For a study, the phenotypic presentation of aberrant motor outputs, either as standalone events or in conjunction with additional clinical, typically neuropsychiatric, symptoms, was the unifying aspect of movement disorders. The concept of a movement disease is defined by supranormal or improved volitional motor control. Based on clinical observations and cases gathered over a number of years, researchers described a fascinating clinical phenomenon in which patients with tic disorders often regulated particular muscle contractions as part of their tic behaviors to a degree that most humans cannot. Examples were found in the accompanying video documentation. 

Researchers examined the medical literature on this subject and made parallels with early studies of fine motor control physiology in healthy persons. By systematically analyzing the likely sources of this unusual capacity and focusing on neuroscientific accounts of voluntary motor control, sensory feedback, and the role of motor learning in tic disorders, they provided a novel pathophysiological account explaining both the presence of exquisite control over motor output and the presence of overall tic behaviors. 

Finally, they discussed crucial topics for upcoming studies on the topic and offer some closing thoughts on the complicated movement disorder of tic behaviors.

Reference:movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.28557

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