Search

There is growing research interest on identification of CT Perfusion (CTP) parameters that predict the outcome in acute ischemic stroke patients. The aim of this study is to produce the model, based on core-penumbra related parameters assessed by CTP processing and commonly used clinical prediction factors, to predict the final infarct volume in thrombolysis-treated anterior circulation wake-up stroke (WUS) patients. The study was conducted on 51 consecutive wake-up ischemic stroke patients. The model for the predictive estimation of final ischemic volume was determined by using the Least Absolute Shrinkage and Selection Operator (LASSO) regularized least-squares regression. The results showed that CTP core volume and CTP total ischemic volume at admission, together with ASPECT score predict the final infarct lesion volume. In particular, the identified model presented 5-fold cross-validation root mean square error RMSE of 8.1 ml and the coefficient of determination (R2=0.94) on our dataset. The results should be confirmed in a lager study. In conclusion, in this study we preliminarily identified a predictive model to estimate final ischemic lesion volume in thrombolysis treated wake-up stroke patients. [ABSTRACT FROM AUTHOR]

Hypohydration may be associated with vascular diseases, poor prognosis and worse outcomes in stroke. The underlying mechanisms have not yet been completely investigated, although some studies suggested potential associations with brain perfusion and collaterals status. Despite the potentially different mechanisms promoting serum or urine biomarkers of hypohydration, few studies have investigated both markers separately. A prospective descriptive study was conducted in stroke patients admitted to a stroke unit <4.5 h from symptoms onset. All patients underwent neurological evaluation and whole‐brain computed tomography perfusion (CTP) upon admission. Blood and urine samples were immediately collected at admission, and patients were defined as "hypohydrated" (HYP) if blood urea nitrogen‐to‐creatinine ratio was >15 and "underhydrated" (UND) if urine osmolality was >500 mOsm/kg. CTP images were processed to calculate core, penumbra, their mismatch and total hypoperfused volume. Forty‐six patients were included and were grouped according to hydration status. Despite no different NIHSS at baseline, at CTP HYP was independently associated with core‐penumbra mismatch (β: −0.157, 95% CI: −0.305 to −0.009; p =.04), while UND was independently associated with the total hypoperfused volume (β: 31.502, 95% CI: 8.522‒54.481; p =.01). Using CTP imaging, this study proposes a physiological insight of some possible mechanisms associated with the better outcomes observed in acute stroke patients when properly hydrated. These results suggest different associations between hydration status and CTP parameters depending on serum or urine biomarkers in the hyper‐acute phase and encourage the association between hydration status and stroke characteristics. [ABSTRACT FROM AUTHOR]

Neuroimaging is crucial for stroke diagnosis and to establish the feasibility of reperfusion therapy, but is not practical for the assessment of continuous evolution of brain ischemia. Electroencephalography (EEG) in the early phase of brain ischemia could be a feasible instrument of functional monitoring. In this context, it would be of great research and clinical interest to assess the relation between EEG parameters and the hypoperfused volume measured by Computed Tomography Perfusion (CTP), as possible real-time surrogate parameters for extent of brain ischemia. This preliminary study aimed at investigating the relation between stroke-related EEG changes, measured on bedside with wireless EEG device, and the extent of hypoperfused volume assessed on CTP during the hyper-acute phase. We studied 12 consecutive ischemic stroke patients who underwent CTP assessment and EEG recording with wireless device within 4.5 hours from symptom onset. Total hypoperfused volume correlated significantly with the delta/alpha power ratio (ρ=0.72; p<0.010), (delta+theta)/(alpha+beta) power ratio (ρ=0.68; p=0.018), as well as with relative delta power (ρ=0.61, p<0.041). A significant negative correlation was found between relative alpha power (ρ=-0.77; p=0.003) and hypoperfused volume. In conclusion, EEG could be useful for the assessment of stroke severity and functional longitudinal monitoring. [ABSTRACT FROM AUTHOR]

