Role of multidetector computed tomography in patients with acute infectious colitis

BACKGROUND

The role of multidetector computed tomography (MDCT) in patients with acute infectious colitis is still unclear.

AIM

To examine the usefulness of MDCT in distinguishing the etiology of acute infectious colitis.

METHODS

Overall, 244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups (bacterial: 204, viral: 40) according to causes of acute colitis, based on stool PCR. Eleven MDCT parameters, including wall thickening, submucosal edema, mucosal enhancement, serosa involvement, empty colon sign, small bowel involvement, comb sign, continuous distribution, accordion sign, mucosal thickening, and lymph node enlargement, were constructed in a blinded fashion.

RESULTS

MDCT parameters of wall thickening (OR: 13.60; 95%CI: 5.80–31.88; P < 0.001), submucosal edema (OR: 36.08; 95%CI: 13.54–96.13; P < 0.001), mucosal enhancement (OR: 22.55; 95%CI: 9.28–54.81; P < 0.001), serosal involvement (OR: 14.50; 95%CI: 3.33–63.23; P < 0.001), empty colon sign (OR: 6.68; 95%CI: 2.44–18.32; P < 0.001), continuous distribution (OR: 24.09; 95%CI: 9.38–61.90; P < 0.001), accordion sign (OR: 9.02; 95%CI: 1.12–72.35; P = 0.038), mucosal thickening (OR: 46.41; 95%CI: 10.38–207.51; P < 0.001), and lymph node enlargement (OR: 4.39; 95%CI: 1.22–15.72; P = 0.023) were significantly associated with bacterial colitis. At least one positive finding in four CT outcomes (submucosal edema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed a high probability of bacterial colitis (sensitivity, 41.67; specificity, 92.50; OR: 24.95).

CONCLUSION

MDCT provides many clues that can be useful in suggesting a specific etiology of acute infectious colitis.

Neuroendocrine Tumor with Metachronous Gastrointestinal Stromal Tumor in a Patient: A Case Report

Neuroendocrine tumors (NETs) that arise from neuroendocrine cells can develop in most organs; however, it is rarely found in the duodenal papilla. Conversely, gastrointestinal stromal tumors (GISTs), which are mostly asymptomatic and detected incidentally, are usually found in the stomach and very rarely occur metachronously with NETs. A 42-year-old female with no specific underlying disease underwent gastroscopy due to epigastric pain. Biopsy of enlarged major and minor duodenal papilla confirmed the diagnosis of a NET. Endoscopic papillectomy of the major and minor papillae was performed. Multiple duodenal and jejunal submucosal nodules were seen on biliary CT performed at the 30 months follow-up. Pylorus-preserving pancreaticoduodenectomy was performed due to the suspicion of multiple recurrent NETs and muscularis propria involvement on endoscopic ultrasound. Surgical specimen biopsy confirmed the diagnosis of multiple duodenal and jejunal GIST lesions and a metastatic NET in the duodenal lymph node. We report a rare case of a GIST detected in the duodenum during follow-up after the diagnosis and papillectomy of duodenal papilla NET.

Hyperattenuating lesions after mechanical thrombectomy in acute ischaemic stroke: factors predicting symptomatic haemorrhage and clinical outcomes

AIM

To evaluate the clinical significance of hyperattenuating lesions on CT after mechanical thrombectomy for acute ischaemic stroke, and to identify imaging factors that predict symptomatic haemorrhage and unfavourable outcomes.

MATERIALS AND METHODS

Seventy-eight patients with acute ischaemic stroke in the anterior circulation who underwent mechanical thrombectomy were evaluated. All patients underwent post-interventional unenhanced computed tomography (CT) within 24 h and follow-up CT or magnetic resonance imaging (MRI) within 7 days. Baseline characteristics and clinical outcomes were compared between patients with and without hyperattenuating lesions. In patients with hyperattenuating lesions, clinical and imaging factors that predict symptomatic haemorrhage and unfavourable outcomes were determined.

RESULTS

Fifty-six of 78 patients (71.8%) demonstrated hyperattenuating lesions on post-interventional CT. Patients with hyperattenuating lesions showed lower Alberta Stroke Program Early CT score (ASPECTS), persistent/symptomatic haemorrhage, and unfavourable outcomes than those without. In patients with hyperattenuating lesions, larger hyperattenuating lesion volume (>21.3 ml; OR, 55.60, p<0.001) and perilesional oedema (OR, 46.04, p=0.015) were independent factors predicting symptomatic haemorrhage. Older age (OR, 1.2, p=0.006) and lower ASPECTS (OR, 0.45, p=0.046) were independent factors predicting unfavourable outcomes in patients with hyperattenuating lesions. Adding the volume of the hyperattenuating lesion to age and ASPECTS increased the predictive performance of unfavourable outcomes (area under the curve 0.874 versus 0.934, p=0.043).

CONCLUSIONS

Hyperattenuating lesions on post-interventional CT are associated with increased risk of symptomatic haemorrhage and unfavourable outcomes. Larger hyperattenuating lesion volume is an independent factor of symptomatic haemorrhage and it has added predictive value for unfavourable outcomes.

Association between body mass index and stroke severity in acute ischaemic stroke with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

The objective of this study was to investigate the association between body mass index (BMI) and both initial stroke severity at presentation and functional outcomes after acute ischaemic stroke (AIS) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

Patients were categorized on the basis of their BMI into underweight (BMI <18.5, n = 111), normal (18.5 ≤ BMI <25, n = 1036) and overweight to obese (BMI ≥25, n = 472) groups. Initial stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score and functional outcomes were assessed using the modified Rankin Scale score at discharge. The differences in stroke severity and functional outcomes were compared between groups using robust log-linear regression with a Poisson distribution and binary logistic regression analysis.

