Magnetic resonance brain imaging in patients with visual vertigo.

INTRODUCTION: Patients with visual vertigo (VV) report dizziness provoked by moving visual surroundings. It has been suggested that these subjects develop a compensation strategy for a vestibulo-proprioceptive deficit and rely excessively on visual input. We have postulated that patients with VV might have brain abnormalities that interfere with appropriate processing of visual stimulation and performed a brain MRI study to verify this hypothesis. MATERIALS AND METHODS: Patients with VV of more than 3 months duration were included. They were asked to complete the Situational Characteristic Questionnaire (SCQ) that scores for the symptoms of VV. Dizzy patients without VV served as controls. A brain MRI was performed with a Siemens 1.5 Tesla scanner in patients and controls. RESULTS: Twenty-four patients with VV were included. Their mean SCQ score was 1.45 ± 0.9 (normal 0.16 ± 0.28). In 50% of patients, abnormalities in MRI imaging were found. Thirty-three percent of 27 controls demonstrated an abnormal brain MRI. The two groups were similar in respect to the prevalence of a localized hemispheric or posterior fossa lesion (P = 0.13), but VV patients had more unspecific white matter brain changes than controls (P = 0.009). Patients and controls did not differ in age and gender distribution (P = 0.9) or the history of a neurotological event preceding their symptoms (P = 0.3). CONCLUSIONS: Our study suggests that multiple white matter lesions might contribute to occurrence of the phenomenon of VV. Future prospective large-scale studies by specific MR techniques are indicated to validate our preliminary findings and elucidate the pathological mechanism of VV.

Detection of anomalous vertebral arteries by ultrasound as an alternative to radiological methods.

In order to examine 'ultrasound' approach in detecting the course of the vertebral artery (VA) and its anomalies important for neck surgery. An observational study with retrospective analysis of ultrasound images. 500 VAs on 250 3D CT angiographies and 500 ultrasound images performed on the same set of patients were analyzed. The relationship between the extraosseous portions of the VA to the neck organs with a special emphasis to the thyroid gland area, and the abnormal position of the VA were detected. Ultrasound and CT 3D images were compared. Ultrasound detected that 29 out of 500 VAs were anomalous (5.8%), 3D CT detected 30 cases. These anomalies were found in 22 patients (8.8%) (23 for 3D CT; 9.2%), in 7 (31.8%) of them bilaterally. An abnormal level of entrance (C3, C4, and C5) was observed in all anomalous cases. An additional case detected by 3D CT indicated C7 level of entrance. The ultrasound data correspond the CT data in 96.7% of cases. In ten cases (33.3%) the anomalous VA run close to the thyroid gland even touching the lower pole (16.7%; n = 5) or the upper pole (10.0%; n = 3) of the gland. In ten cases (33.3%) the anomalous VA crossed common carotid artery and the internal jugular vein by a way of a median loop. The incidence of anatomic variations of the VA is significant. Preoperative ultrasound investigation allows precise identification of anomalous VAs. Radiation-free ultrasound investigation of blood vessels is as precise as CT 3D imaging.

Importance of preoperative detection of vertebral artery anomalies in neck surgery.

OBJECTIVES: The objective of this study were to examine the course of the vertebral artery (VA) and define VA anomalies important for neck surgery using three-dimensional computer tomography (3D CT). STUDY DESIGN: Thee design used was an observational study with retrospective 3D CT angiography analysis. METHODS: Four hundred VAs depicted on 200 3D CT angiographies were analysed to determine the relationship between the extraosseous portions of the VA to the neck organs, with special emphasis on the thyroid gland area, the artery of origin of the VA and the entrance/exit locations of its foraminal segment. RESULTS: Twenty-three out of 400 VAs were anomalous (5.75%). These anomalies were found in 18 patients, unilaterally in 13 in bilaterally five. The level of entrance was abnormal in all cases; it was at C3 in 4.3% (n= 1), at C4 in 17.4% (n= 4), at C5 in 74% (n= 17) and at C7 in 4.3% (n= 1). The VA ran close to the thyroid gland in eight cases (34.8%) even touching the lower pole (17.4%; n= 4) or the upper pole (8.7%; n= 2) of the gland. The anomalous VA crossed the common carotid artery and the internal jugular vein by a way of a median loop in eight cases (34.8%). CONCLUSION: In planning neck or spinal surgery, the surgeon should bear in mind that VA anomalies are present in approximately 5.5-6.5% of cases. Preoperative 3D CT allows precise identification of anomalous VAs, thereby reducing the possible risk of intraoperative injury.