Theta burst stimulation over premotor cortex in Parkinson’s disease: an explorative study on manual dexterity

• Published in: Journal of Neural Transmission 2016-12, Vol.123 (12), p.1387-1393
• Main Authors: Vanbellingen, Tim, Wapp, Manuela, Stegmayer, Katharina, Bertschi, Manuel, Abela, Eugenio, Kübel, Stefanie, Nyffeler, Thomas, Müri, René, Walther, Sebastian, Nef, Tobias, Hallett, Mark, Bohlhalter, Stephan
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Analysis of Variance; Evoked Potentials, Motor - physiology; Female; Functional Laterality - physiology; Humans; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Motor Cortex - diagnostic imaging; Motor Cortex - physiology; Neurology; Neurology and Preclinical Neurological Studies - Original Article; Neurosciences; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Psychiatry; Psychomotor Performance - physiology; Theta Rhythm - physiology; Transcranial Magnetic Stimulation - methods
• ISSN: 0300-9564; 1435-1463
• DOI: 10.1007/s00702-016-1614-6

Dorsal pre-motor cortex (PMd) is thought to play a role in fine motor control. The aim of the present study was to investigate whether inhibitory or excitatory stimulation of PMd would have an impact on manual dexterity in Parkinson’s disease (PD). Fifteen patients with PD participated in this study. High resolution structural MRI was used for neuro-navigated TBS. Participants were targeted with one train of TBS in three experimental sessions: sham stimulation over vertex, continuous TBS (cTBS) over PMd and intermittent TBS (iTBS) over PMd, respectively. Dexterity was measured by a coin rotation task (CRT), which is a valid measure to detect limb kinetic apraxia (LKA). Neither cTBS or iTBS significantly interfered with CRT. Post hoc sub-analysis in a group of PD patients ( n  = 5) with stronger baseline impairment, indicating LKA, revealed further deterioration of dexterous performance for the cTBS condition ( p  = 0.04). This sham controlled pilot study demonstrates that TBS over PMd does not significantly interfere with dexterity in PD. However, patients with dexterous impairment qualifying for LKA may be more susceptible to TBS.