Botulinum Toxin Type A (Botox) in the Management of Levodopa-Induced Peak-Dose Dyskinesias in Parkinson's Disease

The primary objective of this study is to determine whether intramuscular injections of botulinum toxin type A (Botox®) in selected cervical muscles at antidystonic dosages can reduce levodopa-induced peak-dose dyskinesias (LID) in the cervical region in adult patients with idiopathic Parkinson's disease. It is hypothesized that the intramuscular injection of antidystonic doses of botulinum toxin into cervical muscles will decrease the duration and severity of LID in the cervical region in patients with Parkinson's disease (PD).