Neuromuscular disorders

ALS (Lou Gehrig’s disease)

Rapid progressing disorder caused by destruction of motor nerve cells that are replaced by scar tissue. Affects anterior horn neurons, UMN

More common in men > 50

Death often occurs within 3-5 years after diagnosis

Majority of cases are sporadic with no genetic component. Manifests in limbs (more common) or cranial nerves (less common)

Etiology theory includes build-up of free radicals, autoimmune disorder, glutamate excitotoxicity, and lack of CTNF

ALS signs and sx

Asymmetrical weakness. Cardinal signs are foot drop and head droop

Weakness will begin distal and move proximal

May progress to dysphagia, dysarthria, atrophy, fasciculations, hyporeflexia, respiratory impairment

Pts may be over or under-emotional

ALS treatment

Riluzole: inhibits glutamate, can slow progression

Radicava/Radicut: reduces free radicals in body. Most effective administered early in dx process

Other disease-modifying agents used for muscle spasticity, cramps, etc.

Huntington’s disease

Caused by mutation in chromosome 4 that progressively damages the globus pallidus thru the production of too much dopamine

Will NOT skip a generation

Dx onset in 30s-40s. Pt may live 15-20 more years after diagnosis

Huntington’s dx signs and symptoms

Athetosis, hemiballismus, chorea, dystonia, bradykinesia, cognitive impairments

Cardinal signs include hyperkinesia. May resemble PD

Huntington’s dx treatment

Antidopaminergic drugs, neuroleptic drugs to slow muscles down

Post-polio syndrome (acute flaccid myelitis)

Exact etiology unknown, but likely result of acute viral infection

Nervous system is attacked by virus and will progress to muscle paralysis

Early diagnosis and treatment is critical

Condition more likely if pt had long hospitalization in childhood, required mechanical ventilation, and achieved rapid recovery

Treatment is based on pt sx

PPS/AFM signs and sx

Limb weakness, facial droop, dysphagia, respiratory distress, atrophy, weight gain, fatigue

Loss of motor units leads to increased neuron:muscle fiber ratio. Units are less efficient

Guillain-Barre Syndrome (acute inflammatory demyelinating polyradiculoneuropathy)

Exact cause unknown, may be autoimmune response. Characterized by inflammation and demyelination of nerves

Majority of pts will recover from dx

GBS/AIDP signs and sx

Abrupt onset of foot drop or decreased grip, ANS dysfunction, numbness or tingling, symmetrical muscle weakness in LE that ascends

GBS/AIDP treatment

Plasmapheresis, removal of abnormal antibodies, high dose steroids, immunomodulating agents, pain management

Myasthenia gravis

Acquired autoimmune disorder causing loss of ACh receptors at NMJ. Receptors may be blocked or damaged. Pt may also have abnormal thymus or tumors in thymus

More common in women > 50

MG signs and sx

First sx often oculomotor dysfunction.

Weak and fatigable muscles, dysphagia, dysarthria. Sx worse at end of day and with activity

Sx may improve after rest

MG treatment

Drugs to deactivate ACh-ase, high dose steroids, immunoglobulin agents, thymus removal, plasmapheresis

ALS, Huntington’s considerations

Prevent muscle loss, avoid overuse weakness, use supportive devices for weaknesses

Prescribe orthotics, WC, etc. as needed

PPS considerations

Focus on pain management, restore or increase ROM

Muscles that are < 3/5 should be rested; muscles that are > 3/5 should be strengthened but not fatigued

Discontinue treatment if it triggers pain. Start low and slow until you determine pt’s tolerance

GBS considerations

Be aware of chronic fatigue that may lead to relapse

Gradual, progressive program is critical for recovery

MG considerations

Rarely referred to PT, but focus on light activities with short duration and fewer repetitions