Neuromuscular Flashcards
Mutation in giant axonal neuropathy?
GAN gene (gigaxonin)
How does Refsum disease present?
neuropathy, hearing loss, anosmia, ataxia, cerebellar signs, retinitis pigmentosa, cardiomyopathy, skin changes
How does Giant axonal neuropathy present?
sensorimotor neuropathy, corticospinal tract involvement with UPMN signs, and optic atrophy, tightly curled hair
*walk on inner edges of feet
What is a prominent feature in myoneurogastrointestinal encephalopathy?
intestinal pseudoobstruction
*opthalmoparesis, demyelinating neuropathy
what is the mutation in myoneurogastrointestinal encephalopathy?
thymidine phosphorylase
Abetalipoproteinemia is what?
abnormal very low density lipoprotein secretion
*deficiency in vit D, E, K, A
LEMS have what kind of response to rapid repetitive stimunlation?
incremental
*(20-50 hz)
MG shows what with repetitive stimulation?
decrement with SLOW repetitive stim (2-3 Hz)
Type 1 muscle fibers
SLOW oxidative, red
*slow red ox
Type 2a muscle fibers
fast oxidative glycolytic fibers
*fast and resistent to fatigue
Type 2b muscle fibers
fast - oxidative glycolytic fibers, but low oxidative capacity
What is albuminocytolic dissociation?
increased protein but normal cell count
When does wallerian degeneration occur?
7-10 from the injury
A focal nerve injury can cause what?
conduction block
What does FAP1 present?
-3rd to 4th decade of life
-small and large nerve fibers are affected, but loss of pain and temp are most pronounced
-pains, autonomic dysfunction (sex, orthostatic, urinary, GI)
-cardiac and renal
FAP1 and 2 are caused from various mutations of what gene?
transthyretin
FAP2 presents how?
-later than FAP1, 4th and 5th decades
-main features are carpal tunnel with slowly progressive polyneuropathy,
NO autonomic features
FAP3 presents how?
-like FAP1 but with eariler renal involvement and more GI issues, duodenal ulcers
-abnormalities in Apolipoprotein A1
FAP4 presents how?
corneal dystrophy, neuropathies, skin chnages
-cranial nerves 7, 8, 12 more commonly affected
-abnormalities in amyloid protein gelsolin
Which forms of CMT are demyelinating?
CMT1, CMT3, and CMTX
CMT1A presents how?
-1st 2 decades of life
-progressive weakness, muscle atrophy, hyphosis, sensory loss
-hammertoes, high arched feet, palpably enlarged nerves, pes cavus
Gene in CMT1A?
duplication of PMP22
Gene in CTM1B
myelin protein 0 gene
CMT1B presents how?
more severe compared to CMT1A
What type of inheritence in CMT1?
AD
What type of inheritence in CMTX
x-linked
*mutation in connexin 32 gene
What type of neuropathies are CMT2?
axonal
Clinical features in CMT2B?
foot ulcerations
Clinical features in CMT2A2?
optic atrophy
Clinical features of CMT2C?
vocal cord paralysis, intercostal and diaphragmatiic weakness
CMT3 presents how?
infancy, proximal weakness, absent reflexes, hypertrophy of peripheral nerves
Deletion of PMP22 gene is associated with what?
hereditary neuropathy with liability to pressure palsies
Nerve biopsy of HNPP shows what?
tomacula (focal, sausage like areas of thickening in the myelin)
Inferior gluteal nerve innervates what?
gluteus maximus
superior gluteal nerve innervates what?
gluteus medius, minimus and TFL
Lesion in deep peroneal nerve causes what?
foot drop, inability to dorsiflex
without impairing eversion of foot
Gene in Tangier disease?
ABCA1 gene, 9q31
*adenosine triphosphate cassette transporter protein
What nerve provides innervation to semimembranosus, semitendinosus, and long head of biceps femoris?
tibial nerve
Do patients with MMN (multifocal motor neuropathy) have a good response to steroids or PLEX?
no
Which types of CMT are autosomal recesssive?
