Safety and efficacy of remote ischemic preconditioning in patients with severe carotid artery stenosis before carotid artery stenting: A proof-of-concept, randomized controlled trial.

Background: Remote ischemic preconditioning (RIPC) has been proposed as a possible potential treatment for ischemic stroke. This study aimed to investigate the frequency of micro-embolic brain infarcts after RIPC in patients with stroke who underwent elective carotid artery stenting (CAS) treatment. Methods: This study was managed at Shiraz University of Medical Sciences in southwest Iran. Patients undergoing CAS were randomly allocated into RIPC and control groups. Patients in the RIPC group received three intermittent cycles of 5-minute arm ischemia followed by reperfusion using manual blood cuff inflation/deflation less than 30 minutes before CAS treatment. Afterward, stenting surgery was conducted. Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC), was acquired within the first 24 hours after CAS. Results: Seventy-four patients were recruited (79.7% men, age: 72.30 ± 8.57). Both groups of RIPC and control had no significant difference in baseline parameters (P > 0.05). Fifteen patients (40.5%) in the RIPC group and 19 (54.1%) patients in the control group developed restricted lesions in DWI MRI. In DWI+ patients, there were no significant differences according to the number of lesions, lesion surface area, largest lesion diameter, cortical infarcts percent, and ipsilateral and bilateral infarcts between the two groups. Conclusion: Although RIPC is a safe and non-invasive modality before CAS to decrease infarcts, this study did not show the advantage of RIPC in the prevention of infarcts following CAS. It may be because of the small sample size.

The inhibitory effect of functional lesions on eloquent brain areas: from research bench to operating bed.

Objectives: Functioning, but injured cerebral connections are hypothesized to inhibit cortical plasticity. Study of neural networks can validate this hypothesis, and provide further practical clues for clinical and surgical options to restore function in eloquent brain areas. Material and methods: Cortical lesions in eloquent areas were simulated by means of artificial neural networks. Next, functional restoration of these networks after lesional bypass was studied. Results: The accuracy of network outputs was reduced from 92% to 72% (P-value < 0.001) when logical temporal connections with dysfunctional lesions were established. Restoration of function was almost totally achieved by bypassing the lesion, without any significant changes in network nodal weights. Estimated remaining functional fraction errors were trivial (0.0044%-1.4%). Discussion: Examples of functional decline due to disturbing signals are Todd's paralysis and Landau-Kleffner syndrome. Functional restoration after lesionectomy in eloquent areas of the brain is also practiced. Likewise, injured connections provide routes of influence for disturbing impulses. Conclusion: Herein, the proposed evidences provide theoretical clues to formulate new avenues in restorative functional neurosurgery. They may help to identify suitable lesions and suitable techniques for functional restoration including dissection of disturbing connections, bridging and bypassing lesions that can be corroborated by simulation.

Comparison of Clinical and Radiological Outcome of Carotid Angioplasty and Stenting after Direct Navigation Versus Exchange Methods: A Randomized Clinical Trial.

BACKGROUND: The purpose of this study was to compare the frequency of microembolic brain infarcts after direct navigation method versus exchange method in carotid artery stenting and vertebral artery origin angioplasty. METHODS AND MATERIAL: This is a prospective study conducted at Shiraz University of Medical Sciences in southern Iran. Consecutive patients undergoing "carotid angioplasty and stenting" and "vertebral artery origin stenting" were randomly assigned into two groups with "direct navigation method" and "exchange method." Subsequently, postprocedural magnetic resonance imaging (MRI) including diffusion weighted imaging and apparent diffusion coefficient were obtained within the first 24 hours after completion of the procedure. RESULTS: In total, 89 patients were recruited (67% male, mean age: 72 years). Cases comprised of 38 left internal carotid arteries (ICAs), 38 right ICAs, 6 left vertebral artery origin, and 7 right vertebral artery origin. Forty patients underwent exchange method, while 49 underwent direct navigation method. There was only one clinical stroke that occurred in "exchange method" group. Fifteen patients (37.5%) in exchange group and 23 patients (46.9%) in direct navigation group developed diffusion restricted lesions. In exchange group, 13 patients (32.5%) had at least one diffusion restricted lesion ipsilateral to the target vessel, and three patients (7.5%) had at least one diffusion restricted lesion contralateral to the target vessel. In direct navigation group, these measures were 19 (38.8%) and 9 (18.4%). However, no statistically significant intergroup differences were observed. The only significant difference was bilateral infarct percentile, which was more common in the direct navigation method (0.032). CONCLUSION: Diffusion restricted lesions were more common in the direct navigation method, both ipsilateral and contralateral to the target vessel, and in both carotid and vertebral artery study subgroups. However, differences were not statistically significant.

