Do speech difficulties have a predictive value in Parkinson’s disease outcomes?

This study investigated speech (talking) symptoms in patients with Parkinson's disease (PD). Researchers suggested that these symptoms are associated with low levels of dopamine and poorer outcomes.

Parkinson's disease (PD) affects brain cells and dopamine levels. This can cause tremors, muscle rigidity or even talking symptoms. The standard therapy for PD helps increase the levels of dopamine. However, the effects of this therapy in the talking ability of patients is still not fully clear. Also, little is known about the association between talking symptoms and disease progression.

This study included 143 recently diagnosed patients with PD and talking difficulties. The brain function of these patients was compared with patients with PD without speaking difficulties.

Talking difficulties were more present in patients with other symptoms such as muscle rigidity than in patients with tremors. These patients had less resting tremor, more nervous system complications and sleep disorders.

Patients with talking symptoms had a 66% decrease in the odds of better cognitive (thinking ability) outcomes. However, this symptom had no association with the progression of movement complications.

This study concluded that talking complications in PD are associated with decreased levels of dopamine. There was also an association between this symptom and poorer outcomes.