James Leverenz, MD is the director of Cleveland Clinic Lou Ruvo Center for Brain Health and an expert on Lewy body dementia (LBD). In honor of LBD Awareness Month, we spoke with him about LBD and other types of dementia.
WAM: It’s astounding that there are over 100 different kinds of dementia. What are the most common ones, and what do they all share in common?
Dr. Leverenz: There are numerous causes of dementia (changes in thinking or behavior that impact daily function), and more problematically they often occur together (“multietiologic dementia”, MED). Each form has its classic symptom characteristics, but there are many atypical cases, which is why we rely increasingly on biomarkers (blood, spinal fluid, and imaging) to be more precise in our diagnoses. With more disease specific treatments being explored, it will be increasingly important to know exactly what’s causing the issue. Also, since we know the changes are often happening in the brain before symptoms start, we might be able to ultimately treat these diseases before they cause problems by using these markers.
WAM: Is it possible to have more than one form of dementia at the same time, for instance Alzheimer’s disease and another form of dementia?
Dr. Levernz: Yes, different forms of dementia can occur at the same time. For example, it is very common to see Alzheimer’s disease and Lewy body disease changes together. It is estimated that it occurs in over 30% of Alzheimer’s disease cases
WAM: We know women are more likely than men to develop Alzheimer’s disease. Is there a gender disparity with all forms of dementia?
Dr. Levernz: We see a strong male predominance in a disorder called Lewy body dementia (LBD). Some investigators argue that it may be how symptoms manifest in different sexes, but there is data from brain autopsies that note a male predominance of LBD in men. We do not yet know why that predominance exists. Of note, however, when we see LBD together with Alzheimer’s disease, we do not see that sex difference.
WAM: October is Lewy Body Dementia Awareness Month. What makes Lewy body dementia unique and how is it related to Alzheimer’s disease?
Dr. Levernz: The characteristic symptoms of LBD are changes in thinking (dementia) and Parkinson’s disease like symptoms (resting tremor, stooped posture, moving slower). If the dementia starts first, we call it dementia with Lewy bodies (DLB); if the motor symptoms precede the memory changes, then we call it Parkinson’s disease dementia (PDD). Both have Lewy body changes in brain cells of these individuals. Other symptoms we see in the Lewy body dementias are visual hallucinations, fluctuations (daily variations in level of issues), and a unique sleep disorder where people physically act out their dreams (REM sleep disorder).
WAM: Can research into Lewy body dementia help us learn more about the prevention and treatment of Alzheimer’s disease?
Dr. Leverenz: Given the common co-existence of LBD and Alzheimer’s disease, there is a link that certainly will impact our understanding and treatment of these two diseases. This combination does not appear to have the sex differences we see in Alzheimer’s disease or LBD when they happen alone.