Intracranial haemodynamics in patients with spontaneous carotid dissection. Transcranial Doppler ultrasound follow-up studies.

In this study 11 patients aged between 34 and 57 years with clinical and angiographic findings typical of carotid dissection were thoroughly examined with transcranial Doppler ultrasound (TCD) repeatedly during a follow-up period of 1-6 months. Stagnating blood flow velocities in the downstream middle cerebral artery (MCA) were recorded initially as well as enhanced velocities due to postischaemic hyperperfusion syndrome. MCA embolism originating from the extracranial carotid artery with or without resolution could be detected by TCD in 5 cases. TCD findings in another 2 cases pointed to haemodynamic upset. In 3 cases, clinical as well as TCD data did not allow strict differentiation between embolic and haemodynamic complications, suggesting more complex pathophysiological mechanisms as the cause of infarction. Carotid recanalization was seen in 9 cases. The follow-up investigations moreover demonstrated that intracranial haemodynamics may change from day to day in patients suffering from internal carotid artery dissection. TCD data may thus improve the understanding of pathogenetics as well as rationales for individual therapeutic intervention in this particular disease.