Effect of calcitriol supplementation and tail suspension on serum biomarkers of bone formation in rats.

BACKGROUND: Calcitriol is documented to cause significant increase in bone mass densitometry counteracting osteoporosis. Promising results of calcitriol supplementation in studies aiming space flight induced osteoporosis is little and the effect of this hormone on biomarkers of bone metabolism is not examined yet in space flight models of osteoporosis in rats. METHODS: This was an interventional animal study being performed in a 1-month period. We included 21 Sprague Dawley strain rats (>200 gr, >6 week) who were randomly assigned to receive daily supplementation of oral 0.03µgr calcitriol and to be submitted to tail suspension model. Rats were followed for 1 month and were tested for serum osteocalcin (OC), alkaline phosphatase (ALP) and serum calcium at the beginning and the end of the study period. The results were analyzed and compared between groups. RESULTS: Although serum levels of osteocalcin and alkaline phosphatase biomarkers and total serum calcium were not significantly different within and between study groups, their levels were increased in tail suspension model compared to control group. The levels of these biomarkers were lower in those who were submitted to tail suspension model and received calcitriol supplementation compared to those who were only submitted to tail suspension (60.14 ± 11.73 ng/mL vs. 58.29 ± 2.69 ng/mL; p = 0.696 for osteocalcin and 381.86 ± 99.16 mU/mL vs. 362.57 ± 27.41 ng/mL; p = 0.635 for alkaline phosphatase). CONCLUSION: Supplementation of daily diet with calcitriol in rats under weightlessness conditions may results in lower values for bone metabolic biomarkers of alkaline phosphatase and osteocalcin and serum calcium. This pattern of change in biomarkers of bone formation, may point to the capacity of calcitriol supplementation in preventing cellular process of osteoporosis. Thus calcitriol supplementation could be an available, economic and effective strategy for preventing bone metabolic changes related to weightlessness commonly encountered in space flight. The outcome of this study needs to be further studied in future trying to find more definite results.

H1N1 influenza infection complicated with diabetic ketoacidosis.

The 2009 H1N1 Influenza virus was the first infectious pandemic of the 21(st) century which spread rapidly throughout the world. High-risk groups, such as diabetics, suffered more and showed higher hospital admission and death rates due to this virus. Patients with diabetes mellitus (DM) may develop the fulminant picture of their disease after being infected with influenza. From June to December 2009 at Nemazee Hospital, affiliated with Shiraz University of Medical Sciences, two patients with diabetic ketoacidosis (DKA) were admitted. The H1N1 influenza virus triggered DKA and its complications in these patients. Both patients were female, of ages 16 and 40 years. When admitted, they had signs of influenza-like illness (ILI), tachypnea, laboratory confirmation of acidosis, and high blood sugar levels. The 2009 H1N1 influenza viral RNA was detected in their nasopharyngeal specimens by real time polymerase chain reaction (RT-PCR). Both patients received oseltamivir, but eventually both died. This was the first report of an association between DKA and H1N1 influenza in Iran. Conclusively, rapid diagnosis of influenza by RT-PCR and early treatment with oseltamivir should be considered in diabetics and/or DKA patients with flu-like symptoms.

Chronic pain and voluntary euthanasia.

Emotional status and its brain bases change in a chronic pain patient and this change affects his/her decision making ability. Moreover, it is accepted that a mentally disturbed individual is not competent to make critical decisions. According to these bases, this article demonstrates that such patients are not entitled to request voluntary euthanasia.