Visual Hallucinations and Parkinsonism in Dementia

We read with interest the article by Zahirovic et al. 1 Zahirovic I. Wattmo C. Torisson G. Minthon L. Prevalence of dementia with Lewy Body symptoms: A cross-sectional study in 40 Swedish nursing homes. J Am Med Dir Assoc. 2016; 17: 706-711 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar The article is informative; however, the authors’ suggestion that because the setting was a nursing home for patients with dementia, all of the elderly patients fulfilled the basic dementia criterion and, therefore, the addition of specific signs of dementia with Lewy body (DLB) could indicate a diagnosis of DLB 1 Zahirovic I. Wattmo C. Torisson G. Minthon L. Prevalence of dementia with Lewy Body symptoms: A cross-sectional study in 40 Swedish nursing homes. J Am Med Dir Assoc. 2016; 17: 706-711 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar may not be correct. For DLB, a patient must have 2 of the 3 core clinical features (parkinsonism, visual hallucinations, cognitive fluctuations) at the time of diagnosis of dementia and not after a lapse of months or years. What the authors found in this study may have been the symptom manifestation of Alzheimer disease (AD) and related dementia, instead of a manifestation of DLB. When patients with known AD and related dementia have psychosis, such as visual hallucinations, they should be classified as having psychosis because of dementia and not DLB. In patients with DLB, visual hallucinations are present early in the course of a dementing illness. 2 Pelak VS. Approach to the patient with visual hallucinations. uptodate.com Accessed September 23, 2016. Google Scholar Furthermore, if a patient has Parkinson disease (PD) symptoms and later on develops visual hallucination, the patient may well have dementia because of PD and not DLB. As outlined by the authors, DLB has a shorter survival. 1 Zahirovic I. Wattmo C. Torisson G. Minthon L. Prevalence of dementia with Lewy Body symptoms: A cross-sectional study in 40 Swedish nursing homes. J Am Med Dir Assoc. 2016; 17: 706-711 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar Therefore, it is equally important to not over diagnose DLB because of its implication on patient/healthcare proxy decision to forgo life-sustaining measures because of a shorter life expectancy with DLB.