asymmetric Parkinson's disease

Themotorresponses of14patients with Parkinson'sdisease(sixpreviously untreated andeight chronically receiving levodopa) withpronounced asymmetry in theseverity ofmotorsignsbetweenthe left andright sides ofthebodywerestudied.Theeffects ofa short(60minutes) andalong(16-22 hours) intravenous levodopainfusion aswellasofsubcutaneous apomorphine(1-6mg bolus)were assessed. Fourdifferent tappingtests wereusedtomeasuremotorfunction. Forallpharmacological tests, themore affected sideshoweda shorter response duration, increased latency, andgreater response magnitude thanthelessaffected side. Thesedifferences weremorepronouncedin thosepatients receiving chronic levodopa treatment. Asapomorphineisnotdependent ondopamine storagecapacity, thesefindings suggest that postsynaptic mechanisms playanimportantpartintheorigin ofmotorfluctuations inParkinson's disease.