Cranial Nerve VIII, The Vestibulocochlear Nerve
Cranial Nerve VIII is tested by assessing gross hearing. This can be done by simply talking to the patient or determining if patient can hear sound of fingers rubbing together by ears. If decreased hearing is suspected, a Weber tuning fork test (512 Hz tuning fork placed on forehead or against incisors) will lateralize to the affected side in conductive hearing loss and will lateralize to the unaffected side in sensorineural hearing loss. In conductive hearing loss, the Rinne tuning fork test (512 Hz tuning fork placed first on mastoid process, then brought in front of, but not touching, ear) will demonstrate bone conduction greater than air conduction in the affected ear. Although warm and cold calorics and special diagnostic maneuvers can be used to assess the vestibular apparatus, they are not generally performed unless specifically warranted.