Dementia Support Group

Proper differential diagnosis between the types of dementia (see below) will require, at the least, referral to a specialist, e.g. a geriatric internist, geriatric psychiatrist, neurologist, neuropsychologist or geropsychologist. However, there are some brief (5-15 minutes) tests that have good reliability and can be used in the office or other setting to evaluate cognitive status. Examples of such tests include the abbreviated mental test score (AMTS) and the mini mental state examination (MMSE).

An AMTS score of less than six and an MMSE score under 24 suggests a need for further evaluation. Of course, this must be interpreted in the context of the person's educational and other background, and particular circumstances. Routine blood tests are usually performed to rule out treatable causes. These tests include vitamin B12, folic acid, thyroid-stimulating hormone (TSH), C-reactive protein, full blood count, electrolytes, calcium, renal function and liver enzymes. Abnormalities may suggest vitamin deficiency, infection or other problems that commonly cause confusion or disorientation in the elderly. Chronic use of substances such as alcohol can also predispose the patient to cognitive changes suggestive of dementia.

A CT scan or magnetic resonance imaging (MRI scan) is commonly performed. This may suggest normal pressure hydrocephalus, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke) that would point at a vascular type of dementia. Sometimes neuropsychological testing is helpful as well.

The final diagnosis of dementia is made on the basis of the clinical picture. For research purposes, the diagnosis depends on both a clinical diagnosis and a pathological diagnosis (ie, based on the examination of brain tissue, usually from autopsy).