RESULTS

A total of 1619 AIS patients with NVAF from six hospitals were included. Compared with the NIHSS scores [median 5, interquartile range (IQR) 2-14] of normal-weight patients, the NIHSS scores (median 9, IQR 4-19) of underweight patients were more likely to be higher, whereas those of overweight to obese patients were lower (median 4, IQR 1-12) (P < 0.001). In terms of functional outcomes after stroke, underweight patients had a higher risk of poor functional outcomes (odds ratio 1.78, 95% confidence interval 1.09-2.56, P = 0.01) but overweight to obese patients had no significant difference in functional outcomes compared with normal-weight patients.

CONCLUSION

An inverse association was found between BMI and stroke severity in AIS patients with NVAF. This suggests the presence of an obesity paradox for short-term outcomes in patients with NVAF.

[A Case of Biliary Obstruction Caused by Liver Cyst]

Most cystic lesions of the liver are found incidentally in imaging studies because they are not symptomatic, and generally do not require treatment. Rarely, however, symptomatic hepatic cysts may develop complications and require treatment. Here, we describe a case of a 77-year-old woman who developed biliary obstruction with abdominal pain due to compression of the bile duct by a simple hepatic cyst. We confirmed the diagnosis based on symptoms and imaging studies. The patient'ssymptoms improved after simple cyst ablation by sclerotherapy.

Prognostic significance of volume-based 18F-FDG PET/CT parameter in patients with surgically resected non-small cell lung cancer. Comparison with immunohistochemical biomarkers

AIM

We investigated the prognostic value of volume-based 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) parameters compared with other factors including several immunohistochemical biomarkers in patients with surgically resected non-small cell lung cancer (NSCLC).

PATIENTS, METHODS

STUDY PARTICIPANTS

290 patients with surgically resected and histopathologically confirmed NSCLC. The maxmum standardized uptake value (SUVmax) and metabolic tumour volume (MTV) of the primary tumour were obtained on 18F-FDG PET/ computed tomography (CT) for initial staging and Ki-67 labeling index (LI), p16, CD31 and cyclin E were evaluated in the primary tumours by immunohistochemical staining. Survival analyses for variables including PET parameters, immunohistochemical biomarker and other clinical factors were performed using the Kaplan-Meier method and Cox proportional hazards regression analysis.

RESULTS

In univariate analyses, tumour stage, tumour size, and MTV were significant prognostic factors for decreased overall survival (OS) and disease-free survival (DFS). Multivariate analyses showed MTV and tumour stage were significant predictors of poor OS (MTV, hazard ratio (HR) = 1.135, p = 0.015; stage, HR = 0.644, p = 0.025) and DFS (MTV, HR = 1.128, p = 0.043; stage, HR = 0.541, p = 0.009).

CONCLUSION

The MTV of primary tumours is a significant prognostic factor for survival along with tumour stage in patients with surgically resected NSCLC. The MTV can predict OS and DFS better than immunohistochemical biomarkers.

Differential impact of unrecognised brain infarction on stroke outcome in non-valvular atrial fibrillation

There has been little information regarding the impact of unrecognised brain infarctions (UBIs) on stroke outcome in patients with non-valvular atrial fibrillation (NVAF). By using volumetric analysis of ischaemic lesions, we evaluated the potential impact of UBIs on clinical outcome according to their presence and categorised type. This study enrolled 631 patients with NVAF having no clinical stroke history. UBIs were categorised into three types as territorial, lacunar, or subcortical. We collected stroke severity, functional outcome at three months, and the total volume of UBIs and acute infarction lesions. We investigated the association between clinical outcome and the type or volume of UBI, using a linear mixed model and logistic regression analysis. UBIs were detected in 285 (45.2 %) patients; territorial UBIs were observed in 24.4 % of patients (154/631), lacunar UBIs in 25 % (158/631), and subcortical UBIs in 15.7 % (99/631). Although initial stroke severity was not different between patients with UBIs and those without, those with UBIs had less improvement during hospitalisation, leading to poorer outcome at three months. Among the three types of UBIs, only territorial UBIs were associated with poor outcome, especially in patients with relatively smaller acute infarction volume. UBIs, in particular, territorial UBIs, may be considered as predictors for poor outcome after ischaemic stroke in patients with NVAF. Our results suggest that the impact of UBIs on clinical outcome differs according to the type of UBIs and the acute stroke severity.

Comparison of stent retriever and intra-arterial fibrinolysis in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Although the stent retriever (SR) has shown a better reperfusion rate and clinical outcome than the older generation mechanical clot retrieval device, it is uncertain whether the SR is superior to intra-arterial fibrinolysis (IAF).

METHODS

Ischaemic stroke patients who were treated with SR or IAF as initial endovascular treatment modality for unilateral arterial occlusion in the anterior circulation were included. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favourable clinical outcome was defined as a modified Rankin Score ≤2 at 3 months.

RESULTS

Between January 2009 and May 2012, 55 patients were treated with SR and 50 patients were treated with IAF. The baseline characteristics were similar between the two groups except for the occlusion site and rescue treatment. In binary logistic regression analysis adjusted for the occlusion site and rescue treatment, SR was independently associated with increased successful reperfusion [82.0% vs. 47.3%; odds ratio (OR) 5.21; 95% confidence interval (CI) 1.92-14.14) and a more favourable clinical outcome at 3 months (54.0% vs. 43.6%; OR 3.40; 95% CI 1.31-8.84). The frequency of symptomatic intracranial haemorrhage and mortality at 3 months was not different between the two groups.

CONCLUSIONS

Stent retriever was as safe as and more effective than IAF. Our findings suggest that SR may be considered as an initial modality rather than IAF in acute stroke patients who undergo endovascular treatment.

