Focal Hypoperfusion Research Articles

Post-ictal Todd's paralysis associated with focal cerebral hypoperfusion on computed tomography (CT) perfusion studies: A stroke mimic

Post-ictal Todd's paralysis associated with focal cerebral hypoperfusion on computed tomography (CT) perfusion studies: A stroke mimic

Computed tomographic perfusion abnormalities in acute migraine with aura: Characteristics and comparison with transient ischemic attack.

Migraine with aura (MA) accounts for up to 10% of "stroke mimics" and can present cerebral perfusion abnormalities. We aimed to compare perfusion-CT (PCT) findings in acute-onset MA mimicking an ischemic stroke with those observed in transient ischemic attack (TIA). We retrospectively studied patients admitted to our hospital between 2002 and 2014 with suspicion of acute ischemic stroke, having PCT and receiving a final diagnosis of MA. We visually assessed PCT for the presence and extent of focal hypoperfusion (FHP). MA patients with FHP were compared with consecutive TIA patients showing FHP. We performed both qualitative and quantitative analysis of PCT. Of 47 patients with MA (median age = 33 years, 55% females), 16 (34%) displayed FHP. Compared to MA patients without FHP, MA patients with FHP had similar headaches and aura features, but a less frequent history of MA (p = 0.010). Compared to 74 TIA patients with FHP (median age = 69 years, 43% females), MA patients with FHP showed hypoperfusion that more frequently involved adjacent vascular territories or a whole hemisphere (p < 0.001). In addition, hypoperfusion in MA patients had a less pronounced increase in rMTT (1.2 vs 1.8, p < 0.001) and rTTP (1.1 vs 1.2, p < 0.001), and a lesser decrease in rCBF (0.8 vs 0.6, p < 0.001) compared to hypoperfusion in TIA. rMTT displayed the best discriminative ability to differentiate MA from TIA. Focal perfusion abnormalities in acute MA often involve adjacent vascular territories and hypoperfusion is less pronounced than in TIA. MA can be best differentiated from TIA by a smaller rMTT increase.

Atrial fibrillation as a risk factor of cognitive impairment. Review

Atrial fibrillation (AF) and cognitive impairment (CI) are now common problems, especially among the elderly. Numerous studies in recent years demonstrated the relationship between AF and CI, including dementia. Given the increasing prevalence of AF with age and aging, the number of people with CI is prognosed to increase. Leading pathogenetic factors that play a role in the development of CI in AF include focal lesions (macro‑ and microinfarctions, microhemorrhages), cerebral hypoperfusion and systemic inflammatory response. Asymptomatic (hidden, or «silent») cerebral infarcts, which are an accidental finding during neuroimaging, are more common than manifest cerebral strokes and are associated with CI. In patients with AF they are found more often than in people without AF, so, according to many researchers, AF is a significant factor in their occurrence. It should be emphasized that CI, dementia and brain aging can be prevented. Healthy lifestyles (special attention to a healthy diet, adequate physical activity and normal body weight) and proper treatment of vascular risk factors such as hypertension, diabetes mellitus, hypercholesterolemia and AF are of the utmost importance for maintaining healthy brain. Recent studies have shown the advantage of direct oral anticoagulants over warfarin in preventing the development of CD in patients with AF. Promising areas of research are the study of new (including genetic) biomarkers of high risk of KR, comparison of direct oral anticoagulants to determine optimal prevention of KR, increase patient adherence to therapy, the use of non‑pharmacological strategies to maintain sinus rhythm.

Isolated aphasic status epilepticus: CT perfusion, SPECT and EEG reveal neurovascular coupling and support the differential diagnosis.

Objective Among the clinical manifestations of stroke mimics, isolated aphasia is one of the most challenging due to its aetiopathogenic diagnosis. This short communication describes a specific perfusion and brain oscillatory pattern in a challenging case of prolonged isolated aphasia caused by status epilepticus, jointly investigated by computed tomography (CT) perfusion, single-photon emission computerized tomography (SPECT)/CT and EEG qualitative and quantitative analysis. Methods We discuss the different patterns of perfusion neuroimaging and EEG between SE and ischaemic stroke or postictal (Todd's)-related isolated aphasia, and propose these differences as a basis to support the differential diagnosis. Results The pattern associated with SE was characterized by focal hyperperfusion on CT perfusion maps (the left mean transit time was shorter with >10% asymmetry, and left cerebral blood volume and cerebral blood flow increased or slightly altered, relative to the contralateral side) and SPECT (focal left temporal hyperperfusion), without any early ischaemic signs on non-enhanced CT, while the EEG showed a predominant left hemispheric slow delta power. The aforementioned perfusion pattern contrasts with postictal epileptic Todd's phenomenon, which is characterized by hypoperfusion on CT perfusion (the mean transit time is prolonged and cerebral blood volume and cerebral blood flow are reduced, compared to the contralateral hemisphere) and SPECT (focal hypoperfusion), not restricted to the specific vascular territories. Significance CT perfusion patterns may add valuable information to support the differential diagnosis of status epilepticus, rather than acute ischaemic stroke or postictal Todd's phenomenon, in cases with challenging symptoms of prolonged isolated aphasia.

