Vertiginous dizziness: A primary care approach

Dizziness is an extremely common, yet complex neurological symptom that reflects a disturbance of normal balance perception and spatial orientation. Dizziness is a non-specific, catch-all term commonly used by patients to describe a wide array of symptoms, including a sensation of motion, weakness, light-headedness, unsteadiness, emotional upset and depression. The national 1-year prevalence of dizziness is around 50%, accounting for 4% of emergency department presentations and 1% of primary care consultations in South Africa. This article will focus on a diagnostic approach to the most common cause of dizziness (vertigo).


Time course
Carefully establishing the time course is the first step in hypothetico-deductive reasoning and pragmatic classification of vestibular syndrome (see syndromic approach to vertigo; Table 2) 2,3,4 .Vertigo is never continuous for more than a few weeks (although it may be episodic).Even if a permanent vestibular lesion exists, the CNS (other components of equilibrium -see Figure 1) adapts to accommodate for the defect. 2In situations where a patient has vertigo for longer than a week, the clinician should clearly establish whether the patient was actually spinning the entire time (if true, points more to central causes), or was having episodic spinning followed by imbalance.

Triggers and aggravators
At the outset, it is important to differentiate between postural presyncope and positional vertigo -both associated with dizziness upon standing: determine if the dizziness can be provoked when changing position of the head without lowering blood pressure (such as lying down, looking up and rolling over).All causes of vertigo are made worse by head motion. 3If this does not aggravate the dizziness, it is probably not vertigo. 4

Nausea and vomiting
Nausea and vomiting are typical features of acute vertigo, more common (and pronounced) in peripheral causes. 3The severity ranges from mild/brief (BPPV) to severe (such as Meniere's disease), potentially causing dehydration and electrolyte imbalance.

Nystagmus
The presence of nystagmus (although not always readily visible) is strongly suggestive of vertigo. 2 Some types of nystagmus are only seen after provocative manoeuvres (such as the Dix-Hallpike Manoeuvre or the lateral gaze test).Additionally, nystagmus can be unmasked in peripheral vertigo when you remove visual fixation (e.g. when wearing Frenzel lenses).The characteristics of the nystagmus can assist with differentiating peripheral from central causes (see Table 1). 1,2,3,4

Postural and gait instability
Postural and gait instability can be found in several causes of vertigo.Central causes, however, produce more pronounced symptoms (the vestibulospinal tract receives signals from the vestibular nuclei and in turn stimulates antigravity muscles for the maintenance of posture). 5

Other features
Other, less reliable features of vestibular dysfunction include: 2 • Tilt illusion ß Patients feel as if they and/or their environments are tilted with respect to gravity.ß Suggestive of otolith system dysfunction.
• Drop attacks ß Described as a sensation of being pushed or pulled to the ground.Not associated with faintness (presyncope) or loss of consciousness (seizures).

• Oscillopsia
ß Illusory to-and-fro motion of the environment with associated blurred vision when there is movement of the

A syndromic approach
Start by taking a standard history to identify and/or rule out toxic, metabolic and infectious causes.

Patient profile and risk factors play an important role in reaching an accurate diagnosis and informing your index of suspicion (i.e. elderly, hypertensive and smokers raise the suspicion of thromboembolic central causes, while a younger female with a history of migraines would be more indicative of vestibular migraine)
Use a syndromic approach (of three vestibular syndromes -Box 1) when taking a history. 4This facilitates targeted hypothetico-deductive reasoning using timing and triggers (see clinical features) to categorise the type of vertigo.

Physical examination
The physical examination is informed by the classification of the presentation into each of the vestibular syndromes.

Acute vestibular syndrome (AVS)
• Perform a head impulse, nystagmus, and test of skew (HINTS) exam: head impulse test (HIT), nystagmus testing, and testing for skew deviation (alternate cover

Spontaneous-episodic vestibular syndrome (s-EVS)
• By definition, the patient is asymptomatic, and dizziness cannot be triggered at the bedside. 4

Workup
Further workup and/or the need for referral is guided by the syndromic categorisation and suspected disease process.
In AVS, patients with characteristic nystagmus, absent skew deviation, a normal HIT, and a normal neurologic exam (including, cranial nerve, cerebellar and gait testing) need no further workup and can be treated for vestibular neuritis and/ or labyrinthitis. 4 t-EVS, patients with a positive positional manoeuvre (Dix-Hallpike or Supine roll) do not need any workup and can be treated for BPPV (Epley manoeuvre or Gufoni manoeuvre).Patients with t-EVS who are orthostatic need referral for testing for the cause of the orthostasis (dysautonomia, postural orthostatic tachycardia syndrome, etc.).
Patients with spontaneous episodic vestibular syndrome (s-EVS) need a TIA workup, unless vestibular migraine is likely, and/or previously diagnosed. 1,3

TABLE 1 :
Features of peripheral and central vertigo.
Abnormal tympanic membraneMay occur Seldomly occurs -not a primary feature Postural instability Less pronounced.Usually unidirectional instability with preserved walking Severe instability -patient often falls when walking CNS symptoms and/or signs Absent Usually present Diplopia, ataxia, dysarthria dysphasia, focal or lateralised weakness Source: Please see the full reference list of the article Vertigo -Diagnosis and management in primary care.Br J Med Pract [serial online].[cited2022 Dec 13].Available from: https://www.bjmp.org/content/vertigo-diagnosis-and-management-primary-care,for more information CNS, central nervous system; BPPV, benign paroxysal positional vertigo.FIGURE 1: Systems responsible for regulating balance (equilibrium).

TABLE 2 :
Common conditions in the vestibular syndromes.Most patients with vestibular neuritis can ambulate, while most with a central cause cannot ß If the patient is too nauseous to walk, test for truncal ataxia (strongly suggestive of a central cause) Dix-Hallpike will be positive on one side (provoked or triggered symptoms, and usually up-beating torsional nystagmus) and negative on the other side ß If Dix-Hallpike is bilaterally negative, test the horizontal canals by doing the supine head roll test -in the supine head roll, both sides will be positive but one will be much more intense.
Source: Please see the full reference list of the article Schaider JJ, Hayden SR, Wolfe RE, Barkin AZ, Shayne P, Rosen P. Rosen & Barkin's 5-minute emergency medicine consult [