The authors, part of an influential committee of experts of the Bárány Society, proposed this consensus document after reviewing 30 years of research on phobic postural vertigo, space-motion discomfort, visual vertigo, and chronic subjective dizziness. They also reviewed interesting historical data as far back as the 1870s when symptoms of this kind were first reported in the literature. PPPD is the ‘new’ term that describes all these conditions because of what they have in common. The key features of PPPD are “dizziness, unsteadiness, or non-spinning vertigo that are present on most days for more than three months, and are exacerbated by upright posture, active or passive movement and exposure to moving or complex visual stimuli”. They emphasise that PPPD is a functional disorder, not a structural or psychiatric condition. The diagnostic criteria are divided into five sections, A to E, all of which must be fulfilled to make the diagnosis.
A: One or more symptoms of dizziness, unsteadiness, or non-spinning vertigo are present on most days for three months or more. Symptoms last for prolonged (hours-long) periods of time although may wax and wane in severity and symptoms need not be present continuously throughout the entire day. The main symptoms are non-motion sensations of disturbed or impaired spatial orientation – dizziness; feelings of being unstable while standing or walking – unsteadiness; false or distorted sensations of swaying, rocking, bobbing, or bouncing of oneself – internal non-spinning vertigo – or similar sensations of movement of the surroundings – external non-spinning vertigo).
B: Persistent symptoms occur without speciﬁc provocation, but are exacerbated by three factors – upright posture, active or passive motion without regard to direction or position, and exposure to moving visual stimuli or complex visual patterns.
C: Precipitated by conditions that cause vertigo, unsteadiness, dizziness, balance problems including acute, episodic or chronic vestibular syndrome, other neurologic or medical illnesses, or psychological distress.
D: Significant distress or functional impairment.
E: Not better accounted for by another disease or disorder. Whereas there are no pathognomonic signs on examination or testing, the presence of these may signify co-existing conditions.
The authors include very helpful extensive explanatory notes giving details of definitions and controversies. This is an excellent paper worth reading and applying to neuro-otological practice.