Persistent Postural Perceptual Dizziness

A chronic functional vestibular disorder characterised by persistent non vertiginous dizziness and unsteadiness lasting three months or longer, exacerbated by upright posture, active or passive motion, and exposure to complex or moving visual environments. It unifies and replaces the older concepts of phobic postural vertigo, space and motion discomfort, visual vertigo and chronic subjective dizziness.

Pathophysiology

Following an acute vestibular insult, the brain adopts a high risk postural control strategy with increased reliance on visual and somatosensory input and stiffened postural responses. In most people this reverts to normal as recovery proceeds. In persistent postural perceptual dizziness it becomes fixed. There is a shift toward visual dependence, a failure to reweight sensory inputs appropriately, and altered connectivity between vestibular cortical areas, visual cortex and anxiety related networks including the amygdala and insula, with reduced activity in vestibular cortex and increased visual cortical processing.

This is a genuine disorder of function, not a psychiatric diagnosis and not malingering. It should be explained to patients as a software problem rather than a hardware problem, since patients frequently arrive having been told there is nothing wrong.

Precipitants

• Vestibular neuritis and labyrinthitis, in around 25 percent.
• Benign paroxysmal positional vertigo, including after successful repositioning.
• Vestibular migraine, in around 15 to 20 percent.
• Panic attacks and generalised anxiety, in around 15 percent.
• Concussion and whiplash.
• Cardiac arrhythmia, syncope and orthostatic intolerance.
• Adverse drug reactions.

Pre existing anxiety, neuroticism and a tendency to bodily vigilance increase the risk of the acute insult becoming chronic.

Diagnostic criteria require all of the following

• Dizziness, unsteadiness or non spinning vertigo present on most days for 3 months or more, with symptoms lasting for prolonged periods that may wax and wane in severity.
• Symptoms occur without specific provocation but are exacerbated by upright posture, active or passive motion regardless of direction, and exposure to moving or complex visual stimuli.
• Precipitated by a condition causing vertigo, unsteadiness or balance disruption.
• Causes significant distress or functional impairment.
• Not better accounted for by another disease.

Typical description

• Constant background dizziness, described as swaying, rocking, floating, or a sense of being on a boat, rather than spinning.
• Worse on standing and walking, better when lying down or when moving with a clear task and purpose, which patients notice as being better when distracted.
• Marked worsening in supermarkets, shopping centres, busy streets, crowds, on escalators, when scrolling on a phone, watching action films, and in environments with patterned floors or striped surfaces.
• Symptoms fluctuate through the day, typically worse as the day progresses and worse under stress or fatigue.
• Discrete attacks of true rotational vertigo do not occur, and their presence indicates a coexisting active condition.
• Avoidance behaviours develop: avoiding shops, public transport, driving, exercise and social activity, producing deconditioning and reinforcing the disorder.
• Anxiety and depression are common but are not required for the diagnosis. Where they coexist they perpetuate the symptoms.

Examination

• Neurological and vestibular examination is normal or shows only residual findings of the precipitating condition that do not explain the current disability.
• Patients frequently have a stiff, cautious, wide based gait with reduced arm swing, which improves markedly when they are distracted by a cognitive task. This distraction effect is a useful clinical sign.
• Romberg may appear positive with excessive sway that reduces on distraction.

This is a positive clinical diagnosis based on the criteria, not a diagnosis of exclusion. Endless further investigation is itself harmful, reinforcing the patient's conviction that a serious undiagnosed disease is present.

• Detailed history establishing the precipitant, the chronicity, and the three exacerbating factors, which are the diagnostic core.
• Full neurological, oculomotor and vestibular bedside examination including head impulse, nystagmus assessment, test of skew, Dix Hallpike and supine roll tests.
• Pure tone audiometry.
• Vestibular function testing, which may show residual abnormality from the precipitating event. Abnormal test results do not exclude the diagnosis, and normal results do not confirm it.
• Magnetic resonance imaging where there are red flags or where it has not already been done for the precipitating condition. Repeated imaging in the absence of new features is counterproductive.
• Orthostatic blood pressure measurement and electrocardiogram to exclude orthostatic and cardiac causes.
• Screen actively for coexisting and treatable conditions, since persistent postural perceptual dizziness frequently coexists with benign paroxysmal positional vertigo and vestibular migraine. Any untreated coexisting condition will prevent recovery.
• Validated questionnaires such as the Dizziness Handicap Inventory and the Niigata PPPD Questionnaire for baseline severity and response monitoring.
• Screen for anxiety and depression.

