ICD-11 Criteria for Dementia Due to Lewy Body Disease (6D82) Dementia preceding or occurring within one year after the onset of motor parkinsonian signs in the setting of Lewy body disease. Characterized by presence of Lewy bodies, which are intraneuronal inclusions containing α-synuclein and ubiquitin in the brain stem, limbic area, forebrain, and neocortex. Onset is insidious with attentional and executive functioning deficits often present. These cognitive deficits are often accompanied by visual hallucinations and symptoms of REM sleep behaviour disorder. Hallucinations in other sensory modalities, depressive symptoms, and delusions may also be present. The symptom presentation usually varies significantly over the course of days necessitating longitudinal assessment and differentiation from delirium. Spontaneous onset of Parkinsonism within approximately 1 year of the onset of cognitive symptoms is common. Coding Note:       This category should never be used in primary tabula