Emergency CTP detection of cerebral hypofusion caused by cerebrovascular spasms in aSASH patients

Emergency CTP testing was conducted on cases of suspected aSAH post-vascular spasm secondary nerve function deterioration, and it was highly accurate to judge the serious deficiencies of cerebral perfusionThe initial baseline CTP is not requiredThe most sensitive parameter for detecting brain perfusion is TTD- Excerpted from the article chapterRef: Vulcu S, et alWorld Neurosurg.2019 Jan;121:e739-e746doi: 10.1016/j.wneu.2018.09.208Epub 2018 Oct 9.)subcranial hemorrhage (aSAH) in patients with brain rupture aneurysms, which often cause cerebrovascular spasms and subsequent lysis of late-onsis encephalopathy (DCI), which is the leading cause of disability or death in patientsEarly judgment of cerebrovascular spasms and insufficient cerebral perfusion is clinically importantCt perfusion (CTP) imaging detection DCI sensitivity in the range of 20% to 95%, specificity is higher than 66%The accuracy of the diagnosis depends to a large extent on the parameters of the analysis of perfusionAmong the commonly used perfusion analysis parameters, the average pass time (transit transit time, MTT) and peak time (time to peak, TTP) are more sensitive and specific than cerebral blood flow (cerebral blood flow, CBF) and cerebral blood volume (cerebral blood volume, CBV)Recent studies have shown that hemovulson time (time to drain, TTD) is more effective at detecting insufficient brain perfusionTTD refers to the time at which the result of the mTT and the time at which the contrast agent passes from the analysis pixelS Neurosurgery at the University Hospital of Bern, Switzerland Vulcu and others assessed the accuracy of emergency CTP tests in patients with asAH when neurological function deteriorated, and the results were published online in October 2018 in World Surgery the authors collected patients with severe neurofunction and clinically stable patients with post-aSAH cerebrovascular spasms registered in the database between January 2012 and December 2015, except those with hydrocephalus, infections, intra-brain haemorrhage, metabolic disorders, or seizures DCI's acute neurological disorder standard reduced the GCS score by at least 2 points, or the National Institutes of Health stroke score (NIHSS) by at least 2 points An initial CTP test is performed within 24 hours of aneurysm treatment as a baseline CTP During follow-up, if acute neurological dysfunction occurs or for other reasons, the attending physician may propose an increase in CTP testing The study included patients with emergency CTP tests in the first CTP and acute neurological deterioration within 24 hours of aneurysm treatment Patients with stable clinical conditions underwent an initial CTP test within 24 hours of aneurysm treatment, followed by CTP during the vascular spasm period (5-14 days after aSAH) as a control group CtP parameters for pre-determining brain regions, including TTD, MTT, TTP, CBF, and CBV results showed that 33 patients with aSAH had deterioration of nerve function and 23 cases had no deterioration of nerve function In patients with neurological symptoms, the initial CTP test results did not improve the diagnostic accuracy of emergency CTP The same phenomenon occurred when the perfusion parameters of emergency CTP testing between the two hemispheres of the brain were compared The highest rate of diagnosis of positive CTP parameters were TTD in the asymptomatic brain region, with a threshold of 4.7 seconds, sensitivity of 97% and 96% specificity Therefore, emergency CTP testing was performed on cases of suspected aSAH post-blood spasm secondary nerve function deterioration, and it was highly accurate to determine the serious deficiencies of cerebral perfusion The initial baseline CTP is not required The most sensitive parameter for detecting brain perfusion is TTD.