The association between asymptomatic coronary artery disease and CHADS2 and CHA2 DS2 -VASc scores in patients with stroke

BACKGROUND AND PURPOSE

CHADS2 and CHA2 DS2 -VASc scores are measurement tools that stratify thromboembolic risk in patients with non-valvular atrial fibrillation, and are predictive of cerebral atherosclerosis, fatal stroke and ischaemic heart disease. Patients with higher CHADS2 and CHA2 DS2 -VASc scores are more likely to have had an akinetic/hypokinetic left ventricular segment or a recent myocardial infarction, all of which are associated with coronary artery disease (CAD). Most of the CHADS2 score components are also risk factors for atherosclerosis. Thus, CHADS2 and CHA2 DS2 -VASc scores may be predictive of CAD.

METHODS

In all, 1733 consecutive patients with acute ischaemic stroke who underwent multi-slice computed tomography coronary angiography were enrolled. The association of CHADS2 and CHA2 DS2 -VASc scores with the presence and severity of CAD was investigated.

RESULTS

Of the 1733 patients, 1220 patients (70.4%) had any degree of CAD and 576 (33.3%) had significant CAD (≥ 50% stenosis in at least one coronary artery). As the CHADS2 and CHA2 DS2 -VASc scores increased, the presence of CAD also increased (P < 0.001). The severity of CAD was correlated with CHADS2 score (Spearman coefficient 0.229, P < 0.001) and CHA2 DS2 -VASc score (Spearman coefficient 0.261, P < 0.001). In multivariate analysis, after adjusting for confounding factors, CHADS2 and CHA2 DS2 -VASc scores ≥2 were independently associated with CAD. The CHA2 DS2 -VASc score was a better predictor of the presence of CAD than the CHADS2 score on area under the curve analysis.

CONCLUSION

CHADS2 and CHA2 DS2 -VASc scores were predictive of the presence and severity of CAD in patients with stroke. When a patient has high CHADS2 or CHA2 DS2 -VASc scores, physicians should consider coronary artery evaluation.

The frequency of cerebral microbleeds increases with CHADS(2) scores in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMBs) are extravasations of blood from lipohyalinized or amyloid angiopathic cerebral arterioles, and the presence and numbers of CMBs are significantly associated with the development of oral anticoagulation (OA)-related intracranial haemorrhage (ICH). The aim of this study was to investigate whether there is a difference in CMBs burden according to CHADS(2) scores or CHA(2) DS(2) -VASc scores in non-valvular atrial fibrillation (NVAF) patients.

METHODS

We included 550 ischaemic stroke patients who had NVAF and who had undergone brain magnetic resonance imaging (MRI) with gradient-recalled echo (GRE) T2 sequences from our prospective stroke registry between January 2005 and November 2011. We calculated CHADS(2) scores and CHA(2) DS(2) -VASc scores for all patients based on their underlying cardiovascular diseases. The presence, location and number of CMBs were assessed in each patient. We also investigated whether the CMBs were actually associated with the development of ICH during follow-up.

RESULTS

The mean patient age was 70.4 ± 10.5 years, and 324 (58.9%) patients were men. One-hundred and seventy-three patients (31.5%) had CMBs detected on GRE MRI. Higher CHADS(2) scores or CHA(2) DS(2) -VASc scores were strongly associated with the presence and number of CMBs. During follow-up of median 3.1 ± 1.6 years, the presence of CMBs was independently associated with the development of ICH, whilst the CHADS(2) scores or CHA(2) DS(2) -VASc scores were not.

CONCLUSIONS

Considering the positive association between the presence of CMBs and OA-related ICH, our results suggest that the increase in ICH in high-risk groups during OA may be related to an increased burden of CMBs.

Magnesium-doped zinc oxide electrochemically grown on fluorine-doped tin oxide substrate

Nanostructures of magnesium (Mg) doped Zinc oxide (ZnO) were successfully deposited on conducting fluorine-doped tin oxide (FTO) coated glass plates by cathodic electrochemical deposition method at different potentials and temperature conditions. The deposited samples were characterized by XRD and SEM techniques to confirm their structures, morphologies and optical properties. These measurements show that Mg doped ZnO has a wurtzite structure and that the strongest intensity of the (002) peak is found at 60 degrees C and -1.0 V. Tunable transmittance of Mg doped ZnO has a band gap energy from 3.45 eV to 3.82 eV, which is the direct evidence of doping.

Use of a handheld, computerized device as a decision support tool for stroke classification

BACKGROUND

The Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification has been widely used to determine etiology of ischemic stroke. However, interrater reliability is known to be modest. The complexity of abstraction and the interpretation of various clinical and laboratory data might limit the accuracy of the TOAST classification. In this study, we developed a computerized clinical decision support system for stroke classification that can be used in a handheld device and tested whether this system can improve diagnostic accuracy and reliability.

METHODS

Based on the TOAST classification, a logical algorithm was developed and implemented on a handheld device, named iTOAST. After answering six questions using the touch interface, the stroke subtype result is displayed on the screen. Four neurology residents were randomly assigned to classify stroke subtypes using iTOAST or the conventional method (cTOAST). Using a crossover design, they classified the stroke subtypes of 70 patients. The standard subtypes were determined by three stroke experts. Correlated kappa coefficients using iTOAST compared with cTOAST were determined.

RESULTS

The kappa (SE) value of iTOAST [0.790 (0.041), 95% CI: 0.707-0.870] was higher than that of cTOAST [0.692 (0.046), 95% CI: 0.600-0.782] (P<0.001). Neither sequence (P=0.857) nor period effect (P=0.999) was observed.

CONCLUSIONS

The stroke classification tool using a handheld, computerized device was easy, accurate, and reliable over the conventional method. It may have additional benefit because a handheld, computerized device is accessible anytime and anywhere.

Early neurological outcomes according to CHADS2 score in stroke patients with non-valvular atrial fibrillation

BACKGROUND AND PURPOSE

A higher CHADS(2) score or CHA(2)DS(2)-VASc score is associated with an increased risk of ischaemic stroke in patients with non-valvular atrial fibrillation (NVAF). However, there are no data regarding early neurological outcomes after stroke according to the risk levels.

