Effects of Bilateral Subthalamic Nucleus Stimulation and Medication on Parkinsonian Speech Impairment
D’Alatri L, Paludetti G, Contarino MF, Galla S, Marchese MR, Bentivoglio AR. (2007) Effects of Bilateral Subthalamic Nucleus Stimulation and Medication on Parkinsonian Speech Impairment , Journal of Voice. Mar 15; [Epub ahead of print].
According to the authors, some of the most common features of the speech difficulties associated with Parkinson’s disease included flat tone, hypophonia (low volume), “variable rate,” small bursts of speech, and a “harsh or breathy voice.” They also pointed out that there is controversial literature documenting speech deficits after PWP are treated with DBS-STN. So, they set out to measure speech in PWP, with detailed measures of speech (more than just one question of the UPDRS), after DBS-STN. 12 Italian patients were studied that underwent bilateral DBS-STN. It is notable that there was significant improvement in motor functioning after DBS-STN combined with medications. The authors did not find a difference in the quality of the patient’s speech based on the one question of the UPDRS that addresses speech. They did find that there was some improvement in specific vocal areas (vocal tremor and a specific action by a muscle used in talking) when measured by multiple precise vocal instruments after DBS-STN and with medications. However, this did not represent a meaningful functional change for the patients, as they continued to have difficulties talking without difficulty. This study represents one of the first to look closely at speech in PWP after DBS-STN. They used more detailed voice measures in an attempt to look further into a problem many of our readers have found and discussed with us. This study clearly shows that more research needs to be done focusing on speech after DBS-STN with more patients as well as utilizing more specific voice tools than one question on the UPDRS to measure speech changes after this type of treatment.