Is it possible to diagnose Posterior Semicircular Canal BPPV from the sitting position? The role of the Head Pitch Test and the upright tests along the RALP and LARP planes

PURPOSE

The diagnosis of benign paroxysmal positional vertigo (BPPV) involving the posterior semicircular canal (PSC) is traditionally entrusted to positioning tests where patients are rapidly brought in the supine position. This prospective study aims to define the role of a diagnostic protocol for PSC-BPPV including only upright tests.

MATERIALS AND METHODS

109 patients with PSC-BPPV were enrolled. The Head Pitch Test (HPT) was carried out first. If uneventful, the patient's head was turned 45° to each side and bent back-and-forth along the plane aligning either with the right anterior-left posterior (RALP) or left anterior-right posterior (LARP) canals, thus performing the upright RALP / upright LARP (uRALP/uLARP) test. Nystagmus observed was used to predict the diagnosis, which was therefore confirmed by Dix-Hallpike tests.

RESULTS

PSC-BPPV could be correctly diagnosed in 75.2% of cases with the sole HPT and in 87.2% of cases by adding the uRALP/uLARP test (Upright Protocol). The time elapsed from symptoms onset was closely related to the protocol sensitivity, as it reached 100% (64/64) in acute patients while decreased to 68.9% (31/45) in cases evaluated after 7 days (p < 0.001).

CONCLUSIONS

Upright maneuvers could correctly diagnose PSC-BPPV in most cases. uRALP/uLARP test demonstrated to improve the sensitivity of the HPT, mainly in recent-onset BPPV.

Pseudo-spontaneous nystagmus increases Bow and Lean Test accuracy

OBJECT

The aim of this study was to evaluate the effectiveness of the Bow and Lean Test (BLT) based on nystagmus intensity and direction evaluation (NID-BLT) in the diagnosis of benign paroxysmal positional vertigo of the lateral semicircular canal (LSC-BPPV). We hypothesised that the presence of a pseudo-spontaneous nystagmus increases the diagnostic accuracy of the test.

METHODS

The BLT was performed in 32 subjects affected by LSC-BPPV.

RESULTS

BLT was positive in 27 cases with a sensitivity of 84.3% and an accuracy of 70.4%. In other words, it was possible to carry out a BPPV root canal diagnosis (LSC) with BLT in 27 patients, of whom 19 also received a diagnosis of side and form. Pseudo-spontaneous nystagmus was detected in 15 patients, all of whom were BLT positive. In these patients, a clear diagnosis of form and side was also obtained in 14 cases (accuracy 93.3%). In the 12 patients without pseudo-spontaneous nystagmus and BLT positive, a diagnosis of side and form was reached in 5 cases (accuracy 41.6%). The comparison between percentages (Chi square test) showed a significant difference (p = 0.038).

CONCLUSIONS

The presence of a pseudo-spontaneous nystagmus, as an expression of more mobile debris within the canal or a more deflectable cupula, increases the accuracy of the BLT.