Common central vestibular impairments

What are the common central vestibular impairments?

1. Vestibular migraine or migrainous vertigo

This condition previously called migraine-associated vertigo or migraine-related vestibulopathy , is the most common central nervous system vestibular disorder and occurs in 1% of the general population and 11% of patients in specialized dizziness clinics.

It is an underrecognized cause of episodic vertigo and may affect a third of migraine patients.

For a diagnosis of vestibular migraine there are at least five episodes of moderate or severe intensity vestibular symptoms lasting 5 minutes to 72 hours, current or previous history of migraine with or without aura, and migraine features during half of the vestibular episodes and not better accounted for by another vestibular or headache diagnosis.

Another related condition, basilar-type migraine, commonly has vertigo, but requires at least two posterior circulation manifestations lasting between 5 and 60 minutes for the diagnosis. Basilar-type migraine is not synonymous with vestibular migraine.

An early manifestation, benign paroxysmal vertigo of childhood, requires five episodes of severe vertigo, occurring without warning and resolving spontaneously within minutes to hours with a neurologic exam and tests between episodes.

Vestibular migraine may present with positional vertigo, mimicking BPPV. The nystagmus in vestibular migraine during the acute phase is usually persistent and not aligned with a single semicircular canal.

Treatment includes the same medications used to treat migraine (triptans, beta-blockers, membrane channel agents, or acetazolamide) and control of dietary triggers, as well as vestibular rehabilitation for those with gait and balance complaints.

2. Multiple sclerosis (MS)

This condition can affect vestibular function, particularly when it affects brain stem tracts or nuclei.

True vertigo is estimated to occur in 20% of MS patients. Lesions affecting the vestibular nuclei and/or the root entry zone of cranial nerve VIII represent the most common locations where demyelinating activity can provoke vertigo in patients with MS.

However, other causes of vertigo should be explored in MS patients in order to avoid unnecessary treatment with corticosteroids and vestibular suppressants. One study of new onset vertigo in an MS population found that BPPV was the most common cause of vertigo in MS patients.

The patients diagnosed with BPPV were treated successfully with particle repositioning maneuvers, and the remaining patients were treated with conventional therapies appropriate for the specific diagnosis.

Multiple sclerosis of the brain stem often results in internuclear ophthalmoplegia affecting the medial longitudinal fasciculi or neighboring tracts, which can affect visual vestibular interaction (pursuit, cancellation, and vestibular smooth eye movements).

3. Seizures

This can cause vertigo if the vestibular cortex and other projection areas are involved, and have been called vertiginous epilepsy or epileptic vertigo . Vertigo can occur as part of the aura of temporal lobe seizures, but there are other associated aura symptoms and the patient is amnestic during the seizure.

Seizures involving the posterior insula (parieto-insular vestibular cortex), superior temporal gyrus, and temporoparietal cortex have been observed to result in vertigo.

Seizures involving the paramedian precuneus are involved in processing of static and dynamic vestibular otolithic information, hence the vertigo may be linear (to and fro or side to side) rather than rotatory.

Disequilibrium (epileptic dizziness) without vertigo has also been observed in aura from temporal lobe epilepsy.

Nystagmus has been observed in association with seizures or epileptiform discharges originating from the cortical areas involved in the generation of smooth pursuit and fast eye movements.

4. Cerebellopontine angle tumors

such as acoustic neuroma mentioned above may present with a peripheral nerve lesion or central lesion if nearby brain stem structures are compromised.

5. Cerebrovascular disease

including vertebrobasilar insufficiency can present with vertigo and vestibular impairment.

Acute vestibular syndrome is often due to vestibular neuritis but may result from posterior fossa (vertebrobasilar) stroke or ischemia affecting either brain stem or cerebellum.

Misdiagnosis of posterior fossa stroke in the emergency department is common. The three-step bedside oculomotor examination (HINTS: head-impulse, nystagmus, test-of-skew) may reliably identify stroke in acute vestibular syndrome.

The presence of normal horizontal head impulse test, direction-changing nystagmus in eccentric gaze, or skew deviation (vertical ocular misalignment) was 100% sensitive and 96% specific for stroke.

Skew deviation is associated with brain stem lesions.

Lateral medullary syndrome may cause vertigo, disequilibrium, nausea, and nystagmus as well as hoarseness, difficulty swallowing, and mixed sensory loss. Strokes (embolic, ischemic, and hemorrhagic) involving the vestibular cortex have resulted in vestibular symptoms including vertigo.

Acute rotatory vertigo has been seen following a small hemorrhage in the left medial temporal gyrus, presumably affecting the vestibular cortex.

Pusher syndrome is less common, but can result from a cerebrovascular accident (CVA) affecting the vestibular cortex.

Patients often feel they are being propelled or pushed. They may have impaired sense of subjective visual, vertical, ocular torsion, and skew deviation. This condition usually resolves quickly.

Although the acute symptoms may resolve quickly some patients have residual vertigo and disequilibrium. If so, those patients may be helped with vestibular rehabilitation.