METHODS

In this study, a total of 649 stroke patients with NVAF were enrolled and categorized into three groups: low-risk (CHADS(2) score of 0-1), moderate-risk (CHADS(2) score 2-3), or high-risk group (CHADS(2) score ≥4). CHA(2)DS(2)-VASc score was divided into four groups including 0-1, 2-3, 4-5, and ≥6. We investigated whether there were differences in initial stroke severity, early neurological outcome, and infarct size according to CHADS(2) score or CHA(2)DS(2)-VASc score in stroke patients with NVAF.

RESULTS

The initial National Institutes of Health Stroke Scale (NIHSS) score was highest in high-risk group [9.5, interquartile range (IQR) 4-18], followed by moderate-risk (8, IQR 2-17) and low-risk group (6, IQR 2-15) (P=0.012). Likewise, initial stroke severity increased in a positive fashion with increasing the CHA(2)DS(2)-VASc score. During hospitalization, those in the high-risk group or higher CHA(2)DS(2)-VASc score had less improvement in their NIHSS score. Furthermore, early neurological deterioration (END) developed more frequently as CHADS(2) score or CHA(2)DS(2)-VASc score increased. Multivariate analysis showed being in the high-risk group was independently associated with END (OR 2.129, 95% CI 1.013-4.477).

CONCLUSIONS

Our data indicate that patients with NVAF and higher CHADS(2) score or CHA(2)DS(2)-VASc score are more likely to develop severe stroke and a worse clinical course is expected in these patients after stroke presentation.

Effect of warfarin withdrawal on thrombolytic treatment in patients with ischaemic stroke

BACKGROUND AND PURPOSE

  Abruptly discontinuing warfarin may induce a rebound prothrombotic state. Thrombolytic agents may also paradoxically induce prothrombotic conditions, which include platelet activation and thrombin generation. Therefore, prothrombotic states may be enhanced by withdrawing warfarin in patients under thrombolytic treatment. This study was aimed to determine whether patients with warfarin withdrawal have different clinical outcomes from those without warfarin use after thrombolytic treatment.

METHODS

  A total of 148 consecutive patients with atrial fibrillation who were not on anticoagulants at admission and who received thrombolysis were included in this study. We compared the outcomes between a warfarin withdrawal group and a no-warfarin group.

RESULTS

  Fourteen patients (9.5%) were included in the warfarin withdrawal group. Although baseline National Institute of Health Stroke Scale (NIHSS) scores, recanalization rates, and hemorrhage frequencies did not differ between the groups, the warfarin withdrawal group showed poorer outcomes. Increased NIHSS scores during the first 7days were more frequent in the warfarin withdrawal group (57.1% vs. 26.9%, P=0.029). The median percent improvement in NIHSS scores at 24h after thrombolysis was also lower in the warfarin withdrawal group. After adjusting for covariates, warfarin withdrawal was a strong predictor of poor functional outcome at 3months (modified Rankin score≥3) (odds ratio, 17.067, 95% CI 2.703-107.748).

CONCLUSIONS

  Discontinuing warfarin was associated with early neurologic deterioration and poor long-term outcomes after thrombolytic treatment.

Failure of complete recanalization is associated with poor outcome after cardioembolic stroke

BACKGROUND

  Recanalization is strongly associated with outcomes after thrombolytic treatment. Cardiac emboli are known as better response to fibrinolytic agents because they are fibrin-rich; however, cardioembolic stroke itself is associated with poor outcomes and high mortality. Completeness of recanalization may therefore affect the outcome of cardioembolic stroke. We investigated whether degree of recanalization influences outcomes following fibrinolytic therapy in cardioembolic stroke.

METHODS

  Consecutive stroke patients with relevant artery occlusions on baseline CT angiography who had received thrombolytic treatment were enrolled. Completeness of recanalization was assessed by the Thrombolysis in Myocardial Infarction (TIMI) grade, which was compared between patients with and without cardiac sources of embolism (CSE). We also investigated independent predictors of poor outcome (modified Rankin scale score 3-6) at 3 months.

RESULTS

  Of the 127 patients enrolled, 65 (51%) had one or more CSE. Although the overall recanalization rates (TIMI 2 or 3) in patients with CSE (65%) and patients without CSE (68%) were similar (P=0.710), patients with CSE were less likely to show complete recanalization (TIMI 3) compared with those without CSE (19% vs. 39%, P=0.011). Multivariate analysis revealed that CSE was associated with failure of complete recanalization (OR 2.809, 95% CI 1.097-7.192) and was an independent predictor of poor outcome at 3months (OR 3.629, 95% CI 1.205-8.869).

CONCLUSIONS

  In cardioembolic strokes, failure of complete recanalization following thrombolytic therapy was frequent and was associated with poor outcome after thrombolysis.

The different infarct patterns between adulthood-onset and childhood-onset moyamoya disease

BACKGROUND AND PURPOSE

The pattern of infarctions based on the findings of diffusion-weighted image was assessed, and it was also investigated whether there are any age-specific differences in patients with moyamoya disease (MMD).

METHODS

The subjects were 66 consecutive patients with MMD who had an acute cerebral infarction. Each ischaemic lesion was categorised into one of seven patterns (gyral, atypical territorial, honeycomb, classic territorial, multiple-dot, borderzone, deep lacunar) based on diffusion-weighted image findings. The patterns were compared between adulthood-onset MMD (A-MMD, ≥20 years old, 34 patients) and childhood/adolescent-onset MMD (C-MMD, <20 years old, 32 patients) according to their ages of infarct presentation.

RESULTS

A total of 91 infarct patterns were observed from 66 patients. The gyral, atypical territorial, and honeycomb patterns, which are not usually seen in conventional stroke patients, were common in MMD (68.1%). Among all patterns, a gyral pattern was most common (40/91, 44.0%). Borderzone and deep lacunar patterns were infrequent. Gyral and borderzone patterns were more frequently seen in the C-MMD group, whereas a honeycomb pattern was not seen in young patients. Honeycomb pattern was more common at advanced vascular stages. Infarctions confined to the cortex were more common in the C-MMD group (26/32, 75.0%) than in A-MMD patients (14/34, 41.2%).