Differential diagnosis

• Uncompensated unilateral vestibular loss, which improves with vestibular rehabilitation and shows head movement provoked rather than visual environment provoked symptoms.
• Vestibular migraine, which produces discrete episodes with migraine features, and which frequently coexists.
• Bilateral vestibulopathy, with oscillopsia, bilaterally positive head impulse and objective test abnormality.
• Orthostatic hypotension and postural orthostatic tachycardia syndrome, distinguished by the relation to standing and by haemodynamic measurement.
• Cerebellar disease and neurodegenerative disorders, with objective neurological signs.
• Medication effects.
• Anxiety and panic disorder, which may be primary rather than secondary.

Four components: explanation, vestibular rehabilitation, medication, and cognitive behavioural therapy. Combining them works better than any alone.

Explanation, which is the foundation and takes time

• Give the diagnosis a name and explain the mechanism: after the original problem, the balance system stayed on high alert, relying too heavily on vision and stiffening posture, and this pattern became habitual.
• State explicitly that the symptoms are real, that the condition is recognised and treatable, and that it is not imagined, not psychiatric in origin, and not a sign of undiagnosed serious disease.
• Explain that further scans are not needed and that repeated testing perpetuates the problem.
• Explain that avoidance behaviour worsens the condition and that gradual re exposure is the treatment.
• Patients who accept the explanation do markedly better. Time spent here determines the success of everything that follows.

Vestibular rehabilitation, adapted for this condition

• Habituation exercises with graded exposure to provoking movements and environments.
• Optokinetic and visual desensitisation training, using moving visual stimuli of increasing complexity, which targets the visual dependence directly.
• Balance retraining on progressively challenging surfaces to encourage reweighting toward somatosensory and vestibular input.
• Postural retraining to reduce the stiffened high risk strategy, including work on relaxed natural gait with normal arm swing.
• Progression must be gradual. Aggressive provocation causes symptom flare and drop out, in contrast to acute unilateral loss where vigorous provocation is beneficial.
• Aerobic exercise to reverse deconditioning.
• Programmes typically run for 3 to 6 months.

Pharmacological treatment

• Selective serotonin reuptake inhibitors and serotonin noradrenaline reuptake inhibitors are effective, with response rates of around 60 to 70 percent, and this benefit occurs independently of whether the patient has depression or anxiety.
• Sertraline 25 mg daily for 1 week then 50 mg daily, titrated to 100 to 200 mg daily. Start at half the usual dose, since these patients are sensitive to initial adverse effects and early worsening of dizziness is the commonest reason for stopping.
• Alternatives: escitalopram 5 mg daily increased to 10 to 20 mg; fluoxetine 10 mg increased to 20 to 40 mg; venlafaxine modified release 37.5 mg increased to 75 to 150 mg.
• Warn about a transient increase in dizziness, nausea and anxiety in the first 1 to 2 weeks, which settles. Preparing the patient for this substantially improves adherence.
• Continue for at least 12 months after a response before considering gradual withdrawal, since early discontinuation leads to relapse.
• Monitor for hyponatraemia in the elderly, sexual dysfunction, and interactions.
• Vestibular suppressants including prochlorperazine, cinnarizine and betahistine are ineffective and actively harmful in this condition, since they impair the sensory reweighting that constitutes recovery. Stopping them is an important therapeutic step. Many patients arrive on long term prochlorperazine and improve simply on withdrawal.
• Benzodiazepines should be avoided for the same reason and because of dependence.

Cognitive behavioural therapy

• Targets the catastrophic interpretation of symptoms, hypervigilance to bodily sensation, and avoidance behaviour.
• Effective even in patients without a formal anxiety disorder.
• Delivered individually, in groups or through structured digital programmes.
• Combining cognitive behavioural therapy with vestibular rehabilitation and medication gives the best outcomes.

Treat coexisting conditions

• Treat any active benign paroxysmal positional vertigo with repositioning.
• Treat vestibular migraine with prophylaxis, which is frequently transformative in the overlap group.
• Treat depression and anxiety in their own right.

Follow up and prognosis

• Review at 6 to 8 weeks with a repeat severity questionnaire.
• Most patients improve substantially with combined treatment, though a proportion have residual symptoms.
• Longer duration before diagnosis predicts poorer outcome, which is the argument for recognising the condition early rather than after years of investigation.
• Resist the temptation to reinvestigate on the basis of persistent symptoms alone. Reinvestigate only for genuinely new features.