Sensorimotor Integration in Childhood Dystonia and Dystonic Cerebral Palsy—A Developmental Perspective

Verity M Mcclelland,Jean-Pierre Lin

doi:10.3389/fneur.2021.668081

Abstract

Dystonia is a disorder of sensorimotor integration, involving dysfunction within the basal ganglia, cortex, cerebellum, or their inter-connections as part of the sensorimotor network. Some forms of dystonia are also characterized by maladaptive or exaggerated plasticity. Development of the neuronal processes underlying sensorimotor integration is incompletely understood but involves activity-dependent modeling and refining of sensorimotor circuits through processes that are already taking place in utero and which continue through infancy, childhood, and into adolescence. Several genetic dystonias have clinical onset in early childhood, but there is evidence that sensorimotor circuit development may already be disrupted prenatally in these conditions. Dystonic cerebral palsy (DCP) is a form of acquired dystonia with perinatal onset during a period of rapid neurodevelopment and activity-dependent refinement of sensorimotor networks. However, physiological studies of children with dystonia are sparse. This discussion paper addresses the role of neuroplasticity in the development of sensorimotor integration with particular focus on the relevance of these mechanisms for understanding childhood dystonia, DCP, and implications for therapy selection, including neuromodulation and timing of intervention.

Highlights

Dystonia is a neurological syndrome characterized by involuntary, sustained, or intermittent, muscle contractions causing abnormal, often repetitive, movements, postures, or both
The abnormalities were seen predominantly in the acquired dystonia group, of which the majority had dystonic-dyskinetic CP [93, 94]. This was not a longitudinal study, it is likely that these abnormalities were long-standing and that sensory pathway dysfunction had been present since the perinatal period in these individuals, with a consequent adverse impact on the activity-dependent refinement of sensorimotor circuits in the early post-natal period, and an enduring effect on their function [86]
This study found that children with either isolated genetic dystonia or with Dystonic cerebral palsy (DCP) show impaired mu modulation in response to a proprioceptive stimulus, indicating an abnormality in sensorimotor processing which is common across different dystonia etiologies [20]—Figure 3

Summary

Introduction

Dystonia is a neurological syndrome characterized by involuntary, sustained, or intermittent, muscle contractions causing abnormal, often repetitive, movements, postures, or both. These findings emphasize that the disrupted plasticity and activity in the sensorimotor network caused by TOR1A or THAP1 dysfunction are not just manifest at the time of clinical onset (usually mid-childhood) but are likely to impact on the early development of sensorimotor circuits and on their function, perhaps shifting the balance between excitation and inhibition.

Results

Conclusion