Acute Ischemic Stroke Infarct Topology: Association with Lesion Volume and Severity of Symptoms at Admission and Discharge

BACKGROUND AND PURPOSE:Acute stroke presentation and outcome depend on both ischemic infarct volume and location. We aimed to determine the association between acute ischemic infarct topology and lesion volume and stroke severity at presentation and discharge.MATERIALS AND METHODS:Patients with acute ischemic stroke who underwent MR imaging within 24 hours of symptom onset or last seen well were included. Infarcts were segmented and coregistered on the Montreal Neurological Institute-152 brain map. Voxel-based analyses were performed to determine the distribution of infarct lesions associated with larger volumes, higher NIHSS scores at admission and discharge, and greater NIHSS/volume ratios.RESULTS:A total of 238 patients were included. Ischemic infarcts involving the bilateral lentiform nuclei, insular ribbons, middle corona radiata, and right precentral gyrus were associated with larger infarct volumes (average, 76.7 ± 125.6 mL versus 16.4 ± 24.0 mL, P < .001) and higher admission NIHSS scores. Meanwhile, brain stem and thalami infarctions were associated with higher admission NIHSS/volume ratios. The discharge NIHSS scores were available in 218 patients, in whom voxel-based analysis demonstrated that ischemic infarcts of the bilateral posterior insular ribbons, middle corona radiata, and right precentral gyrus were associated with more severe symptoms at discharge, whereas ischemic lesions of the brain stem, bilateral thalami, and, to a lesser extent, the middle corona radiata were associated with higher ratios of discharge NIHSS score/infarct volume.CONCLUSIONS:Acute ischemic infarcts of the insulae, lentiform nuclei, and middle corona radiata tend to have larger volumes, more severe presentations, and worse outcomes, whereas brain stem and thalamic infarcts have greater symptom severity relative to smaller lesion volumes.

The primary goal of acute-phase stroke imaging is to exclude intracranial hemorrhage and to estimate the volume of irreversible ischemic infarct, to identify candidates for thrombolytic therapy. Currently, NCCT is the most widely used imaging technique for this purpose, given its availability, speed, and reliability for ruling out intracranial hemorrhage. However, acute stroke imaging could also have the potential to provide additional prognostic information. For example, the DWI infarct volume, ASPECTS, and malignant CTA collateral profile are imaging markers that have shown prognostic value in patients with acute ischemic stroke.^1–3Patients with acute ischemic stroke with larger infarct volumes have a higher risk of developing symptomatic intracranial hemorrhage and worse clinical outcome following intravenous thrombolysis.^4,5 The presence of ischemic changes of greater than one-third of the MCA territory on noncontrast CT may exclude patients from reperfusion therapy. Certain studies have suggested that a DWI infarct volume of >70–100 mL represents a malignant profile that has a higher risk of hemorrhagic transformation and poor outcome.^4,5 Consequently, the ASPECTS, which has been correlated with outcome, was developed as a means of quantifying ischemic changes on NCCT to identify candidates for thrombolysis.^6,7In addition to volume, the location of an infarct is fundamentally linked to neurologic deficits. There is a limited correlation between the infarct volume and the severity of stroke symptoms; while the infarct volume accounts for 38% of the variation in stroke severity, the combination of both infarct volume and location can account for 62% of the variation in NIHSS scores.⁸ Thus, there has been recent effort to assess the relationship between the infarct topology and outcome in patients with stroke.^9–12 Specifically, some studies reported that ischemic infarcts in the insular ribbon, lentiform nucleus, and corona radiata are associated with poor prognosis in patients with stroke.^10,13,14 However, there are limited prior studies on voxel-based evaluation of the relationship between acute infarct location and volume in these patients.The primary goal of our study was to determine the location of acute ischemic infarcts with larger volumes on admission MR imaging by using a voxel-based analysis. It is likely that the distribution of infarct lesions with larger volumes could, at least in part, explain some of the recent findings on the topographic correlation of admission infarct distribution and clinical presentation, as well as outcome. Also, the present study investigated the interconnection of infarct topology, lesion volume, and severity of symptoms at admission and discharge. Additionally, we evaluated the distribution of infarct lesions with higher ratios of NIHSS-to-infarct volume, which represent worse clinical deficits relative to smaller lesion size. The voxel-based analysis of lesion-location volume or location-symptom relation can search for significant associations between infarct topology and outcome variables without a priori cerebral parcellation, compared with an atlas-based image analysis methodology.^11,12 Such findings can potentially be the basis for development of a “hazard atlas” of the brain to predict clinical outcome and, perhaps, response to treatment on the basis of infarct distribution and size at the time of admission.     

Titanium-Pillared Clay: Preparation Optimization,Characterization, and Artificial Neural Network Modeling

Titanium-pillared clay (Ti-PILC), as one of the most suitable types of porous adsorbents/(photo)catalysts, was prepared from a local type of Iranian clay and titanium isopropoxide. The production process was optimized by changing three operating parameters, including the clay suspension concentration (in the range of 0.5–10% w/v), the H⁺/Ti ratio (2–8 mol/mol), and the calcination temperature (300–700 °C). The largest specific surface area for the Ti-PILC was about 164 m²/g under the clay suspension of 0.5% w/v, H⁺/Ti = 6, with a surface area 273% larger than that of the raw clay. The surface areas obtained from more concentrated clay suspensions were, however, comparable (159 m²/g for 3% w/v clay and H⁺/Ti = 4). An increase in the calcination temperature has a negative effect on the porous texture of Ti-PILC, but based on modeling with artificial neural networks, its contribution was only 7%. Clay suspension and H⁺/Ti ratio play a role of 56 and 37% of the specific surface area. The presence of rutile phase, and in some cases anatase phase of TiO₂ crystals was detected. FTIR and SEM investigations of Ti-PILCs produced under different operating parameters were analyzed.     

