Sachen Clinical Flashcards
EMG records what type of fibers
myelinated
Describe the fibers for Proprioception, Touch and pressure
type A, myelinated, big diameter, fast
describe fibers for Pain and Temp
Type C, unmyelinated, small diameter, slow
Most common nerve roots involved in Radiculopathy
- C6 (C5-C6)
- C6 (C6-C7)
- L5
- S1
what is part of the slcerotome for every cervical nerve root and thus there is pain here for each cervical radiculopathy
scapula
where is T1 dermatome
medial forearm . . there isn’t a T1 on chest
Sensory Symptoms of peripheral Nerve Disease
- No loss of sensation
- Paresthesias: secondary to large myelinated fiber disease (“pins and needles”)
- Pain: secondary to small unmyelinated fiber disease (Burning, Dysesthesia-pain upon gentle tough, hyperalgesia- lower threshold to pain, hyperpathia- pain threshold is elevated, but pain is excessively felt)
Motor symptoms of peripheral Nerve Disease
- distal weakness
- cramps
- muscle fasciculations (twitching)
- Atrophy
- DECREASED deep tendon reflexes
- reduced tone
pain in shoulder and within a few days atrophy develops in deltoid and probably biceps and pain subsides . . inflammatory/idiopathic cause of brachial plexopathy
Parsonage Turner
Cause of plexopathy if there is history of cancer and treatment and it’s painless, lateral cord?
Painful, medial cord?
radiation injury
Neoplastic (breast or lung)
sensation to lateral calf and dorsum of foot EXCEPT flip flop zone
superficial fibular (peroneal) nerve
sites for median entrapment and mononeuropathy
- wrist: carpal tunnel, sensory loss and thenar atrophy
- Elbow: pronator teres syndrome, repetitive elbow motions
- ligament of struthers
hand sensory distribution of median nerve
medial palmar surface, thenar eminence, 1st 2 and a half fingers
what is a key in distinguishing pronator syndrome from carpal tunnel syndrome
ABSENCE of nocturnal awakening because of pain or numbness . .this is typical of carpal tunnel
what median mononeuropathy gives you abnormal pinch sign
anterior interosseous syndrome
describe the nerve conduction studies with anterior interosseous syndrome
- normal routine median and ulnar studies
- abnormalities in needle EMG: FPL, FDP, PQ
- other median, medial cord, C8 muscles are normal
Common sites of entrapment of ulnar nerve
- Axilla
- Elbow: b/t medial epicondyle and olecranon
- Cubital tunnel: b/t tendinous arch of FCU
- Wrist: Guyton’s canal
Froment sign
- ulnar neuropathy
- have to flex thumb DIP joint to grip a piece of paper
Common sites of entrapment of Radial nerve
- Axilla: Crutch palsy
- Humerus/Spiral Groove: “Saturday night Palsy” . . most common
- Supinator: posterior interosseous Branch
- Wrist: superficial radial sensory branch
wrist drop
Radial nerve in spiral groove of humerus
sciatic nerve is what nerve roots
L4-S2
distribution for peripheral neuropathy
glove and stocking
-legs first and more severely than arms
CMT1 and 2 are hereditary neuropathies. Which one is demyelinating?
which is axonal?
- 1
- 2
another name for Charcot-Marie tooth (CMT)?
Hereditary Motor Sensory Neuropathies (HMSN)
features of CMT1?
- autosomal dominant
- onset 1st or 2nd decade
- often see difficultly walking or running first
- distal symmetric atrophy (legs>arms)
- arreflexia
- mild sensory loss
- skeletal deformities (pes cavus, HAMMER TOES, scoliosis)
- EMG shows slowing of motor nerve conduction velocities (demyelination)
features of CMTII?
- autosomal dominant
- onset in adulthood
- distal symmetric atrophy (legs>arms)
- arreflexia
- mild sensory loss
- EMG shows normal or nearly normal motor nerve conduction velocities (axonal loss)
severe belly pain and polyneuropathy
porphyria: defect in heme biosynthesis
Orange tonsils and polyneuropathy
-Phytanic acid storage (Refsum’s) Disease
Acute inflammatory demyelinating polyneuropathy
Guillain-Barre Syndrome
what often precedes Guillain-Barre Syndrome
- antecedent illness, surgery, immunization
- viral syndrome: Epstein-Barr, mycoplasma pneumonia, Campylobacter
symptoms of Guillain Barre Syndrome
- low back/leg pain at onset
- ascending usually symmetric weakness
- hypo or absent DTRs
- no/minimal sensory symptoms or signs
- possible respiratory failure
what are the key lab findings in Guillain Barre syndrome
- CSF: albumino-cytologic dissociation (increase protein, normal cell count/normal glucose)
- NCVs: slow conduction velocity, focal conduction block, prolonged F waves. focal spotty demyelination
treatment of Guillain-Barre Syndome
- supportive care
- Plasma exchange or IVIG
describe the Miller fisher syndrome variant of Guillain Barre
- ophthalmoplegia, ataxia, arreflexia
- Facial weakness, dysarthria, dysphagia
- GQ1b and GT1a antibodies
time frame for Chronic inflammatory demyelinating polyneuropathy (CIDP)
->2months
treatment for CIDP
-IVIG, steroids, plasma exchange, immunosuppressive agents
clinical finding in multifocal motor neuropathy
- adults
- slowly progressive distal weakness of hands>feet
- no sensory signs/symptoms, no UMN signs
Lab findings in multifocal motor neuropathy
- elevated serum GM-1 in 50-80%
- EMG shows conduction block or demyelinating features
- CSF normal
treatment of Multifocal motor neuropathy
-IVIG
cranial neuropathies associated with DM
- CN III most common
- also VI and VII
what are acquired axonal peripheral neuropathies usually from
toxins
- DM
- EtOH
- uremia
- CA
- Metals
- chemo
- MM
Hu antibody
carcinomatous sensory neuropathy
anti MAG
MGUS
aANCA
systemic vasculitis
skin biopsy is done for what neuropathies
small fibeer
metabolic cause of motor neuron disease. alpha-glucosidase (acid maltase) deficiency
pompe’s disease
acquired motor neuron disease associated with asthma
Hopkins Syndrome
highlights for ALS
- no definite risk factors related to occupation, trauma, socioeconomic status
- mixed upper (spasticity, hyperreflexia, Babinski sign) and lower (atrophy, fasciculations) motor neuron signs
- may also be bulbar involvement of upper or lower motor neuron type
pathophysiology of ALS
-degeneration of anterior horn cells and lateral and ventral corticospinal tracts
age for ALS?