CONCLUSIONS

Moyamoya disease showed various characteristic and age-specific infarct patterns. Different infarct patterns between the A-MMD and C-MMD groups may be associated with age-specific vulnerability of the brain to ischaemia, stage of arteriopathy or changes of abnormal collateral pathways.

Comparison of the characteristics for in-hospital and out-of-hospital ischaemic strokes

BACKGROUND AND PURPOSE

Patients who are being admitted to a hospital due to diseases other than stroke may develop a stroke (in-hospital stroke; IHS).

METHODS

We enrolled 111 consecutive patients who developed IHS outside a neurology ward during a 5-year period at a single hospital. The frequency, characteristics, and outcomes for IHS patients were compared with patients who develop ischaemic stroke outside of the hospital (out-of-hospital stroke; OHS).

RESULTS

Forty-six percent of IHS occurred in the department of cardiology or cardiovascular surgery and 60% were associated with surgery or procedures. In comparison with the OHS patient group, the IHS patient group showed an increased frequency of cardiac disease, leukocytosis, and anemia. Cardioembolism, stroke of other determined etiologies, and an incomplete evaluation were more common in the IHS group, whereas large artery atherosclerosis was more frequent in the OHS group. The IHS group had up to a 10-fold higher mortality than the OHS group, with sepsis being the most common cause of death in the IHS group.

CONCLUSIONS

IHS has distinct etiologies and stroke mechanisms from OHS. The prevention and management of infection could decrease mortality in IHS patients.

Thrombus volume comparison between patients with and without hyperattenuated artery sign on CT

BACKGROUND AND PURPOSE

Although the hyperattenuated middle cerebral artery sign is known to be related to acute infarction, the volume of clot associated with it is not known. We investigated whether the presence or absence of hyperattenuated artery sign (HAS) on noncontrast CT (NCCT) can predict the thrombus volume.

MATERIALS AND METHODS

We enrolled 90 consecutive patients with acute infarction who underwent both 5- and 1.25-mm NCCT and CT angiography (CTA). HAS was determined on 5-mm NCCT retrospectively. According to the location of thrombi, the patients were classified into ICA (ICA terminus/ICA and others), M1 (M1/both M1 and M2), and M2 (M2) groups. Thrombus volumes were measured by 1.25-mm NCCT and were compared between patients with and without HAS.

RESULTS

Occlusion of major arteries was seen on CTA in 78 patients. HAS was found in 46 patients (59.0%). The mean thrombus volume was significantly larger in patients with HAS than in those without except for the M2 group (ICA group: [n = 14], 188.7 +/- 122.5 mm(3) versus 39.4 +/- 12.1 mm(3) [P = .022]; M1 group: [n = 42], 128.1 +/- 119.2 versus 56.8 +/- 32.5 [P = .005]; M2 group: [n = 22], 34.7 +/- 32.2 versus 20.0 +/- 20.0 [P = .18]). Thrombus volumes determined by receiver operating characteristic curve analysis were 52.36 mm(3) in the ICA group (sensitivity, 90.9%; specificity, 100%) and 53.96 mm(3) in the M1 group (sensitivity, 88.0%; specificity, 58.8%).

CONCLUSION

Thrombus volumes were significantly larger in patients with HAS than in those without in ICA and M1 occlusions. The detection of HAS may provide an idea concerning rapid and dichotomized estimation of thrombus volume, which may be helpful for treatment decisions in potential candidates for thrombolysis.

Prediction of thrombolytic efficacy in acute ischemic stroke using thin-section noncontrast CT

Thin-section noncontrast CT (NCT) can detect thrombi in large arteries and can provide a measure of thrombus composition based on Hounsfield Units (HU). A study using polyethylene tubes as a model of intracranial arteries concluded that the HUs of platelet-rich thrombi are lower than those of erythrocyte-rich thrombi. Thrombus HUs were measured by NCT in 34 patients with acute ischemic stroke before thrombolysis. Thrombi with lower HU counts were resistant to thrombolytics.

Association of aortic plaque with intracranial atherosclerosis in patients with stroke

OBJECTIVE

To determine whether there is a relationship between aortic plaques and intracranial (IC) atherosclerosis.

METHODS

We reviewed 922 patients with stroke who had both transesophageal echocardiography and cerebral angiography. The plaques of these patients were classified as either complex aortic plaques (CAP), which protruded > or =4 mm or were present as mobile lesions in the proximal aorta, or simple aortic plaques (SAP), which were <4 mm or present in the descending aorta. Cerebral artery atherosclerosis was classified as either an IC or extracranial (EC) atherosclerosis.

RESULTS

Among the 922 patients, we found aortic plaques in 237 patients (26%). There were 111 (47%) patients of SAP, 74 (31%) patients with CAP, and 52 (22%) patients that had both SAP and CAP. Angiography showed IC or EC atherosclerosis in 511 patients (55%). The presence of aortic plaques was significantly associated with IC or EC atherosclerosis. The significance appeared to be due to the strong association between the presence of SAP and IC atherosclerosis (51% SAP vs 35% no plaques; odds ratio = 1.94, 95% CI: 1.17 to 3.21). In the multiple logistic regression analysis, SAP were independent predictors of IC atherosclerosis

CONCLUSIONS

The presence of simple aortic plaques may be a marker of advanced vascular disease. Detection of simple aortic plaques during transesophageal echocardiography may have clinical implications because patients with these plaques frequently had concomitant intracranial atherosclerosis, a risk factor for stroke.

Hemodynamic changes in limb shaking TIA associated with anterior cerebral artery stenosis

Limb shaking TIA is a rare but well-known feature of severe carotid artery stenosis. The authors report a patient who developed recurrent shaking movements of a leg. An angiogram showed the focal stenosis of the anterior cerebral artery. Ictal and postacetazolamide SPECT scans suggested a local hyperfunction of cortical neurons and an impaired hemodynamic reserve in the vicinity of the ischemic area.

