RESUMO
INTRODUCTION: The aim of this work was to evaluate the diagnostic value of the neck torsion test in VNG, Doppler ultrasonography and brainstem auditory evoked potentials in patients with vertigo and/or hearing loss due to intracranial vascular malformations. MATERIAL AND METHODS: The study covered 47 patients, 30 female and 17 male (mean age, 55.5 years; range, 19-74 years) with vertigo and/or hearing disorders and the asymmetry of vertebral arteries. Each patient underwent a subjective examination, an otolaryngological examination, otoneurological diagnostics, VNG with gaze tracking in the straight ahead position and in the 600 left and right neck torsion, the neck torsion test, audiological diagnostics including I-, III- and V-wave latency of the brainstem evoked potentials in the straight ahead position and the right ear stimulation in the 600 right neck torsion and the left ear stimulation in the neck torsion to the left, Doppler ultrasonography with measuring the diameter of vertebral arteries and the velocity of the blood flow in these vessels with the use of the neck torsion test. RESULTS: In own study, in VNG, the positive neck torsion test was observed in 76.5% of the study patients, while square waves in both directions were found in 46.5% and in one direction in 10.6%. Cervical nystagmus was noticed in 19.1% of these patients. In the auditory evoked potentials test, the differences in I-, III- and V-wave latency time were not statistically significant, either at rest or in the neck torsion. In the Doppler ultrasound examination, the asymmetry of vertebral arteries were present (below 25%) in 7 women (14.9%) and 4 men (8.5%), whereas large asymmetries (above 25%) were observed in 23 women (48.9%) and 13 (27.7%) men (range, 25% - 215%) and was statistically insignificant. The resting blood flow velocity in vertebral arteries of large asymmetries, both in systole and diastole heart phases, was significantly higher in the artery with larger asymmetry. CONCLUSION: The neck torsion test can be diagnostically useful in monitoring the vertebrobasilar system as well as qualify for microsurgical procedures if the vertebrobasilar insufficiency has been diagnosed.
