Epley maneuver and the head autorotation test in benign paroxysmal positional vertigo

Active Head Auto-Rotations in Patients With Benign Paroxysmal Positional Vertigo

Background

Utricular degeneration is the source of traveling otoconia inside the semicircular canals in patients with benign paroxysmal positional vertigo (BPPV). The underlying pathology is not clear. The aim of this study was to analyze vestibulo-ocular reflex (VOR) during sudden head accelerations in those patients since clinical reports designating an association of BPPV with inner ear problems are increasing.

Methods

VOR reaction to impulsive head rotations were tested in 34 patients with BPPV (13 lateral, 21 posterior canal BPPV) and 15 healthy subjects in a prospective controlled study. Main outcome measure was the gain (the ratio of head and eye velocity) of vertical and horizontal head auto-rotations to the pathologic and normal sides.

Results

All patients with BPPV and control subjects had normal gain (≥ 0.9) at 1 and 2 Hz but the gain decreased at higher frequencies. No statistically significant difference was found when comparing the gain between the horizontal head rotations toward the pathologic and those toward the normal side (P = 0.89, P = 0.90, P = 0.78, P = 0.20 and P = 0.16, at 1, 2, 3, 4 and 5 Hz, respectively) and between upward and downward vertical head rotations (P = 0.28, P = 0.53 and P = 0.15, at 1, 2 and 3 Hz, respectively) in patients with lateral and posterior canal BPPV.

Conclusion

VOR gain was reduced in some patients. However, head auto-rotation test (HART) does not show any functional abnormality of VOR during head rotations toward the pathologic side. HART is not suitable as a screening test for BPPV.

Vestibulo-ocular reflex in patients with superior semicircular canal benign paroxysmal positional vertigo (BPPV)

CONCLUSION

The function of all the semicircular canals in patients with idiopathic benign paroxysmal positional vertigo (BPPV) in whom otoconial debris is located in the superior semicircular canal (SSC) is normal.

OBJECTIVE

BPPV of SSC is an infrequent entity in which otoconial debris evokes vertigo and nystagmus in the head-hanging position and during anterior flexion of the patient.

METHODS

We studied the vestibulo-ocular reflex (VOR) in 12 patients with this particular type of BPPV. The reflex was evoked by rapid head impulses in the plane of the three semicircular canals in the affected and the normal ear. The reflex was evaluated with a video system that analyzes the head and eye velocity: the gain (the relation between both magnitudes) was the objective measure.

RESULTS

The mean gain of VOR was within normal limits for the six semicircular canals and there were no significant differences between the same canals on each side of patients with BPPV in whom canalolithiasis was located in the SSC. However, gain asymmetry was different for each pair of canals.

Computer-aided vestibular autorotational testing of the vestibulo-ocular reflex in senile vestibular dysfunction

BACKGROUND AND OBJECTIVE

Studies have already investigated vestibulo-ocular reflex (VOR) responses in elderly subjects, mostly at low frequencies (<1 Hz) during passive head turns, or continuous active head turns in a rotational chair. However, natural head movements usually occur at frequencies above 1 Hz and at varying rates, rather than at continuously increasing rates as tested in most studies to date. The aim of this study was to compare VOR responses within or between normal and bilateral peripheral vestibular hypofunction (BPVH) elderly subjects with a computer base program incorporating random active high-frequency head movements.

SUBJECTS

Seventeen senior patients with bilateral peripheral vestibular hypofunction and 13 age-matched paid healthy subjects participated in this study.

DESIGN

All the subjects performed 8s of active, side-to-side head motions at 1 Hz, 2 Hz and 3 Hz in response to four experimental conditions: (A) a stationary visual target; (B) a stationary visual target and a moving target with a horizontal trajectory; (C) a stationary visual target and a moving target with a spiral trajectory; and (D) a stationary visual target with combined horizontal- and vertical-spiral moving targets.

RESULTS

Repeated-measures ANOVA showed that across the different frequencies of headshaking, a significant increase took place in the phase lag of the BPVH subjects (p<0.001) compared with the normal controls. Post hoc analysis showed significant within-group differences in BPVH subjects (1 Hz vs 2 Hz, 2 Hz vs 3 Hz) and normal controls (1 Hz vs 2 Hz, 1 Hz vs 3 Hz). A significant VOR gain took place among the BPVH subjects at 3 Hz VAT (p<0.001) as compared with 1 Hz VAT and no significant differences in VOR gain could be detected among the controls at either of these frequencies. Repeated-measures ANOVA revealed that under our test conditions, significant main effect was noted for VOR asymmetry (F=4.45, p<0.05). Post hoc analysis showed significant within-group differences in the BPVH subjects (test A vs test B, test A vs test C, and test A vs test D).

CONCLUSIONS

Our results showed that the VAT paradigm can be improved by using concurrent horizontal and vertical moving targets. The VOR phase may be useful for differentiating VAT responses between BPVH and healthy elderly subjects. Moreover, the results of this study demonstrate that gains in VOR at different frequencies of headshaking and asymmetry during different test conditions can be useful parameters for within-group assessment.