Ischemic stroke on hormonal contraceptives: Characteristics, mechanisms and outcome.

Systemic contraceptives increase the risk of ischemic stroke but little is known about the characteristics, mechanisms and long-term outcome post stroke of patients on hormonal contraception. We sought to To assess characteristics and outcome of acute ischemic stroke (AIS) in young women using systemic hormonal contraceptives (SHC) and compare them to strokes in non-contraceptive users. Using the Acute STroke Registry and Analysis of Lausanne (ASTRAL), we analyzed demographics, risk factors, clinical, radiological and treatment data of consecutive female patients of <50 years between 2003 to 2015. We compared groups with and without SHC in a logistic regression analysis. Of the 179 female patients of <50 years during the observation period, 57 (39.6%) used SHC, 71.9% of whom, a combined oral contraceptive pill. On logistic regression contraceptive users were significantly younger but had comparable stroke severity. They had less migraine with aura and tobacco use, and more hyperlipidaemia. Also, contraceptive users had significantly less intra and extracranial stenosis and occlusion on arterial imaging, but more focal hypoperfusion on CT-perfusion. Undetermined mechanism of stroke was more frequent with SHC users, whereas rare mechanisms were more frequent in non-users. The contraceptive user group had a more favourable adjusted 12-month outcome with significantly fewer ischemic recurrences after stopping systemic contraception in all. Contraceptive users with ischemic strokes are younger and have lesser tobacco use and migraine with aura and more hyperlipidemia. Their stroke mechanism is more often undetermined using a standardised work-up, and their adjusted long-term outcome is more favourable with less stroke recurrence.

Diastolic blood pressure is associated with brain atrophy in hemodialysis patients: A single center case–control study

AbstractBrain atrophy (BA) is often found in neuroimaging of hemodialysis patients, representing parenchymal cerebral damage. Likely contributing factors to BA are age, chronic hypertension, diabetes mellitus and other cardiovascular risk factors of atherosclerosis that are also common among hemodialysis patients. BA may also occur due to focal ischemia and hypoperfusion during hemodialysis. However, data on optimal blood pressure (BP) in these patients are limited. The goal of this study was to determine whether the prevalence and severity of BA would be higher among hemodialysis patients with lower BP. A blinded neuroradiologist graded BA of all hemodialysis patients who underwent brain non‐contrast computerized tomography (CT) from 2015 to 2017 in our institution. Age‐ and sex‐matched patients with normal kidney function who underwent brain CT during the same period and technique served as the control group. A total of 280 patients were included in this retrospective study, with average BP of 140/70 mmHg among hemodialysis patients and 142/75 mmHg in the control group. BA was more common in dialysis patients and its severity increased with age and traditional cardiovascular risk factors. We observed a significant negative correlation between diastolic BP (DBP) at dialysis initiation and BA. Average DBP decreased with increasing severity of BA. These findings were observed in both hemodialysis and non‐CKD patients. BA was associated with lower DBP, which may induce cerebral hypoperfusion and ischemia. This finding should discourage over‐treatment of hypertension among hemodialysis patients.

