
Hypokalemia - AD - CACNA1S most common type 1 or SCN4A (type 2)
-triggers: meals/carbs, during exercise. Tx: K sparing diuretics
-can provoke with giving glucose
Tx: carbonic anhydride inhibitors
Andersen-Tawil - KCNJ2 mutation
Steroid myopathy
CK normal, EMG nonspecific
-histo: atrophy type II fibers
Type I vs type II muscle fiber atrophy
type 1 fibers - slow oxidative,
- slow ATPase, large oxidative capacity
-red, small
2 - fast oxidative-glycolytic
-fast ATPase, large glycolytic capacity, moderate
oxidative capacity, fatigue resistant
-red, large
2b - fast oxidative-glycolytic fibers
-low oxidative capacity, fatigable
-pale, large
Type I - myotonic muscular dystrophy, nemaline, centronuclear myopathies
Type II - steroid induced myopathy
Centronuclear myopathy
- Progressive infantile
- Severe X-L neonatal - myotubular myopathy most common -
- Adult-onset
Hypotonia + ptosis , ocular palsy, bulbar weakness; can get resp failure
-CK mild elevation
EMG: myopathic pattern with sharp waves and fibrillations
Path: central nucleation, predominance type I fibers which are small and hypotropic
Vs muscular dystrophy: normal CK, no CNS involvement
X-linked myotubular myopathy -MTM1 gene
dynamin 2 (DNM2), bridging integrator 1 (amphiphysin 2) (BIN1) mutations
Myasthenia gravis
In bimodal distribution, early peak, more common in women and present earlier vs men
Not associated with HLA B27
Thyroid problems - lymphoid follicular hyperplasia
Edrophonium - increases ACh at NMJ - Tensilon test - transient improvement of weakness
-anti-striational muscle Ab positive in thymoma
-if seronegative ACh, MUSK positive in 50%
Repetitive nerve stim: 10% decrease CMAP amplitude -> if seronegative and normal repetitive nerve stim, can do single fiber EMG - most sensitive but not specific - JITTER on EMG - increase jitter/increase interpotential time
Myasthenic crisis: intubate if Nif< -30 or FVC <15 or downtrend of Nif/VC +clinic evidence resp compromise
NO: B blockers, aminoglycosides (gentamicin etc), neuromuscular blocking agents (succinylcholine)
-penicillamine - zero positive myasthenic syndrome
Thymectomy: if Sx before age 60 even if no thymoma can induce remission; myasthenic Sx can worsen peri-op - pre-op IVIG/plasma exchange
Botulinum toxin MOA
Inhibits exocytosis of presynaptic vesicles of ACh
Congenital muscular dystrophy
All: Autosomal recessive except Bethlem
-may have decreased movement in utero
- Collagenopathies -
Ullrich’s congenital muscular dystrophy-Calcanei protrusion - type VI collagen mutation
Bethlem myopathy - Autosomal dominant type VI collagen mutation - contractures elbow, ankles, hyperextend interphalangeal joints
- Merosinopathies - laminin-alpha 2 related CMD
-reduced merosin on muscle staining
-EOM spared
-intelligence normal - Dystroglycanopathies - (note dystrophin is muscular dystrophy)
muscle-eye-brain disease - muscle+brain+eye eyes less affected+less cortical change vs Walker-Warburg
Walker-Warburg - brain, eye, muscle dystrophy, elvated CK, cataract, corneal opacity
-Fukuyama: AR, fukutin mutation ; — frontal white matter changes - weakness, ocular problems , CNS abnormalities, contractures , seizures, intellectual disability
biopsy: dystrophic; reduced alpha-dystroglycan
Core myopathy
AD
Central clearing b/c no mitochondria
-RYR1 mutation
-malignant hyperthermia association
Weakness, hypotonia after birth; prox weakness
-facial, bulbar, ocular muscles spared
CK slight elevation
Oculopharyngeal muscular dystrophy
AD late onset
-dysphasia, dysarthria, ptosis, EOM involved late
-French Canadian, GCG repeat expansion in poly-A binding protein 2 gene PABP2
-biopsy: fiber size variation, rimmed vacuoles, intranuclear tubular filaments
-no myotonia, CK and aldolase normal
glycogen storage disorders
AR except phosphorylase b kinease deficiency
McArdle - myophosphorylase deficiency
Tarui - PFK deficiency
Cori - glycogenosis III-debranching enzyme deficiency; liver disease weakness adult or kid
Andersen - glycogen branching enzyme deficiency - hepatomegaly , cirrhosis, liver fail
(Von Gierke - type 1 - G6phosphatase deficiency in liver and kidney)
McArdle
glycolytic disorder (glycogenosis type V) myophosphorylase gene mutation PYGM, no glycogen to G6P ->accumulate glycogen b/c myophosphorylase deficiency
AR
-exercise induced weakness
