A new method for evaluating lateral semicircular canal cupulopathy.

OBJECTIVES/HYPOTHESIS: Persistent direction-changing positional nystagmus (DCPN) during the supine head-roll test is a typical finding of cupulopathy. The aim of this study was to introduce a simple method of evaluating patients with cupulopathy (light cupula and heavy cupula), which is performed in a seated position, and investigate its diagnostic utility and use for lateralization.

STUDY DESIGN

Retrospective case series.

METHODS

Using video-oculography, nystagmus during head roll in the leaning and bending head positions while seated upright was evaluated in 26 patients with cupulopathy (five light cupula and 21 heavy cupula). The diagnosis of cupulopathy was confirmed with the supine head-roll test.

RESULTS

Spontaneous nystagmus while seated upright was directed toward the ipsilesional side in heavy cupula and the contralesional side in light cupula. The first null point was identified when the head was slightly bent in the pitch plane in all 26 patients. Head rolling elicited a persistent geotropic DCPN in light cupula patients and persistent apogeotropic DCPN in heavy cupula patients during both leaning and bending head positions. In both light and heavy cupula, nystagmus disappeared when the head was turned slightly toward the affected side in both leaning (second null point) and bending (third null point) head positions.

CONCLUSIONS

Cupulopathy and its affected side can be diagnosed by identifying the three null points while seated upright.

LEVEL OF EVIDENCE