TRANSCRANIAL DOPPLER IN THE ACUTE-PHASE AND FOLLOW-UP OF INTERNAL CAROTID-ARTERY DISSECTION - CASE-REPORTS OF 2 PATIENTS

Internal carotid artery dissection (ICD) causes transient ischemic att ack (TIA) or stroke by hemodynamic or thromboembolic mechanisms. Diagn osis of ICD is made by angiography. The aim of this study was to evalu ate the role of three-dimensional transcranial Doppler (TCD-3D) in ICD . The authors report a fifty-seven-year-old man presenting sudden apha sia, left neck pain, and homolateral headache and a sixty-year-old man presenting sudden right neck pain, homolateral headache, and Horner's syndrome. Selective digital subtraction angiography showed the typica l elongated regular stenosis (string sign) of ICD. At onset TCD-SD rev ealed in both patients: (1) decreased blood flow velocity over the int ernal carotid dissected segment and inverted flow velocity over the ho molateral anterior cerebral and ophthalmic artery; (2) reduced pulsati lity index with normal blood flow velocity over the homolateral middle cerebral artery suggestive of valid autoregulation of cerebral blood flow (CBF). TCD-3D at days 15 and 40 and at months 2 and 6 after strok e showed progressive recanalization beginning from the day 40 in the f irst patient and from the day 15 in the second patient with successive complete normalization of Doppler parameters. Although angiography re mains the most reliable diagnostic study, TCD-3D results are useful fo r evaluating, in the acute phase, the efficacy of collateral blood sup ply and autoregulation of CBF, which are important as prognostic index es and as indications for therapeutic strategy, and, afterward, for th e timing of recanalization indicative of a good long-term prognosis.