The latest article from the Dystonia Society continues a series exploring what is thought to be happening in the brain when a person has dystonia.
Their first article covered the role of the basal ganglia and the second the role of the cerebellum. This article explores the sensory abnormalities that are thought to be contributing factors in the development of primary dystonia.
Initially it might seem strange to connect subtle changes in the sensory system with the onset of dystonia.
However, muscle movement is only possible when there is sensory input from the eyes, touch, or sensory receptors such as proprioceptors (the sensors that tell the brain where a limb is positioned). The sensory system provides the major drive to the motor system and the basal ganglia plays an important role in the central processing of somatosensory (sensory/motor) input.
In a person who does not have dystonia, the brain is able to manage and control movement through the integration of all the messages / signals it receives from receptors and proprioceptors within the skin, muscles, joints etc.
In people with dystonia it has been identified that the brain is not receiving or integrating all sensory messages correctly and in particular the proprioceptive messages (sensory information) from muscles are misprocessed in the brain.