Chief Sensory Nucleus of V
Principal sensory nucleus of the trigeminal nerve; Principal sensory nucleus of V
Nucleus responsible for proprioceptive feedback from the muscles of facial expression, stereognosis or fine tactual discrimination, and vibratory sensations from the face. Located in the dorsolateral pons just medial to the middle cerebellar peduncle and inferior to the superior cerebellar peduncle, it is the functional equivalent of the nuclei cuneatus and gracilis in the medulla, which mediate similar input from the trunk and extremities. It gives rise to trigeminothalamic fibers, which terminate in the ventral posterior medial nucleus of the thalamus.
Because of its size and density, it is rare for brainstem lesions to be isolated to a single nucleus or pathway. Theoretically, lesions which involve this nucleus might most readily be distinguished on a routine neurological exam by changes (asymmetries) in two-point discrimination on the ipsilateral face. In...