Magnetic resonance angiography and transcranial Doppler ultrasound findings in patients with a clinical diagnosis of vertebrobasilar insufficiency

OBJECTIVE: To evaluate the findings of magnetic resonance angiography (MRA) and transcranial Doppler ultrasound (TCD) in patients with a clinical diagnosis of vertebrobasilar insufficiency (VBI). METHOD: From our outpatient neurotology clinic, we selected patients (using the criteria proposed by Grad and Baloh) with a clinical diagnosis of VBI. We excluded patients with any definite cause for vestibular symptoms, a noncontrolled metabolic disease or any contraindication to MRA or TCD. The patients in the study group were sex- and age-matched with subjects who did not have vestibular symptoms (control group). Our final group of patients included 24 patients (study, n=12; control, n=12). RESULTS: The MRA results did not demonstrate significant differences in the findings between our study and control groups. TCD demonstrated that the systolic pulse velocity of the right middle cerebral artery, end diastolic velocity of the basilar artery, pulsatility index (PI) of the left middle cerebral artery, PI of the right middle cerebral artery, and PI of the basilar artery were significantly higher in the study group than in the control group, suggesting abnormalities affecting the microcirculation of patients with a clinical diagnosis of VBI compared with controls. CONCLUSION: MRA failed to reveal abnormalities in patients with a clinical diagnosis of VBI compared with controls. The PI of the basilar artery, measured using TCD, demonstrated high sensitivity (91%) and specificity (91%) for detecting clinically diagnosed VBI.

Arteritis de células gigantes en el sistema vertebrobasilar, isquemias cerebelo-occipitales y parálisis III par: caso clínico / Giant cell arteritis of the vertebrobasilar system, posterior ischemia and palsy of the third nerve: report of one case

Giant cell arteritis is the most common vasculitis in patients aged over 50 years. We report an 89-year-old woman with significant weight loss and persistent frontal-occipital headaches lasting two months. The neurological examination at admission identified a decrease in visual acuity of the left eye, paralysis of the third cranial nerve of the right eye and alterations of body motility without objective signs of damage of the motor or sensitive pathways. Magnetic resonance imaging showed changes of the temporal artery wall and in both vertebral arteries, as well as bilateral cerebellar and occipital ischemic lesions. The Doppler ultrasound of the temporal arteries was compatible with Giant cell arteritis. Treatment with steroids was started. While receiving oral prednisone, the patient suffered new infarcts of the posterior territory, documented with a CAT scan.

Spontaneous Basilar Artery Dissection: A Case Report and Literature Review

Spontaneous basilar artery dissection is a rare condition and a diagnostic challenge with a high potential for morbidity and mortality if untreated. It has an estimated incidence of 1 to 1.5 cases per 100,000 people. Few cases have been described in the literature up to the present day. The clinical outcomes, prognosis and treatment remain uncertain. The authors report the rare case of a 55-year-old female patient who presented to the Interventional Neuroradiology service at Hospital São Marcos, Teresina, in the state of Piauí, Brazil, with a history of severe headache located in the occipital region and in the nape with no improvement using common analgesics. A magnetic resonance imaging of the brain showed a saccular dilatation in the basilar artery, and a digital cerebral angiography showed a basilar artery dissection associated with a dissecting aneurysm.

Plasma Total Homocysteine Level Is Associated with the Pulsatility Index of Cerebral Arteries in Lacunar Infarction

PURPOSE: The pulsatility index (PI), measured by transcranial Doppler (TCD), is a surrogate marker for distal vascular resistance in cerebral arteries, and elevated plasma total homocysteine (tHcyt) is regarded as a cause of ischemic stroke, including lacunar infarction. We investigated the relationship between the PI of cerebral arteries and plasma tHcyt in patients with lacunar infarction. MATERIALS AND METHODS: Plasma tHcyt level and TCD examination were performed in 94 patients with lacunar infarction. Mean flow velocity (MFV) and PI were assessed at the ipsilateral middle cerebral artery (MCA) and contralateral MCA, relative to the infarction, and the basilar artery (BA). Multivariate regression analysis was conducted between log-transformed tHcyt levels (logHcyt) and the PI of individual arteries. RESULTS: There was a significant correlation between logHcyt and the PI in all tested arteries (ipsilateral MCA: r=0.21, p=0.03; contralateral MCA: r=0.21, p=0.04; BA: r=0.35, p=0.01). In multivariate regression analysis, this significance remained unchanged after adjusting for vascular risk factors, creatinine, hematocrit and platelet count (ipsilateral MCA: beta=0.26, p=0.01; contralateral MCA: beta=0.21, p=0.04; BA: beta=0.39, p=0.001). There was no significant association between logHcyt and MFV of individual arteries. CONCLUSION: A significant association between plasma tHcyt and the PI of cerebral arteries indicates that homocysteine plays a role in the increase of distal arterial resistance in lacunar infarction.

Atlantoaxial joint distraction for treatment of basilar invagination secondary to rheumatoid arthritis.

We present our experience of treating two cases of rheumatoid arthritis involving the craniovertebral junction and having marked basilar invagination by an alternative treatment method. In both the cases, the facets were osteoporotic and were not suitable for screw implantation. The patients were 66 and 72 years of age and both patients were females. Both the patients presented with complaints of progressively increasing spastic quadriparesis. Surgery involved attempts to reduce the basilar invagination and restore the height of the 'collapsed' lateral mass by manual distraction of the facets of the atlas and axis and forced impaction of titanium spacers in the joint in addition to bone graft harvested from the iliac crest. The procedure also provided stabilization of the region. No other fixation procedure involving wires, screws, plate and rods was carried out simultaneously. Following surgery both the patients showed symptomatic improvement and partial restoration of craniovertebral alignments. Follow-up is of 2 and 24 months. Distraction of the facets of atlas and axis and impaction of metal implant and bone graft in the facet joint can assist in reduction of basilar invagination and fixation of the region in selected cases of rheumatoid arthritis involving the craniovertebral junction.

Bilateral Paramedian Thalamic Contrast Enhancement on CT after Intra-arterial Thrombolysis

A 58-year-old woman presented with an acute embolic occlusion of the distal basilar artery. She underwent angioplasty and intra-arterial thrombolysis. Angiography performed after recanalization revealed a single perforating thalamic artery. A nonenhanced CT scan carried out immediately after the procedure revealed hyperdense lesions in the bilateral paramedian portions of the thalami, which disappeared on the 24-hour follow-up CT scan. Three months later, the patient improved to functional independence, but had some memory dysfunction and vertical gaze palsy. This case suggests that contrast enhancement or extravasation can occur in the thalamus after intra-arterial thrombolysis performed to recanalize a basilar artery occlusion.