Investigation of the vertebrobasilar arterial system in vertigo by vestibulocochlear test, SPECT and angiography

Objective: Perfusion of the areas of cochleovestibular structures was inves tigated using Tc-99m HMPAO single photon emission computerized tomography ( SPECT) in the young patients with vertigo presumed to have peripheral vesti bular abnormalities and compared the results with cochleovestibular test re sults, and vertebrobasilar angiography findings. Methods and patients: The study was performed on 20 patients with vertigo and 17 control subjects who had performed vertebral arteriography due to another disease. The patients with vertigo presumed to be on peripheral vestibular disorder were include d in the study. Systemic and otorhinolaryngological examination were carrie d out. Audiovestibular function was evaluated in all patients and control s ubjects. Brain SPECT was performed with a one-head rotating gamma camera sy stem from 64 projections into a 64 x 64 matrix, using low energy and high-r esolution fan beam collimators with a sampling time of 30 s. The images tak en from cerebellum, temporal, parietal and occipital lobes which are suppli ed by a vertebrobasilar system were compared visually with the other side a nd asymmetry in the perfusion was searched. After cochleovestibular tests a nd laboratory had been completed, vertebral arteriography was performed bil aterally in all patients. Results of digital subtraction angiography (DSA) and the vestibulocochlear test were compared with images of SPECT. Data ana lysis was done with Yates chi (2) and percentages of sensitivity and specif icity were calculated. Results: There was vestibular test and cochlear test abnormalities in eight and ten of the patients with vertigo, respectively. SPECT imaging showed hypoperfusion and decreased regional blood flow in 12 of the patients. There was statistically significant differences between t he study and control groups in SPECT (P < 0.05). Five patients showed abnor mal findings in DSA examinations. Conclusion: It is believed that SPECT may be helpful in the detection of vascular pathology in the patients with ver tigo. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.