Cloning and expression of a novel esterase gene cpoA from Burkholderia cepacia

AIMS

To screen and clone a novel enzyme with specific activity for the resolution of (R)-beta-acetylmercaptoisobutyrate (RAM) from (R,S)-beta-acetylmercaptoisobutyrate [(R,S)-ester].

METHODS AND RESULTS

A micro-organism that produces a novel esterase was isolated and identified as the bacterium Burkholderia cepacia by using the analysis of cellular fatty acids, Biolog automated microbial identification/characterization system, and 16S rRNA gene sequence analysis. A novel esterase gene was cloned from the chromosomal DNA of B. cepacia and was designated as cpoA. The cpoA encodes a polypeptide of 273 amino acids which shows a strong sequence homology with many bacterial nonhaeme chloroperoxidases. In addition, a typical serine-hydrolase motif, Gly-X-Ser-X-Gly, and the highly conserved catalytic triad, Ser95, Asp224, and His253, were identified in the deduced amino acid sequence of cpoA by multiple sequence alignment.

CONCLUSION

The cpoA cloned from B. cepacia encodes a novel esterase which is highly related to the nonhaeme chloroperoxidases.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes the isolation and cloning of a serine esterase gene from B. cepacia, which is useful in the chiral resolution of (R,S)-ester. The cloned gene will allow additional research on the bifunctionality of the enzyme with esterase and chloroperoxidase activity at the structural and functional levels.

Yonsei Stroke Registry. Analysis of 1,000 patients with acute cerebral infarctions

BACKGROUND AND PURPOSE

The hospital-based stroke registry is a well-established method useful for understanding diverse clinical characteristics of stroke related to geographical, racial or environmental differences. We analyzed the data from 1,000 patients with acute cerebral infarctions registered with the Yonsei Stroke Registry (YSR) which is the first prospective hospital-based observational study in Korea.

METHODS

All patients had cerebral infarctions and presented within 7 days of onset. CT or MRI was performed in all patients and a vascular imaging study (digital subtraction or magnetic resonance angiography) was conducted in 53.9% of the patients. Subtype classification was made through a consensus approach based on the strict application of TOAST criteria.

RESULTS

The mean age of patients was 62 +/- 12 years, and 60.8% were males. Undetermined cause (UD) was the most frequent subtype (40.6%), which was followed by lacunar stroke (LS 21.5%), cardiac embolism (CE 18.3%), large-artery atherosclerosis (LAA 16.5%) and other determined causes (3.1%). Hypertension was found in 64.3%, smoking in 35.2%, diabetes mellitus in 26.9%, hypercholesterolemia in 24.1%, high hematocrit (> or = 50%) in 21.8%, clinically identified potential cardiac sources of embolism in 18.3%, a history of previous stroke in 22.0% and a history of previous transient ischemic attack in 4.7%. Recurrent stroke was associated with a higher number of risk factors (p < 0.001) and a higher incidence of LAA (p = 0.003) than the first stroke. Vertebrobasilar artery territorial infarction was found in 39.8%, which was associated with higher incidences of LAA and LS and a lower incidence of CE than carotid artery territorial lesions (p = 0.001). The 30-day mortality rate was 5.3% and cerebral herniation caused early death in 52%.

CONCLUSION

The distribution of stroke subtypes in the YSR was largely comparable with that of western registries. The highest incidence of UD might be related to the strict application of TOAST criteria.

Localization of Claude's syndrome

Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.

Effect of the absence of heat shock protein 70.1 (hsp70.1) on retinal photoreceptors in normal and rd mice

The purposes of this study are to elucidate the retinal changes of heat shock protein 70.1 (hsp70.1) knockout mice and to compare them between in normal and in retinal degeneration (rd) mice. Eyes of hsp70.1 wild type (+/+) and knockout (-/-) mice in the C57BL/6 or FVB genetic backgrounds respectively, which were reared in the normal environment, were examined by fundus photography, electroretinography, light microscopy, terminal dUTP nick-end labeling (TUNEL) stain, and immunohistochemistry. In C57BL/6 mice, fundus photography showed no changes between hsp70.1+/+ and -/- mice at 1 and 6 months of age. Electroretinographic examination showed a tendency of decreased amplitude of a- and b-wave with aging in both genotype, but there were not different statistically. The ratios of the thickness of inner nuclear and outer nuclear layer to the retinal thickness were respectively decreased with aging in both genotype, but there were not different statstically. TUNEL assay showed a few positively labeled cells in the ganglion cell, inner nuclear and outer nuclear layers and the immunohistochemistry showed no immunopositivity of hsp70 in the inner segments of photoreceptor cell layer in both genotype. In rd mice, fundus photography showed a narrowing of the retinal vessels at the age of 4 weeks, however, there were no differences of retinal changes including pigment epithelial layer in both genotype. Electroretinographic examination at the postnatal 2, 3 and 4 weeks showed no differences between them. Loss of photoreceptor cell and outer nuclear layers showed no differences in both genotype. In conclusion, there were no differences of the retinal changes at least under the normal environmental condition in hsp70.1+/+ and -/- mice. These results show that hsp70.1-/- mice can be used to study the role of hsp70.1 to the external stress to the retina.

Rescue treatment with abciximab in acute ischemic stroke

In acute ischemic stroke, reocclusion after an initially successful thrombolysis treatment can occur and is associated with increased morbidity and mortality. The authors present the successful use of abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, in a patient with a thrombotic occlusion of the proximal middle cerebral artery, which was refractory to combined IV and intra-arterial thrombolysis and percutaneous intracranial balloon angioplasty.

