The Predictable Clinical Factors for the Levodopa Responsiveness of Resting Tremor in Patients with Parkinson's Disease

ABSTRACT

BACKGROUND: The pathophysiology of resting tremor in Parkinsons disease (PD) remains unclear. Dopaminergic treatment provides variable effects on resting tremor in PD. We aimed to evaluate the predictable clinical factors for the levodopa responsiveness of resting tremor in patients with PD. METHODS: Eighty-five PD patients with prominent resting tremor who visited Asan Medical Center between June 2004 and June 2005 were included. The prominent resting tremor was defined as tremor scoring more than 3 in at least one limb in the Unified Parkinsons Disease Rating Scale (UPDRS). Subjects were divided into the responsive group (RG) or non-responsive group (NRG) according to the responsiveness of resting tremor to dopaminergic treatment. Responsiveness was defined as a minimum 2 points reduction of UPDRS score for the resting tremor after dopaminergic treatment for more than 3 months. RESULTS: Among the 85 patients, there were 35 men and 50 women ages 34-87 years (mean age, 67 years). Thirty-six patients (42.4%) were grouped into RG and 49 (57.6%) into NRG. Mean age of RG was significantly younger than that of NRG. RG showed significantly higher initial UPDRS part III subtotal score (p=0.015) and more severe Hoehn & Yahr stage (p=0.010) than those of NRG. UPDRS subscores for rigidity (p=0.012), bradykinesia (p=0.021) and postural impairment (p=0.018) were correlated with the responsiveness of dopaminergic treatment. CONCLUSIONS: Resting tremor in PD patients more favorably responded to dopaminergic treatment when it presented in combination with bradykinesia and rigidity suggesting dopaminergic role in the genesis of resting tremor in those PD patients.