ALS / Lou Gehrig’s Disease

Basics

  • A disease that affects motor neurons (both Upper and Lower motor neurons) resulting in weakness of voluntary muscles
  • Rarely associated with cognitive problems (2% develop some type of dementia)
  • While the exact cause is unknown, the disease attacks neurons in the cervical (neck) spine and the medulla (brainstem)
  • Treatment options are currently lacking though trials with Riluzole have demonstrated some benefit
  • Triad: Atrophic weakness of hands and formarms, Mild lower extremity spasticity, and diffuse hyperreflexia

Symptoms and Signs

  • Classically presents with weakness and atrophy of the hands (lower motor neuron) with spasticity and hyperreflexia of the lower extremities (this picture may very depending on the type of neuron involved)
  • Progressive disorder
  • Difficulty speaking (dysarthria) and swallowing (dysphagia)
  • Sphincter control is usually maintained

Demographics

  • Prevalence: 5 per 100,000
  • Familial in about 10% of cases- usually autosomal dominant (consecutive generations affected)
  • Onset normal after the age of 40

Diagnosis

  • Clinical features
  • EMG- demonstrates fibrillations and sharp waves
  • Lumbar puncture (aka spinal tap)- may demonstrate increased protein

Treatment

  • Riluzole (Rilutek©) has demonstrated modest improvement in tracheostomy-free survival
  • Main treatment aimed at minimizing disability: Trach, Feeding tube, etc.
  • Spasticity and cramps can be treated with baclofen

Prognosis

  • Median survival: 3-4 years
  • Most patients die within 5 years of onset

Differential Diagnosis

  • Cervical spondylotic myelopathy- will usually see neck pain and sensory findings. The diagnosis becomes easier as ALS progresses

References and Additional Reading