Dementia with Lewy Bodies (DLB) is a form of progressive dementia. DLB is characterized by slowly progressive cognitive decline, combined with three additional defining features:
- fluctuations in alertness and attention
- frequent visual hallucinations, and
- motor symptoms similar to those seen in Parkinson’s disease, such as rigidity and the loss of spontaneous movement.
Usually DLB occurs simultaneously with Alzheimer’s disease (AD) or Parkinson’s disease (PD). Occasionally, DLB occurs alone, without evidence of either AD or PD. The overlap between these conditions makes accurate diagnosis difficult.
A comprehensive work-up, including a neurological exam, brain imaging and neuropsychological testing is generally needed in order to make the diagnosis. The symptoms of DLB are caused by the accumulation of abnormal structures in the brain called Lewy Bodies, which develop inside the nerve cells in the outer layer of the brain (the cerebral cortex) and as well as deep inside the midbrain.