Physical Exam

A full head and neck with otologic and cranial nerve exam is performed. Neurologic exam can also give insight into central causes of dizziness. Use of Frenzel goggles can help accentuate nystagmus on exam by removing visual fixation. Physical exam should include evaluation of spontaneous, gaze, and headshake nystagmus. Gait is assessed for ataxia and wide stance. Romberg and Fukuda stepping tests are done to evaluate for sway. A Dix-Hallpike test will assess presence of posterior canalolithiasis. Cerebellar testing (such as finger-to-nose) can test for dysmetria and tremor. A head impulse test can demonstrate catch-up saccades. Proprioception of upper and lower extremities can be assessed with a tuning fork. Mobility of the neck (e.g., cervicogenic dizziness) and vertebral artery (e.g., vertebral artery stenosis) should be tested as well.

Basic Balance Testing

Other Tests

An audiologic evaluation should be conducted when a balance disorder is suspected to be vestibular in origin.

Pathology

Balance disorders can be caused by disorders of the peripheral vestibular system or the central vestibular system, systemic issues with parts of the body other than the head and brain, and vascular disorders. Peripheral vestibular system issues can be caused by Ménière′s disease, labyrinthitis, BPPV, perilymphatic fistula, vestibular neuritis (VN), ototoxicity, vestibular schwannomas, superior canal dehiscence syndrome (SCDS), autoimmune disease, and other disorders. Central vestibular system issues can be caused by migraine, hydrocephalus, brain tumors, multiple sclerosis, cerebrovascular disease including transient ischemic attack or stroke, stress, tension, fatigue, vision disturbances, and other disorders. Systemic issues can include peripheral neuropathies, hyperventilation, and dehydration. Vascular disorders can include orthostatic hypotension, arteriosclerosis, vertebral artery stenosis, and vasovagal syndrome. Cervicogenic dizziness can occur after neck injury or in association with neck pain.

Signs

In posterior canalolithiais, upbeating, geotropic rotatory nystagmus is noted when a patient is placed in the Dix-Hallpike position. There may be a short latency (delay) in the onset of nystagmus, and the duration is brief (less than 1 minute). Nystagmus reverses upon sitting upright (i.e., downbeating, ageotropic rotary nystagmus). The response fatigues with repetition. In horizontal canalolithiasis, geotropic or ageotropic nystagmus is demonstrated on supine roll test. In anterior canalolithiasis, downbeating torsional nystagmus toward the affected ear can be seen during Dix-Hallpike; it is controversial whether anterior canalolithiasis is a true entity.

Symptoms

The patient experiences a spinning sensation that lasts less than a minute, which is associated with head movement, most often when bending forward, looking upward, or lying down and rolling from one side to another. Patients may also have mild, generalized imbalance. Symptoms may also include nausea and vomiting.

Differential Diagnosis

Most diagnoses can be eliminated on history alone. The differential diagnosis for dizziness lasting seconds includes perilymphatic fistula, BPPV, vertebrobasilar insufficiency, superior semicircular canal dehiscence, and cervicogenic dizziness. Dizziness lasting hours can suggest endolymphatic hydrops, Ménière′s disease, and vestibular migraine. When symptoms last for days, labyrinthine concussion, labyrinthitis, and vestibular neuritis are suspected. Dizziness lasting months may indicated a retrocochlear mass, vestibulotoxicity, or cerebellar disorder. Central etiologies such as stroke and multiple sclerosis can also present with dizziness.

Physical Exam

A full neurotologic exam should be performed. A basic vestibular exam is described in Chapter 3.6.1.

Imaging

Patients with positioning nystagmus suggestive of canalolithiasis do not typically require imaging. Computed tomography (CT) of the temporal bones may be useful in evaluating other causes of dizziness, such as superior semicircular canal dehiscence or temporal bone trauma. Magnetic resonance imaging (MRI) of the brain with and without gadolinium may be useful in ruling out intracranial process or retrocochlear mass.

Labs

Laboratory evaluation is not useful in the diagnosis of BPPV.

Other Tests

Other causes of vertigo may be evaluated with electronystagmography or videonystagmography, vestibular evoked myogenic potentials, rotary chair, and posturography. Tullio phenomenon and Hennebert sign for fistula can also be performed. Audiologic testing is obtained in vestibular symptoms other than BPPV.

Pathology

Cadaveric temporal bone dissections and labyrinthine operations performed in patients with symptoms of BPPV have demonstrated the presence of small calcium crystals (thought to be displaced otoconia from the saccule or utricle) within the posterior semicircular canal. Changing head position causes movement of otoliths within the canal, inducing motion of the cupula. There has also been speculation that cupulolithiasis (presence of otolithic crystals trapped on the cupula) plays a role in some cases. The most common canal affected is the posterior semicircular canal. The second most common canal is the horizontal canal.

Medical

For posterior canal BPPV, the Epley repositioning maneuver is the mainstay of treatment, with success rates exceeding 90% ( Fig. 3.12 ). This maneuver entails performing a Dix-Hallpike maneuver to elicit vertigo. Following cessation of vertigo, the patient′s head is rotated 90° to the unaffected side. After 45 to 60 seconds, the head is then turned 90° further by having the patient lie on his or her side, such that the face is toward the floor. The patient is then brought back to the upright position with his or her chin tucked to the chest. Each of these positions can be kept for approximately one minute. The canaliths are ultimately repositioned in the vestibule away from sensory epithelium. This procedure may be repeated as needed for relapses or refractory cases. Following the Epley, patients are instructed not to lie flat or assume any provoking position for a few days. Habituation exercises such as Brandt-Daroff exercises can be prescribed for relapsing cases or patients who cannot tolerate the Epley maneuver in the office. The Semont maneuver is an alternative repositioning maneuver for posterior canal BPPV.

Lateral canal BPPV can be treated with the barbecue roll (logroll), Gufoni, or Vannucci maneuvers. Anterior canal BPPV can be treated with an Epley maneuver on the opposite ear or modifications of the Semont maneuver. Habituation exercises can also be prescribed. Referral to vestibular therapy may be necessary when maneuvers cannot be performed in the office (e.g., cervical disease or reduced mobility).