Vestibular neuritis is a disorder characterised by acute, isolated, spontaneous, and prolonged vertigo of peripheral origin. The terms 'vestibular neuritis' and 'labyrinthitis' have been used interchangeably in the past but:
- Vestibular neuritis is thought to be due to inflammation of the vestibular nerve.
- Labyrinthitis is a different diagnosis that involves inflammation of the labyrinth. Hearing loss is a feature of labyrinthitis, but hearing is not affected in vestibular neuritis.
Diagnosis
Most cases follow a recent viral illness (for example an upper respiratory tract infection). Men and women are equally affected, and onset occurs most commonly at 30–60 years of age.
Symptoms:
- Rotational vertigo occurs spontaneously, may be sudden, develop on waking, or may worsen over the course of the day. It is exacerbated by changes of head position, but is initially constant even when the head is still. Acute symptoms usually settle in a few days and gradual recovery occurs over 2–6 weeks.
- Nausea (and often vomiting) occur, often with other autonomic symptoms such as malaise, pallor, and sweating.
- Balance may be affected, increasing the risk of falls. People with vestibular neuritis may be unsteady and veer to the affected side.
- Hearing loss and tinnitus are not features of vestibular neuritis (but may be present in labyrinthitis).
- There are no focal neurological symptoms.
Signs:
- Nystagmus is present and is usually fine horizontal but may be mixed horizontal-torsional with the fast phase away from the affected ear. It always beats in the same direction (unidirectional), even if the head is rotated, and is reduced when the vision is fixed on a point.
- The head impulse test may be positive (but it may also be positive for other peripheral causes of vertigo and so cannot be used to differentiate between them). It is useful for helping to differentiate vestibular neuritis from a central lesion.
- Hearing and otoscopy are normal on examination.
Vestibular neuritis is a clinical diagnosis — a careful history and examination are all that is usually required. Investigations are not usually necessary, unless another cause of vertigo is suspected.
Management
Patient advice
- Reassure the person that symptoms will usually settle over several weeks, even if no treatment is given. Advise that factors such as alcohol, tiredness, or intercurrent illness may have a greater than usual effect on their balance. Explain that there may be periods during their recovery when their symptoms appear to be worsening again.
- Advise that bed rest may be necessary if symptoms are particularly severe during the acute phase, but that activity should be resumed as soon as possible (even if vertigo becomes more prominent during movement).
- Advise the person not to drive when they are dizzy, or if they are likely to experience an episode of vertigo while driving.
Treatment
- If symptoms are severe, offer short-term symptomatic drug treatment.
- To rapidly relieve severe nausea or vomiting associated with vertigo, consider giving buccal prochlorperazine, or an intramuscular injection of prochlorperazine or cyclizine.
- To alleviate less severe nausea, vomiting, and vertigo, consider prescribing a short oral course of prochlorperazine, or an antihistamine (cinnarizine, cyclizine, or promethazine teoclate).
- Advise the person to take medication regularly for up to 3 days. Explain that medication should be taken for the minimum time possible, as it may delay recovery by affecting the body's compensatory mechanisms.
- Consider hospital admission if they have severe nausea and vomiting and cannot tolerate oral fluids or symptomatic drug treatment.
Prognosis
Although the severe initial symptoms usually last 2–3 days, people with vestibular neuritis usually recover gradually over a period of weeks through a process of central nervous system compensation. Benign paroxysmal positional vertigo (BPPV) can develop following vestibular neuritis in around 1 in 10 people.