What is Lewy Body Dementia?
Recently, Robin Williams, one of my favorite comic actors, committed suicide. During his autopsy, Lewy bodies were found in his brain. In addition, reports are that he also suffered from Parkinson's disease. Since his death, there has been a growing interest in Lewy body dementia (referred to as LBD throughout the rest of this article), and some individuals suggest his suicide was caused by his disease(s). The following is a brief over view of Lewy body disease that may explain why such speculation about Robin Williams occurred.
In general, there are two main types of LBD; doctors and researchers use the "one year rule" to diagnose LBD; if cognitive symptoms appear within a year of movement problems, the diagnosis is dementia with Lewy bodies, but if cognitive problems develop more than a year after the onset of movement problems, the diagnosis is Parkinson's disease dementia. These diagnoses are usually made by a neurologist. LBD disease is also termed dementia with Lewy bodies (DLB) in the medical literature.
LBD is a progressive and degenerative disease of the brain caused by the presence of Lewy bodies, abnormal proteins that disrupt communication among brain cells. Lewy bodies were first noted in autopsy brains from patients with Parkinson's disease in 1914 by Frederick Lewy. LBD is a progressive disease so identifiable stages are not present; however, there has been mention in the literature of "early-stage" and "late stage" symptoms.
The cause of LBD is not known, but the condition is related to an abnormal protein in the brain, termed alpha-synuclein, that makes up the Lewy bodies. The findings from autopsy studies suggest about 10% to 20% of individuals with dementia have LBD. This disease is described in all races and is slightly more common in men; it may begin in late middle age (50 years old) or most often in the elderly. As previously mentioned, is often closely associated with Parkinson's disease dementia.
Lewy body dementia symptoms
Symptoms of LBD can fluctuate but usually become progressively worse over time. Early in the disease, fluctuations between normal and abnormal behavior, mood, and cognitive ability can occur. The central feature of this disease is progressive dementia shown by deficits in attention and minor dysfunctions in the early stages that can progress to severe dementia.
In severe dementia, the person's inability to carry out normal daily functions, loss of recognition of family members, and other severe cognitive, behavior and mood problems can render the individual virtually helpless. Other features include fluctuating cognition, visual hallucinations, and spontaneous features of Parkinsonism such as body stiffness, tremors, shuffling gait, emotionless facial features and/or decreased coordination.
As mentioned previously, the diagnosis is made on the basis of symptoms and their time of occurrence in patients. However, most doctors that make the diagnosis (neurologists) also typically use other tests primarily to rule out other causes for the symptoms.
There are no sensitive or specific blood or urine tests that diagnose LBD. However, routine laboratory tests such as a basic metabolic panel, CBC, thyroid studies, vitamin B12 levels; and tests for syphilis, Lyme disease, or HIV also may be ordered. MRI, CT scans, and other studies of the brain are used to help distinguish LBD from other problems that have similar symptoms.
Medications for Lewy body dementia
Currently there is no evidence that any medications can decrease rate of LBD cognitive decline. However, the following medications are often used in patients who have LBD:
- cholinesterase inhibitors,
- second-generation antipsychotics,
- benzodiazepines, and
- dopamine precursors.
These medications help to control or reduce the symptoms associated with LBD.
Unfortunately, LBD is a progressive disease (usually over years), although the rate of progression varies. In general, the lifespan of patients diagnosed with LBD varies from about 5 to 8 years. Patients die from multiple complications (immobility, falls, poor nutrition, swallowing difficulties, or pneumonia). The prognosis of LBD over time is fair to poor.
LBD is a difficult disease for the patient and the patient's loved ones and caregivers to manage because of its unpredictable exacerbations and continual progression. This disease robs patients of their body and brain functions, sometimes slowly, other times more rapidly. It is difficult for patients and their caregivers to deal with an ever-increasing decline in function; most patients may require daily care, home health, or institutionalization as their disease progresses.
Some individuals suggest that Robin Williams' death by suicide was caused by his disease affecting his judgment; others suggest he suspected what was coming with his Parkinson's disease and decided suicide was a better choice. Although no one can be sure what triggered his suicide decision, it is fairly easy to understand why people speculate, given the symptoms and prognosis of the disease, that his Lewy body disease diagnosed at autopsy, either alone or in conjunction with Parkinson's disease dementia, played a role in his suicide. Whatever the cause, we lost a comic genius far too soon, and we will continue have this body and brain thief (LBD) continue its plundering until we find a way to halt its actions by research.
Medically reviewed by Joseph Carcione, DO; American Board of Psychiatry and Neurology
Medscape. Dementia with Lewy Bodies.
Lewy Body Dementia Association. Lewy body dementia symptoms and diagnostic criteria.