= 2^nd most common neurodegenerative disorder in patients >65 years

Histo: loss of dopaminergic neurons in substantia nigra

• classic clinical triad:
  1. Fluctuating levels of cognitive arousal
  2. Visual hallucinations
  3. Spontaneous parkinsonism
• clinical condition may worsen under neuroleptic medications

PET:

• hypometabolism in both parietal + posterior temporal lobes and posterior cingulate gyrus (similar to Alzheimer's)
• ± involvement of occipital lobes (spared in Alzheimer's)