Speech dysfluency exacerbated by levodopa in Parkinson's disease.

The role of dopamine in the modulation of speech fluency is complex. In this report we describe two patients with Parkinson's disease whose speech dysfluency was exacerbated by the administration of levodopa. In doing so, we extend the observation that dopaminergic mechanisms may be involved in the regulation of speech fluency. It is important for clinicians to recognize that, in some instances, dopaminergic replacement therapy may exacerbate an underlying dysfluency syndrome in PD.