Vestibular paroxysmia: brief vertigo attacks

The eighth cranial nerve carries signals from the inner ear to the brain, both for balance and for hearing. In vestibular paroxysmia the nerve is irritated where it leaves the brainstem, so that it fires abnormally for a few seconds at a time.

A review by vertigo specialists says the leading symptoms are recurrent, spontaneous, short attacks of spinning or non-spinning vertigo that generally last less than a minute and can occur in a series. They explain that arteries in the cerebellopontine angle can cause pressure-induced dysfunction of the nerve. A loop of the anterior inferior cerebellar artery seems to be most often involved.

The mechanism is compared with trigeminal neuralgia and hemifacial spasm, in which blood vessels pressing on other cranial nerves cause short bursts of pain or twitching.

A systematic review describes frequent short attacks of vertigo and dizziness with unsteadiness that last seconds to minutes. They may be accompanied by one-sided ear symptoms such as tinnitus or hyperacusis. Head movements and hyperventilation can bring on attacks, though most occur spontaneously.

In one study of 146 people, attacks ranged from 5 to 30 a day, and the review notes that in extreme cases up to 70 attacks a day can occur. About two-thirds of attacks were spontaneous and a quarter were triggered by head movements. Most people had no accompanying symptoms, while 20 to 30% had mild one-sided hearing symptoms.

• Very short bouts of spinning or swaying, often over in seconds.

• Unsteadiness of stance or gait during the attack.

• Ringing, muffled hearing or sound sensitivity in one ear, occasionally.

• Attacks that may be set off by turning the head or by rapid breathing.

Vertigo has many causes, and most are not serious. The NHS says to see a GP if vertigo will not go away or keeps coming back. It advises an urgent GP appointment or NHS 111 if you have vertigo with a severe headache, are being sick or feel very sick, or have a very high temperature.

The NHS says to call 999 or go to A&E if you have vertigo with double vision or loss of vision, hearing loss, trouble speaking, or leg or arm weakness, numbness or tingling. Sudden severe hearing loss with vertigo, or any signs of stroke, should not wait for an outpatient appointment. If you drive, the NHS says you must tell the DVLA about your vertigo.

The reviews describe three forms. Classical vestibular paroxysmia results from neurovascular cross-compression of the nerve. Secondary forms arise from space-occupying processes such as tumours or cysts, or a narrow internal auditory canal. Idiopathic cases have no verified cause.

The systematic review gives a mean age at first appearance of 47 to 51 years with equal sex distribution, and says it very rarely affects children. An earlier review suggests two age peaks and says the course is generally chronic, though the compression syndrome may sometimes resolve spontaneously.

The Bárány Society, the international society for neuro-otology, set diagnostic criteria in 2016. Definite vestibular paroxysmia requires at least 10 attacks of spontaneous spinning or non-spinning vertigo, lasting under a minute, with the same pattern each time, a response to a sodium channel blocker, and no better explanation. Probable vestibular paroxysmia needs at least 5 attacks lasting under 5 minutes.

High-resolution MRI of the area around the nerve can show a vessel in contact with it, and the earlier review says compression is seen in more than 95% of cases. However, the systematic review says MRI findings support rather than prove the diagnosis, and that the response to a sodium channel blocker is the most reliable clinical sign. Imaging is also needed to exclude tumours or other causes.

Doctors also consider benign positional vertigo, Ménière's disease, vestibular migraine and other causes of episodic vertigo, which the NHS lists among common causes of vertigo.

The reviews describe sodium channel blockers as the treatment of choice, in particular carbamazepine or oxcarbazepine, usually at low doses. Lacosamide is also named. Other drugs used for trigeminal neuralgia may be tried if these are not suitable. Dose and drug choice are decisions for a specialist, since these medicines need monitoring and have side effects.

Both reviews note that randomised trials of treatment are still needed. Microsurgical decompression of the eighth nerve is described as the last resort for people who cannot tolerate or do not respond to medicine, and as an effective treatment where a tumour or cyst is the cause.

Many people improve substantially on medicine, and the reviews describe it as a treatable condition. The course is generally chronic, so some people need treatment for a long time, and some find it can be reduced later under specialist guidance.

During a spell, the NHS advice for vertigo applies: lie still in a quiet, dark room, move your head carefully, sit down when you feel dizzy, and avoid bending or stretching the neck. Because attacks are brief and unpredictable, practical precautions around stairs, driving and work are worth discussing with your doctor.

On the NHS, people with repeated brief vertigo are usually seen by a GP and referred to ENT, neurology or a balance clinic, with MRI as needed. Rare conditions like this can take time to diagnose.

A private ENT or neuro-otology consultation may help with quicker MRI and expert interpretation. Ask whether an MRI of the nerve has been done, how the attacks fit the diagnostic criteria, and what monitoring the medicine needs.