Visual Hallucinations and HLA Class II Antigens in Cortical Dementia

Abstract

Background: Visual hallucinations are a core feature of dementia with Lewy bodies (DLB) and have been proposed as being part of a narcolepsy-like REM sleep disorder. Selective loss of hypothalamic hypocretin-producing neurons is common to both narcolepsy and the spectrum of Lewy body diseases. We hypothesized that the genetic marker associated with narcolepsy, the HLA class II DR2-DQ6 haplotype, could confer some degree of susceptibility to brainstem-hypothalamic damage leading to the manifestation of visual hallucinations. Methods: We examined HLA class II haplotypes in 30 patients with prominent visual hallucinations in the context of clinical criteria for DLB and in 30 patients affected by a cortical-type dementia without hallucinations. Results: No significant differences were found in the distribution of DR and DQ antigens. Conclusions: We conclude that hypothalamic vulnerability in different diseases is not mediated by a common HLA haplotype.

Sleep Disorders in Atypical Parkinsonism

“…Because some features of DLB are similar to narcolepsy, including hypersomnia and visual hallucinations, and there is loss of hypocretin neurons in both, an evaluation was performed looking at the prevalence in DLB patients of the human leukocyte antigen haplotype, DR2‐DQ6, which is more common in narcolepsy. In this study, no significant increase in this specific haplotype in DLB patients was observed, suggesting that these two disorders do not share the same mechanism of hypocretin neuronal loss …”

“…In this study, no significant increase in this specific haplotype in DLB patients was observed, suggesting that these two disorders do not share the same mechanism of hypocretin neuronal loss. 85…”