-second wind phenomenon after rest b/c mobilize blood glucose
-physiologic muscle contractures = silent on EMG
Tarui
glycogenolytic disorder no phosphofructokinase
No G6P to G1P in muscle + RBC
-jaundice - hemolysis
-gouty arthritis (“rui” “owie “)
glycogen storage disease vs FA oxidation defect vs mitochondrial disorder
- glycogen storage -
- FA oxidation
- Mitochondrial
lysosomal storage diseases
POMPE-acid maltase deficiency - Tx alpha-glucosidase alpha - early resp muscle fail
Carotid sinus hypersensitivity
Head movement triggers-exaggerated response to baroreceptor stim
-syncope + asystole x 3 sec or fall in 50 mm Hg SBP when pressure on carotid sinus
-or hypotension without bradycardia
-reproduce Sx with carotid massage
-CN IX innervates -Nuc solitarius
Vs vasovagal: bradycardia, hypotension, triggered by neck turn
Syncope pathophysiology
- Vasovagal - inhibit vascular symathetic tone, increase vagal tone
- Carotid sinus hypersensitivity - increase parasympathetic response, reduce sympathetic tone
- 3rd ventricular tumor - colloid cyst - postural change then obstruct 3rd ventricle ->increase ICP
Glossopharyngeal neuralgia
Severe pharynx, tongue, ear pain + hypotension + bradycardia /syncope
-post traumatic or neck tumors
Adult myopathies/muscular dystrophies
Early adult onset distal myopathies:
1. Nonaka myopathy - AR distal muscle weakness LEGS first, foot drop, anterior tibial muslcle weakness, onset 20s; extensor forearm muscle weak, no proximal/bulbar involvement
GNE gene mutation = Nonaka GNAT (tubular filaments, rimmed vacuoles)
Histo: rimmed vacuoles
microscopy: tubular filaments like IBM
- Miyoshi myopathy - DYSF / dysferlin gene - AR
Dysferlin -transmembrane protein- Calcium-mediated sarcolemma resealing + repair
-[ANO5 mutation (LGMD)-anterior compartment weak]
-CK elevated, calf muscle atrophy
-DISTAL myopathy vs limb/girdle
biopsy: necrotic fibers + inflammation-
Laing myopathy - distal, anterior tibial + neck flexors then finger extensors/shoulder/hip girdle - myosin heavy chain MYH7
Late adult onset:
3. Recessive Limb Girdle Muscular Dystrophy Type 2 - DYSF mutation LGMD2B dysferlin protein (fusion/repair) - AR
-account for about a quarter of LGMD mutations
-distal localization of weakness, late onset
-shoulder girdle + hip + gastroc/plantar flexion weak
( no foot drop )-> difficulty walking UP stairs b/c can’t plantarflex ; contractures
-spares facial muscles
-absent reflexes, fatty muscle replacement
-significant elevation of CK
-biopsy: inflammation, dystrophic; NO rimmed vacuoles
-no cardiac or pulm involvement
- Markesbery-Griggs distal myopathy - AD - ZASP gene mutation; foot drop then wrist drop; late adulthood (“marcus wallberg titin with achilles foot drop, AD”) - rimmed vacuoles
- Welander - AD - onset 40-60 yrs - weak HANDS then legs (“Weleda hand cream”)
-biopsy: rimmed vacuoles - IBM - rimmed vacuole, inflammatory invasion of fibers
-NO deltoid weakness vs dermato/polymyositis
-thumb flexion weakness with interossei strong
Pyridostigmine
GI Sx side effect - muscarinic R activation
-excess dosing: cholingergic crisis, worsening weakness, respiratory involvement (wet Sx N/V/diarrhea is cholinergic crisis vs MG crisis)
-no CNS Sx, doesn’t cross BBB
-inhibits AChesterase, no destruction
Acute pandysautonomia
Orthostatic hypotension, no HR variability, anhidrosis, dry mouth, early satiety, constitution - over weeks (vs primary autonomic failure )
-Ab vs ganglionic nicotinic ACh R in 50%
-autoimmune or paraneoplastic (SCLC)
-may be triggered by illness
Tx: plasma exchange, IVIG, no full recovery
Inflammatory myopathies
- Dermatomyositis -mi2 - nail prob
TIF1y - cancer
NXP-2 - cancer
MDA-5 - ILD - Antisynthetase - AntiJo1 - mechanic’s hands, Raynaud
- Immune mediated necrotizing
SRP - aggressive , myocarditis , CK>10,000-myonecrosis but no inflammation
EMG: fibs, intertional activity, positive sharps. Tx: immunosuppression
HMG-CoA - cancer
Statin toxicity
Statin + fibrates increases risk toxicity
SLCO1B mutation associate with risk of developing statin toxicity
10x CK elevation
muscular dystrophies disorders of cardiac conduction and contractility,
including myotonic dystrophy, Emery-Dreifuss muscular dystrophy, and LGMD types 1A (myotilin); 1B (laminin); 1C (caveolin); 1E (desmin); 2C, 2D, 2E, and 2F (sarcoglycans); 2G (telethonin); and 2I (fukutin-related protein).
