Dissezione della carotide interna e attuale valore diagnostico della sonografia

Internal carotid dissection has increasingly been reported as a cause of stroke particularly in young patients; accounts for up to one fifth of ischemic strokes occurring before 45 years. It may be due to hemodynamic factors or emboli. These lesions are often located in the distal segments of the extracranial carotid artery. The study of the dissected artery can be carried out not only by angiography (still considered the gold standard), but also by Angio Helical CT, angio MRI, ultrasound. Extracranial sonographic assessment may be of limited value only in those cases in which the dissections occur in the distal segments of the internal carotid even though an accurate evaluation of the hemodynamic parameters may indicate the diagnosis. As transcranial doppler and in particular the echo color coded transcranial doppler, allows detection of blood flow velocities in intracranial circulation, it may identify the changes produced by proximal restriction in flow. Ten patients with Spontaneous Internal Carotid Dissection has been studied in our hospitals from June 1997 to June 1998 (3 males and 7 females) with age between 27 to 68 years). Duplex scanning of the epiaortic arteries and transcranial doppler is considered one easy way to monitor these patients and in particular we can follow the possible recanalization of the carotid artery and the hemodynamic changes occurring in the circle of Willis. Now it is possible a more friendly use of color enhanced contrast during the doppler examination. The combined use of these techniques increases the accurancy of ultrasound diagnosis of carotid dissection.