Laterality and deep brain stimulation of the subthalamic nucleus: applying a dichotic listening task to patients treated for Parkinson’s disease

Abstract

Ear advantage during a dichotic listening task tends to mirror speech lateralization. Previous studies in stroke patients have shown that lesions in the dominant hemisphere often seem to produce changes in ear advantage. In this study six Parkinson’s disease (PD) patients treated for motor symptoms with deep brain stimulation (DBS) of the left subthalamic nucleus (STN) were tested preoperatively and at approximately 6 and 18 months postoperatively with a dichotic listening task. Results show a significant decline of the right ear advantage over time. In three of the patients a right ear advantage preoperativley changed to a left ear advantage 18 months postoperatively. This suggests the possibility that additional longitudinal studies of this phenomenon could serve as a model for understanding changes in indirect measures of speech lateralization in stroke patients.

Keywords:

• dichotic listening
• aphasia
• hemispheric dominance
• deep brain stimulation
• subthalamic nucleus

Additional information

Funding

This work was supported by grants from Olle Engkvist Byggmästare, the University of Umeå and the Foundation for Clinical Neuroscience at the University Hospital of Umeå. M.H. is supported by the Edmond J. Safra Philanthropic Foundation, the Monument Trust and the Parkinsons Appeal, UK.