Insulin Resistance is Associated with Central Pain in Patients with Fibromyalgia

Insulin resistance (IR) is a pathological condition in which cells fail to respond normally to insulin. IR has been associated with multiple conditions, including chronic pain. Fibromyalgia (FM) is one of the common generalized chronic painful conditions with an incidence rate affecting 3% to 6% of the population. Substantial interest and investigation into FM continue to generate many hypotheses.The relationship between IR and FM has not been explored. IR is known to cause abnormalities in the cerebral microvasculature, leading to focal hypoperfusion. IR also has been shown to cause cognitive impairment in FM patients, as in parkinsonism. As demonstrated by advanced imaging methods, similar brain perfusion abnormalities occur in the brain of patients with FM as with IR. To determine the potential association between FM and IR. Subspecialty pain medicine clinics. Observational cross-sectional study. Laboratory data was extracted through a retrospective review of medical records from patients who had met the American College of Rheumatology (ACR) criteria for FM. The Hemoglobin A1c (HbA1c) values from 33 patients with FM were compared with the means of the glycated HbA1c levels of 2 control populations. In addition, established indices of IR [Quantitative Insulin Sensitivity Check Index (QUICKI) and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)] were calculated in a subgroup of patients in whom the analytes necessary for these calculations were available. To assess for confounding factors, the associations between HbA1c, QUICKI, HOMA-IR, fasting insulin levels, and glucose, after controlling for age, were explored by multiple analyses of variance with relation to gender and ethnicity. We found an association between IR and FM that was independent of age, gender, and ethnicity. We found that patients with FM belong to a distinct population that can be segregated from the control groups by their HbA1c levels, a surrogate marker of IR. This was demonstrated by analyzing the data after introducing an age correction into a linear regression model. This strategy showed significant differences between patients with FM and control subjects (P < 0.0001 and P = 0.0002, for 2 separate control populations, respectively). A subgroup analysis using the QUICKI and HOMA-IR showed that all patients with FM in this subgroup (100%) exhibited laboratory abnormalities pointing to IR. Small observational cross-sectional study. There are also intrinsic limitations that are attributed to cross-sectional studies. The association demonstrated in this study warrant further investigation, including the pursuit of randomized, double-blind clinical trials to determine the effect of improving insulin sensitivity in FM related pain scores. Such studies could unveil a potential pathogenetic relationship between FM, central pain, and IR. Based on these initial findings, we present the hypothesis that IR may underlie pathological mechanisms leading to central pain. If confirmed, this may lead to a paradigm shift in the management of central pain.

The proatherogenic effect of high salt diet combined with focal hypoperfusion on spontaneous hypertension rat

Objective: To explore the histopathology, monocytes phenotypes and brain mRNA transcription of angiogenic and atherogenic factors preliminarily in spontaneous hypertensive rats (SHRs) fed with high salt diet and subjected to chronic focal hypoperfusion. Methods: A total of 21 SHRs were randomly assigned into SHR with normal diet (SHR-ND group, n=7), SHR fed with high salt (8%) chows (SHR-HSD group, n=14) groups. After induction of high salt diet for 20 weeks, unilateral carotid artery occlusion was applied to one half of SHR-HSD (SHR-HSD-UCAO, n=7) group for 10 weeks to mimic chronic focal cerebral hypoperfusion. The neuropathology, monocytes phenotypes and brain transcription of fibroblast growth factor (FGF-b), platelet-derived endothelial cell growth factor (PD-ECGF), angiogenin (ANG), transforming growth factor-β (TGF-β) and vascular endothelial growth factor A (VEGF-A) among three groups were compared. Results: The systolic blood pressure ((246±12) mmHg vs (220±16) mmHg, P=0.0291, 1 mmHg=0.133 kPa) and diastolic blood pressure ((189±15) mmHg vs (164±12) mmHg, P=0.0143) of SHR-HSD group were elevated significantly compared with those of SHR-ND group. Compared with normotensive Wistar-Kyoto (WKY), SHR-ND, SHR-HSD and SHR-HSD-UCAO groups demonstrated lipohyalinosis, vessel wall thickening, lumen narrowing and multiple enlarged perivascular space and diffuse disarrangement of nerve fiber and myelin vacuolation in corpus callosum pathologically. The ratio of CD11b(+) CD68(+) monocytes in peripheral blood of SHR-HSD group was higher compared with both SHR-ND and SHR-HSD-UCAO groups (P=0.000 8). The mean inflorescence index (MFI) of CD86 and CD206 showd considerable decline in SHR-HSD-UCAO group compared with those of SHR-HSD group (P=0.018 7 and 0.016 8, respectively). The CD86 MFI of CD11b+CD68+ monocytes in SHR-HSD-UCAO group was remarkably higher than that of SHR-ND and SHR-HSD groups (P=0.000 5). Compared with SHR-ND and SHR-HSD groups, the brain mRNA transcription of angiogenic factors including PD-ECGF and ANG were down-regulated (P=0.004 6 and 0.000 2, respectively), while the atherogenic factors including TGF-β and VEGF-A were up-regulated in SHR-HSD-UCAO group (P<0.000 1 and P=0.045, respectively). Conclusion: SHR-HSD-UCAO group shares the pathophysiological characteristics with advanced stage arteriosclerotic cerebral small vessel disease (aCSVD), including neuropathology, imbalanced circulating monocytes phenotypes and down-regulated angiogenic factors.

