Mechanisms underlying focal cranial-cervical dystonia

University Of South Dakota, Vermillion SD

Investigators

Linked publications & trials

Abstract

DESCRIPTION (Adapted from the applicant's abstract): Benign essential blepharospasm (BEB) and spasmodic torticollis (ST) are progressive forms of focal dystonia characterized by their unique presentation in upper facial musculature and cervical musculature, respectively. Little is known about the role of the cerebral cortex despite the fact that emotional and stress-related events, behaviors regulated by the cerebral cortex, often trigger and exacerbate these disorders. Furthermore, cortical control of lower motor neurons innervating muscles implicated in these movement disorders is poorly understood. This study is designed to isolate for the first time cortical neural systems that directly innervate facial motor neurons selectively engage in BEB and spinal accessory motor neurons selectively engage in ST. Once identified, synaptic interactions of these neuronal assemblies will be anatomically characterized. The major goals of this project are to examine the corticobulbar projection from the face/neck representation of the cingulate motor cortex (M3 or Area 24c) to the facial and spinal accessory nuclei. The investigators will determine if the M3 projection: 1) targets lower motor neurons innervating the orbicularis oculi, corrugator supercilia, frontalis, sternocleidomastoid and trapezius; 2) makes direct contact with these motor neurons; 3) is excitatory or inhibitory. Their studies are designed to test the hypothesis that the cerebral cortex plays a role in the physical expression of BEB and ST. It is further hypothesized that recruitment of musculature in BEB and ST patient is a consequence of neuroplastic alterations, such as local sprouting. This project will lead to an increased understanding of cortical systems governing upper facial expression and cervical torsion. These data will be used to design a cortical model of focal dystonia and provide guidance in developing new approaches to surgical treatment of intractable cranial-cervical dyskinesias.