Thrombolysis: Stroke Subtype and Embolus Type

Abstract

The use of thrombolytic agents in acute ischemic stroke is still experimental [5, 8, 9]. It requires clear hypotheses and strict definitions concerning the group of patients considered possible candidates for this treatment. On the other hand, the decision to treat or not to treat a patient must be made under considerable time constraints prohibiting extensive diagnostic evaluation of the individual patient [2, 6]. It is nearly impossible to perform sufficient cardiac tests in case cardiac embolism is suspected. Angiography is not anymore a prerequisite for thrombolysis in ongoing major controlled studies. Routine Doppler ultrasound, both extra- and intracranially, has only rarely been performed in pretreatment diagnostic evaluation. In the majority of studies the subtype of stroke was not reported and only rarely was information on the embolus origin given. If cardiac or arterial embolus sources have been suspected, it remains unclear how they have been identified. In the majority of cases the distinction between cardiac and cervical source embolus or local thrombotic disease has been made arbitrarily. In consequence, most statements in this paper are not based upon sound scientific data. In recent angiographic open thrombolysis studies, a gross distinction of the occlusion sites often has been reported. In most studies, the distinction was made between the carotid and the vertebrobasilar (VB) territory, in some reports the distinction extracranial internal carotid artery (eelCA), intracranial ICA (icICA), and middle cerebral artery (MCA) is mentioned. Only rarely were distal MCA occlusion sites further differentiated.