Hypoglycemia Causing Focal Cerebral Hypoperfusion and Acute Stroke Symptoms.

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The effects of hyperbaric oxygen therapy on the brain with middle cerebral artery occlusion.

Middle cerebral artery occlusion (MCAO) causes focal cerebral hypoperfusion, resulting in cerebral ischemia or ischemic stroke. The main therapeutic approach is to restore an adequate blood flow to the brain via the process of reperfusion. However, rapid reperfusion can itself aggravate brain damage; this adverse effect is known as ischemic/reperfusion (I/R) injury. The pathological conditions that occur after cerebral ischemia and cerebral I/R are microvascular injury, blood-brain barrier dysfunction, post-ischemic inflammation, increased oxidative stress/reactive oxygen species, and a reduction in neuronal survival, leading to brain infarction. Animal and clinical studies on hyperbaric oxygen therapy (HBOT) have recently been carried out, and there is evidence of positive effects on neurological outcomes after cerebral ischemia. However, some evidence has shown that HBOT may not affect the functional recovery after ischemic injury. This review describes the current evidence, both in vivo and clinical data, regarding the potential benefits of HBOT after MCAO and cerebral I/R injury. The contrary data are also discussed to verify the effectiveness of HBOT in stroke outcomes.

P1255DIASTOLIC BLOOD PRESSURE IS ASSOCIATED WITH BRAIN ATROPHY IN HEMODIALYSIS PATIENTS: A SINGLE CENTER CASE CONTROL STUDY

Abstract Background and Aims Brain atrophy (BA) is a common finding in neuroimaging of hemodialysis (HD) patients, representing a parenchymal cerebral damage. Likely contributing factors to BA are age, chronic hypertension, diabetes mellitus and other cardiovascular risk factors of atherosclerosis that are also common among HD patients. BA may also occur due to focal ischemia and hypoperfusion during HD. However, data on optimal blood pressure (BP) in these patients are limited. The goal of this study was to determine whether the prevalence and severity of BA would be higher among HD patients with lower BP. Method A blinded neuroradiologist graded BA of all HD patients who underwent brain non-contrast computerized tomography (CT) from 2015 to 2017 in our institution. Age-and sex-matched patients with normal kidney function who underwent brain CT during the same period and technique served as the control group Results A total of 280 patients were included in this retrospective study, with average BP of 140/70 mmHg among HD patients and 142/75 mmHg in the control group. BA was more common in dialysis patients and its severity increased with age and traditional cardiovascular risk factors. We observed a significant negative correlation between diastolic BP (DBP) at dialysis initiation and BA. Average DBP decreased with increasing severity of BA. These findings were observed in both HD and non-CKD patients. Conclusion Brain atrophy was associated with lower DBP, which may induce cerebral hypoperfusion and ischemia. This finding should discourage over-treatment of hypertension in hemodialysis patients.

Multimodal imaging in a case of a congenital retinal macrovessel associated with a retinal cavernous hemangioma: a case report

BackgroundTo report the results of multimodal imaging in a case of a congenital retinal macrovessel associated with a retinal cavernous hemangioma.Case presentationA 52-year-old female patient presented with progressive vision loss in the right eye. BCVA was 8/20 in the right eye and 18/20 in the left eye. Fundus examination of the right eye showed an aberrant retinal macrovessel arising from the inferior temporal major vein. It crossed the foveal area and overstepped to the superior retina. A “brunch of grapes” shaped retinal lesions arised from the macrovessel. Fluorescein angiography showed saccular lesions that filled slowly during the venous phase and became brightly hyperfluorescent saccular caps. SS-OCT of the right eye revealed a highly back-scattering hyper-reflective vessel across the fovea with shadow effect and adhesions between the vitreous and the aberrant macrovessel. It also revealed hypo reflective saccules with hyperreflective borders located in the inner retina corresponding to the cavernous retinal hemangioma. Retinal pigment epithelium undulations and vascular dilations at the level of Haller’s layer were observed in both eyes. Indocyanine green angiography revealed chroidal vascular dilatations in both eyes in the late phase. OCT-A showed the aberrant vessel emerging from the inferior temporal vein and splitting the foveal avascular zone horizontally. RCH appeared as small heterogeneous saccular flow areas associated with focal capillary hypo perfusion areas. Asymmetry and distorsion of the foveal avascular zone were also noticed.A diagnosis of retinal macrovessel associated with a retinal cavernous hemangioma was made.ConclusionsCongenital retinal macrovessels and retinal cavernous hemangioma are benign lesions. Their association is rare. Abnormal vascular development is likely to be responsible for their association. Swept source OCT and OCT angiography may be of a great contribution to better evaluate these retinal vascular disorders.

