Dizziness and vertigo diagnosis

Dizziness is a broad term used by patients to describe a range of sensations that include vertigo, gait ataxia and presyncope. Vertigo is an illusion of motion and is usually rotatory (ie a spinning sensation), but sometimes linear (ie a sense of falling or pitching). Autonomic symptoms (eg nausea, retching, vomiting, pallor, sweating) often accompany vertigo.

Vertigo is often due to pathology of one of the inner ear balance organs, causing hypofunction (eg vestibular neuritis) or hyperfunction (eg benign paroxysmal positional vertigo). Peripheral features suggest inner ear pathology (see Clinical features differentiating peripheral and central causes of vertigo for the clinical features that differentiate peripheral from central causes of vertigo). Acoustic neuromas and acute middle ear infections rarely cause vertigo. Central causes of vertigo (ie neurological disorders that affect vestibular pathways in the brain stem, cerebellum and cortex) other than vestibular migraine are uncommon. However, suspect a central cause (eg multiple sclerosis, vertebrobasilar ischaemia, tumour) if the patient has other neurological or central features.

Table 1. Clinical features differentiating peripheral and central causes of vertigo
[NB1]
Peripheral features	Central features
hearing loss tinnitus aural fullness positive head impulse test	gait ataxia out of proportion to extent of vertigo visual field loss diplopia hemisensory loss limb weakness and ataxia slurred speech (dysarthria) difficulty swallowing (dysphagia) eye movement abnormalities (direction-changing nystagmus, skew deviation)
Note: NB1: For advice on bedside assessment of vertigo (including eye movement abnormalities and the head impulse test), see Welgampola MS, Bradshaw AP, Lechner C, Halmagyi GM. Bedside assessment of acute dizziness and vertigo. Neurol Clin 2015;33(3):551-64, vii. [URL]

Vertigo is classified according to clinical syndromes, and may be spontaneous (present when the head is stationary) or motion-induced (present only when the head is moving)—spontaneous forms of vertigo are also worse with head movement. Further differential diagnosis is based on duration, periodicity and associated features (see summary in Differential diagnosis of vertigo ). Episodic spontaneous vertigo attacks are usually due to Ménière disease or vestibular migraine. In unexplained episodic vertigo, especially without the auditory symptoms that suggest another cause (eg Ménière disease), an empirical trial of migraine prophylaxis may be considered.

Figure 1. Differential diagnosis of vertigo .
[NB1]

Vertigo caused by acute unilateral loss of vestibular function (eg vestibular neuritis) is mostly self-limiting—it improves over hours to days due to central vestibular compensation, even when peripheral vestibular function has not recovered. Some patients still have motion-induced dizziness after the acute vertigo resolves, due to incomplete compensation (see uncompensated peripheral vestibular lesion).

Dizziness can also be due to drugs, postural hypotension and other medical disorders. It can be a somatic symptom in primary psychiatric disorders (eg panic disorder, agoraphobia). Chronic intractable dizziness can occur in persistent postural-perceptual dizziness.