Levodopa effect and motor function in late stage Parkinson’s disease

Objective: To assess responsiveness to Levodopa (L-dopa) in patients with late stage Parkinson’s disease (PD). Moreover, to investigate if the L-dopa effect is stable or whether motor fluctuations and dyskinesias are present.

Background: A majority of PD patients treated with L-dopa develop motor complications, in many cases within a few years of treatment. It is unclear to which degree L-dopa remains effective also in the last stages and whether motor fluctuations and dyskinesias remain a problem.

Methods: The study included 30 patients with PD in Hoehn and Yahr (HY) stages IV and V in “on” and/or having a substantial need of help with ADL (<50% Schwab and England Scale) and having been diagnosed with PD for =7 years. Nineteen were men, median age 83 and median PD duration 12 years. Nineteen were in HY stage IV and 11 in V. L-dopa responsiveness was assessed with an L-dopa test and motor evaluation according to a standardized protocol in the defined “off” and defined “on” state. Motor performance was assessed by the Unified PD Rating Scale (UPDRS) III and timed tests for gait and hand-arm. The participants were further evaluated with a mobile movement-analyses-system, the Parkinson’s Kinetigraph (PKG) for 10 days.

Results: The number of participants with an improvement in UPDRS III during L-dopa test of =15% were 15 (50%) and of =30% were 6 (20%). The median UPDRS III score in “off” was 46 (q1-q3, 37-53) and in “on” 36 (28-46), with a median improvement of 15.5% (8-27%), p<0.001. There was a statistically significant effect in almost all variables; UPDRS III total score; speech (item 18); resting tremor (item 20); tremor (items 20, 21); rigidity (item 22); bradykinesia (items 23-26, 31); gait (item 29); axial signs (items 18, 19, 22, 27-30); dyskinesias (Clinical Dyskinesia Rating Scale); hand-arm movement; gait test and blood pressure. According to the UPDRS IV, 67% experienced predictable off-fluctuations, while 30% had unpredictable off-fluctuations. The prevalence of dyskinesias according to item 32 (duration of dyskinesias =1) of the UPDRS IV was 47%. According to the PKG registrations, some patients were experiencing significant motor fluctuations, though very few had significant dyskinesias.

Conclusions: Half of a group of patients with late stage PD (HY IV-V in “on”) had a significant L-dopa response (=15% on the UPDRS III). According to the UPDRS IV, a majority of the patients still had motor fluctuations and about half had dyskinesias.