Effective Treatment of Pure Akinesia with L-threo-3,4-Dihydroxyphenylserine (DOPS)

Abstract

A patient with pure akinesia, who experienced freezing only when starting to walk backward or when turning, is reported. L-DOPA, maprotiline, clonazepam, DL-threo-3,4-dihydroxyphenylserine (DOPS), and L-threo-DOPS were administered to the patient. Only DL-threo-DOPS and L-threo-DOPS were effective, but they concurrently brought on a hypomanic state. Combining carbidopa with DL (or L)-threo-DOPS did not change the effectiveness of the treatment. DL (or L)-threo-DOPS did not affect monoamine metabolites in the cerebrospinal fluid (CSF). The effectiveness of L-threo-DOPS on freezing, the induction of affective changes, and the absence of 3-methoxy-4-hydroxyphenylglycol alteration in the CSF suggest that L-threo-DOPS acts centrally but may not directly involve the noradrenergic system.