Can hyperventilation test and duration of spontaneous nystagmus help differentiate between vascular and inflammatory aetiology of acute unilateral vestibular deficit?

OBJECTIVE

To relate clinically the duration of spontaneous nystagmus and hyperventilation-induced nystagmus (HVIN) to vascular or inflammatory aetiology of acute unilateral vestibulopathy observed in a very early stage.

METHODS

This is a retrospective study on 198 patients with acute unilateral vestibulopathy.

RESULTS

In the short-lasting nystagmus group (spontaneous nystagmus < 48 h), mean age and cardiovascular risk were significantly higher; the rates of negative HVIN and paretic HVIN were 41.7% and 58.3%, respectively. In the long-lasting nystagmus group (spontaneous nystagmus > 48 h), mean age and vascular risk were lower; HVIN was absent in 12.6% of the cases, HVIN excitatory patterns were observed in 40.3% of cases and a paretic pattern in 47.1%.

CONCLUSIONS

A vascular aetiology should be considered the most likely in patients with spontaneous nystagmus < 48 hours: all patients were > 60 years old, cardiovascular risk was higher and HVIN was always absent or paretic. In the group with nystagmus > 48 hours, similarly, data indicate a higher incidence of paretic HVIN in older patients and higher vascular risk, even if the data does not allow us to lean clearly towards one of the two aetiological hypotheses.