Dementia that is not Alzheimer’s disease
By Laurie E. Knepper, M.D.
What are the other kinds of dementia, in addition to Alzheimer’s disease?
Alzheimer’s disease is the cause of 60 to 70% of dementias. It is primarily characterized by prominent short-term memory loss, impairment in other areas of cognition, and a decline in the activities of daily living. The second most common type of dementia is Lewy body disease or dementia with Lewy bodies. Vascular dementia is the third most common cause of memory impairment, occurring in people who have had strokes or have stroke risk factors. A less common, but quite disabling type of dementia is called frontotemporal dementia, which leads to early deterioration in speech and abnormal behavior.
What is Lewy Body disease?
Lewy Bodys are abnormal accumulations of protein like material that develop with brain cells. They are most commonly seen in the brain stems of patients who have Parkinson’s disease. They are found in 20 to 35% of patients with dementia. Lewy Body dementia closely resembles Parkinson’s disease without a tremor, with two notable exceptions: It does not respond well to Parkinson’s medications and cognitive impairment with visual hallucinations occur very early in the clinical course. Two other features are: marked fluctuations in the level of alertness, and extreme sensitivity to certain sedative/antipsychotic medication (i.e. neuroleptics including Haldol)
What is the treatment of Lewy Body dementia?
Sinemet, early in the disease, can help to improve the slowness of movement, the rigidity, and imbalance. Other Parkinson’s medications can increase the confusion. Cognitive impairment can be slowed by the use of Aricept, Razadyne, and Namenda, also used in Alzheimer’s disease, but these may also cause increased confusion. Visual hallucinations can sometimes be managed with seizure medications such as Tegretol, Depakote or Lamictal. Klonapin can be used to treat the associated sleep disorder at very small doses.
What is frontotemporal dementia?
Frontotemporal dementias (previously called “Pick’s disease”), are neurodegenerative diseases that specifically affect the frontal and temporal lobes of the brain. Frontotemporal dementia patients are younger than those with Alzheimer’s disease (35 to 75 years) and 20 to 40% have a family history. Frontal lobe degeneration behavioral issues include: lack of inhibitions, socially inappropriate behavior, or apathy. In some forms, the temporal lobe is more involved and expressive speech deteriorates, but comprehension may remain relatively intact. These dementias can be distinguished from Alzheimer’s dementia by the early behavioral changes and the prominent speech impairment.
How do you treat frontotemporal dementia?
Sadly, there is no specific treatment for frontotemporal dementia. Most treatments are focused on managing the behavioral issues, which can be very disruptive and distressing to caregivers. Antidepressant medications and antiseizure medications can be helpful. A structured environment and behavioral modification is beneficial.
Dr. Laurie E. Knepper is a Clinical Associate Professor of Neurology at the University of Massachusetts School of Medicine, and has a practice in Lenox.