Characterized by?
- b/t 20-60
- degeneration of pyramidal (Betz) cells, anterior horn cells, brainstem motor nuclei of the lower cranial nerves, and corticospinal aand corticobulbar tracts
Clinical presentation of ALS
- gait disorder, limb weakness, speech or swallowing difficulty are common initial complaints
- unexplained weight loss (due to loss of muscle bulk), cramps, and fascuculations
- tongue atrophy and fasciculations commonly seen
Diagnostic tests for ALS
- EMG - widespread denervation and reinnervation
- CPK - normal or slightly increased
- CSF - normal
- imaging studies of brain and spine- normal
- muscle biopsy only in confusing cases
important “Rule of thumb” diagnostic negatives for ALS
- no sensory symptoms
- normal mentation
- No extraocular muscle involvement
- bowel or bladder symptoms not prominent
- Decubiti rare (ulcers from lying down)
mean duration of symptoms for ALS
2-5 years
highlights of progressive bulbar palsy
- selective involvement of the motor nuclei of the lower cranial nerves
- Dysarthria, Dysphagia, chewing difficulty, respiratory difficulty usual presenting features
- often progresses to generalized involvement (ALS)
highlights for progressive spinal muscle atrophy
- mean age is 64
- LOWER MOTOR NEURON deficits affecting the limbs due to degeneration of anterior horn cells
- no upper motor neuron involvement
- Weakness, atrophy, respiratory difficulty
- can progress to ALS but usually does not
highlights of infantile spinal muscular atrophy
- Werdnig Hoffman Disease
- hypotonia
- arreflexia
- poor suck
- breathing difficulty
- death in 6-12 months
highlights for intermediate spinal muscular atrophy
-Chronic Werdnig Hoffman disease
highlight for juvenile spinal muscular atrophy
- Kugelberg-Welander Disease
- MIlder than Werdnig Hoffman
What is a false transmitter in that it acts like Ca and can be taken up by the presynaptic Ca channel but doesn’t cause release of Ach
Mg
caused by a defect of neuromuscular transmission due to an antibody-mediated attack upon nicotinic acetylcholine receptor (AChR) on muscle membrane
Myasthenia Gravis
HLAs associated with Myasthenia Gravis
B8 and DR3
what are the 3 general clinical characteristics of myasthenia Gravis
- fluctuating weakness: “excessive fatigability”
- Distribution of Weakness: ocular muscles (ptosis and diplopia), dysarthria, dysphagia, limb and neck weakness
- clinical response to cholinergic drugs
Lab finding for Myasthenia Gravis
- anti AChR Ab’s
- MUSK antibodies
- EMG findings: decremental response on repetitive stimulation, increased “jitter” on single fiber EMG
- Tensilon (edrophonium) test: watch for side effects
Tensilon (edrophonium) test can cause what
HTN and cardiac arrhythmias so be careful and maybe hook up to EKG
Treatment of Myasthenia Gravis
- Acetylcholinesterase inhibitor
- Prednisone
- thymectomy
- immunosuppressive agents
- plasma exchange/ IVIG
drugs that exacerbate or unmask myasthenia gravis
lots of them
-aminoglycosides most significant
due to autoimmune attack against voltage gated calcium channels (VGCC’s) on presynaptic nerve terminal
-Lambert Eaton Myasthenic syndrome (LEMS)
Lambert Eaton associated with what malignancy
Small cell cancer of lung
Clinical Presentation of Lambert Eaton that distinguish it from Myasthenia Gravis
- LOSS of DTRs (MG usually preserved)
- Dry mouth and impotence (autonomics)
- Strength may improve after exercise
Treatment of Lambert Eaton
- first look for and treat malignancy
- Actylcholinesterase inhibitors
- 3-4 Diaminopyridine
- Guanidine hydrochloride
what does Botulism toxin block
presynaptic mechanisms for release of ACh
clinical presentation of Botulism
- dry, sore mouth and throat
- blurred vision
- diplopia
- nausea
- vomiting
- hypohydrosis
- total external ophthalmoplegia
- facial, oropharyngeal, limb and respiratory paralysis
treatment of botulism
-ICU monitoring with respiratory support and general medical care
what is a common symptom of Nerve Gas exposure (Sarin and VX) that you don’t see in MG or lambert eaton
Miosis (pupil involvement)
if somone comes in with lambert eaton and has migraine headaches are you going to give Mg for headaches?
no . . can make lambert eaton worse
if someone comes in with MG or lambert eaton and its getting worse and they have to take more ACheI’s how do you tell if its the disease or medication
-if you see fasciculations, increased secretions, diarrhea and abdominal cramps then ACh overload from meds