LGMD
Autosomal dominant:
1A (myotilin);-Myot
1B (laminin LMNA/emerin); A/C; Emery Dryfuss - Life threatening cardiac problems, early contractures, biceps and triceps weakness -NO pseudohypertrophy of calves
-start adolescence
-mutation in EMD/LMNA genes (encodes lamin A/C)
Cardiac conduction problems
LMNA - AD; Emerin- X linked
1C (caveolin); rippling muscle disease
1E (desmin)
Autosomal recessive:
2A: CapN3, calpain3-related - scapular winging, ankle contractures, peroneal weakness,, high CK (vs FSHMD), difficulty going up stairs
2B: Dysferlin - DYSF mutation LGMD2B dysferlin protein (fusion/repair) - AR - calf weakness, difficulty walking UP stairs
-no pulm/resp involved (Myoshi related dysferlin)
2C-F - sarcoglycans gamma, alpha, beta, delta
2I fukutin-related protein=FKRP
2L- fukutin
Cardiac conduction problems: 1A (myotilin); 1B (laminin); 1C (caveolin); 1E (desmin); 2C, 2D, 2E, and 2F (sarcoglycans); 2G (telethonin); and 2I
-if dysphagia, use feeding tube
Neurotransmitters of ANS
- Norepinephrine = neurotransmitter (epi - hormone from adrenal medulla, similar action at alpha1)
-activates alpha-1, Vasoconstriction, increase MAP
Presynaptic alpha2 R - norepinephrine decrease presynaptic release of norepi
-beta-1-increases HR
B2-bronchodilation vasodilation
Alpha1 - vasoconstriction arteries, increase peripheral arterial resistance and MAP, and increase venous return (venocontrict), mydriasis, urethral spine contraction, urinary retention
Beta1 - sinus node - cardiac contractility, vasoconstriction
Beta2 - bronchial smooth muscle, blood vessels
Sketchy: Alpha coupled Q - QISS - alpha1, alpha2, beta1, beta 2 - coupled go Gq, Gi, Gs, Gs receptors
- ACh -
M1-R on autonomic ganglia - decrease expresan release norepi, ACh
M2-sinus node - REDUCE HR
M3-salivary -(SNS) increase secretions, bronchodilation
Trichinosis
Rash: puffy eyelids,
diplopia, dysphasia, strabismus, myalgias, proximal weakness
High eosinophils
Muscle biopsy: trichinella spiralis parasite (pork with larvae), survive in muscle as calcified cysts
GI Sx then 1 month later fever, myalgia, fatigue, EOM weakness
Dx: ELIZA for trichinella, muscle biopsy, eosinophilia
Tx: thiabendazole, steroids
Vs HIV, Lyme ->neuropathy. Leptospirosis - affects muscle + other organs (thin coil bacteria)
Congenital myopathy
- Nemaline - severe neonatal congenital to adult onset - AD or AR (not XL vs centronuclear)
-*respiratory dysfunction, cardiac dysfunction *
Neonate: dysmorphic features
Various muscle protein mutations
-histo: fibers - sarcoplasmic rods beneath sarcolemma = nemaline bodies/rods; type 1 fibers small - Central Core (RYR)
- Centronuclear
-Progressive infantile
-Severe X-L neonatal - myotubular myopathy most common -
-Adult-onset
Hypotonia + ptosis , ocular palsy, bulbar weakness; can get resp failure
-CK mild elevation
Path: central nucleation, predominance type I fibers which are small and hypotropic
ANS testing
Normal: transient decrease BP then increase HR -
-tilt table-> SBP decrease 5-15, 5-10 increase DBP, 10-15 bpm increase HR
Late hypotension -Neurocardiogenic hypotension delayed then happens with bradycardia
Early hypotension - insufficient sympathetic tone and baroreceptor problems
Hypotension + tachycardia = hypovolemia
Sudor motor function:
-qualitative - sudomotor thermoregulatory sweat test TST - look for patterns of hypo/ anhidrosis
-global hypohidrosis: MSA, pure autonomic failure, autonomic neuropathy
-distal hypohydrosis: large, small fiber neuropathies
-quantitative: sudomotor axon reflex test, sympathetic post ganglionic axon - sweat cell applied to skin, give current, ACh stimulates sweat glands, sweat production measure from adjacent sweat glands - if low response, lesion of postganglionic sympathetic axon
-test small fiber neuropathy
Acid Maltese deficiency
Type II glycogenosis - Acid Maltese (alpha-1, 4 glucosidase) deficiency, no glycogen to glucose; glycogen accumulation
AR
-biopsy: vacuolated sarcoplasm with glycogen accumulation, stains with acid phosphatase
Pompe - infantile - 1st months life - macroglossia, cardiomegaly, hypotonia, die after months
Childhood: 2nd yr - motor delay, large calves, MR, pulm problems, rare cardiac prob
Adult: slow progressive proximal weakness respiratory weak, no MR, no cardiomegaly, no hepatolomegaly
-enzyme replacement therapy: alpha glucosidase
Congenital myasthenia
Present at birth or childhood/adult
Facial diparesis, ptosis, ophthalmoparesis in infancy, limb weak
ACH R deficiency - most common - AR or sporadic
Vs *acetylcholinesterase deficiency *- delayed pupillary response - axial + resp weak in infancy - do NOT response to ACHE inhibitors (Edrophonium does not improve)
Edrophonium - transient improves Sx
No immunosuppressant or thymectomy
EMG: decrement on repetitive nerve stim, jitter on single fiber
Vs transient myasthenic Sx - if mom has MG - improve within 2 weeks
Sympathetic and parasympathetic nervous system anatomy
all preganglionic: ACh -nicotinic R at ganglia
SNS: short preganglionic neurons, ganglion in interomediallateral column T1-L2->preganglionic white rami synapse on paravertebral ganglia-(release ACh) - T1-L2 superior cervical, mid cervical, stellate, celiac ganglion, superior/inf mesenteric ganglia
