Brain Circulation

The endocannabinoid system and stroke: A focused review Bradley Kolb, Hamidreza Saber, Hassan Fadel, Gary Rajah Brain Circulation 2019 5(1):1-7 Stroke is an important cause of morbidity and mortality worldwide. Development of novel neuroprotectants is of paramount importance. This review seeks to summarize the recent evidence for the role of the endocannabinoid signaling system in stroke pathophysiology, as well as the evidence from preclinical studies regarding the efficacy of cannabinoids as neuroprotective therapies in the treatment of stroke. Recent evidence from rodent models implicating cannabinoid 1 receptor (CB1R), cannabinoid 2 receptor (CB2R), and CB1R and CB2R co-antagonism as neuroprotective strategies in stroke are reviewed. Rodent evidence for the therapeutic role of the endocannabinoid system in treating poststroke depression is reviewed. Finally, evidence for the role of cannabidiol, a publicly available cannabinoid that does not bind directly to known endocannabinoid receptors, as a stroke neuroprotectant is also reviewed. The review closes with a consideration of the role of human cannabinoid abuse in stroke and considers future directions for research on endocannabinoid-based stroke therapeutics.

Treatment for ischemic stroke: From thrombolysis to thrombectomy and remaining challenges Tiandong Leng, Zhi-Gang Xiong Brain Circulation 2019 5(1):8-11 Stroke is a leading cause of death and long-term disabilities. Despite decades of extensive efforts in search of brain injury mechanisms and therapeutic interventions, pharmacological treatment is limited to the use of thrombolytic agent tissue plasminogen activator, which has limited therapeutic time window and potential side effect of intracranial hemorrhage. Over the past few years, endovascular thrombectomy with stent-retriever devices combined with advanced imaging modalities has transformed the standard of stroke care, offering an opportunity to improve the outcome in selected patients as late as 24 h after the onset of stroke. This mini-review summarizes the advancement in the treatment of ischemic stroke, from thrombolysis to thrombectomy and remaining challenges in the field.

Effect of remote ischemic preconditioning on cerebral vasospasm and biomarkers of cerebral ischemia in aneurysmal subarachnoid hemorrhage (ERVAS): A protocol for a randomized, controlled pilot trial RP Sangeetha, VJ Ramesh, Sriganesh Kamath, Rita Christopher, Dhananjaya I Bhat, HR Arvinda, Dhritiman Chakrabarti Brain Circulation 2019 5(1):12-18 INTRODUCTION: Cerebral vasospasm is a dreaded complication of aneurysmal subarachnoid hemorrhage (aSAH) predisposing to delayed cerebral ischemia. We intend to study the cerebroprotective effects of remote ischemic preconditioning (RIPC) in patients with aSAH. MATERIALS AND METHODS: This is a single-center, prospective, parallel group, randomized, pilot trial, approved by the Institutional Ethics Committee. Patients with aSAH admitted to our hospital for surgical clipping; fulfilling the trial inclusion criteria will be randomized to true RIPC (n = 12) (inflating upper extremity blood pressure cuff thrice for 5 min to 30 mmHg above systolic blood pressure) or sham RIPC (n = 12) (inflating blood pressure cuff thrice for 5 min to 30 mmHg) in 1:1 allocation ratio using a computerized random allocation sequence and block randomization. RESULTS: Our primary outcome measure is vasospasm on cerebral angiography and transcranial Doppler study, and concentration of serum S100B and neuron-specific enolase at 24 h after RIPC and on day 7 of ictus. Our secondary outcomes are safety of RIPC, cerebral oxygen saturation, and Glasgow coma score, and extended Glasgow outcome scale scores at discharge and at 1, 3, and 6 months following discharge. Outcome measures will be assessed by an observer blinded to the study intervention. CONCLUSION: If our preliminary results demonstrate a beneficial effect of RIPC, this would serve as a clinically applicable and safe preemptive method of protection against cerebral ischemia.

Increase in cerebral blood flow indicated by increased cerebral arterial area and pixel intensity on brain magnetic resonance angiogram following correction of cervical lordosis Evan A Katz, Seana B Katz, Curtis A Fedorchuk, Douglas F Lightstone, Chris J Banach, Jessica D Podoll Brain Circulation 2019 5(1):19-26 CONTEXT: Loss of cervical lordosis is associated with decreased vertebral artery hemodynamics. AIM: The aim of this study is to evaluate cerebral blood flow changes on brain magnetic resonance angiogram (MRA) in patients with loss of cervical lordosis before and following correction of cervical lordosis. SETTINGS AND DESIGN: This study is a retrospective consecutive case series of patients in a private practice. MATERIALS AND METHODS: Cervical lordosis of seven patients (five females and two males, 28–58 years) was measured on lateral cervical radiographs ranging from −13.1° to 19.0° (ideal is −42.0°). Brain MRAs were analyzed for pixel intensities representing blood flow. Pixel intensity of the cerebral vasculature was quantified, and percentage change was determined. STATISTICAL ANALYSIS USED: A Student's t-test established significance of the percentage change in cerebral blood flow between pre- and postcervical lordosis adjustment images. Regression analysis was performed. An a priori analysis determined correlation between cervical lordosis and change in MRA pixel intensity. The statistician was blinded to the cervical lordosis. RESULTS: Pixel intensity increased 23.0%–225.9%, and a Student's t-test determined that the increase was significant (P < 0.001). Regression analysis of the change in pixel intensity versus the cervical lordosis showed that as the deviation from a normal cervical lordosis increases, percentage change in pixel intensity on MRA decreases. CONCLUSION: These results indicate that correction of cervical lordosis may be associated with an immediate increase in cerebral blood flow. Further studies are needed to confirm these findings and understand clinical implications.

