Dementia With Lewy Bodies

Dementia with Lewy bodies (DLB) is a neurodegenerative synucleinopathy. Misfolded alpha-synuclein accumulates as Lewy bodies and Lewy neurites in brainstem, limbic, and neocortical regions. Degeneration affects both cholinergic and dopaminergic systems, which helps explain why cognition, alertness, perception, movement, sleep, and autonomic function can deteriorate together. Alzheimer disease neuropathologic change commonly coexists and may make the phenotype less clear-cut. The required clinical feature is dementia: progressive cognitive decline severe enough to interfere with usual social or occupational function. Early memory loss does not have to dominate. A person may first struggle with sustained attention, planning, visual-spatial tasks, or interpreting what they see. Four core clinical features form the recognizable DLB pattern: - Fluctuating cognition: pronounced variation in attention and alertness, sometimes over minutes or hours. - Recurrent, well-formed visual hallucinations: people, animals, or objects may be seen in striking detail. - REM sleep behaviour disorder (RBD): dream enactment caused by loss of normal REM-related muscle atonia; it may precede dementia by years. - Spontaneous parkinsonism: bradykinesia, rest tremor, or rigidity not explained by dopamine-blocking medication or another cause. Probable DLB...