Focal Hypoperfusion in Acute Ischemic Stroke Perfusion CT: Clinical and Radiologic Predictors and Accuracy for Infarct Prediction.

Perfusion CT may improve the diagnostic performance of noncontrast CT in acute ischemic stroke. We assessed predictors of focal hypoperfusion in acute ischemic stroke and perfusion CT performance in predicting infarction on follow-up imaging. Patients from the Acute STroke Registry and Analysis of Lausanne data base with acute ischemic stroke and perfusion CT were included. Clinical and radiologic data were collected. We identified predictors of focal hypoperfusion using multivariate analyses. From the 2216 patients with perfusion CT, 38.2% had an acute ischemic lesion on NCCT and 73.3% had focal hypoperfusion on perfusion CT. After we analyzed 104 covariates, high-admission NIHSS, visual field defect, aphasia, hemineglect, sensory deficits, and impaired consciousness were positively associated with focal hypoperfusion. Negative associations were pure posterior circulation, lacunar strokes, and anticoagulation. After integrating radiologic variables into the multivariate analyses, we found that visual field defect, sensory deficits, hemineglect, early ischemic changes on NCCT, anterior circulation, cardioembolic etiology, and arterial occlusion were positively associated with focal hypoperfusion, whereas increasing onset-to-CT delay, chronic vascular lesions, and lacunar etiology showed negative association. Sensitivity, specificity, and positive and negative predictive values of focal hypoperfusion on perfusion CT for infarct detection on follow-up MR imaging were 66.5%, 79.4%, 96.2%, and 22.8%, respectively, with an overall accuracy of 76.8%. Compared with NCCT, perfusion CT doubles the sensitivity in detecting acute ischemic stroke. Focal hypoperfusion is independently predicted by stroke severity, cortical clinical deficits, nonlacunar supratentorial strokes, and shorter onset-to-imaging delays. A high proportion of patients with focal hypoperfusion developed infarction on subsequent imaging, as did some patients without focal hypoperfusion, indicating the complementarity of perfusion CT and MR imaging in acute ischemic stroke.

Arterial spin-labeling perfusion imaging of childhood encephalitis: correlation with seizure and clinical outcome.

In childhood encephalitis, perfusion abnormalities have been infrequently reported to associate with clinical status. We investigated whether perfusion abnormalities correlated with seizure and clinical outcome in encephalitis. We retrospectively analyzed the MR studies of 77 pediatric patients with encephalitis. Pseudo-continuous arterial spin-labeling (ASL) imaging was performed on a 3-T scanner. The patients were divided into five groups according to ASL perfusion imaging pattern: normal perfusion (NP), focal hypoperfusion (Lf), extreme global hypoperfusion (LE), focal hyperperfusion (Hf), and extreme global hyperperfusion (HE). Clinical outcome at 3weeks was dichotomized to unfavorable or favorable outcome according to the Glasgow outcome scale. Multivariate logistic regression was conducted to predict unfavorable outcome and presence of seizure separately, based on explanatory variables including age, sex, and ASL pattern. Twenty-seven (35%) patients were designated as in group Hf, five (7%) in group Lf, 11 (14%) in group LE, none in group HE, and 34 (44%) in group NP. Multivariate logistic regression analysis showed that ASL pattern was significantly associated with unfavorable outcome (P = 0.005) and with presence of seizure (P = 0.005). For ASL pattern, group LE was 17.31 times as likely to have an unfavorable outcome as group NP (odds ratio confidence interval [CI] 3.084, 97.105; P = 0.001). Group Hf was 6.383 times as likely to have seizure as group NP (CI 1.765, 23.083; P = 0.005). In childhood encephalitis, patients with extreme global hypoperfusion had poor neurological outcome and those with focal hypoperfusion were more likely to have seizure.