Commentary on "Increase in cerebral blood flow indicated by increased cerebral arterial area and pixel intensity on brain magnetic resonance angiogram following correction of cervical lordosis" Kenneth I Maynard Brain Circulation 2019 5(1):26-26

Early signs of middle cerebral artery infarction on multidetector computed tomography: Review of 20 cases Sultan Alshoabi, Ramzi Alnajmani, Mohamed Shamsuddin, Moawia Gameraddin Brain Circulation 2019 5(1):27-31 OBJECTIVE: This study intended to assess the occurrence of early signs of middle cerebral artery (MCA) on multidetector computed tomography (MDCT) in correlation with duration of the clinical features of stroke. PATIENTS AND METHODS: This retrospective study analyzed the electronic records of 20 patients with MCA infarction. The detected signs studied according to the onset of the clinical features of stroke to the time of CT imaging. RESULTS: Out of 20 patients with MCA infarction included in this study, the results revealed a significant relationship between the presence of insular ribbon sign and/or subtle hypodensity and hyperacute infarction (P < 0.001 and 0.003, respectively). Results revealed significant relationship between the occurrence of hypodense area, effacement of the cortical sulci, and compression of the ipsilateral lateral ventricle with acute infarction (6–72 h), (P = 0.006, 0.007, and 0.002) (odds ratio = 0.047, 0.050 and 0.028) and (95% confidence interval = 0.004–0.552, 0.004–0.597 and 0.002–0.367) respectively. CONCLUSION: MDCT can detect nearly half of MCA infarctions in the first 6 h. Insular ribbon sign and subtle hypodensity were the most significant findings in the first 6 h of stroke. Hypodense area was a significant sign after 6 h. Diabetes mellitus and ischemic heart disease were the most common risk factors. Hemiparesis was the most common clinical finding in MCA infarction.

Utilization and safety of extracranial–intracranial bypass surgery in symptomatic steno-occlusive disorders Hamidreza Saber, Gary Rajah, Mohan Palla, Sunil A Sheth Brain Circulation 2019 5(1):32-35 OBJECTIVE: The objective of this study was to investigate patterns of utilization and safety of extracranial–intracranial (EC-IC) bypass in patients with symptomatic cerebrovascular steno-occlusive disorders. METHODS: Patients with one of the steno-occlusive conditions (defined as symptomatic intracranial stenosis, extracranial stenosis, and moyamoya disease) were identified using all nonfederal hospitalizations in New York (2005–2014) and Florida (2005–2015). EC-IC bypass surgery was defined using the corresponding procedure codes. Patients were included if there was a prior history of ischemic stroke or transient ischemic attack. Patients were excluded for any preceding diagnosis of cerebral hemorrhage, aneurysm, or trauma. The primary outcome was perioperative ischemic stroke, cerebral hemorrhage, or mortality occurring within 30 days of surgery. We also determined yearly trends for the volume of EC-IC bypass procedures in the study period. RESULTS: Among 346 patients with steno-occlusive disease treated with EC-IC bypass, median age was 52.5 years and 52.5% were female. Rates of EC-IC bypass surgery procedure increased until 2011 and then decreased coinciding with the publication of the Carotid Occlusion Surgery Study trial. Thirty-day event rates of stroke, hemorrhage, or death decreased in patients treated with EC-IC bypass (odds ratio: 0.2, confidence interval: 0.0.4–0.99; P = 0.03) over the 10-year study period. CONCLUSIONS: Overall utilization of EC-IC bypass procedure is relatively low, whereas the 30-day complication rates for patients with steno-occlusive conditions appear to be relatively low and improving. Further research is needed to confirm these findings and to determine the subset of patients who would most likely benefit from this intervention.

Snuff box radial access: A technical note on distal radial access for neuroendovascular procedures Gary Rajah, Richard Justin Garling, Miles Hudson, Ali Luqman Brain Circulation 2019 5(1):36-40

Prevention of traumatic brain injury-related death using the brain-gut axis Usama Khan, Yuchuan Ding Brain Circulation 2019 5(1):41-42