ScharreResearchers at The Ohio State University Medical Center have discovered specific diagnostic differentiators between Lewy body dementia, Alzheimer’s disease and Parkinson’s disease to support more definitive diagnoses. Initial findings of a multi-year study have already provided insight regarding cognitive, functional, behavioral and motor skill differences. Researchers are now exploring differences in sleep issues and brain imaging patterns related to each disease.

“Interestingly, we have found that a significant number of patients can have Lewy body dementia in addition to Alzheimer’s or Parkinson’s,” says Douglas Scharre, MD, director of the Division of Cognitive Neurology at Ohio State’s Wexner Medical Center and principal investigator of the study. “Knowing this can transform our approach to treatment and improve early identification of disease before dementia begins.” 

“The similarities between these three diseases presents a challenge, so our study carefully matches our patient groups – one for Lewy body, one for Alzheimer’s and one for Parkinson’s – by age, gender, education, race and degrees of cognitive and physical impairment,” explains Dr. Scharre. 

Already confirmed Lewy body dementia differences include:

  • A clinical profile that involves retrieval memory disturbance, deficits in visuospatial and executive domains, motor axial postural instability and gait imbalance
  • More executive and visuospatial deficits and less amnesia and disorientation compared to Alzheimer’s disease
  • More daytime sleepiness, cognitive/behavioral fluctuations, hallucinations and sleep apnea than either Alzheimer’s or Parkinson’s diseases
  • Significant correlations noted between axial motor, balance and gait disturbances and executive functioning, visuospatial abilities and global cognitive deficits 
  • Stiffness and trouble with gait, memory loss and visual processing difficulties 
  • Fluctuations and visual hallucinations 

In addition, Lewy bodies, which are collections of alpha-synuclein proteins that accumulate abnormally in the brain, are not typically seen in Alzheimer’s, and are deposited in different parts of the brain than in Parkinson’s. 

“These toxic proteins accumulate gradually and impact specific brain regions, which causes the unique clinical symptoms and disease course of Lewy body dementia,” says Scharre. “The earlier we can detect these symptoms, the better, and our current focus on sleep issue differences and brain imaging patterns will provide even more delineating details.”

For this current portion of the study, Ohio State researchers are using the same kind of carefully matched patient groups and conducting overnight sleep studies to explore patterns related to sleep apnea, REM sleep behavior and other sleep issues. Patients will have brain imaging biomarkers measured and compared to their clinical profiles and sleep findings.  

Following these studies, the researchers will then investigate biomarkers found in cerebrospinal fluid (CSF), blood and genetic material to discover even more predictors by disease type. 

Initial findings from the first stage of the Ohio State Lewy body dementia study have been published in the Journal of Alzheimer’s Disease.

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