Stress and burnout in health care workers during COVID-19 pandemic: validation of a questionnaire

Journal of Public Health - To validate a questionnaire to assess stress and burnout in healthcare workers during COVID-19 pandemic. In this study, content validity, Cronbach’s alpha, and...     

The effects of bladder neck incision on urodynamic abnormalities of children with posterior urethral valves

PURPOSE: We evaluated the effects of simultaneous bladder neck incision and valve ablation on urodynamic abnormalities in patients with posterior urethral valves. MATERIALS AND METHODS: A total of 46 patients with posterior urethral valves entered our prospective study between 1998 and 2003. Group 1 consisted of 22 patients who underwent simultaneous valve ablation and bladder neck incision at the 6 o'clock position. Group 2 consisted of 24 age matched patients with comparable prognostic factors who underwent simple valve ablation. Trends in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated throughout followup. RESULTS: Mean patient age at presentation was 1.6 years in group 1 and 1.8 years in group 2. Preoperatively, all patients in both groups had hypercontractile bladders and comparable high maximum voiding detrusor pressures. At the end of followup (mean 4.5 years) no patient in group 1 had bladder hypercontractility or detrusor overactivity, and the mean maximum voiding detrusor pressure was 53 +/- 15 cm H(2)O. In comparison, 9 patients in group 2 had bladder hypercontractility, 6 had detrusor overactivity and the mean maximum voiding detrusor pressure was 87 +/- 45 cm H(2)O (p <0.01). Myogenic bladder failure developed in 5 patients in group 2. The number of patients requiring anticholinergic medication and the duration of treatment were also significantly higher in group 2 compared to group 1. CONCLUSIONS: Valve ablation with bladder neck incision may result in better bladder urodynamic function in comparison to simple valve ablation. However, long-term studies with followup through puberty are required to evaluate the final effects on renal function.     

Management of multiple failed repairs of the phallus using tissue expanders: long-term postpubertal results

PURPOSE: We present the long-term results of our experience with application of tissue expanders for phallic reconstruction in patients with a history of multiple surgical repairs. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 16 patients who underwent penile tissue expansion for treatment of failed phallic reconstruction. The patients were 5 to 22 years old (mean age 9.9) at the time of the procedure. The original diagnoses were congenital adrenal hyperplasia (1 patient), partial penile amputation (1), epispadias (3) and proximal hypospadias (11). We used different shapes and numbers of tissue expanders according to the estimated skin augmentation requirement for final reconstructive surgery. The injection port was placed at the suprapubic area lateral to the penile base, with a small incision between the anticipated expander pouch and the reservoir. Penile tissue expanders were inflated by injections after 1 to 2 weeks postoperatively. Definitive reconstructive surgery was then planned and the tissue expander was removed at penile reconstruction at 2 to 11 months (mean 4.6) after implantation. RESULTS: Only 1 tissue expander was removed due to erosion. However, sufficient expanded skin was available for urethral reconstructions and penile skin coverage in all patients (100%). There were 2 cases of overlying penile skin redness, which resolved with temporary balloon deflation. Two patients had urethrocutaneous fistulas, which were successfully repaired later. Two additional patients required meatal dilation/urethromeatoplasty for meatal stenosis. These complications were corrected within 1 year postoperatively. After a long-term followup of 3 to 10 years (mean 6.5) as patients progressed through puberty, only 3 had mild chordee. At the end of followup acceptable cosmetic and functional results were achieved in 13 patients (81%). CONCLUSIONS: Tissue expansion is associated with few complications and good cosmetic results for phallic reconstruction in patients with minimal residual skin available for additional reconstructive efforts after repeated surgeries.     

Traffic accidents and related injuries in Iranian professional drivers

Aim

The WHO statistics show that Iran has one of the highest rates of morbidities and mortalities due to traffic accidents in the world, which occurs in professional and nonprofessional drivers and motorcyclists, pedestrians, etc. This study investigates the rate of accidents in heavy vehicle drivers and related factors.

Subjects and methods

This study was performed on 1,136 heavy vehicle drivers who presented for periodic examinations to one of the official centers for examining drivers in the city of Yazd, Iran. Necessary information such as the history of traffic accidents, age, work experience, weekly working hours, etc were gathered using a checklist.

Results

The rate of reported accidents was 88 cases (7.7%) in 1?year. A significant relationship was observed between age, body mass index (BMI), working hours, and shift working with the rate of accidents (P?<?0.05). However, no significant relationships were found between having a second occupation, chronic diseases, and work experience with the rate of accidents (P?>?0.05). Even after adjustment of the study variables by regression analysis, a significant relationship was seen between traffic accidents and weekly working hours, BMI, and age over 60?years old and less than 29?years old (P?<?0.05).

Conclusion

This study shows that increased risk of traffic accidents is associated with increasing work hours. Therefore, the reduction of work hours for professional drivers may decrease the rate of accidents and related injuries.