primary lateral sclerosis (PLS)

Epidemiology

• rare
• onset usually occurs after age 50

Pathology

• exclusively upper motor neuron disease

Genetics

not hereditary

Clinical manifestations

• progressive muscle weakness
• difficulty with balance
• weakness & stiffness in the legs
• clumsiness
• spasticity in the hands, feet, or legs
• foot dragging
• dysarthria due to involvement of the facial muscles
• usually begins in the legs, but it may also start in the tongue or the hands
• progresses gradually over a number of years, or even decades
• no amyotrophy that occurs in amyotrophic lateral sclerosis (ALS)

Differential diagnosis

• amyotrophic lateral sclerosis (ALS)

Management

• treatment is symptomatic
• baclofen & tizanidine may reduce spasticity
• quinine or phenytoin may decrease cramps
• Physical therapy often helps prevent joint immobility
• Speech therapy may be useful for those with involvement of the facial muscles.
• prognosis
  • no cure, but not fatal
  • patients rarely lose the ability to walk

More general terms

• motor neuron disease

Additional terms

• amyotrophic lateral sclerosis (ALS); Lou Gerig's disease

Patient information

primary lateral sclerosis patient information