CMT4
How does diabetic amyotrophy present?
during a transition (initiation or adjustment of insulin), preceding unintentional weight loss, low back pain radiating down lower limb, severe pain at night
then days to weaks later develop weakness and atrophy involving pelvic girdle and thighs
Ulnar nerve is most suspectible to injury where?
postcondylar groove
Pain, numbness and paresthesias in anterolateral thigh?
meralgia paresthetica
What nerve is associated if someone can’t make the okay sign
anterior interosseous nerve
Is radiation induced plexopathy painful or painless?
painless
protnator teres syndrome results from what?
compression of the median nerve as it passes through the 2 heads of the pronator teres
*associated with medial epicondylitis, or golfers elbow
where is the most common site of radial nerve injury?
spiral groove
What can cause a superficial sensory radial neuropathy?
tight handcuffs, watches, venipuncture, surgery
What are the symptoms of superficial sensory radial neuropathy?
numbness, dysesthesias over dorsolateral aspect of hand
Deficiency in Fabry’s disease?
alpha galacosidase A
*accumulation of globotriaosylcermamide –>can lead to dolichoectasia, increasing risk of thrombosis
HSAN1
-AD
-starts in young adulthood
-painful sensory symptoms
-sensory loss with pain and temp more affected
-main autonomic manifestation is hypohidrosis
Gene mutated in HSAN1?
gene encoding for serine palmitoyltransfersase
HSAN2
-starts in infancy
-generalized loss of sensation and insensitivity to pain
-risk of mutilation of hands, feet, lips, tongue
-autonomic symptoms are not prominent
-normal cognition
-areflexia, retinitis pigmentosa
HSAN3
AKA familial dysautonomia
-AR
-prominent autonomic features
-dysphagia, vomiting, recurrent infections, BP lability
-no lacrimation
-smooth tongue
HSAN3 is due to what mutation?
IKAP gene
-abnormal mRNA splicing
HSAN4
AKA congenital insensitivity to pain
-AR
-insensitivity to pain-leading to repeated injury, self mutilation
-cognitive delay
-hyperactivity
-anhidrosis, heat intolerance, frequent fevers
What is mutated in HSAN4
tyrosine kinase receptor for nerve growth factor NTRK1
Cryoglobulins are what?
immunoglobulins that precipiate when exposed to cold temps and redissolve on rewarming
are complement levels elevated or reduced in cryoglobulinemia?
reduced
clinical manifestations of cryoglobulinemia?
constitutional symptoms, palpable purpura, arthralgias, LAD, peripheral neuropathy, hepatosplenomegaly
What is primary erythromelalgia?
-AR
-episodes of severe burning and erythema in distal extremities
-can be triggered by either heat or cold
-mutation in voltage gated sodium channel SCN9A
Erb’s palsy
upper trunk lesion
Are superficial peroneal SNAP normal in L5 radiculopathies?
yes
*abnormal in common peroneal nerve lesions
What can you use to treat HYPOkalemic periodic paralysis?
carbonic anhydrase inhibitors and potassium sparing diuretics
Gene for HYPOkelamic PP?
CACNA1S
*less often SCN4A
Triggers for HyPOkalemic PP
exercise, carbs, ethanol, cold exposure, emotional stressors
Triggers for HYPERkalemic PP
fasting, exercise
Botulinum toxin inhibits what?
exocytosis of presynpatic vesicles containing Ach
Gene in myotonic dystrophy 2?
CCTG
How does Fukuyama present?
hypotonic, floppy, joint contractures, ocular and CNS abnormalities
Muscular dystrophy in French - Canadian person?
oculopharyngeal muscular dystrophy
*AD
Gene associated with myotonic dystrophy 1?
CTG
ptosis, facial weakness, frontal balding, atrophy of masseters/temporalis, weakness and atrophy of small muscles of hands, peroneals
myotonic dystrophic 1
McArdle’s disease defienecy
myophosphorylase deficiency
Which glycogen storage disease get a “second wind” phenomenon?
McArdles
Nonaka myopathy
-onset early adulthood
-foot drop with weakness in anterior tibial muscles
-eventually will get involvement of upper extremities (flexors)
-A.R distal myopathy
Gene associated with Nonaka myopathy?