• Neurovascular coupling is of paramount importance to define physiopathology of ischemic penumbra. • EEG alterations in hyperacute phase of stroke (<4.5 h) are assessed and related to hypoperfusion. • Topographic EEG power and CT perfusion maps are associated for the first time. The combined use of perfusion neuroimaging and brain oscillatory activity may provide a better clinical picture of neurovascular coupling of the injured area in ischemic stroke. The aim is to assess stroke-related topographic electroencephalography (EEG) changes during the earliest phase of ischemic stroke and to compare them with hypoperfusion identified by computer tomography perfusion (CTP). The study included 15 patients with ischemic stroke, who underwent both CTP and EEG recording within 4.5 h. Topographic representation of power for each band was calculated and compared with hypoperfusion areas estimated by CTP maps. Predominance of slow delta frequencies was found in all patients. The main finding is the agreement between slow rhythms hemispheric prevalence on EEG maps and cerebral hypoperfusion area identified using CTP. The results of this preliminary study show that the combined use of EEG and CTP, as highly available techniques, in acute ischemic stroke may be helpful in clinical practice and provide information about functional and metabolic aspects of brain involvement. The joint use of these methodologies may give a better clinical insight of the functionality of injured area in the hyperacute phase. [ABSTRACT FROM AUTHOR]

Purpose: Isolated speech impairment is one of the most challenging clinical manifestations of stroke mimic (SM). We aimed to investigate perfusional and EEG pattern of isolated aphasia to better differentiate between vascular and epileptic etiology in emergency settings.Method: We retrospectively analyzed 481 cases with acute focal neurological symptoms admitted to our Stroke Unit. The patients showing isolated aphasia and confirmed ischemic infarction or SM with seizure etiology on follow-up were included for subsequent analysis of clinical, neuroimaging, and EEG data. We investigated differences in CT Perfusion maps between ROI in the anatomical area compatible with clinical presentation, contralateral ROI and EEG in order to evaluate perfusion and brain oscillatory activity abnormalities.Results: 45 patients presented isolated aphasia as principal neurological symptom: 27 cases due to acute ischemic event, 11 due to seizure SM, while 7 were SM due to other etiologies. Out of 11 SM patients with seizure etiology, significant hyperperfusion on CTP maps (MTT AI%<-10%) and sharp EEG waves were observed in 8 patients, while in 3 patients slight hypoperfusion (MTT AI%<20%) and slow EEG rhythms were detected. 24 out of 27 ischemic stroke patients presented severe hypoperfusion with MTT AI above the stroke threshold (MTT AI > 45%). All ischemic stroke patients presented slower EEG rhythms.Conclusions: The main finding of this study is the identification of different clinical and neuroimaging patterns of isolated aphasia with epileptic or ischemic etiology in emergency settings. [ABSTRACT FROM AUTHOR]

Crossed cerebellar diaschisis (CCD) is a common finding in hyper-acute ischemic stroke, related to supratentorial dysfunction of the contralateral hemisphere. Several studies investigated a possible relationship between CCD and clinical outcomes but still no evidence emerged. We proposed a novel quantitative whole cerebellum analysis using CT perfusion (CTP) imaging to investigate the relationship between CCD and stroke severity, hypoperfused volume and outcome measures. 55 patients with supratentorial ischemic stroke who underwent CTP evaluation within 4.5 h since symptom onset were enrolled. CCD was evaluated by CTP image-processing and by calculating the mean transit time (MTT)-map asymmetry index in the whole cerebellum. MTT asymmetry correlation with ischemic volume and clinical outcomes was investigated. MTT asymmetry was found in most of the included patients and significantly correlated with NIH Stroke Scale (NIHSS) score at baseline and CTP ischemic volume. MTT asymmetry was significantly correlated with hemorrhagic transformation, NIHSS and modified Rankin Scale (mRS) score on discharge in treated patients. CCD was detectable by CTP in acute supratentorial ischemic stroke by processing the whole cerebellum volume. CCD perfusion asymmetry was significantly correlated with neurological and perfusion deficit on admission as well as with clinical outcomes in treated patients. • CCD could have a relevant role regarding the outcome of stroke and the rehabilitation potential. • CCD was detectable by whole cerebellum CTP processing. • CCD perfusion asymmetry correlated with neurological and perfusional deficit at admission. • CCD perfusion asymmetry correlated with clinical outcomes in treated patients. [ABSTRACT FROM AUTHOR]