Intelligibility of speech in Parkinson's disease relies on anatomically segregated subthalamic beta oscillations.

Background: Speech impairment is commonly reported in Parkinson's disease and is not consistently improved by available therapies - including deep brain stimulation of the subthalamic nucleus (STN-DBS), which can worsen communication performance in some patients. Improving the outcome of STN-DBS on speech is difficult due to our incomplete understanding of the contribution of the STN to fluent speaking.

Objective: To assess the relationship between subthalamic neural activity and speech production and intelligibility.

Neurophysiological evaluation of visual function in iRBD: potential role in stratifying RBD conversion risk.

Study Objectives: To evaluate neurophysiological alterations of visual function in idiopathic REM sleep Behavior Disorder (iRBD) both as markers and predictors of neurodegenerative disorders.

Methods: In a longitudinal follow-up study of 46 consecutive iRBD patients (follow-up duration 8.4 ± 3.