Trochlear nucleus

The nucleus nervi trochlear ( " Trochleariskern ") is an existing on both sides of the core area (nucleus ) of which the trochlear nerve ( cranial nerve IV) proceeds. He belongs to the nucleus nervi oculomotorii, the Edinger - Westphal nucleus and the motor nucleus nervi abducentis ( medial longitudinal fasciculus ) are connected to the eye muscle nuclei via the medial longitudinal fasciculus.

The nucleus nervi trochlear located in the rear part of the hood midbrain ( midbrain tegmentum ), approximately at the level of the inferior colliculi. His nerve cells receive impulses from the equilateral cerebral cortex. The outgoing from the mainland of nerve fibers run dorsal to the central gray matter and cross above the fourth Hirnventrikels on the other ( contralateral ) side. In the brainstem, the nerve fibers then exit as trochlear nerve from the brain. Due to the complete intersection of the efferent fibers of the left Trochleariskern is responsible for the right superior oblique muscle.

For damage this core area there is on the other side (contralateral ) to a deformity of the eyeball upward and medially to the external rotation, since the fibers completely cross to the other side after their exit. Damage to the trochlear nerve itself thus causes the same symptoms on the same (ipsilateral ) side.