214 - 6D82 Dementia due to Lewy body disease

6D82 Dementia due to Lewy body disease

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Additional clinical features • Neurocognitive symptoms often follow cerebrovascular compromise. In stroke, the type of neurocognitive impairment varies depending on the brain region in which the stroke occurred. Stroke-related neurocognitive impairment typically begins abruptly after a stroke. Improvement in initial neurocognitive deficits is typically seen, with recovery reaching a plateau over time. Residual neurocognitive deficits often remain chronic over time. • In contrast, in microvascular events, neurocognitive impairment typically affects socalled subcortical neurocognitive functions (e.g. attention, processing speed, executive/ frontal lobe-related functions). If microvascular events are attributed to progressing chronic conditions (e.g. hypertension, diabetes), as is common, the clinical course of neurocognitive impairment may be slowly progressive. Note: an appropriate diagnosis from the Cerebrovascular diseases grouping in Chapter 8 on diseases of the nervous system should also be assigned. Dementia due to Lewy body disease Essential (required) features • All diagnostic requirements for dementia are met. • Dementia is presumed to be attributable to underlying Lewy body disease, as demonstrated by neuropsychological test data, neuroimaging data, genetic testing, medical tests, family history and/or clinical history. • Clinical history involves the presence of two or more of the following symptoms: • recurrent visual hallucinations (typically well-formed) • episodic confusion • REM sleep behaviour disorder • one or more features of parkinsonism (e.g. resting tremor). Additional clinical features • Neurocognitive symptoms are progressive, and often involve relatively greater impairment in visuospatial skills, attention and executive functioning (as opposed to primary memory impairment, as seen in Alzheimer disease). • Additional clinical features may include repeated falls, syncope, hallucinations in other sensory modalities, delusions and autonomic dysfunction (e.g. constipation, urinary incontinence). Note: a diagnosis of 8A22 Lewy body disease in Chapter 8 on diseases of the nervous system should also be assigned. Neurocognitive disorders | Dementia due to cerebrovascular disease and Lewy body disease 6D82