Transient worsening of Parkinson's disease after cigarette smoking.

We report a patient with probable Parkinson's disease who experienced a temporary worsening of his symptoms and signs after cigarette smoking. Deterioration of tremor, rigidity, and writing disturbance began soon after the inhalation of cigarette smoke and persisted for 15 minutes. Chewing nicotine gum also induced a brief worsening of the patient's symptoms. Aggravation of parkinsonian symptoms after cigarette smoking appeared to be caused by nicotine alone, although the mechanism for this effect remains unclear.