Cognitive impairment in amyotrophic lateral sclerosis can range from little or no impairment to frontotemporal dementia (FTD) associated with ALS.


About 50 percent of people with ALS develop symptoms of cognitive impairment. There are four subgroups:

  • 49 percent do not develop cognitive impairment
  • 45 percent develop mild to moderate changes
  • Six percent develop FTD

Mild Cognitive Impairment in ALS

These mild symptoms might be so subtle that they are only detectable by neuropsychological testing or they may cause slight frustration for the patient. These symptoms may include:

  • Poor planning
  • Difficulty with problem solving
  • Inattention or distractibility
  • Poor word generation
  • Short-term memory problems
  • Language difficulties


  • The presence of cognitive impairment may call in to question the ability of ALS patients to make medical and end-of-life decisions.
  • Neuropsychological evaluations may be beneficial in helping the family make future plans.
  • Medical and financial powers of attorney should be discussed to verify the patient's wishes are followed.


If changes in cognition and behavior begin about the same time as the motor symptoms, are severe, and interfere with the person's ability to perform their daily routines, it is diagnosed as FTD associated with ALS.

FTD is often associated with brain shrinkage in the frontal and temporal lobes of the brain. There are no lab tests that can be done. The diagnosis is made through interviewing the patient and family about the symptoms and family history and through neuropsychological testing.

FTD behavioral changes include:

  • Lack of interest or withdrawal
  • Reduced spontaneity
  • Lack of emotion or an increase in emotional reactivity
  • Loss of inhibition or inappropriate social behavior
  • Changes in sleep and eating patterns
  • Repetitive behaviors such as hoarding or craving foods

FTD cognitive changes include:

  • Inattention
  • Poor planning or organization skills
  • Memory loss
  • Loss of language
  • Problem solving difficulties or poor judgment

Treatment of FTD in ALS Patients

There is no specific treatment. Doctors focus on trying to lesson the symptoms and help the family cope with the changes.

  • Rilutek and Neurontin, medications often used to treat ALS, have not been shown to improve cognitive impairments in ALS.
  • Aricept, Exelon and Reminyl, commonly used medications to treat Alzheimer's disease, have been shown to worsen irritability in FTD.
  • SSRIs, such as Prozac, Zoloft and Celexa and dopamine blockers, are sometimes used to treat behavioral disturbances in FTD.