Abstract
Purpose: :
The ability to detect abnormal subjective tilt is dependent on input from visual, vestibular and somatosensory systems. Inflammation of the vestibular nerve, which transmits impulses from the gravity-sensing otolithic organs, can often lead to a false suggestion that the head is tilted and may transiently cause the eyes to counter-roll.
Methods: :
In patients with vestibular neuritis who consulted the neurological department of the University of Munich from 2004 to 2009, the degree of ocular torsion (OT) and the deviation of the subjective visual vertical (SVV) after the onset of the symptoms of neuritis were evaluated retrospectively. Normal findings for the SVV are ± 2.5. Values of the angle of OT ranging from 0 degree to 12 degrees are still physiological. Inside this dispersion, individual right-left asymmetries of less than 4 degrees are still normal as well.
Results: :
Within 7 days after the onset of symptoms the deviation of SVV and OT increased on the side of the lesion compared to normal findings: in 162 patients the SVV was 5.8 ± 3.8 and the OT was 12.6° ± 5.6° ipsilaterally and -0.64° ± 6.1° contralaterally, with a right-left asymmetry of 13.7 ± 9.7. In week 2 patients showed minor deviations (SVV: 4.0 ± 3.1; OT: 9.8° ± 4.0° ipsilaterally and 2.0° ± 5.1° contralaterally, with an asymmetry of 8.6 ± 6.8; n=30). From day 15 up to 3 months after the onset of symptoms patients showed normal values (SVV: 1.8 ± 2.5; OT: 6.1° ± 3.4° ipsilaterally and 4.5° ± 3.9° contralaterally with an asymmetry of 4.2 ± 4.8; n=77).
Conclusions: :
Within the first week after the first onset of the symptoms of vestibular neuritis peripheral vestibular function is considerably impaired, whereas after two weeks the function returns to normal in most cases.