Early whole-brain CT perfusion for detection of patients at risk for delayed cerebral ischemia after subarachnoid hemorrhage

Abstract

C erebral infarction with permanent vasospasminduced delayed ischemic neurological deficits (DIND) after aneurysmal subarachnoid hemorrhage (aSAH) is a feared and unfortunately frequent complication, responsible for poor functional and overall outcome. 2 The pathophysiology of DIND and vasospasminduced delayed cerebral infarction (DCI) after aSAH is multifactorial and still not fully understood. It is well accepted that vasospasm is a major contributor to DIND and DCI, but it is also assumed that processes already initiated shortly after aSAH render some brain areas more vulnerable for vasospasm than others. 20,27,33 In up to 15% of patients, cerebral infarction and a fixed neurological deficit (including death) are irreversible end points of a dynamic process starting with tissue predisposition and asymptomatic vasospasm, followed by symptomatic vasospasm and transient DIND. For the successful prevention of infarction by antivasospastic therapy, timely recognition of abbreviatioNs aSAH = aneurysmal subarachnoid hemorrhage; BFV = blood flow velocity; CBF = cerebral blood flow; CBV = cerebral blood volume; CTA = CT angiography; CTP = CT perfusion; DCI = delayed cerebral infarction; DIND = delayed ischemic neurological deficits; DSA = digital subtraction angiography; MIP = maximum-intensity projection; MTT = mean transit time; NPV = negative predictive value; PPV = positive predictive value; ROI = region of interest; TCD = transcranial Doppler sonography; TTP = time to peak; TTS = time to start. obJective This prospective study investigated the role of whole-brain CT perfusion (CTP) studies in the identification of patients at risk for delayed ischemic neurological deficits (DIND) and of tissue at risk for delayed cerebral infarction (DCI). methods Forty-three patients with aneurysmal subarachnoid hemorrhage (aSAH) were included in this study. A CTP study was routinely performed in the early phase (Day 3). The CTP study was repeated in cases of transcranial Doppler sonography (TCD)-measured blood flow velocity (BFV) increase of > 50 cm/sec within 24 hours and/or on Day 7 in patients who were intubated/sedated. results Early CTP studies revealed perfusion deficits in 14 patients, of whom 10 patients (72%) developed DIND, and 6 of these 10 patients (60%) had DCI. Three of the 14 patients (21%) with early perfusion deficits developed DCI without having had DIND, and the remaining patient (7%) had neither DIND nor DCI. There was a statistically significant correlation between early perfusion deficits and occurrence of DIND and DCI (p < 0.0001). A repeated CTP was performed in 8 patients with a TCD-measured BFV increase > 50 cm/sec within 24 hours, revealing a perfusion deficit in 3 of them (38%). Two of the 3 patients (67%) developed DCI without preceding DIND and 1 patient (33%) had DIND without DCI. In 4 of the 7 patients (57%) who were sedated and/or comatose, additional CTP studies on Day 7 showed perfusion deficits. All 4 patients developed DCI. coNclusioNs Whole-brain CTP on Day 3 after aSAH allows early and rel...

Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods

“…225 Static metrics of whole brain CBF, CBV, and MTT using perfusion CT are used routinely to assess cerebral vasospasm and DCI but can also help to risk-stratify those who may develop DCI during the course of their illness. 226 This modality can be limited clinically by the risks of intravenous contrast agents and multiple exposures to radiation. Though proven as feasible, continuous TCD measurement of response to therapy in patients with cerebral vasospasm has proven cumbersome to do at the bedside and is not routinely used in practice.…”

<p>The association of neutrophil-to-lymphocyte ratio and delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage: possible involvement of cerebral blood perfusion</p>

“…Instead of detecting the areas of arterial narrowing as CTA and DSA work, CTP provides direct visualization of brain tissue perfusion. Early CTP evaluation (on day 3) is reported to be reliable for the identification of risk for DCI 20. Although earlier CTP is valueless in predicting DCI, a wider time window of 4–14 days after SAH for CTP exam is valuable for the diagnosis of DCI 21.…”

The influence of angiospasm on the results of microsurgical treatment of cerebral arterial aneurysms in the acute period of rupture

“…Прежде всего, это касается ишемии головного мозга, основным патогенетическим механизмом развития которой, по мнению многих авторов, является АС разной степени выраженности, не всегда верифицируемый при выполнении церебральной ангиографии (ЦАГ) и транскраниальной допплерографии (ТКДГ). Как правило, в таких случаях АС распространяется на мелкие артерии -перфоранты, что затрудняет диагностику [11][12][13][14][15]. Наличие ишемии мозга, выявленной клинически и методами нейровизуализации у лиц с разорвавшимися АА, осложненными САК, всегда свидетельствует о выраженности АС [16,17].…”