postganglionic fibers = gray rami-carry through spinal nerves -> long post-synpatic, release norepi or Ach if sweat-M3
PNA: cranial (III, V, IX, X CN) and sacral portion (S2-S4)
long presyn,
short post-synaptic ganglion, release ACh - ganglia close to target site
M2-sinus node - REDUCE HR
Horner’s
superior cervical ganglia then post-synaptic ganglia travel along common carotid A
-ICA: sphincter pupillae - (dilation) - anisocoria more prominent in dim light
-can still constrict to light and accommodation b/c parasympathetic intact
Muller’s smooth muscle/superior tarsal muscle
apparent enophthalmos - eye appear sunken, no lid retractors
NO anhidrosis vs apical lung mass/Pancoast tumor
ECA - fibers for sweat glands of face
detrusor sphincter dyssynergia
detrusor muscle contracts, urethral sphincter unrelaxed
Micturition reflex
- voluntary micturition ->detrusor reflex (PNS)->external sphincter relax(SNS), detrusor contracts against relaxed internal sphinter (SNS)
-if external sphincter contracted->detrusor relaxes automatically
Voluntary contraction external urethral sphincter - L1-L2 ; bladder innervation by sympathetics L1-L2
Detrusor - paraympathetic nervous system
-pontine micturition center controls detrusor reflex
S2-S4-nerve roots relay afferent sensory info to GU, bladder, anorectal
Onuf-S2-S4-urethral and anal sphincters
Urinary incontinence lesions
- paracentral lobule (medial continuation precentral gyrus in frontal lobe) - NPH, tumor - no voluntary control external urethral sphincter = no voluntary suppression of detrusor reflex
- Lesions above conus: flaccid bladder+ urinary retention /overflow
->over time then hyperreflexive, overactive detrusor contraction - urge incontinence
-MS lesions - Cauda equina -* loss detrusor tone>flaccid bladder, can’t sense fullness->overflow incontinence*
-intermittent cath - detrusor sphincter dyssynergia- neurogenic detrusor overactivity- detrusor muscle contracts against unrelaxed urethral sphincter - SC disorders
enteric nervous system
myenteric/Auerbach plexus-btw innter+outer smooth muscle GI tract - motility
+
submucous/Meissner’s plexus - secretory
Hirschsprung - segments with no myenteric plexus, cannot relax ->constipation
-some due to RET mutations
Myofibrillar myopathy -
AD or AR,
weakness distal LE>UE +/- cardiomyopathy, neuropathy
hyporeflexia, myotilin mutation,
desmin/alpha-crystallin
path: focal dissolution of myofibril and subsarcolemma accumulation granular, filamentous material,* rimmed vacuoles*, central nucleation
disintegration of the Z-disk, accumulation of myofibrillar degradation products, and
-ectopic expression -desmin, αB-crystallin, dystrophin, congophilic material
chloride channelopathy
ClCn1
AD - Thomsen
AR - Becker (just like Becker muscular dystrophy is XLR) - beta recessive
critical illness myopathy vs polyneuropathy
polyneuropathy: low SNAPS, low CMAPs - axonal degeneration. Need EMG: neurogenic changes
myopathy: normal SNAPs, low amp CMAPs
-myopathy +/- polyneuropathy , myopathy improves first b/c muscle regeneration faster than nerve
-flaccid weakness, limb+diaphragm
-myosin loss
-risk factors: SIRS associated, steroids, neuromuscular blocking agents, hyperglycemia, sepsis
Tx orthostatic hypotension
abdominal binder-shunts blood from splanchnic mesenteric circulation
-fludrocortisone-expands plasma volume
midodrine,
-pyridostigmine
droxidopa: converts to norepi
Nerve conduction studies
CV = distance / latency (time)
CV >50 in arms, >40 in legs
-hereditary demyelinating - slow CV, no conduction block or temp dispersion
acquired demyelinating slow CV, + conduction block + temp dispersion
SNAPs
-normal in radiculopathy b/c record postsynaptic (Dx on EMG) and damage is presynaptic despite sensory Sx
CMAP CV - difference in onset latencies btw two stim sites vs SNAP [subtracts out time to NMJ and triggered muscle AP]
conduction block: decrease CMAP BTW prox and distal stim sites
F wave, H reflex - late responses
F wave - supramax stim antidromic along motor axon then orthodromic to record at muscle
H reflex - S1 ankle reflex arc - stim tibial N -orthodromic -to go spinal cord
EMG
insertional activity -needle insertion
- increased in myotonia, denervation
-decreased if dystrophic and during episodes of periodic paralysis
Spontaneous: muscle at rest - fibs, fasics, myokymia, myotonic potentials - all abnormal
voluntary movement - MUPs-
1. axonal loss: reduced recruitment = few MUPs firing more rapidly
-denervation/renervation (prox to distal) - longer and bigger, polyphasic
(axon loss, denervation, fibrillations, decreased recruitment, then large MUPs when reinnervation)
- myopathic: short small MUPs, polyphasic
- poor effort/CNS disordres causing weakness - recuirtment reduced, normal MUPs firing slow
CIDP
time course=8 wks
Dx: CSF, EMG, then sural N biopsy
prolong F wave/absent F
-partial conduction block, abnormal temporal dispersion
vs MMN - sensory problems in CIDP
Tx - plasmapharesis, steroids, IVIG, azathioprine
peripheral nerve injury
- focal nerve injury->segmental demyelination (before axonal loss) ->conduction block without temp dispersion:
-conduction block reversible
- severe: axonal loss -> Wallerian degeneration - completed in 7-10 days (“pseudoconduction block” due to axon loss)
-after 10 days: distal axon degenerates, can’t conduct ->pseudoconduction block resolves
