LMN Injury

Damage to an alpha motor neuron causes?

Atrophy, myotomal weakness, decrease tone, decrease reflexes

Damage to spinal nerve roots cause?

Myotomal weakness, dermatomal paresthesia, decreased reflexs

Damage to peripheral nerves cause?

Decreased sensation anatomically, weakness occuring to muscles innervated distally

Where are each of the cranial nerves located?

1-2 in cerebellum, 3-4 in midbrain, 5-8 in pons, 9-12 in medulla

Sensory loss from a peripheral nerve (location)

Amatomical distribution

Sensory loss from a spinal nerve or dorsal root ganlia (location)

Dermatomal pattern

Motor loss from a peripheral nerve

Anatomically distal to lesion

Motor loss from a ventral root or spinal nerve injury

Myotomal pattern

What sx may you see from a lower motor lesion

Hyporeflexia, decreased tone, muscle fibrillations

Function of nerve conduction velocity

Measures stimulus response latency of a peripheral nerveE

Function of a electromyogrpahy

Records waveforms generated by select muscles (needs needle)

What is a mononeuropathy?

damage to a single peripheral nn

Three types of mononeuropathy and definition?

Neuropraxia (myelin damage), axonotmesis (axon damage), neurotmesis (axon severance)

What is polyneuropathy?

Damage to multiple peripheral nerves (can impact sensation or motor), typically starts distally

What is a radiculopathy

Damage to a nerve root as it leaves the spinal cord

Genetic Disorders

Charcot-Marie Tooth and Autoimmune disorders

Metabolic disorders

Diabetic peripheral neruopathy and alcoholic neuropathy

Disorders from infections

Guillan Barre, Post-polio, herpes zoster, tirgeminal neuralgia, HIV/AIDs

Patho of Charcot-Marie Tooth

Genetic mutations of schwann cells that cause demyelination of distal nerves

What nerve is most impacted by Charcot-Marie Tooth?

Fibular nerve

Sx of Charcot-Marie Tooth

Foot weakness, lack of DF/eversion, pes cavus, atrophy of foot muscles, foot drop, tripping, decreased DTR, loss of hand and wrist muscles, distal parethesia

Patho of Diabetic peripheral neuropathy

Microvascular damage from hyperglycemia

What nerves are affected durng Diabetic peripheral neuropathy

Small sensory - large sensory - motor nerve fibers (stocking glove)

Sx of Diabetic peripheral neuropathy

Hyperalgesia, impaired sensation, tripping, weakness in chronic cases (atrophy is rare), autonomic dysfunction (B+B, skin temp and wounds)

Patho of alcoholic neuropathy

Direct toxic effect on nerves, decreased vitamin B, accumulation of ethanol

SX of alcoholic neuropathy

Impaired sensation in feet, dimished ankle refelxes, calf aches, pain, decrease vibration, weakness, foot drop and wrist drop

What is the impact on senation testing if one has acute withdrawl of alcohol?

Decreased DTR in achilles, increased DTR in UE and patellar

Patho of GB

Autoimmune disorder that attacks myelin or after an illess

How long does maximal weakness take in GB?

2-4 weeks

What are the 4 types of GB?

Acute inflammataory demyelinating polyneuropathy, chronic IDP, Miller-Fischer syndrome (affects the eyes and CNIII, double vision and drooping eyelid), Acute autonomic neuropathy (B+B changes, sweating, postural hypotesion, lacrimation)

Sx of GB

Rapid bilateral symmetrical motor weakenss, distal sensory loss, absense of DTR, possible sx start in hands and feet, ANS involvement

Dx for GB

Increased albumin, slowed NCV, FVC <20Tr

Treatment for GB

IVIGs or plasmapheresis

Factors that decrease prognosis in GB

Increased age, past of illness with diahrrea, need for ventilation

What are the sx called when a patient is in need for possble ventilation

Bulbar sx (difficulty swallowing and speech)

