Disorders of the Peripheral Nervous System Flashcards
NCV
Nerve conduction velocity
Amplitude - number of conducting fibers reduced in axonal loss
Conduction velocity - reflects myelin sheath…decreased in demyelinating process
EMG good for
Myopathyic vs. neurologic causes
Babinski sign in UMN vs. LMN
May be present in UMN…not in LMN
PNS sensory presentation in general
Worse at night
Negative
Positive
Stocking-glove pattern
ALS type of dz and what to look for generally
Acquired, chronic, motor neuron disease
UMN and LMN signs and symtoms
Diagnosis of ALS
Weakness
No sensory loss of sphincter distrubance
Progressive course
No cause other than genetic
ALS symptoms and signs
Mixed UMN and LMN in limbs
Cognitive decline in some cases
Weakness and wasting of muscles
Risk factors and pop of ALS…what degenerates
SMoking
30-60
CN motor nuclei, anterior horn cells, corticospinal tracts
ALS clinical findings
UMN and LMN
If bulbar - trouble chewing, swallowng, breathing (worse prognosis)
Drooping of palate and fasciculating tongue
Cog change
Motor weakness in limbs or stifness
ALS labs
EMG - chronic partial denervation..sponatneous activity in resting muscle
Tx of ALS
Riluzole reduces glutamate release
Supportive
Course of ALS
Progressive
Fatal in 3-5 years from pulmonary infection
Worse if bulbar
Spinal nerve disorders (herniated disc related radiculopathies)
Pain in a dermatomal region
Weakness of muslce in myotome
Causes of spinal nerve dz
Herniated disc
Osteo or rehumatoid arthritis
Cancers
Signs and symptoms of nerve root disorders
All LMN signs
Diminished reflexes
Shock-like pains may radiate down
Grading of reflexes
0 - none 1 - dimished 2 - normal 3 - brisker but not necessarily dz 4 - very bad with clonus
Anke reflexx Knee reflex Brachioradilais Biceps Triceps
Sacral 1 Lumbar 2-4 Cervical 5-6 Cervical 5-6 Cervical 6-7
Guillain Barre is also
Acute inflammatory demylinating polyneuropathy
Guillan barre histo and clinically
Weakness in distal that rapidly advances to proximal (ascending paralysis)…areflexia…can progress to resp failure
Demyelination of spinal nerve roots and peripheral nerves
Pathogen of G-B
GI realted often
Acute-onset immune mediated demyelinating neuropathy
G-B tx and prognosis
Plasmapheresis and IV Ig
Supportive
May spend weeks in ICU but can survive
Diabetes
Most common cause of peripheraly nerupathy
Patterns of diabtetes
Ascending distal symmetric sensorimotor polyneuropathy
Auto dysfunction
Pathology of diabetic symmetric sensorimotor polyneurpathy
Axonal neuropathy
Clinical features of diabetes
Numbness with stocking-glove distribtuion
Parethesias or dysethesias
Hyporeflexia that may progress to weakness
Charcot foot or skin ulcers
Varicella Zoster
Latent infection within neurons of sensory ganglion
Follows a dermatome
Peripheral axonal degeneration
Most common dermatomes of zoster
Trigeminal or throacic
Carpal tunnel Cubital tunnel Saturday night Tarsal tunnel Meralgia paresthetica
Median nerve Ulnar nerve Radial nerve Posterior tibial nerve Lateral femoal cutaneous
Carpal tunnel syndrome risk factors and presnetation
Thumb and first two digits numb…thenar atrophy…weakness in opposition
Diabetes or excessive wrist motions
Ulnar nerve palsy
Cubital tunnel syndrome
Guyon’s canal or ulnar groove
Decreased 4th and 5th sensation with claw hand (hand of benediction) and weakness of finger abduciton
Radial nerve palways
Extension of wrist and fingers - drop hand
Decreased back of hand sensation
Lateral femoral cutaneous neuropathy
Trapped under inguinal ligament
Pure sensory over lateral thigh
Eliminate the cause
Tight belt, pregnant
Peroneal neuropathy
Pain in laterla lower leg and foot drop
Posterior tibial nerve neuroapthy
Pain in medial ankle and plantar surface…weakned toe flexors
CMT type of dz
Herediatry motor and sensory neuropahty
CMT symtpoms and findings
Hypertrophic neuropathy with onion bulb formation from schwann cell hyperplasia
Distal muscle atrophy with sensory loss and pes cavus
