Central Vertigo

Definition and epidemiology

Central vertigo covers conditions in which vertigo arises from the vestibular nuclei of the brainstem, the cerebellum or the pathways linking them to the cerebral cortex. In peripheral vertigo the problem lies in the inner ear or vestibular nerve. The most important clinical picture is the acute vestibular syndrome (AVS): sudden vertigo lasting days, with nausea or vomiting, head-motion intolerance, nystagmus and gait unsteadiness. Although the commonest cause of AVS is peripheral vestibular neuritis or labyrinthitis, about 25±15% of cases are due to stroke (Tarnutzer et al., 2011).

The main causes of central vertigo are posterior circulation (vertebrobasilar) stroke and transient ischaemic attacks, brainstem and cerebellar haemorrhage, multiple sclerosis (MS), posterior fossa tumours and vestibular migraine. In the United States stroke is the cause in 3-4% of emergency department visits for dizziness or vertigo, and in large prospective studies dizziness is among the presenting symptoms in 47-75% of patients with posterior circulation stroke (Kim et al., 2022). Vestibular migraine affects 1-2.7% of the population and accounts for about 11% of patients seen in specialised dizziness clinics (Lempert et al., 2022).

Symptoms and signs

Central vertigo may appear as sudden, continuous vertigo or, in transient ischaemic attacks, as recurrent attacks lasting minutes. Accompanying neurological symptoms help the diagnosis: slurred speech (dysarthria), double vision, difficulty swallowing, facial numbness, clumsiness or weakness of an arm or leg, and severe truncal ataxia that prevents sitting or standing. These are not always present, however: about two thirds of AVS patients with stroke have no focal neurological sign that a non-neurologist would readily recognise (Tarnutzer et al., 2011). In one cohort, 26% of 132 patients with posterior circulation stroke presented with isolated vestibular symptoms, and in 67.6% of these the lesion lay in the cerebellum, mostly in the medial PICA territory (Kim et al., 2022).

Eye signs are discriminating. Direction-changing gaze-evoked nystagmus, pure vertical (downbeat or upbeat) or pure torsional nystagmus, nystagmus not suppressed by fixation, vertical misalignment of the eyes (skew deviation), impaired smooth pursuit and inaccurate saccades suggest a central lesion. Because the labyrinthine artery that supplies the inner ear usually arises from the AICA, vertigo in AICA stroke may come with sudden hearing loss and tinnitus, and recurrent vertigo with fluctuating hearing loss or tinnitus may precede AICA infarction by 1-10 days (Kim et al., 2022). New moderate to severe head or neck pain suggests vertebral artery dissection and, in one study, markedly increased the likelihood of stroke (Kim et al., 2022).

Causes and risk factors

The posterior circulation comprises the vertebral and basilar arteries with the posterior inferior cerebellar artery (PICA), anterior inferior cerebellar artery (AICA) and superior cerebellar artery. Occlusion of these vessels causes brainstem and cerebellar infarction; with lateral medullary involvement (Wallenberg syndrome) vertigo is a typical feature. About 5% of strokes in the AICA territory present with prolonged vertigo and canal paresis without hearing loss, a picture that may be indistinguishable from vestibular neuritis (Kim et al., 2022). Older age, hypertension, diabetes, smoking, atrial fibrillation and previous stroke or transient ischaemic attack are the main risk factors, so vascular vertigo should be strongly suspected in an AVS patient with an ABCD2 score of 4 or more or atrial fibrillation (Kim et al., 2022).

Among non-vascular causes, multiple sclerosis plaques come first: a plaque at the root entry zone of the vestibular nerve or in the vestibular nuclei can mimic a peripheral vestibular disorder. Posterior fossa tumours, cerebellopontine angle masses and haemorrhages usually present with more gradually developing unsteadiness. Vestibular migraine causes at least five moderate or severe vestibular episodes lasting 5 minutes to 72 hours, with migraine features during the episodes (Lempert et al., 2022). Vertebrobasilar transient ischaemic attack must be distinguished from vestibular migraine, particularly in older people with vascular risk factors and attacks of sudden onset recurring over less than a year (Lempert et al., 2022).

Audiological and clinical assessment

The HINTS examination (Head Impulse, Nystagmus, Test of Skew), developed to distinguish stroke from a peripheral cause in AVS, consists of three bedside tests. A central result on any one of them is regarded as dangerous for stroke (Kattah et al., 2009):

• Head impulse test: in AVS, a normal horizontal head impulse test, with no corrective (catch-up) saccade, is a central sign. In a peripheral lesion a catch-up saccade follows a rapid head turn towards the affected side. Of the three components, this sign best discriminates central causes (Kim et al., 2022).
• Nystagmus: direction-changing gaze-evoked nystagmus is a central sign. In a peripheral lesion nystagmus is unidirectional, horizontal-torsional, increases on gaze towards the fast phase and is suppressed by fixation.
• Test of skew (alternate cover test): a vertical refixation movement as each eye is covered in turn indicates skew deviation and is associated with brainstem lesions (Kattah et al., 2009).
• HINTS-plus: adds an assessment for new hearing loss (finger rub test) to HINTS. In AICA stroke the head impulse test may be abnormal because the labyrinth is involved, so hearing assessment matters; in one study HINTS was negative in 5 of 17 patients with AICA stroke (Kim et al., 2022).
• Gait and truncal ataxia: inability to sit or stand unsupported suggests a central lesion.