-fibs - 3 weeks after injury
carpal tunnel syndrome
-thenar eminence sensory spared b/c palmar sensory branch outside carpal tunnel
-motor branch distal to tunnel: thenar/recurrent motor branch - weakness thumb abduction, opposition
familial amyloid polyneuropathy - AD
Autosomal dominant - amyloid deposition - mutations in transthyretin FAP1/2- (made in liver and transports thyroxine)
-loss pinprick and temp , relative sparing of proprioception
**FAP1 - loss pain/temp + autonomic SX + cardiac/renal
Sx 30s-40s, polyneuropathy
pain+temp, relative spares dorsal columns
-cardiac + renal involved **
-congo green stain
FAP2 - carpal tunnel+ no autonomic features - 40s-50s, no ANS dysfxn, slow polyneuropathy loss pain and temp
FAP3, FAP4 - not transthyretin
FAP 3 - apolipoprotein A1 gene -like Fap1 but more renal, GI involvement
FAP4-start in 20s - amyloid protein gelsolin mutation - CN VII, VIII, XII affected, no ANS fxn
vs primary amyloidosis - AL amyloid deposition ; vs secondary amyloidosis (AA amyloid deposition)
brachial plexus
formed by ventral/anterior Rami of nerve roots
dorsal ramus-motor innervation to the deep (a.k.a. intrinsic or true) muscles of the back, and sensory innervation to the skin of the posterior portion of the head, neck and back
benign fasciculation syndrome
no weakness, no atrophy, normal exam
-need to rule out bad things with EMG -
EMG-fasciculation potentials without denervation
Lumbrosacral plexus
L5 - normal SNAPS in L5 radiculopathy although H reflex reduced/absent
Plexopathy: SNAPs abnormal; no paraspinal fibrillations
Radiculopathy - paraspinal fibrillations, normal SNAP
-paraspinal abnormal in L5, normal in plexus (T12-L4)
-foot inversion normal = common peroneal neuropathy not L5 neuropathy b/c inversion posterior tibial (innervated by tibial N)
-L5 - glut muscle weakness
-tibialis anterior - L5 deep peroneal innervated and L4
-fem N injury intrapelvic vs inguinal ligament: if after inguinal ligament, no hip flexion weakness b/c iliacus and psoas innervation intact
Lumbar plexus: T12-L4 -
3 minor N -
(T12-L1), iliohypogastric,
(T12-L1) ilioinguinal
(L1-L2)-genitofemoral
3 major N -
L2-3 - lateral femoral cutaneous - pure sensory, meralgia paresthetica , worse with standing, walking, better with flexion at hip
L2-4 anterior division- obturator - medial thigh sensation + adduction
L2-4 posterior division- femoral - quads, anterior thigh sensation- thigh flexion+leg extension (patellar reflex)
-inntervates psoas major, iliacus then under inguinal canal
-intrapelvic injury: hip flexion weakness and iliacus fibrillation potentials; if after inguinal ligament, no hip flexion weakness
-in intrapelvic region: iliacus fibrillations, psoas weak, hip flex weak
L4/L5-lumbrosacral trunk joins sacral plexus to give off sciatic nerve
Sacral plexus: Lumbrosacral trunk L4/5 + S1-S4
L4-S3 - Sciatic nerve - first gives off superior/inferior gluteal nerves
L4-S1 - * superior gluteal nerve - glut med+min+tensor fascia lata*
L5-S2- inferior glueal N- glut max - extends and externally rotates hip
sciatic nerve-Tibial division - adductor magnus/semimembranous/semitendinous, long head biceps femoris (long winded mnemonic) flexes knee
sciatic N common peroneal division - short head biceps femoris - only peroneal innervated above the knee
Long head biceps femoris-tibial nerve
Hamstring-Semitendonosus and semimembranosus - sciatic/tibial nerve
L4-S3 anterior division - tibial - in knee - gastros, tibialis posterior - A-TIP
-tibial gives off sural N after knee - sensory innervation to lateral leg+ foot
-tibial nerve at tarsal tunnel: plantar pain, sense loss on sole, no weakness
L4-S2 posterior division - common peroneal - P-PED
-deep peroneal - tibialis anterior (L5), extensor hallucis, extensor digitorum - foot drop; sensory to web space btw first two toes
-superficial peroneal - eversion
S1-S3 -posterior femoral cutaneous nerve lower buttock/post thigh sensation
S2, 3, 4 - pudendal nerve - sensory info to genitals
glut med out - abductor, lifts pelvis up trendelenberg gait
glut min - internal rotator
HNPP
PMP22 deletion, autosomal dominant
conduction block sites
-peroneal most common N involved, then ulnar
-Hx compression/traction
-NO pain - distinct vs. hereditary neuralgic amyotrophy (Parsonage Turner)
-prolonged distal latency, focal slowing at compressive sites
-biopsy: sausage thickening in myelin = tomacula- demyelination, axon loss; not inflammation
paraneoplastic Ab
Anti-Hu - SCLC - dorsal root ganglionopthy, peripheral neuropathy
anti-yo - ovarian cancer, almost all females cerebellar degeneration
Anti-Ri - lung (NSCLC, SCLC), breast - opsoclonus myoclonus
Anti-Ma - NSCLC, testicular cancer, young males - limbic encephalitis, brain stem encephalitis
KLHL11- brainstem/cerebellar syndrome - testicular tumors young males
Amphiphysin - stiff person-SCLC, breast cancer
SOX1-LEMS
tangier
AR, mutation ATP-binding cassette transporter protein - ABCA1 gene, 9q31
symmetric polyneuropathy-loss pain + temp feet, can mimic syringomyelia
-hand weakness, UE+LE weakness
-or multi focal mononeurpathy
-orange tonsils because TG deposited
-low LDL, LOW HDL, high TG
TG in reticuloendothelial
-bone marrow biopsy: fat laden macrophages, premature atherosclerosis
