Is Dementia Reversible?

by Mark L. Prohaska, Ph.D.

The answer is… it depends on the type. Most people equate the word dementia with Alzheimer’s disease which, of course, is a progressive, non-reversible dementing illness. There are other types of dementia that are also progressive and non-reversible. These include Lewy Body Disease, Frontal or Frontotemporal Disease, Subcortical Disease (e.g., Parkinson’s Disease, Huntington’s Disease, Progressive Supranuclear Palsy), and dementia due to stroke or cerebrovascular disease, all of which have a different presentation and course of progression than Alzheimer’s disease. However, you may be surprised to learn that there are some types of dementia that are entirely reversible. The term dementia is actually very nonspecific – it simply refers to the presence of cognitive or intellectual deterioration without regard to cause. So, while Alzheimer’s disease is indeed a type of dementia, having dementia does necessarily mean one has Alzheimer’s disease. This is a very important realization. I have had many patients experiencing forgetfulness or other thinking problems who were terrified of being evaluated because they were convinced that they had Alzheimer’s disease, but did not want to be told this by a doctor. On evaluation, many of these patients were found to not have Alzheimer’s disease at all; rather, they were suffering from other conditions for which treatments were available that cleared up their problem altogether. Some of the more common types of reversible dementia are described below.

Depression: Depression is often accompanied by a dementia syndrome characterized by memory and concentration problems that start slowly and grow progressively worse as the depression increases. It is not uncommon for older adults with depression to be misdiagnosed with Alzheimer’s disease. This type of dementia typically goes away with successful treatment of the underlying depression.

Delirium: Delirium is characterized by confusion and, very often, auditory and/or visual hallucinations. It typically has a very quick onset – often after a change in medications or following a surgical procedure. Symptoms typically fluctuate, with the individual alternating between seeming perfectly fine to being very confused. A delirium may persist for days or months, if the source is not treated. Typically, this type of dementia goes away with successful treatment of the underlying cause.

Medication Side Effects: Numerous medications have a direct effect on brain functioning, and this varies a great deal among individuals. Thus, where one person will be able to tolerate a particular drug with no difficulty, the same drug may cause a great deal of confusion and memory problems in another individual. These types of problems can usually be addressed through appropriate changes in medications and/or dosage with the related cognitive difficulties resolving fully.

Substance-induced persisting dementia: The most common form of this type of dementia is caused by excessive alcohol intake and associated nutritional deficiencies. The most common presentation is severe memory deficits and very poor problem solving. Although severe alcohol abuse canresult in an irreversible dementia, more often cognitive abilities improve over time after the use of alcohol has stopped.

Metabolic and Endocrine disorders: Uncontrolled or poorly controlled diabetes, hypo or hyperthyroidism, and B-12 deficiency are just some of the medical disorders that can result in significant alterations of cognitive functioning. Appropriate medical treatment of these conditions typically results in a full restoration of memory and thinking abilities.

Normal Pressure Hydrocephalus: This is a fairly rare type of dementia that is associated with normal pressure in the brain, but impaired absorption of the cerebrospinal fluid. This disorder presents with a classic triad of symptoms that includes cognitive changes, difficulty walking, and incontinence. Early detection of this disorder can lead to symptomatic improvement with a full return to functioning.

Hopefully, the message is clear - if there are concerns about your memory/thinking abilities, or those of a loved one, consult your doctor for a thorough physical examination and a medication review. Cognitive problems can be due to many things other than Alzheimer’s disease – many of which are treatable and reversible. If your doctor does not find the cause of your memory problem, seek a referral to a neurologist for a neurological evaluation. This will likely include taking some pictures of your brain (a CT scan or MRI) and a referral for a neuropsychological evaluation to get a detailed analysis of your memory functioning and other cognitive abilities. Understanding the cause of these problems is critical and, even if Alzheimer’s disease is the cause, early detection is critical in order to maximize the benefits of the interventions currently available.