Articulation disorders and duration, severity and l-dopa dosage in idiopathic Parkinson's disease

As PD progresses a significant decline in vocal articulation can be observed, which is due to reduced mobility within the lips and the jaw. Exacerbation of articulation disorders resulting from progression of the disease does not materially influence the UPDRSS scores. l-dopa has been found to positively affect the mobility of the lips while the patient is speaking and their arrangement at rest.