Histo: foamy macrophages
Dx: clinical + lipid panel
Multi focal motor neuropathy
Pure motor, no sensory Sx
CSF: normal protein
Can have anti-GM1 Ab, doesn’t mean anything
EMG: if other demyelination features don’t need conduction block to Dx and block does not correspond to Tx response
Tx: IVIG, NOT plasmapharesis or steroids; ritux, cyclophosphamide
Diabetic amiotrophy
Significant weight loss or during adjustment of insulin
-low back/hip PAIN radiates down leg, worse at night, sensory deficit then weakness, atrophy, absent patellar reflex; unilateral
EMG: denervation in myotomes
Pain can resolve spontaneously then weakness better
L2, L3, L4 distribution
Radial N
Radial - sole triceps innervation
Innervates brachioradialis
Mostly extensor except abductor pollicis longus
Sensory: posterior +*lateral *arm, posterior forearm
R neuropathy proximal to spiral groove: triceps weak, posterior arm sense loss - sat night palsy, crutches; triceps reflex can be absent but pronation strong (pronator teres C7)
-**if not axillary/posterior cord: strong deltoid and teres minor **
Distal to spiral groove: intact triceps and upper arm sensation
Posterior interosseus nerve - pure motor syndrome; no wrist drop obvious b/c only weakness wrist extension in ulnar direction
-supinator syndrome: posterior interosseus N compressed as it travels through supinator; pain with supination
-diabetic mononeuropathy
Handcuffs/watch injury- superficial sensory radial neuropathy - numbness over dorsolateral hand
Ulnar N
Compression at elbow - postcondylar groove entrapment - proximal to wrist - flexor carpi ulnaris, flexor digitorum profundus weak, loss of sensation to hypothenar eminence
-truck driver leaning arm on window
-conservative management , surgery rare
Compression at wrist - Guyon’s canal - hypothenar eminence sensation spared (palmar cutaneous branch proximal to canal)
sensory: only to anterior/posterior 4th and 5th digit to hand
vs. neurogenic Thoracic outlet syndrome: C8/T1 nerve root compression - scalene triangle (scalenes+first rib), fibrous band forms - holding up pompoms
-intrinsic hand muscle weakness + sensory loss medial forearm (t1+C8)
-arm abduction, external rotation precipitates Sx and decreases radial pulse
diabetic neuropathy
Small fiber - DM neuropathy - pain burning, no vib/propio abnormalities
-alpha-delta and C fibers (unmyelinated)
-can come with ANS symptoms b/c ANS neuropathy
Complications: Charcot joint - ankle arthropathy - loss of sensation and sensory ataxia
Arm/forearm/hand anatomy
Flexor pollicis longus - Median - in forearm
Flexor pollicis brevis- ulnar - in hand + median in hand
Adductor pollicis - ulnar in hand
Median N
All anterior forearm muscles except flexor carpi ulnarnis and flex digitorium profundus (DIPs) in 4th, 5th digit (ulnar),
flexor pollicis longus (anterior interossei branch median nerve)
In hand: 1/2 LOAF brev - 1/2 lumbricles 1 and 2 OAF - opponens policis, abductor pollicis brevis (palmar abduction away from plane of palm), flexor pollicis brevis
(Ulnar: adductor pollicis, flexor pollicis brevis (MCP join flexion), interossei, digiti minimi )
Radial: forearm = abductor pollicis longus = radial abduction in plane of palm
Extensor pollicis longus (extend at Inter phalange al joint), extensor pollicis brevis )extent at MCP joint)
Median N injury: brachial N in antecubital fossa
Anterior interosseus N syndrome: NO sensory Sx can’t make OK sign - deep muscles flex dig profundus, flex pollicis longus, pronator quadratus
Pronator teres syndrome - forceful pronation +/- medial epicondylitis ; compresses median N as goes through pronator teres; strength full in pronation but pain
Ischemic monomelia
AV shunt for dialysis
-painful circumferential sensory loss in multiple distributions
Parsonage turner
Acute brachial plexitis/neuralgic amyotrophic
-acute shoulder arm PAIN RESOLVES THEN weakness
-brachial plexus or lumbrosacral plexus
-monophasic
-hereditary neuralgic amyotrophy- autosomal dominant - SEPT9 gene
Ddx after surgery - hematoma
anterior spinal A infarct
Dorsal columns spared
AIDP
Aidp - prolonged lantency, slow conduction velocity
MADSAM - demyelinating - asymmetric, upper limbs then lower limbs , no GM1 Ab vs MMN
Acute motor and sensory axonal neuropathy - no demyelination; low sensory and motor amplitudes
Acute motor axonal neuropathy - reduced motor amplitude, no demyelination
Spinal accessory nerve
Lower medulla +C1-C4 fibers
-innervates SCM and trap (arm abduction >90 degrees; elevates scapula)
-no sensory deficit
Radical neck dissection injury
Vs cervical plexus: C1-C4 ventral rami, neck muscles and sensory innervation to post head/neck
musculocutaneous vs lateral cord lesion
musculocutaneous: sensory to lateral forearm
coracobrachialis, brachialis, biceps brachii
if stronger forearm supination when extended = brachioradialis strong- (not C6 radiculopathy or RADIAL)
-lateral cord lesion: C5, C7 muscles affected - flexor carpi radialis, pronator teres, hand sensory loss
axillary neuropathy
anterior shoulder dislocation
-C5/C7 continuation posterior cord
-deltoid (abducts 30-90 degrees), teres minor
sensory lateral arm
C5/C6 differentiation
C5 - rhomboids - at C5 root - dorsal scapular - intrascapular wasting, scapular wining
