A Case of Biopsy-proven Early-onset Alzheimer's Disease with Hemiparkinsonism.

Patients with dementia and concomitant parkinsonism are frequently encountered in the elderly population. When it comes to young adults, however, coexistence of Alzheimer's disease (AD) and Parkinson's disease (PD) is rare. We described a case of 47-year old man with presenile onset dementia associated with hemiparkinsonism involving the right extremities. Brain biopsy showed neurofibrillary tangles and neuritic plaques, compatible with Alzheimer's disease. Iodine-123 labelled N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl) tropane ([(123)I]IPT) SPECT, dopamine transporter imaging, revealed a decreased uptake in both basal ganglia, more severe on the left side, particularly the caudal putamen, which is consistent with the finding of idiopathic Parkinson's disease. This case is unique in that damage on the nigrostriatal dopaminergic system in a patient with Alzheimer's disease was demonstrated by a functional neuroimaging study and that early-onset AD and early-onset PD, two rare conditions, coexist in the same individual.