Transient Neurologic Deficit without Vascular Pathology Correlates with Reversible Focal Hypoperfusion on Arterial Spin Labeled Perfusion Imaging

AbstractWe present the case of a 16-year-old boy with altered mental status and magnetic resonance imaging demonstrating left hemispheric hypoperfusion without evidence of stroke, based on arterial spin labeling (ASL) and dynamic contrast-enhanced perfusion imaging. Vessel imaging on magnetic resonance angiography and computed tomography angiography, in addition to an echocardiogram, showed no evidence of an embolic source. Electroencephalography showed left posterior temporal slowing. Within 8 hours, he was awake and alert but with receptive aphasia, and within 24 hours his symptoms completely resolved. Repeat ASL perfusion imaging demonstrated complete resolution of the perfusion abnormality, and diffusion imaging revealed no areas of infarct. This report demonstrates the correlation between a transient neurologic deficit and reversible focal hypoperfusion measured by ASL cerebral perfusion.

Perfusion computed tomography in posterior circulation stroke: predictors and prognostic implications of focal hypoperfusion.

The aim was to determine the predictors of focal hypoperfusion on computed tomography (CT) perfusion (CTP) in patients with acute posterior circulation stroke and its association with long-term outcome. Patients with posterior circulation stroke were selected from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) who underwent CTP within 24h of stroke onset as part of the stroke imaging protocol. Hypoperfusion was defined as an area of visually well demarcated mean transit time prolongation corresponding to an arterial territory on standard reconstruction CTP imaging maps. Areas of hypoperfusion were assessed with the posterior circulation Acute Stroke Prognosis Early CT Score. Clinical and imaging associations with focal hypoperfusion were identified using multiple imputation analyses, and the adjusted functional outcome measured by the modified Rankin Scale at 3 and 12months was determined. Of the 3595 consecutive patients from the ASTRAL registry between 2003 and 2014, 1070 (29.7%) had a posterior circulation stroke and 436 of these (40.7%) patients had a good quality baseline CTP. 23.1% had early ischaemic changes and 37.4% had focal hypoperfusion. In multiple imputation analysis, visual field deficits, reduced level of consciousness, cardiac and multiple stroke mechanisms, significant vessel pathology and ischaemic changes visible on plain CT were associated with focal hypoperfusion. Focal hypoperfusion was independently associated with outcome at 12months (odds ratio 2.04, 95% confidence interval 1.22-3.42, P<0.01). In posterior circulation stroke patients undergoing acute CTP, multiple clinical, aetiological and radiological variables were associated with focal hypoperfusion. Patients with focal hypoperfusion had a worse 12-month outcome.

Cerebral perfusion and compensatory blood supply in patients with recent small subcortical infarcts

Hypoperfusion is the typical perfusion pattern associated with recent small subcortical infarcts of the brain, but other perfusion patterns may be present in patients with these infarcts. Using CT perfusion, we studied 67 consecutive patients who had a small subcortical infarct at a follow-up MRI study to investigate the correlation between the perfusion pattern and the clinical and radiological course. On CT perfusion map analysis, 51 patients (76%) had focal hypoperfusion, 4 patients (6%) had hyperperfusion and the remaining 12 patients (18%) showed no abnormalities. On dynamic sequential imaging analysis obtained from the source perfusion images, 32 patients (48%) had a sustained hypoperfusion pattern, 11 patients (16%) had a reperfusion pattern, and 18 patients (27%) had a delayed compensation pattern. Systolic blood pressure was higher in patients with sustained hypoperfusion although the perfusion pattern was independent of the final volume of infarction. These results reinforce the notion that mechanisms other than hypoperfusion are at play in patients with small subcortical infarcts including the intervention of compensatory sources of blood flow. The ultimate clinical significance of these perfusion patterns remains to be determined in larger series of patients assessed longitudinally.