In 101 high-risk AVS patients, HINTS detected stroke with 100% sensitivity and 96% specificity, whereas initial diffusion-weighted MRI (DWI) was falsely negative in 12% of cases in the first 48 hours (Kattah et al., 2009). In a systematic review the pooled sensitivity of HINTS was 98% and specificity 85%; DWI-MRI in the first 24 hours had a sensitivity of about 80%, and up to one in five posterior fossa strokes may be missed in the first 24-48 hours (Tarnutzer et al., 2011). In small strokes (10 mm or less) the false-negative rate of early MRI rises to 53% (Kim et al., 2022). In a study of 190 patients, HINTS-plus detected any central lesion with 99.2% sensitivity and 97.0% specificity, whereas the sensitivity of the ABCD2 score for stroke was only 61.1% (Newman-Toker et al., 2013).

These results come from experienced examiners, and HINTS applies only to AVS patients with ongoing nystagmus; it is not used when vertigo has resolved, when dizziness is positional or when there is no nystagmus. In transient vestibular syndromes the signs have usually gone by the time of examination, so HINTS has a limited role (Kim et al., 2022). In audiological assessment, the video head impulse test (vHIT) can document the head impulse finding objectively. On videonystagmography, abnormal smooth pursuit, saccade and optokinetic tests support a central lesion, and caloric testing is usually normal. Pure-tone audiometry shows any sensorineural loss accompanying AICA stroke. On positional testing, pure downbeat nystagmus that starts without latency and does not fatigue suggests central positional nystagmus and must be distinguished from BPPV. When a red flag is found, testing stops and the patient is sent to the emergency department. For a general overview, see an introduction to vertigo and balance disorders.

Treatment and audiological rehabilitation

Treatment of central vertigo is directed at the cause, and decisions rest with neurology, neurosurgery and emergency medicine. Acute ischaemic stroke is a time-critical emergency: treatments to reopen the blocked vessel can only be given within certain time limits in suitable patients, so diagnosis must not be delayed. Oedema after cerebellar infarction or haemorrhage, with compression of the brainstem, may require intensive monitoring and sometimes surgery. After discharge, treatment of blood pressure, glucose, cholesterol and heart rhythm disorders and antithrombotic medication are planned by the doctor to reduce the risk of another stroke.

In multiple sclerosis, relapse treatment and disease-modifying therapy are managed by neurology; posterior fossa tumours are treated with surgery or radiotherapy by neurosurgery and oncology. In vestibular migraine, lifestyle measures, attack treatment and, where needed, preventive medication are planned with the doctor.

For unsteadiness and gait disturbance remaining after the acute phase, vestibular rehabilitation and physiotherapy are used. Because central lesions can affect the compensation mechanisms themselves, recovery may be slower and less complete than after peripheral lesions; the programme is tailored to the person’s falls risk and accompanying neurological signs. The audiologist seeing a dizzy patient in clinic must recognise red flags and refer urgently:

• Sudden, persistent vertigo with slurred speech, double vision, difficulty swallowing, or numbness or weakness of the face or limbs.
• Inability to sit or stand unsupported.
• In AVS, a normal head impulse test, direction-changing or pure vertical or torsional nystagmus, or skew deviation.
• Sudden hearing loss with vertigo in a person with vascular risk factors (see sudden hearing loss).
• New moderate to severe head or neck pain.
• Recurrent brief attacks of vertigo over recent days (possible transient ischaemic attack).

Impact on quality of life and advice

Vertigo due to stroke or another central cause can affect daily life well beyond the acute phase through persistent unsteadiness, fear of falling and fatigue. Driving, using stairs and walking in crowds may become difficult, and returning to work can take time. In multiple sclerosis the fluctuating course, and in vestibular migraine the unpredictability of attacks, can cause anxiety.

Practical advice: take your prescribed medicines regularly and keep up with blood pressure, glucose and cholesterol checks; stop smoking. Do your vestibular rehabilitation exercises every day and share your progress with your physiotherapist. To prevent falls at home, use night lighting, remove loose rugs and have grab rails fitted in the bathroom. Ask your doctor when you can return to driving. If sudden vertigo, slurred speech, weakness or visual problems recur, call emergency services immediately, and make sure the people close to you know these warning signs.