gms | German Medical Science

Objective: Transcranial Doppler Sonography (TCD) is an established noninvasive technique for the identification of patients with vasospasm in the acute phase after aneurysmal subarachnoid hemorrhage (SAH). The aim behind is the avoidance of delayed ischemic neuriological deficits (DIND). However, blood flow velocity increase in the basal arteries does not allow identification of tissue at ischemic risk. CT perfusion (CTP) possibly can be used to fill this gap. Aim of this prospective study was to investigate the role of CTP in the identification of patients at risk for DIND in the early phase after aSAH (day 1–5) in comparison to daily TCD measurements.

Method: We studied 32 patients with aSAH. Daily neurological examination as well as TCD were performed within the first two weeks after aSAH onset. Standard CT was routinely performed after intervention (clipping/coiling) to rule out intervention-associated ischemia. Guided by TCD and/or neurological worsening, CTP perfusion was performed. In 19 patients CT perfusion was performed in the acute phase (day 1–5) after aSAH. For the evaluation of early perfusion deficits following parameters were used: cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), time to drain (TTD) and time to start (TTS). In most patients CT angiography or conventional angiography was additionally performed for the evaluation of cerebral vasospasm.

Results: Early perfusion deficits in the first 5 days not related to the intervention were found in 53% of the patients (10/19), 9 out of them developed cerebral vasospasm and DIND. 6 patients developed stroke with irreversible deficits. Only 5 of these patients had TCD values >120 cm/sec. A statistically significant correlation was found between early perfusion deficits and cerebral vasospasm (MWU-Test, p=0,0003) as well as with DIND (MWU-Test, p=0,00061). No correlation was identified between early perfusion defitits and TCD values in the acute phase after aSAH (MWU-Test, p=0,142742).

Conclusions: CT perfusion is a rapid imaging technique which allows a sufficient early identification of patients at risk for developing cerebral vasospasm and DIND after aSAH. On the basis of the findings of this study a routinely use of CT perfusion in the acute phase of aSAH seems to be useful.