Diagnosis and Management of Cognitive and Behavioral Changes in Dementia With Lewy Bodies

Babak Tousi

Proper diagnosis of dementia with Lewy bodies (DLB) in clinical practice remains suboptimal as many cases are misdiagnosed, usually as Alzheimer disease (AD) or Parkinson's disease (PD) and, in rare cases, psychosis. Therefore, it is important for patients with dementia to be thoroughly evaluated by a specialist who is familiar with current diagnostic tests and treatment options. New diagnostic criteria from the Dementia with Lewy Bodies Consortium have been developed to increase diagnostic sensitivity for DLB (Diagnosis and management of dementia with Lewy bodies: fourth consensus report of the DLB Consortium; McKeith et al.; Neurology, 89(1): 88-100). REM sleep behavior disorder (RBD) has been studied more thoroughly in correlation with DLB and is now considered a core feature. D2 receptor blocking antipsychotics, which can cause severe antipsychotic sensitivity, are now rarely prescribed for treatment. Therefore, severe antipsychotic sensitivity, which was a suggestive criterion for DLB diagnosis, is now listed as a supportive feature. Reduced DAT uptake in basal ganglia demonstrated by SPECT or PET imaging has high specificity (90%) for distinguishing DLB from AD. Reduced uptake on metaiodobenzylguanidine myocardial scintigraphy correlates with reduced postganglionic sympathetic cardiac innervation in Lewy body diseases, which can increase specificity for discriminating probable DLB from probable AD in milder cases of dementia. However, the latter is more commonly used in Japan and is not used in the USA. The evidence supporting the benefit of other therapeutic modalities is limited in DLB due to lack of extensive studies. There are no FDA-approved medications for the treatment of DLB, although some effective drugs have been used off label to treat various symptoms.