Effects of five years of chronic STN stimulation on muscle strength and movement speed

• Published in: Experimental brain research Vol. 205; no. 4; pp. 435 - 443
• Main Authors: Sturman, Molly M., Vaillancourt, David E., Verhagen Metman, Leo, Bakay, Roy A. E., Corcos, Daniel M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2010; Springer; Springer Nature B.V
• Subjects: Aged; Ankle Joint - physiology; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Brain stimulation; Deep Brain Stimulation - methods; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Female; Fundamental and applied biological sciences. Psychology; Human mechanics; Humans; Male; Medical sciences; Middle Aged; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Movement - physiology; Muscle strength; Muscle Strength - physiology; Neurology; Neurosciences; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Physiological aspects; Research Article; Subthalamic Nucleus - physiology; Time Factors; Treatment Outcome; Vertebrates: nervous system and sense organs; United States; Long-term stimulation; Velocity; Parkinson’s disease; Strength; STN deep brain stimulation; Human; Freedom degree; Nervous system diseases; Parkinson's disease; Deep brain stimulation; Central nervous system; Parkinson disease; Joint; Muscle contraction; Motor control; Long term; Cerebral disorder; Encephalon; Osteoarticular system; Ankle; Central nervous system disease; Degenerative disease; Muscle; Subthalamic nucleus; Extrapyramidal syndrome
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-010-2370-8

This study examined the long-term effects of chronic subthalamic nucleus (STN) deep brain stimulation (DBS) using both clinical evaluation and laboratory motor control measures. Over a 5-year time period, changes in the motor section of the Unified Parkinson’s Disease Rating Scale (UPDRS) and movement speed and strength at the ankle joint were evaluated on and off STN DBS in eight patients with Parkinson’s disease (PD). Four patients were also studied at the elbow joint. Patients with PD originally received unilateral STN DBS between years 2001 and 2003. They were re-evaluated after 5 years of long-term STN DBS between years 2006–2008. At baseline (year 0) and after 5 years, patients with PD were tested off treatment and on STN DBS. In each testing condition, patients performed ballistic, single degree of freedom ankle dorsiflexion and ankle plantarflexion movements and peak velocity was calculated. Patients also performed maximal voluntary contractions at the ankle joint in both directions, and peak torque was calculated. Results showed increased motor UPDRS scores from year 0 to year 5, but STN DBS was efficacious in reducing them. In contrast to the increase in motor UPDRS scores, motor control results showed a marked improvement in peak velocity and peak torque over the 5-year time period in the off treatment condition, and STN DBS was efficacious by improving both peak velocity and peak torque. The current findings suggest that 5 years of chronic STN DBS can have beneficial effects on the motor system over the long term in discrete motor tasks in which maximal effort and maximal neural output is required.