Which vestibular pathway descends ipsilaterally to the ventral horn of the spinal cord?

• A. Medial vestibular pathway
• B. Lateral vestibular pathway
• C. Corticospinal tract
• D. Tectospinal tract

Answer: (B)

The lateral vestibular pathway handles vestibular control of posture by sending signals down to the spinal cord on the same side. It begins in the lateral vestibular nucleus in the brainstem and descends ipsilaterally through the ventral (anterior) funiculus to the ventral horn, where it mainly facilitates extensor motor neurons to help maintain upright posture when the head moves. This ipsilateral descent to the ventral horn differentiates it from other vestibular paths. The medial vestibular pathway, in contrast, descends bilaterally via the medial longitudinal fasciculus to cervical and upper thoracic levels, coordinating head and neck movements with gaze. The corticospinal tract and tectospinal tract are not vestibular pathways. Therefore, the lateral vestibular pathway is the one that descends ipsilaterally to the ventral horn of the spinal cord.