Snapshot A 67-year-old male presents with poor attention and getting lost while driving. He is accompanied by his wife. She reports that he would have episodes of staring into space and disorganized speech. His wife also reports that he would have full conversations with himself in the living room. She says that he was talking to his brother, who is deceased. Postural instability and bradykinesia is noted on physical exam. Introduction Degenerative dementia associated with dementia appears later in the disease memory deficits seen early in Alzheimer's disease visual hallucinations parkinsonism fluctuations in cognition Poor response to dopamine agonist therapy Lewy body eosinophilic intracytoplasmic inclusion in neurons α-synuclein aggregation is the major component of lewy bodies Epidemiology second most common neurodegenerative dementia Alzheimer disease is the most common Presentation Symptoms dementia later-onset visual hallucinations parkinsonism cognitive fluctuations impairment in executive function and attention visuospatial impairment neuroleptic sensitivity worsens parkinsonism Evaluation Clinical diagnosis Histology Lewy body eosinophilic cytoplasmic inclusions composed predominately of alpha-synuclein can be found in cortical layers throughout the brain in Parkinson's disease, Lewy bodies can be found in the substantia nigra, locus ceruleus Differential Alzheimer disease Parkinson disease Vascular dementia Creutzfeldt-Jakob disease Treatment Cholinesterase inhibitors may be considered first-line rivastigmine donepezil Prognosis, Prevention, Complications Prognosis shortened life expectancy relative to patients with Alzheimer's disease