Dopa Responsive Parkinsonism in an Early Onset Alzheimer's Disease Patient with a Presenilin 1 Mutation (A434T)

Alzheimer's disease patients with presenilin 1 (PSEN1) mutations commonly show parkinsonism in addition to dementia. Yet, whether these patients show dopaminergic deficit and response to L-dopa is largely unknown. We report a 43-year-old woman with a PSEN1 mutation (A434T) who showed right side dominant parkinsonism. As disease progressed, she developed bilateral parkinsonism which was markedly relieved by L-dopa. Amyloid (Florbetaben) positron-emission tomography (PET) showed cortical florbetaben uptake, relatively sparing the striatum. Initial dopamine transporter (FP-CIT) PET showed asymmetrically decreased FP-CIT uptake in the left striatum. We suggest that in Alzheimer's disease patients with PSEN1 mutation, parkinsonism may be relieved by L-dopa when it is associated with presynaptic dopaminergic deficit.