Amyotrophic lateral sclerosis

Question 1

Def

Answer 1

formerly known as Lou Gehrig disease
LMN dysfunction
Starts at 50–70 y/o
90% sporadic

often beginning with asymmetric weakness in the hands or feet

usually starts in one arm and/or leg then progresses to the contralateral side

life-threatening symptoms: respiratory impairment and dysphagia

Neuronal degeneration:
UMN in the precentral gyrus and, frequently, prefrontal cortex
LMN in the anterior horn of the spinal cord and brainstem

Question 2

Symptoms

Answer 2

Asymmetric limb weakness, often beginning with weakness in the hands and feet
Bulbar symptoms such as dysarthria, dysphagia, and tongue atrophy (20% of cases at disease onset)
Pseudobulbar palsy with pseudobulbar affect may develop.
Fasciculations, cramps, and muscle stiffness
Weight loss
Split hand sign: a wasting pattern in which the muscles of the thenar eminence atrophy due to degeneration of the lateral portion of the anterior horn of the spinal cord
Autonomic symptoms.
Cognitive impairment

Question 3

Diff dx

Answer 3

Multifocal motor neuropathy (MMN) ( solely affects motor neurons)
Myasthenia
Lambert-Eaton myasthenic syndrome
Cervical spondylosis
Thyrotoxicosis
Poliomyelitis

Question 4

Tx

Answer 4

Riluzole
A sodium-channel blocker that inhibits glutamate release in the CNS and decreases glutamate excitotoxicity

Edaravone
A free radical scavenge

Sodium phenylbutyrate-taurursodiol