Rapid differential endogenous plasminogen activator expression after acute middle cerebral artery occlusion

BACKGROUND AND PURPOSE

During focal cerebral ischemia, the microvascular matrix (ECM), which participates in microvascular integrity, is degraded and lost when neurons are injured. Loss of microvascular basal lamina antigens coincides with rapid expression of select matrix metalloproteinases (MMPs). Plasminogen activators (PAs) may also play a role in ECM degradation by the generation of plasmin or by MMP activation.

METHODS

The endogenous expressions of tissue-type plasminogen activator (tPA), urokinase (uPA), and PA inhibitor-1 (PAI-1) were quantified in 10-microm frozen sections from ischemic and matched nonischemic basal ganglia and in the plasma of 34 male healthy nonhuman primates before and after middle cerebral artery occlusion (MCA:O).

RESULTS

Within the ischemic basal ganglia, tissue uPA activity and antigen increased significantly within 1 hour after MCA:O (2P<0.005). tPA activity transiently decreased 2 hours after MCA:O (2P=0.01) in concert with an increase in PAI-1 antigen (2P=0.001) but otherwise did not change. The transient decrease in free tPA antigen was marked by an increase in the tPA-PAI-1 complex (2P<0.001). No significant relations to neuronal injury or intracerebral hemorrhage were discerned.

CONCLUSIONS

The rapid increase in endogenous PA activity is mainly due to significant increases in uPA, but not tPA, within the ischemic basal ganglia after MCA:O. This increase and an increase in PAI-1 coincided with latent MMP-2 generation and microvascular ECM degeneration but not neuronal injury.

MRI features of infarcts with potential cardiac source of embolism in the Yonsei Stroke Registry (YSR), Korea

The determination of the embolic source is crucial to understanding the pathogenesis of ischemic stroke, the initiation of appropriate therapy, and the prevention of recurrent infarctions. In this study we undertook to identify the characteristic features on magnetic resonance images of patients who had suffered from stroke due to cardiac embolism (CE), as classified by TOAST (possible and probable). We retrospectively studied magnetic resonance imaging (MRI) findings of patients with ischemic stroke from the Yonsei Stroke Registry (YSR). On the basis of the TOAST classification, 92 patients were identified to have a potential cardiac source of embolism (PCSE), in which 69 patients were found to have high-risk PCSE and 23 patients medium-risk PCSE. To compare their imaging characteristics, another group of 49 patients who were found to have had a stroke due to large artery-to-artery (ATA) embolism-common or internal carotid artery (CCA, ICA)-were identified. Involvement of the simultaneous superficial and deep territories (58.7%; 6.1%, p < 0.001), and combined new anterior and old posterior circulation (15.2%; 2.0%, p = 0.016) were more frequent in PCSE than ATA embolism. Bilateral anterior hemispheric involvement was also more frequent in the PCSE group, but it did not reach statistical significance (13.0%; 4.1%, p = 0.090). ATA embolism tended to involve only superficial territories compared to PCSE (71.4%; 28.3%, p < 0.001). There were no topographic differences between the high-risk and medium-risk groups. With respect to the etiology of PCSE in our population, atrial fibrillation was the most common. Characteristic MRI features of patients with PCSE, which were not documented previously by computed tomography (CT) included: old and new, involvement of multiple different vascular territories, bilateral anterior hemisphere, as well as anterior and posterior circulation. These MRI features, together with simultaneous superficial and deep territorial involvement, help to differentiate the underlying embolic sources, whether they are cardiac or ATA in origin.

Activated microvessels express vascular endothelial growth factor and integrin alpha(v)beta3 during focal cerebral ischemia

Both vascular endothelial growth factor (VEGF) and integrin alpha(v)beta3 play roles in angiogenesis. In noncerebral vascular systems, VEGF can induce endothelial integrin alpha(v)beta3 expression. However, it is unknown whether VEGF, like integrin alpha(v)beta3, appears in the initial response of microvessels to focal brain ischemia. Their coordinate expression in microvessels of the basal ganglia after middle cerebral artery occlusion (MCAO) in the nonhuman primate model was examined quantitatively. Cells incorporating deoxyuridine triphosphate (dUTP+) by the polymerase I reaction at 1 hour (n = 3), 2 hours (n = 3), and 7 days (n = 4) after MCAO defined the ischemic core (Ic) and peripheral regions. Both VEGF and integrin alpha(v)beta3 were expressed by activated noncapillary (7.5- to 30.0-microm diameter) microvessels in the Ic region at 1 and 2 hours after MCAO. At 7 days after MCAO, the number of VEGF+, integrin alpha(v)beta3+, or proliferating cell nuclear antigen-positive microvessels had decreased within the Ic region. The expressions of VEGF, integrin alpha(v)beta3, and proliferating cell nuclear antigen were highly correlated on the same microvessels using hierarchical log-linear statistical models. Also, VEGF and subunit alpha(v) messenger ribonucleic acids were coexpressed on selected microvessels. Here, noncapillary microvessels are activated specifically early during a focal cerebral ischemic insult and rapidly express VEGF and integrin alpha(v)beta3 together.

Matrix metalloproteinases increase very early during experimental focal cerebral ischemia

Microvascular integrity is lost during focal cerebral ischemia. The degradation of the basal lamina and extracellular matrix are, in part, responsible for the loss of vascular integrity. Matrix metalloproteinases (MMPs) may play a primary role in basal lamina degradation. By using a sensitive modification of gelatin zymography, the authors investigated the activity of MMP-2 and MMP-9 in frozen 10-microm sections of ischemic and nonischemic basal ganglia and plasma samples of 27 non-human primates after middle cerebral artery occlusion/reperfusion (MCAO/R) for various periods. The gelatinolytic activities were compared with parallel cell dUTP incorporation in the ischemic zones of adjacent sections. In the brain, the integrated density of MMP-2 increased significantly by 1 hour after MCAO and was persistently elevated thereafter. Matrix metalloproteinase-2 expression was highly correlated with the extent of neuron injury and the number of injured neurons (r = 0.9763, SE = 0.004, 2P < 0.0008). Matrix metalloproteinase-9 expression only was significantly increased in subjects with hemorrhagic transformation. In plasma, only MMP-9 increased transiently at 2 hours of MCAO. These findings highlight the early potential role of MMP-2 in the degradation of basal lamina leading to neuronal injury, and an association of MMP-9 with hemorrhagic transformation after focal cerebral ischemia.