-C5 contributes to phrenic N (C3, C4, C5 - diaphram)
-prox to C5 lesion-diaphragm weakness
biceps - C5 innervated
(C5-C6-C7) Long thoracic N - innervates serratus anterior - scapular winging
suprascapular N - 30 decrees abduction, entrapment
thoracodorsal - posterior cord - arm adduction-lat dorsi
fabry
alpha-galactosidase A , X linked
lysosomal storage disorder
-angiokeratomas - dark lesion, axilla, scrotum
-small fiber , Autonomic neuropathy
strokes dolieoctasia , deposites of globotriasylceramide
-painful acroparesthesias (numbness, tingling, prickling, and reduced sensation, affecting fingers + toes) worse with heat and exercise
-vs. primary erythromelalgia (SCN9A, AD) -no small fiber neuropathy
thoracoabdominal polyradiculopathy
bulges in abdominal wall, unilateral ab pain, fibrillation, loss reflexes in abdominal wall in DM
weakness of abdominal wall
hereditary sensory and autonomic neuropathy HSAN
HSAN -** sensory+autonomic Sx, motor ok**
-stress fracture, Charcot joints, calluses, ulcers, infection, osteomyelitis
HSAN1 - most common - AD - adult, lancinating pain, temperature/pain sense loss, hypohidrosis
-serine palmitoyltransferase mutation- rate limiting sphingolipid synthesis
HSAN2 - infancy - insensitivity to pain, NO ANS symptoms, cognitive fxn normal, retinitis pigmentosa, no SNAPS on NC
HSAN3 - Riley Day familial dysautonomia - AR, IKAP gene, infancy, SWEAT with stimulation, no lacrimation mutation-abnormal mRNA splicing, dysfxn endocytosis
start infancy; vomiting, infections, dysphagia, smooth tongue
biopsy: decrease unmyelianted axons
HSAN4- AR insensitivity to pain+cog dysfxn+NO SWEAT; fevers; hyperactivity
- tyrosine kinase R mutation for nerve growth factor NTRK1
vs CMT: CMT has motor weakness, no early dysphagia, no autonomic dysfxn
mononeuritis multiplex
two or more mononeuropathies
-vasculitis - polyarteritis nodosa, granulomatosis with polyangiitis, Sjogren’s, Churg/Strauss, cryoglobinlinemia, HIV, lyme, sarcoid, RA, Diabetes
cryoglobulinemia
constitutional Sx, palpable purpura, LAD, HSM,
*peripheral neuropathy, mononeuritis multiplex, ischemic stroke**
-hep C, HIV, multiple myeloma association
Tx: steroids, cyclophosphamide
primary erythromelalgia
AD inheritance, SCN9A mutation ->hyperactivity dorsal root ganglia
episodic burning pain and redness worse with heat, no small fiber neuropathy
secondary erythromelalgia - polycyethemia, SLE
DDx Fabry: alpha-galactosidase A - heat triggered acroparethesias but biopsy with small fiber neuropathy
DDx HSAN1 - symptoms not episodic like primary erythromelalgia
sensory neuronopathy/ganglionopathy
neuronopathy = cell bodies +axons involved
-sensory ataxia, areflexia
cause: pyridoxine intoxication, paraneoplastic (anti-Hu, SCLC)
Hereditary amyotrophy
SEPT 9 gene
Familial brachial plexopathy
ALS
Onuf nuc spared, sphincter functional, rare sensory and rare dysautonomia
-present LMN findings first
-riluzole - inhibits glutamate release - slows disease, extends survival by 3 months
pseudobulbar affect - dextromethorphan-quinidine
Familial ALS: C9orf72 ; SOD1 (copper/zinc superoxide dismutase), TDP-43, and FUS.17,18,20
-autosomal dominant
DDx: spinocerebellar ataxia 3, adrenoleukodystrophy, MMA (GM1 Ab), anti-Hu paraneoplastic Ab (SCLS-dorsal root ganglionopathy, peripheral neuropathy), hyperparathyroidism
spine tumors
metastatic - more symptoms and deficits since grow faster
primary - slow growing, Sx less than imaging
meningioma: T1- iso to hyperintense
T2- isointense to cord
intradural, extra vs intra medullary
-intramedullary: astrocytoma (more common in kids),
ependymomas (most common SC tumor in adults)
-myxopapillary ependymoma - from filum terminale
-extramedullary: meningioma, neurofibroma, schwannoma
rare metastatic intramedullary mets
breast lung prostate kidney most common
B12 deficiency
B12-cofactor methionine synthase - convert homocysteine to methionine
-B12 can be normal in deficiency ->check homocysteine + MMA
MCC malabsorption
-high gastrin levels, anti-IF Ab, antipareital (achlorhydria (no HCl from stomach) 2/2 pernicious anemia)
-2/2 nitrous oxide toxicity makes B12 inactive
-white matter vacuolization
upper motor neuron disease
- Primary lateral sclerosis-UMN only for 4 years
Sx in 60s, spastic tetraparesis, CN involved,
-spasticity more than weakness/atrophy
-no autonomic Sx
Autopsy: loss Betz cells layer 5 motor cortex
DDx cervical myelopathy, MS, 1 (tropical spastic paraparesis), stiff person, hexosaminidase A deficiency
Tx: baclofen: GABA-B agonist
tizanidine: alpha 2 agonist
- tropical spastic paraparesis - HTLV1 - painful, bladder dyxfxn, LE weakness/spasticity (vs HIV Myelopathy-no pain)
-associated with lymphoma, leukemia - Hereditary spastic paraparesis
- variable inheritance and expression; but commonly AD SPG4 gene mutation
-LE spasticity, excludes UE
-cog chances, seizures, hearling loss, optic atrophy, ataxia - Adrenomyeloneuropathy -ABCD1 gene on Chr Xq28
-adrenal insufficiency, cog change, peripheral neuropathy
Friedreich ataxia - hypertrophy cardiomyopathy, optic atrophy, hearing loss, nystagmus, peripheral neuropathy
lower motor neuron disease
- Hexosaminidase A deficiency is a rare cause of lower motor neuron dysfunction- limb weakness and atrophy, +/- dysphagia and dysarthria- HEXA gene.
