Paroxysmal positional vertigo: short- and long-term clinical and methodological analyses of 794 patients.

Between 1995 and 2001, eight Italian clinical centres used the same diagnostic and therapeutic protocol in order to assess the clinical progress of paroxysmal positional vertigo and the benefits of an appropriate follow-up in prevention of relapse. The study population comprises 794 patients affected by paroxysmal positional vertigo. The study protocol comprised diagnostic staging including a complete otoneurological test, an anamnestic questionnaire aimed at identifying any possible risk factor, a blood test in basal conditions and monitoring of blood pressure. If necessary, more specific instrumental tests have been carried out. Appropriate rehabilitative manoeuvres were performed from 1 to 3 times within the same session. The patient was checked 3-5 days later: in the presence of a positive result, the treatment was repeated; if negative, patients were seen at clinical follow-up 7, 30, 180 and 365 days after recovery. Wherever possible, patients have been contacted 2 years after the first treatment and asked to answer a questionnaire and to attend for a clinical check-up. The incidence of paroxysmal positional vertigo appeared to be higher in females and in patients aged 50-70 years, being low in patients under 30. In 88.8% of cases posterior semicircular canals showed a significant involvement; in 6.8% of cases, only involvement of lateral semicircular canals; monolateral (2.7%) and bilateral (1.7%) multicanalar forms were rare. Paroxysmal positional vertigo forms involving posterior semicircular canals have been treated with Semont (simplified by Toupet), Epley, Parnes Price-Jones manoeuvres; those, involving lateral semicircular canals with Vannucchi-Vicini forced position and "barbecue" or Gufoni manoeuvre. Whilst all these manoeuvres were equally effective, longer recovery times have been observed in paroxysmal positional vertigo forms involving lateral semicircular canals when the Vannucchi-Vicini forced position was ineffective. Any relapses have been evaluated at least 15 days after a negative clinical pattern. Possible involvement of other semicircular canals (recurrence) some time after the first onset has been considered separately. Follow-up at 6 months showed recurrence in 12.4% of cases, while being chronic in 1.5% of cases. Only 9.3% of cases showed recurrence at 6 months, no statistically significant difference being observed between vertical (8.9%) and lateral canal (9.6%), forms. Relapses occurred in 3.1% of cases, in one third of which at least two risk factors were detected.