Lewy Body Dementia

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