Motor Timing in Tourette Syndrome: The Effect of Movement Lateralization and Bimanual Coordination

In conclusion, our study demonstrates that TS patients manifest “trait” abnormalities in the timing of sequential motor tasks, which are in keeping with the continuation phase of time processing, likely controlled by the sensorimotor loop of the cortico-basal ganglia network. We also show that the abnormal lateralization of fine motor control, previously reported in the context of the structural sequencing of fine motor tasks, extends also to motor timing accuracy. Finally, we highlight SMA connectivity as a potentially pivotal neural substrate of adaptive compensation of motor timing deficits in fine manual tasks in TS. We acknowledge that our results are based on a relatively small sample size. Another potential limitation is the lack of assessment for sub-diagnostic threshold ADHD symptomatology, although none of our TS patients had any history of current or past ADHD diagnosis. In this respect, future studies on larger samples should explore the presence of compensatory activation patterns using functional MRI, and correlate the level of this compensatory activation to the pattern of lateralization of motor timing abilities in TS patients. As for many other aspects of this complex neurodevelopmental disorder, longitudinal studies of multivariate datasets combining brain structure, brain performance and brain activation would have the potential to reveal the temporal trajectory of compensatory mechanisms that underlie phenotypic heterogeneity. Ethics State...
Source: Frontiers in Neurology - Category: Neurology Source Type: research