Until recently vascular dementia - the kind of brain deterioration caused by stroke - was thought to be the second most common cause of dementia (after dementia of the Alzheimer's type). Researchers now believe that Lewy Body Dementia (LBD) accounts for somewhere between 20 and 35 percent of dementia cases. So Lewy Body Dementia has moved into second place after Alzheimer's Disease, and few people have even heard of it.

Studies are also showing that many general practitioners don't recognize LBD, so patients often go home with a diagnosis of AD or Parkinson's Disease (PD) instead. Although at this time Lewy Body Dementia is no more curable than are AD or PD, it's important to know which of the three is causing symptoms because there are important differences in medication management.

To inconveniently complicate things, Lewy Body Dementia can exist by itself or in conjunction with other brain disorders, including Alzheimer's Disease and Parkinson's Disease.

Why does it matter whether it's AD, PD or LBD?

The medications used to treat Parkinson's Disease can have strong adverse effects on the cognitive/mental symptoms that Lewy Body Dementia patients experience. And the psychiatric drugs used to treat Alzheimer's disease can produce debilitating Parkinson's-type symptoms. So, although we can never know for sure while the patient is alive, it is extremely important to have as accurate a diagnosis as possible so we don't make the patient's final years worse than they might have had to be.

Diagnosis of Lewy Body Disease

An LBD patient usually first visits the doctor with symptoms that could be mistaken for Parkinson's Disease (or Parkinsonism): hallucinations, short-term memory loss, sleep disturbances and unpredictable personality and cognitive swings.

In order to make a diagnosis of "probable" Lewy Body Disease specialists will generally look for a steady decline in cognitive abilities plus two of the following. If only one of the following is present, then the diagnosis is usually "possible" Lewy Body Disease:

Recurring visual hallucinations;

Fluctuating (changing irregularly) cognitive ability;

•  Memory loss
•  Decreasing judgment
•  Loss of initiative
•  Confusion regarding time and place
•  Difficulty finding words and completing tasks

Parkinson's-like symptoms;

•  Very slow movement or "frozen" posture, shuffling gait
•  Muscle stiffness or rigidity
•  Poor balance, frequent falls
•  Tremor (resting tremor is less common)
•  Leaning or stooped posture, often to one side
•  Blank facial expression

In addition to the above many patients with Lewy Body Disease are reported to also experience:

•  Increased sensitivity to medications used to treat psychiatric symptoms (neuroleptics);
•  Frequent falls, instances of fainting;
•  Difficulty with autonomic functions: blood pressure, temperature regulation, urinary and
   constipation issues;
•  Hallucinations of sound or taste, in addition to the visual hallucinations mentioned above;
•  Delusions;
•  Impaired sense of direction, depth perception;
•  Weak voice and difficulty swallowing.

Treatment of Lewy Body Disease

Many patients have increased sensitivity to the drugs that are prescribed for AD and PD, making it difficult to treat the movement symptoms and hallucinations without making one or the other worse. Because there is no cure, medicine today can only treat the symptoms of LBD. An experienced neurologist or neuropsychiatrist should oversee care if at all possible.

Prognosis For LBD

There is as yet no cure for Lewy Body Dementia. Average duration is commonly 5 to 7 years, although some patients have lived much longer. Onset is most usually between the ages of 50 and 85. LBD appears to be slightly more common in men than in women. Although researchers have not discovered any genetic risk factors, there does appear to be a slightly higher risk if a family member has had LBD.