This short summary of Lewy Body Dementia was in a Johns Hopkins Health Alert recently. If you sign up to receive these health alerts, note that Johns Hopkins uses the email list to try to sell its publications, and the same alert can be sent out multiple times over a few-month period.
Accurate diagnosis of LBD is quite difficult. Of the brain donation
cases I’ve handled, LBD is found upon brain investigation less than half the time. Locally, the diagnostic accuracy rate is much higher! LBD commonly co-occurs with Alzheimer’s pathology and other pathologies, which makes an accurate diagnosis while the person is alive very difficult.
Talking About Lewy Body Dementia
Johns Hopkins Health Alert
Posted in Memory on January 21, 2013
Lewy body dementia is a form of dementia that accounts for 5 to 15 percent of all dementia cases. Lewy bodies — named for Frederick Lewy, the physician who first identified them in 1912 while working in the laboratory of Dr. Alois Alzheimer — are tiny spherical deposits of a protein called alpha-synuclein that are found in the brains of patients with Lewy body dementia. The presence of Lewy bodies throughout the brain disrupts the brain’s normal functioning.
There is considerable overlap between Lewy body dementia and two other disorders: Alzheimer’s disease and Parkinson’s disease. In Lewy body dementia, patients experience a loss of dopamine-producing nerve cells similar to that seen in Parkinson’s disease. They also lose acetylcholine-producing nerve cells, similar to what occurs in Alzheimer’s disease.
Patients with Lewy body dementia often experience cognitive problems associated with Alzheimer’s disease, such as memory loss, spatial impairment and language difficulties. They may also develop parkinsonian symptoms, such as muscle rigidity, a blank facial expression, soft voice, tremor, poor balance and gait disturbances. Some patients initially diagnosed with Parkinson’s disease later go on to develop a dementia that closely resembles Lewy body dementia.
Certain symptoms of Lewy body dementia help distinguish it from
Alzheimer’s disease and other forms of dementia. For example, unlike people with Alzheimer’s disease, Lewy body dementia patients often experience detailed and extremely vivid hallucinations early in the illness. People with Lewy body dementia also tend to show marked fluctuations in their cognitive functioning, often several times a day. In addition, they tend to fall asleep easily during the day and have restless, disturbed sleep with behavioral acting out.
Recognition of these symptoms leads to an accurate diagnosis of Lewy body dementia. A correct diagnosis is particularly important because the medical management of patients with Lewy body dementia presents special challenges. The drugs that are normally used can aggravate other problems and cause potentially serious adverse reactions. In particular, antipsychotic (neuroleptic) drugs can provoke dangerous side effects, including a return to psychosis, and must be used cautiously, if at all. In addition, levodopa, a drug normally used to treat parkinsonian symptoms, may worsen hallucinations, so its dosage needs to be carefully adjusted in patients with Lewy body dementia.