Central Vertigo

Excerpt

Central vertigo is a clinical condition in which an individual experiences hallucinations of motion in their surroundings or a feeling of spinning even when stationary as a result of dysfunction of the vestibular structures in the central nervous system. The patient typically complains of dizziness with hallucinations or a sense of spinning. This condition differs from light-headed dizziness or presyncope, which is more commonly secondary to a global impairment of cerebral perfusion.

The peripheral vestibular system consists of the saccule, utricle, and semicircular canals. Neuroepithelial hair cells within the peripheral vestibular apparatus send projections to the vestibular nuclei in the caudal pons and rostral dorsolateral medulla by way of the vestibular division of the eighth cranial nerve (vestibulocochlear nerve). The vestibular nucleus on each side is divided into 4 sub-nuclei with 3 lateral nuclei and 1 medial nuclear column; they are labeled as the superior vestibular nucleus, lateral vestibular nucleus, medial vestibular nucleus, and descending vestibular nucleus. Some nuclei receive only primary vestibular afferents, but most receive afferents from the cerebellum, reticular formation, spinal cord, and contralateral vestibular nuclei. The projections from the vestibular nuclei extend to the cerebellum, extraocular nuclei, and spinal cord. With these neuroanatomic arrangements, it is easy to understand the functions of the vestibular system, for example, maintaining visual fixation through the vestibulo-ocular reflex when changing head and body positions in space and during extended or erect body posture. The maintenance of visual fixation also requires the normal function of the oculomotor central neural integrator, which consists mainly of the medial vestibular nucleus and the nucleus prepositus hypoglossi.

Any lesion affecting the vestibular nuclei or their projections, especially those to and from the cerebellum, results in symptoms of vertigo and associated signs of nystagmus.