[¹⁸F]THK5351 uptake in multiple system atrophy compared with other parkinsonian disorders

The pathological processes in the early stages of multiple system atrophy (MSA) are still incompletely understood. Moreover, early-stage MSA is difficult to diagnose.

We investigated the monoamine oxidase-B positron emission tomography findings with an aim to characterize degeneration in the early stages of MSA.

Positron emission tomography using [¹⁸F]THK5351 was performed on three patients with relatively early stages of MSA: two with cerebellar-type MSA and one with parkinsonian-type MSA. The findings were compared with nine patients with other parkinsonian disorders (Lewy body disease, progressive supranuclear palsy, or spinocerebellar ataxia type 31) and six control subjects (Alzheimer disease or normal aging).

Uptake of [¹⁸F]THK5351 in the middle cerebellar peduncles was distinctly higher in all three patients with MSA than in patients with other parkinsonian disorders or control subjects (both p < 0.001; unpaired t-tests).

The results of the presented patients suggest the potential diagnostic utility of [¹⁸F]THK5351 imaging and may help to clarify the preclinical pathology of the middle cerebellar peduncle in MSA.