3 Patterns of polio

asymptomatic, nonparalytic with flu sx, paralytic with flu sx

Patho of paralytic polio

Viral infection that invades the anterior horn cell bodies (techincally in SC, but presents peripherally)

Sx of Post-polio syndrome

Decades after acute polio, weakness, fatigue, decline of mobility, pain (like a relapse of polio)Path

Patho of post-polio syndrome

Muscle denervation, reinnervation from other nerves as compensation, attrition of the oversprouting of motor neurons (sprouts die off causing a relapse of sx)

Cardinal features of myasthenia gravis

Fluctuationg weakness and fatigue of muscles, CN III weakness (diplopia and ptosis) // no sensation deficits and normal reflexes!

Double vision

Diplopia

Drooping of eyelid

Ptosis

Patho of Myasthenia Gravis

The ACh receptors are attacked and decreased by antibodies at the motor end plate at NMJ, decreasing contraction ability

What kind of disorder is MG

Autoimmune

Risk factors of MG

Hyperthyroidism, RA, lupus, chronic infections

Methods for dx MG

Immunologic (detection of anti-ACH antibodies), pharmacologic (use of Tensilon to show decrease of ACh receptor), electrophysiolic testing (with EMG reports)

Treatment of MG

AChE inhibitor medication, removal of thyoma, corticosteroids (increase OP risk)

Trigemial neuralgia is AKA

Tic douloureux

Causes of trigeminal neuralgia

Herpes zoster (shingles), MS, vascular lesion, tumor, CN V lesion

Sx of trigeminal nerualgia

Neuropathic pain / hyperalgesia, no motor or sensort loss

Patho of Trigeminal neuralgia

Demyleinated fibers of trigeminal nerve becomes hyperexcitable

What portion of the trigeminal nerve is most effected in TN

V2

Patho of herpes zoster

Virus that attacks the nervous system and affects sensory ganlia of SC and BS

Sx of herpes zoster

Blister/pustules along a dermatomal pattern, hyperalgesia, unilateral (doesnt cross midline)

Treatment of herpes zoster

Antiviral medication, analgesic, tricyclic antidepressant (contagious until blisters have scabbed)

Sx of HIV/AIDS

distal symmetrical peripheral neuopathy (dysethesias), sensory until severe/chronic, then becomes motor

Autoimmune disorders

GB and MG

Disorder that occurs at motor endplate

Myasthenia gravis

Disorder that occurs at CNS

Post polio (at alpha motor neuron)

Which disorder impacts respiration

GB, MG, PPS

Which disorders impact the eyes

GB (Miller-fischer), MG

Which disorders impact sensory first?

DPN, AN, TN, HZN

Which disorders impact motor first?

MG, PPS, maybe CMT

How is neuropraxia improved

Schwann cells surround the area

How in axontmesis improved

Wallerian degeneration

What occurs during neurotmesis

Flaccid paralysis, atrpohy, trophic changes, sensory loss distal to injuryC

Carpal tunnel syndrome sx

diminished 2 point discrimination, monofilament, thenar atrophy, decrease grip, clumsiness of hands

TOS areas of compression

Between anterior and middle scalene, under first rib and under the pec minor

Sx of tardy ulnar palsy

RClaw hand deformity, paralysis of 3+4 interossei, loss of add/abd of fingers, sensory in C8-T1 dermatome

Radial nerve palsy AKA

Sleep palsy or crutch palsy

Sx of radial nerve palsy

Triceps weakness, lebow flexion and supination, wrist/finger extension weakness, decrease grip, sensory loss to hand or thumbBel

Path of Bells palsy

Compression, inflammation or swelling of facial nn (CNVII)

Sx of bells palsy

Unilateral face drooping, unilateral facial mmotor function loss, imapired taste and lacrimation, dry eye, dry mouh, possible pain (can’t close eye, wrinkle foreheaf or smile)

Tx for bells palsy

Corticosteroids and antivrial medications, eye patch

What pathology will more likely start in the hands

Guillan barre