Factors Associated With Focal Computed Tomographic Perfusion Abnormalities in Supratentorial Transient Ischemic Attacks

Computed tomographic perfusion (CTP) is useful in diagnosis of patients with transient focal neurological symptoms. In acute imaging of patients with a suspected transient ischemic attack (TIA), it remains unclear which patients develop focal perfusion abnormalities (FPA), that is, hypoperfusion or hyperperfusion. We aimed at determining independent factors associated with FPA in patients with supratentorial TIAs. We prospectively collected consecutive patients with supratentorial TIAs defined by the traditional time-based definition who underwent CTP within 24 hours of symptom onset. We recorded demographics, risk factors, clinical features, severity, and timing from onset. We documented the Age, Blood Pressure, Clinical Features, Duration, and Diabetes (ABCD2) scores, vascular territories, and presence of relevant arterial pathology. Variables were tested for an association with FPA with univariate and multivariate analyses. A hundred and ten of 265 patients (42%) with supratentorial TIAs had FPA on CTP. Acute noncontrast computed tomography showed early ischemic lesions in 6%, and acute/subacute magnetic resonance imaging was pathological in 52 of the 109 cases (47.7%) where it was performed. Clinical factors associated with FPA were high-admission National Institutes of Health Stroke Scale (odds ratio [OR], 1.22), right hemispheric TIA (OR, 3.09), and cardioembolic mechanism (OR, 2.19). Persistence of symptoms during CTP (OR, 2.59), shorter duration of TIA (OR, 0.93), major intracranial arterial pathology (OR, 12.5), and extracranial arterial occlusion (OR, 7.44) were also associated with FPA. Supratentorial TIAs are often associated with FPA in CTP, even after symptom resolution. FPAs are frequent in severe TIAs and those associated with cardioembolism or specific arterial pathologies. These findings can help clinicians in accurate diagnosis of TIA and its underlying mechanisms.

The syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis mimicking an acute stroke.

The syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) can present as sudden onset of focal neurological deficits which are clinically and radiologically indistinguishable from an ischaemic stroke. Its diagnosis requires a lumbar puncture (LP), which contraindicates intravenous thrombolytic therapy (IV-tPA). All patients referred to our stroke centre as a stroke code resulting in a final diagnosis of HaNDL syndrome from June 2005 to June 2015 were retrospectively analysed. Nine cases were identified: seven women and two men (mean age 27.6 years, range 15-51). Clinical onset consisted of isolated aphasia (two) and aphasia with right hemiparesis/hemiparaesthesia (seven). All patients had headache in the acute setting, lasting 2-12 h. Cranial computed tomography (CT) and CT angiography (CTA) were normal in all patients. Perfusion CT was performed in seven patients, showing left hemispheric focal hypoperfusion in five cases; the remaining two were normal. Five patients were initially diagnosed as stroke and treated uneventfully with IV-tPA. Cranial magnetic resonance imaging within 48 h was normal in all cases. LP performed in all patients showed pleocytosis (range 17-351 cells/mm(3) ), high protein levels (range 0.4-1.6 g/l) and normal glucose levels. All cases recovered within 12 h and suffered a second episode within 72 h. Patients were asymptomatic between episodes and after remission. The decision to thrombolyse or perform an LP in HaNDL patients mimicking a stroke is difficult in the acute setting. Perfusion CT can provide misleading results and CTA may be useful in ruling out occlusion of a cerebral vessel.

Interferon-β Modulates Inflammatory Response in Cerebral Ischemia.

BackgroundStroke is a leading cause of death in the world. In >80% of strokes, the initial acute phase of ischemic injury is due to the occlusion of a blood vessel resulting in severe focal hypoperfusion, excitotoxicity, and oxidative damage. Interferon‐β (IFNβ), a cytokine with immunomodulatory properties, was approved by the US Food and Drug Administration for the treatment of relapsing‐remitting multiple sclerosis for more than a decade. Its anti‐inflammatory properties and well‐characterized safety profile suggest that IFNβ has therapeutic potential for the treatment of ischemic stroke.Methods and ResultsWe investigated the therapeutic effect of IFNβ in the mouse model of transient middle cerebral artery occlusion/reperfusion. We found that IFNβ not only reduced infarct size in ischemic brains but also lessened neurological deficits in ischemic stroke animals. Further, multiple molecular mechanisms by which IFNβ modulates ischemic brain inflammation were identified. IFNβ reduced central nervous system infiltration of monocytes/macrophages, neutrophils, CD4+ T cells, and γδ T cells; inhibited the production of inflammatory mediators; suppressed the expression of adhesion molecules on brain endothelial cells; and repressed microglia activation in the ischemic brain.ConclusionsOur results demonstrate that IFNβ exerts a protective effect against ischemic stroke through its anti‐inflammatory properties and suggest that IFNβ is a potential therapeutic agent, targeting the reperfusion damage subsequent to the treatment with tissue plasminogen activator.