Do patients with late-stage Parkinson's disease still respond to levodopa?

Abstract

LSPD patients show a slight response to a supra-maximal levodopa dose, which is greater if dyskinesia are present, but it is frequently associated with adverse effects. A decrease in levodopa response is a potential marker of disease progression in LSPD.

Response of non-motor symptoms to levodopa in late-stage Parkinson's disease: Results of a levodopa challenge test

“…LSPD patients were first assessed in the practically defined "MED OFF" condition and then 60-90 minutes after L-dopa intake in the best "MED ON" condition [10].…”

“…Advanced patients were first assessed in the practically defined "MED OFF" condition and with the neurostimulator switched OFF for at least 60 minutes ( MED OFF/STIM OFF), and then after taking the same L-dopa dose as they did in the L-dopa challenge performed for DBS selection years before (MED ON/STIM OFF). The protocol of the L-dopa challenge performed for DBS selection was the same as for LSPD patients, as previously reported [10]. Indeed each patient took her/his usual morning L-dopa equivalent dose plus 50% (supra-maximal dose=150%).…”

“…For the purpose of our study only the 20 items for state anxiety assessment have been administered to patients. MDS-UPDRS motor part III [13] was performed in "MED OFF" and then best "MED ON" condition [10]. MDS-UPDRS parts II and IV were used to assess the impact of motor symptoms on activities of daily life and L-dopa-induced MCs, respectively [13].…”

“…[9]. Overall, L-dopa responsiveness seems to decrease with disease progression, but very few studies have indeed investigated L -dopa responsiveness among LSPD patients [4,10], and even less the benefit of L-dopa on NMS. To assess this, we report the response of NMS to an acute L-dopa challenge in a population of LSPD.…”

Development of new levodopa treatment strategies in Parkinson’s disease—from bedside to bench to bedside

“…It could be demonstrated by simultaneous measurement of clinical effects and cerebral kinetics that even in very advanced stages of PD the striatal ability to decarboxylate exogenous levodopa is preserved and a motor response is obtained at low concentrations of striatal dopamine formed (25). Not all symptoms are levodopa-responsive in late-stage PD, but the typical cardinal symptoms still respond (26). The cerebral decarboxylase activity may decline with time but is obviously well preserved for many years (27).…”