Post-movement beta synchronization in subjects presenting with sensory deafferentation

Objective We studied the time course and location of post-movement beta synchronization (PMBS) in patients presenting with sensory deafferentation, in order to assess the hypothetical relationship between the PMBS and the cortical processing of movement-related somatosensory afferent inputs. Methods We used the event-related synchronization (ERS) method. EEG activity was recorded (via a 128-electrode system) during brisk, unilateral right and left index finger extension by 10 patients presenting with neuropathic pain related to sensory deafferentation. Intra- and post-movement changes in beta source power were calculated relative to pre-movement baseline activity. We compared the PMBS results for the painful and non-painful body sides. Furthermore, PMBS patterns in patients were compared with those in nine healthy volunteers. Results PMBS pattern related to the painful side had a spatial distribution, with an ipsilateral preponderance, significantly more restricted than PMBS pattern on the non-painful side and in the control group. There were no significant differences between patient PMBS patterns on the non-painful side and those in the control group. Conclusions Sensory deafferentation disrupts normal PMBS patterns. Significance This work provides additional arguments to the hypothesis supporting that the PMBS is influenced by movement-related somatosensory input processing