# 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