Neurosonology in cerebral ischemia: Future application of transcranial Doppler in acute stroke

Transcranial Doppler (TCD) has become a general practice in recent years in the diagnostic study of patients with cerebral ischemia. This is due to th e fact that it is a rapid, noninvasive, reproducible and dynamic examinatio n of intracranial circulation. In the acute phase of cerebral infarction, i t can detect MCA occlusion with a good correlation with angiographic findin gs and, what is even more important, the patients who will later suffer lac unar infarctions almost always show a normal Doppler examination. Acute abn ormalities can also demonstrate the mechanism of the clinical signs; the ex amination informs us of the existence of collaterals and severe occlusions or stenoses of the extracranial arteries, and can change the priority in th e search for the etiological diagnosis. The diagnosis of intracranial steno ses as a cause of clinical signs is another immediate application of TCD, r ight from the acute phase. If in the future anticoagulation is shown to be an optimum treatment for secondary prophylaxis in intracranial stenoses, TC D will probably become the diagnostic technique of choice. The ability to p redict the prognosis based on parameters obtained by TCD opens up the possi bility of using it as an auxiliary technique for the selection of patients for reperfusion treatment, having in its favor that it is quick and easy to perform, and therefore suitable for treatment monitoring. It seems clear t hat the data obtained by Doppler in the first 6h are a good predictor of bo th spontaneous improvement and early impairment, which could help to avoid treatment in patients in whom a rapid improvement can be expected. Finally, the hemodynamic data of the TCD could be of inestimable value in the asses sment and monitoring of intracranial hypertension treatments and for hemody namic management of the patient, allowing the treatment margins of the acut e phase of arterial hypertension to be reliably established without comprom ising the perfusion pressure. In conclusion, TCD will possibly be more wide ly used in the future in the acute phase of cerebral infarction as a guide to diagnostic procedures, for treatment selection and for monitoring of cer ebral hemodynamics.Copyright (C) 2001 S. Karger AG, Basel.