+/- cerebellar atrophy
-psychiatric Sx - Kennedy disease - - X linked CAG repeat androgen receptor, fertility problems, gynecomastia, diabetes
-proximal muscle start vs progressive muscle atrophy
-face fasciculations
-bulbar dysfxn late
-rare in females 2/2 random X inactivation - Monomelic amyotrophy/Hirayama - young Asian pts
-asymmetric wasting of hands/forearms
-atrophy + fasciculations, no sensory deficits, no pain; does not progress
-may be caused by neck flexion-cervical collar - Progressive muscle atrophy - ALS but LMN signs only (need isolated LMN signs at least 3 years from Sx onset)
-starts as focal distal weakness
-presents earlier vs ALS + live longer; bulbar involvement late; progresses over 3-5 yrs
-CK only mild elevation
-vs SMA: indolent progression + prox muscle
- vs IBM -only finger flexor + quad weak - SMA -AR SMN1 mutations, lose survival motor neuron proteins, anterior horn cells
type 1 - infantile - Werdnig-Hoffman - hypotonia, areflexia, dysphagia, death by 2 yrs -
type 2 - intermediate - Sx 1-2 yrs of life
type 3 - juvenile - Kugelberg Welander - tremor, prox muscle weakness, fasciculations. EMG-complex repetitive discharges
SMA 4- adult /pseudomyopathic - prox muscle weakness esp quads, fasciculations
-rare CN, respiratory involvement
CK: 10x normal for juvenile forms
EMG: large polyphasic motor units, chronic and acute denervation/renervation
Biopsy: atrophy of muscle fascicles, some neighboring normal and hypertrophied fascicles.
spine vascular supply + anatomy
watershed infarct : T4-T8 - watershed (vs A Adamkiewicz-T8-L3)
ASA+PSAs from vertebrals
ASA infarct - paraplegia + STT loss bilaterally
Brown Sequard: ipsilateral loss vibes+proprioception+ motor, contralateral loss pain/temp
-segmental A from aorta, internal iliac ->thoracic, lumbar
-epidural venous plexus connects pelvic venous plexus + intracranial venous system
-odontoid process-C2
Horner’s syndrome: above T1
superficial abdominal reflex: T6
atlantoaxial dislocation - Klippel-Feil syndrome, Morquio (odontoid process aplastic/absent), Downs, RA
spinal cord: dorsal to posterior longitudinal ligament
-enlargements at cervical + lumbosacral levels
-denticulate ligament: from pia mater to dura mater on both sides of cord
cervical nerves: exit above vertebral body except C8
-> exits between C7-T1 foramen
all others exit below
spinal epidural hematoma
T2: hypointense (if acute blood)
SWI/T2*: blooming artifact
-Sx over days vs dural AV fistula - chronic Sx with acute exacerbations ->venous infarcts
radiation induced myelopathy
transient form: 3-6 months after Tx; dysesthesias, resolve
delayed: 6 months after, insidious, increase T2 signal in MRI
toxic myelopathy
lathyrism - neurotoxin - subacute spastic paraparesis - Lathyrus sativus - legume
Konzo - spastic pareparesis - visual problem - cassava - cyanide
epidural lipomatosis
Hypertrophy extramedullary adipose tissue in spinal canal causing stenosis
-Tx: stop steroids
copper deficiency
excess zinc -> metallothionein activity increased -> copper binds metallothionein ->sloughed off in mucosa->decreases copper
-T2 hyperintensity cervical spinal cord
-can get optic neuronopathy
-peripheral neuropathy
nmo
NMO-IgG: aquaporin 4 on astrocyte foot processes
-not encephalopathic vs ADEM (ADEM can get transverse myelitis-over multiple segments; Tx: steroids)
adrenomyeloneuropathy
X linked ABCD1
-accumulate VLCFA
-starts at 20s: paraparesis, sphincter control problem, hypogonadism; cognitive/hearing/vis impairment
-adrenal insufficiency
increase VLCFA in plasma, fibroblasts
superficial siderosis
recurrent bleeding into SAH (unknown source) -> hemosiderin deposits in subpial layers
-unknown cause, possibly risk of prior bleeds
-Sx: gait ataxia + hearing loss
-anosmia, cognitive problems, myelopathy
CSF: xanthrochromia
MRI: T2 hypointensity around brain, brainstem, spinal cord
conus medullaris vs cauda equina
conus medullaris: saddle anesthesia, symmetric pain (not radicular)
-bowel and bladder dysfxn early
cauda equina: hyporeflexia, asymmetric, radicular, bowel/bladder spared early
spinocerebellar ataxia
spinocerebellar ataxia type 3-Machado Joseph
Nitrous oxide toxicity
anesthesia paresthetica: myelopathy, neuropathy +/- encephalopathy
NO inactivates B12
-if B12 deficiency can get myelopathy after one exposure to NO
-chronic exposure from healthcare workers + acute exacerbations if big NO load
MRI: T2 hyperintensity in cord
spinal epidural abscess
NO LUMBAR PUNCTURE - spread disease
-MCC Staph
