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Adjusted for stroke severity, patients who received general anesthesia for treatment are less likely to have a good outcome than those managed with local anesthesia. This may be due to preintervention risk not included in the stroke severity measures. Hypotension, more frequent in the general anesthesia patients, may also contribute.

-Spontaneous cervical arterial dissection (SCAD) is a non-traumatic tear or disruption in the wall of the internal carotid arteries or the vertebral arteries. It accounts for about 25% of strokes in patients aged under 45 years. Awareness of its clinical features and advances in imaging over the last two decades have contributed to earlier identification of this condition. SCAD has become the commonest form of vascular lesion identified in the cervical carotid and vertebral arteries, second only to atherosclerosis. This review is an update on the epidemiology, vulnerable arterial segments, risk factors, clinical features, diagnosis, current treatment and prognosis of SCAD.Key worDS: dissection, carotid, vertebral artery, stroke, angiography. Dissecção espontânea da artéria cervical: atualização sobre aspectos clínicos e diagnósticosResumo -Dissecção arterial cervical espontânea (DACe) é uma laceração ou ruptura na parede de artérias cervicais responsáveis pela irrigação sanguínea cerebral: artérias carótidas internas e artérias vertebrais. É responsável por cerca de 25% dos acidentes vasculares cerebrais isquêmicos em pacientes abaixo de 45 anos de idade. Ao longo das duas últimas décadas, com a maior conscientização sobre suas manifestações clínicas e o avanço das técnicas de neuroimagem, a DACe tem sido diagnosticada mais precocemente, tornando-se o tipo de lesão vascular mais comumente identificado nas artérias cervicais, sendo superada apenas pelas lesões ateroscleróticas. esta revisão é uma atualização sobre a epidemiologia, segmentos arteriais mais vulneráveis, fatores de risco, manifestações clínicas, diagnóstico, tratamento e prognóstico da DACe.PAlAvrAS-ChAve: dissecção, artéria vertebral, acidente vascular cerebral, arteriografia.

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Background: Impaired cerebral vasoreactivity (CVR) detected by Transcranial Doppler (TCD) is predictive of stroke in patients with carotid stenosis. Functional MRI (fMRI) can evaluate CVR either. Few studies have compared both methods for CVR assessment already. However, none of them used breath holding test (BHT) as the vasodilatory stimulus. Objectives: To assess CVR through BHT using TCD and fMRI in patients with carotid stenosis and controls in order to verify whether fMRI can detect any difference on BOLD-signal intensities between these groups. Additionally, we aimed to verify if fMRI can discriminate correctly any subject with impaired CVR as compared to TCD. Methods: Fifteen patients with carotid stenosis defined as stenosis ≥50% by angiography or ≥70% by ultrasound or ≥70% by CTA or MRA (11men;52-90yo;mean:67.7yo) and 7 matched-controls (5men:51-85yo;mean:64.6yo) performed BHT during TCD. Impaired CVR was diagnosed if mean percentage increase of MCA velocities ≤31% on 3-consecutive intervals of 30s of apnea intercalated by 4-minute-interval of normal breathing. During fMRI, BHT was performed using a traffic lights-based code for instruction on when it was time to stop breathing and was composed by 3-consecutive intervals of 24s of apnea intercalated by 4-minute-intervals of normal breathing. BOLD-signal intensity was measured in the lentiform nucleus ipsilateral to the carotid stenosis. In controls, the mean signal intensity of both lentiform nuclei was considered. Results: Patients and controls showed significantly different BOLD-signal intensities (p:0,0053). Based on CVR defined by TCD, there was an agreement between TCD and fMRI of 6/7 (85,7%) in controls, 11/15 (73.3%) in patients, and 17/22 (77,2%) overall. Conclusion: fMRI showed different BOLD signal intensities in patients and controls using BHT as the vasodilatory stimulus for CVR assessment. Additionally, there was a good agreement between fMRI and TCD on detecting patients with impaired CVR. Further studies are needed to evaluate whether impaired CVR on fMRI with BHT is predictive of stroke in patients with carotid stenosis, but these results suggest that fMRI may be a potentially useful tool for stroke risk assessment in clinical practice.