Responses to Stimulation of the Subthalamus

 Responses to Stimulation of the Subthalamus

Electrical stimulation results in an increasein muscle tone, increased reflex excitability and promotion of cortically induced movements.

Automatic motions can be induced in certainareas. As passing fiber bundles are also af-fected, the stimulatory effects cannot pro-vide information on the function of in-dividual nuclei. Stimulation at the level of the posterior commissure (fiber region of the interstitial nucleus) results in lowering the head (+); medial stimulation in the prerubral field results in lifting the head (+). The field for turning and rolling mo-tions (+) corresponds to the fiber area of the superior cerebellar peduncle. The field for ipsilateral turning motions (+) corre-sponds to the dorsolateral tegmental fasciculus (vestibulothalamic tract). The area for contralateral turning motions (+) corresponds to the zona incerta.

B17 Fornix.

B18 Mamillothalamic tract.

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