July 26, 2026

@michaelokun

T minus 5 hours until liftoff of the 36th annual Aspen movement course. Tip of the hat to the late Mark Hallett to get things started. Could dystonia be a disorder of brain networks rather than simply of abnormal muscles? Dystonia refers to involuntary muscle co-contractions that lead to twisting movements or abnormal postures. While it was once considered primarily a basal ganglia disorder, our understanding has evolved to recognize dystonia as a disorder involving multiple interconnected brain networks. Latorre and colleagues describe in a new paper in Clinical Parkinsonism & Related Disorders how the pioneering work of Mark Hallett transformed our understanding of dystonia from abnormal muscle activation to dysfunction of distributed sensorimotor networks. Key points: - Impaired inhibition throughout the motor system appears to allow competing motor programs to intrude, resulting in overflow movements, co-contraction and loss of motor selectivity. - Abnormal sensorimotor integration and altered sensory processing suggest dystonia is not purely a motor disorder, but one in which sensory information is processed differently and influences movement abnormally. - Deranged plasticity may stabilize abnormal motor programs over time, helping explain why many forms of dystonia become persistent and difficult to reverse despite treatment. My take: This thoughtful review beautifully captures Mark Hallett's enormous scientific legacy. His work shifted the field away from searching for a single anatomical culprit and toward understanding dystonia as a disorder of interacting brain networks. That conceptual change continues to influence how we think about diagnosis, rehabilitation, neuromodulation and future therapies. Here are 3 points that resonated w/ me: 1- Dystonia is not simply excessive movement, it reflects a failure of the brain to properly select and refine intended movements. 2- Healthy movement depends on balanced inhibition, and when this balance is lost unintended motor programs can emerge. 3- Sensory signals are active partners in movement control, helping explain why sensory tricks can temporarily improve symptoms in some folks.