GNE, chromosome 9
MOA of pyridostigmine?
acetylcholinesterase inhibitor
Central core myopathy gene?
RYRI
*be careful with anesthesia
Autonomic ganglionopathy presents how?
-develop over weeks
-dysfunction of parasympathetic and sympathetic systems
-antibody to ganglionic nicotinic acetylcholine receptor
Miyoshi myopathy
-AR
-weakness and atrophy in distal leg muscles, predominately posterior compartment
-mutation in dysferlin or ANO5
Is dystrophin absent in Becker’s MD?
no, just abnormal or found in smaller amounts
Pure autonomic failure is due to what?
loss of intermediolateral cell column neurons
*deposition of alpha synuclein in autonomic nervous system
Adult onset periodic paralysis is suggestive of what?
a possible secondary cause
ie thyrotoxic perioidic paralysis
*more common in asians
How does trichinosis present?
elevated CK, elevated eosinophils, fever, myalgias, fatigue, edema of eyelids and conjuctiva, ocular muscle weakness
congential myasthenic syndrome
opthalmoparesis, ptosis in infancy, facial diparesis
*most common form is congential achetylcholine receptor deficiency
Mutation in emery-dreifuss MD?
X linked form- emergin
AD - LMNA
How does emery dreifuss present?
contractures, weakness
NO pseudoatrophy of calves
normal IQ
neonatal weakness, contractures, distal hyperlaxity and protrusion of calcanei. Diagnsois?
Ullrich’s congenital MD
Does myotonia congentia have a warm up phenomenon?
yes– myotonia improves with repetitive muscle activation
Myopathy that is associated with mutations in collagen type VI?
Bethlem myopathy
Primary lateral sclerosis presents how?
upper motor neuron signs at least 3 years
No lower motor neuron signs
What is the path behind HIV related myelopathy?
vacular myelopathy, lateral and posterior column demyelination with microvaculour changes and axnal preservation
Hereditary spastic paraparesis presents how?
progressively worsening spasticity of lower extremities
Progressive muscular atrophy presents how?
-only affects lower motor neurons
-focal asymmetric distal weakness that later involves proximal regions
-earlier onset and survive longer compared to ALS
Neurotoxic disorder presenting as myelopathy, subacute spastic paraparsis in ethiopia, india and bangladesh?
lathyrism - consumption of lathyrys sativus (legume)
Konzo
spastic paraparesis, abrupt onset, some invovlement of visual pathways
*africa.. consumption of poorly processed cassava
What kind of virus is west nile?
flavivirus
*mosquitos
meningitis, encephalitis, myeloradiculitis diagnosis?
west nile
West nile presentation
AMS, GI symptoms, back pain, flaccid weakness, areflexia, proximal and asymmetric weakness
Polio is caused by what?
an enterovirus
Polio symptoms
areflexic flaccid paralysis
*does NOT commonly cause AMS
CSF in NMO
elevated WBC, elevated protein, normal glucose
Cauda equina syndrome presents how
radicular pain, asymmetric deficits, hyporeflexia
*LOWER MOTOR NEURON
How does Kennedy’s disease present?
proximal weakness with LMN signs
-fasiculations involving face
-GYNECOMASTIA
-endocrine abnormalities
Mutation in Kennedy’s disease?
expansion of CAG repeat in androgen receptor protein on X chromosome
How does SMA 1 present?
decreased fetal movements, neonatal hypotonia, weak cry
-head lag, frog leg posture when supine
-never can sit up
-DIE BY AGE 2
How does SMA 2 present
-start 1-2 years of life
-motor delay and tremor
-less severe than SMA1
-can sit unsupported, but develop contractures
-cant ambulate
How does SMA 3 present
-ages 5-15
-proximal weakness, tremor, fasiculations
-remain ambulatory into adulthood
How does SMA 4 present
least common and least severe
-3rd-4th decade, prox weakness with quads being involved, fasicultaitons
Patients with B12 deficiency who get nitrous oxide can present as what?
anesthesia paresthetica
-myelopathy, neuropathy, encepahlopathy
How does Hirayama disease present?
-asians
-progressive asymmetric wasting of one or both hands/forearms
-MRI c spine shows cervical cord thinning with signal changes
