Sunday, May 24, 2015
The subthalamic nucleus (STN) is a cluster of nerve cell bodies located at the base of the brain, with the aspect of a biconvex mass of grey matter surrounded by bundles of myelinated axonal fibers, which constitute the white matter. Being part of the basal ganglia, it is linked up with the globus pallidus as it receives massive projection from its lateral segment. The subthalamic nucleus contains glutamatergic neurons. Although its function is not clearly known, the subthalamic nucleus has been considered an important modulator of the basal ganglia output. STN lesions cause choreiform abnormal movement and ballism on the contralateral side of the body.