DBS: deep brain stimulation, a form of surgery that is used to treat some of the symptoms of Parkinson's.

Dopamine agonists: drugs that stimulate dopamine receptors in the brain.

Duodopa^®: enterally administered levodopa/carbidopa gel used for the treatment of advanced Parkinson's in patients with motor fluctuations and dyskinesias.

Dysarthria: inability to speak normally due to loss of control of the muscles of the tongue, lips, cheeks or larynx.

Dyskinesia: involuntary movements caused by long term use of levodopa.

Dysphagia: Swallowing difficulties.

Dysphasia: difficulty with speaking and sometimes with comprehending speech.