Changes in corneal epithelial barrier function after excimer laser photorefractive keratectomy

PURPOSE

To use fluorophotometry to measure corneal epithelial barrier function after excimer laser photorefractive keratectomy (PRK).

SETTING

Seoul National University Hospital, Seoul, Korea.

METHODS

Twenty-five eyes of 21 patients (13 women, 8 men) had PRK to correct myopia. Corneal epithelial healing time was measured and corneal epithelial permeability to sodium fluorescein evaluated by fluorophotometry 1, 2, and 3 weeks after surgery.

RESULTS

Epithelial permeability showed a statistically significant increase 1 week after surgery and returned to its preoperative level 1 week later. Comparative studies according to epithelial healing day and corrected diopter showed results that were not statistically significant (P > .05).

CONCLUSION

These results suggest that PRK delays complete reconstruction of corneal epithelial barrier function. In humans, the corneal epithelium regained its normal barrier function 2 weeks after PRK. Thus, at least during these weeks, care should be taken to minimize further epithelial trauma.

Recurrent herpes zoster myelitis

Recurrent zoster myelitis is quite rare. We present a previously healthy 27-year-old woman who developed recurrent attacks of myelopathy shortly after the characteristic skin rashes of herpes zoster. Magnetic resonance imaging studies demonstrated each lesion in the spinal cord at the same segments as the skin lesions. She had two attacks at opposite sites at the same spinal cord level and complete recovery after being treated with intravenous acyclovir. We suspect that direct invasion of varicella zoster virus was the cause of recurrent myelopathy in our patient.

Large cerebral infarction during praziquantel therapy in neurocysticercosis

BACKGROUND

Large cerebral infarction is a rare complication of neurocysticercosis. Endarteritis by inflammation of the leptomeninges is known to be its cause.

CASE DESCRIPTION

A 59-year-old man with known neurocysticercosis developed a large cerebral infarction during praziquantel therapy. A follow-up MRI obtained immediately after his cerebral infarction demonstrated notable decrease in the size of the cysts and more prominent enhancement around the peripheral margins of the cysts and the major vessels in comparison with the initial MRI. Cerebral angiography disclosed occlusions and narrowing of both internal carotid arteries at the supraclinoid portions, where multiple cysts were found on the MRI.

CONCLUSIONS

Findings in our patient strongly suggest that a secondary inflammation reaction caused by the destruction of the cysts might have enhanced the process of endarteritis. The possible deleterious effects of praziquantel therapy should be considered in the treatment of patients with subarachnoid cysticerci.

Vertigo of cerebrovascular origin proven by CT scan or MRI: pitfalls in clinical differentiation from vertigo of aural origin

To get a better insight into the clinical differentiation between vertigo of cerebrovascular origin and of aural origin, we investigated radiologically proven stroke patients who presented with vertigo as an initial clinical manifestation. Of 154 stroke patients, 30 patients with vertigo (20%) had the relevant lesion, demonstrated with the initial computerized tomographic scan (13 patients) or the follow-up magnetic resonance imaging (MRI) study (17 patients) of the brain. Every lesion was in the vertebrobasilar arterial territory; 19 in the cerebellum, 8 in the pons, and 3 in the medulla oblongata. Although 12 of the 30 patients (40%) presented with vertigo in isolation at the onset of stroke, eight patients (27%) developed additional neurologic abnormalities from four hours to seven days later. Patients with isolated vertigo (13%) had the small lesion exclusively in the cerebellum of the PICA medial branch territory. The most frequent accompanying neurological sign was swaying in the cerebellar and medullary lesion, and dysarthria in the pontine lesion. The direction of nystagmus or swaying did not match the lesion side in some patients. Our findings suggest that cerebellar stroke may commonly manifest isolated vertigo or vertigo with swaying mimicking labyrinthine disorder, particularly at the onset of the disease. MRI study and tests for truncal ataxia and lateropulsion may be crucial for the detection of vertigo of cerebrovascular origin.

Pure motor hemiplegia with conjugate lateral gaze palsy in pontine lacunar infarction

The combination of pure motor hemiplegia and horizontal gaze palsy is a rare but identifiable lacunar syndrome. Among horizontal gaze palsies, one-and-a-half syndrome and abducens nerve palsy are reported to be associated with pure motor hemiplegia in pontine lacunar infarction. Although conjugate lateral gaze palsy is also hypothesized, pure motor hemiplegia with conjugate lateral gaze palsy has never been reported. We present a 75-year-old man who showed right hemiparesis and impaired left horizontal conjugate eyeball movement. Both the findings of the brain CT scan and those of the MRI study were consistent with a small infarction in the left midpontine tegmentum. Magnetic resonance angiography revealed no stenotic narrowing of the vertebrobasilar artery. Radiological findings suggested that pure motor hemiplegia with conjugate lateral gaze palsy, in our patient, might have been produced by the occlusion of a single penetrating branch of the basilar artery.

Dimethylthiourea prevents MPTP-induced decrease in [3H]dopamine uptake in rat striatal slices

To determine whether oxygen free radicals are involved in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity, the effect of dimethylthiourea (DMTU), an effective hydroxyl radical scavenger, on MPTP-induced changes of [3H]dopamine uptake was investigated in rat striatal slices. The uptake of [3H]dopamine was decreased by MPTP treatment, and DMTU prevented the MPTP-induced decrease of [3H]dopamine uptake in a dose-dependent manner. The highest dose of DMTU used in this study completely prevented the MPTP-induced decrease of [3H]dopamine uptake. These results indicate that free radicals play a major role in the pathogenetic mechanism of MPTP-induced neurotoxicity.