[Oculographic findings in 145 patients with benign paroxysmal positional vertigo]

Benign paroxysmal positional vertigo (BPPV) can be produced by specific manoeuvres and be studied by electrooculography (EOG). It allows an exhaustive study of features in the positional nystagmus. Although most of the patients with BPPV express typical nystagmus, there exists a group of them that exhibit a non typical form. In this work, a comparative study was carried out between two groups of patients.

We have studied retrospectively 145 patients with BPPV and Dix-Hallpicke (D-H) positive manoeuvre registered by EOG techniques. All patients were explored in a complete EOG tests. Two groups were identified: typical response/atypical response according to the features of nystagmus response. Possible alterations in other EOG tests in each group were investigated and differences between both types of response were analyzed.

83.5% of cases showed typical nystagmus and atypical in the rest. Other EOG alterations observed in these patients, were (group typical response/atypical response): caloric hypofunction (17.3%/23%), positional nystagmus (12.4%/62.5%), alterations in visual-oculomotor function tests (10%/50%).

Frequent alterations were observed in the classic manoeuvres and also in the rest of EOG tests. Probably atypical response in the first is due to or can explain the existence of the second.