Rapid-onset Alzheimer's: Could it be something else?

My mother has been diagnosed with Alzheimer's disease. But she seems to be deteriorating at a very rapid rate. Everything I've read about Alzheimer's says that it has a slow progression. What can you tell me about this?

- No name / No state given

Mayo Clinic neuropsychologist Glenn Smith, Ph.D., and colleagues answer select questions from readers.

Answer

Alzheimer's is a degenerative disease, which usually implies a slow progression. However, rarely Alzheimer's can progress more rapidly — over weeks or months instead of years.

A rapid progression may also suggest that a second type of dementia is complicating the Alzheimer's — such as vascular dementia or Lewy body disease. In addition, rapid progression may indicate another condition that mimics the symptoms of Alzheimer's, such as:

Infections that affect the central nervous system, such as HIV and Creutzfeldt-Jakob disease
A side effect of certain medications, such as anticholinergic drugs and narcotic pain relievers
Vitamin B-12 deficiency
Depression
Hypothyroidism

A prompt and thorough medical evaluation is important to determine the exact cause of rapidly progressing dementia. Some causes are treatable.