Effects of contact location and voltage amplitude on speech and movement in bilateral subthalamic nucleus deep brain stimulation.
2008 (English)In: Movement disorders : official journal of the Movement Disorder Society, ISSN 1531-8257, Vol. 23, no 16, 2377-83 p.Article in journal (Refereed) Published
Subthalamic nucleus deep brain stimulation (STN-DBS) is particularly effective in improving limb symptoms in Parkinson's disease. However, speech shows a variable response. Contact site and amplitude of stimulation have been suggested as possible factors influencing speech. In this double blind study, we assessed 14 patients post bilateral STN-DBS, without medication. Six conditions were studied in random order as follows: stimulation inside the STN at low voltage (2 V) and at high voltage (4 V); above the STN at 2 V and at 4 V, at usual clinical parameters, and off-stimulation. The site of stimulation was defined on the postoperative stereotactic MRI data. Speech protocol consisted of the assessment of intelligibility of the dysarthric speech, maximum sustained phonation, and a 1-minute monologue. Movement was assessed using the UPDRS-III. Stimulation at 4 V significantly reduced the speech intelligibility (P = 0.004) independently from the site of stimulation. Stimulation at 4 V significantly improved the motor function. Stimulation inside the nucleus was significantly more effective than outside the nucleus (P = 0.0006). The significant improvement in movement coupled with significant deterioration in speech intelligibility when patients are stimulated inside the nucleus at high voltage indicates a critical role for electrical stimulation parameters in speech motor control.
Place, publisher, year, edition, pages
2008. Vol. 23, no 16, 2377-83 p.
IdentifiersURN: urn:nbn:se:umu:diva-25345DOI: 10.1002/mds.22296PubMedID: 18785648OAI: oai:DiVA.org:umu-25345DiVA: diva2:230191