Kunakorn Atchaneeyasakul

Large animal canine endovascular ischemic stroke models: A review

BACKGROUND Stroke is one of the leading causes of death and long-term disability worldwide. Recent exciting developments in the field with endovascular treatments have shown excellent outcomes in acute ischemic stroke. Prior to translating these treatments to human populations, a large-animal ischemic stroke model is needed. With the advent of new technologies in digital subtraction angiography, less invasive endovascular stroke models have been developed. Canines have gyrencephalic brain similar to human brain and accessible neurovascular anatomy for stroke model creation. Canine stroke model can be widely utilized to understand the disease process of stroke and to develop novel treatment. Less invasive endovascular internal carotid emboli injection and coil embolization methods can be used to simulate transient or permanent middle cerebral artery occlusion. Major restriction includes the extensive collateral circulation of canine cerebral arteries that can limit the stroke size. Transient internal carotid artery occlusion can decrease collateral circulation and increase stroke size to some degree. Additional method of manipulating the extent of collateral circulation needs to be studied. Other types of canine stroke models, including vertebral artery occlusion and basilar artery occlusion, can also be accomplished by endovascular thrombi injection. CONCLUSIONS We extensively review the literature on endovascular technique of creating canine ischemic stroke models and their application in finding new therapies for ischemic stroke.

Large Amount of Cannabis Ingestion Resulting in Spontaneous Intracerebral Hemorrhage: A Case Report

Although multiple cases of cannabis-associated ischemic stroke have been reported, there are only 2 reported cases of hemorrhagic stroke with an associated cerebral vasoconstriction. To our knowledge, we present the first case of basal ganglia hemorrhage after a large-volume oral ingestion of cannabis without other identified risk factors. In our case, cerebral digital subtraction angiography within 24 hours of presentation did not reveal vasoconstriction leading to a possible alternative explanation for hemorrhagic stroke, including cannabis-induced transient arterial hypertension and autoregulation disruption.

Utilizing CT with Maximum Intensity Projection Reconstruction Bypassing CTA Improves Time to Groin Puncture in Large Vessel Occlusion Stroke Thrombectomy

Background and Purpose: Prior to thrombectomy for proximal anterior circulation large vessel occlusion (LVO) stroke, recent trials have utilized CT angiography (CTA) for vascular imaging immediately following noncontrast CT (NCCT) for decision-making, but thin-section NCCT with automated maximum intensity projection (MIP) reconstruction also has high accuracy in demonstrating the site of an occluding thrombus. We hypothesized that performing thin-section NCCT with MIP alone prior to thrombectomy improves the time to groin puncture (GP) compared to performing CTA after NCCT. Materials and Methods: We performed a retrospective cohort study of anterior circulation LVO thrombectomy at our tertiary care academic medical center. All stroke patients evaluated with thin-section NCCT (0.625 mm) with automated MIP reconstructions alone and those who had additional CTA were included. We excluded transfer patients, in-hospital strokes, posterior circulation strokes, and patients that were evaluated with stroke imaging other than NCCT or CTA prior to thrombectomy. The study groups were compared for duration from NCCT to GP and total stroke imaging duration. Results: From March 2008 through August 2015, 34 thrombectomy patients met the inclusion/exclusion criteria - 13 in the NCCT and 20 in the NCCT+CTA group. The total stroke imaging duration was shorter in the NCCT group than in the NCCT+CTA group (2 min [1-6] vs. 28 min [23-65]; p < 0.001). The NCCT-only group had a shorter time from NCCT to GP (68 min [32-99] vs. 104 min [79-128]; p = 0.030). Conclusion: Avoiding advanced imaging for patients with anterior circulation LVO in whom thin-section NCCT with MIPs reveals a hyperdense sign significantly shortens the imaging-to-GP time.

White Matter Hyperintensity Volume and Outcome of Mechanical Thrombectomy With Stentriever in Acute Ischemic Stroke

Background and Purpose— Finding of white matter hyperintensity (WMH) has been associated with an increased risk of parenchymal hematoma and poor clinical outcomes after mechanical thrombectomy using old-generation endovascular devices. Currently, no data exist with regard to the risk of mechanical thrombectomy using stentriever devices in patients with significant WMH. We hypothesized that WMH volume will not affect the hemorrhagic and clinical outcome in patients with acute ischemic stroke undergoing thrombectomy using new-generation devices. Methods— A retrospective cohort of consecutive acute ischemic stroke patients >18-year-old receiving mechanical thrombectomy with stentriever devices at a single academic center was examined. WMH volume was assessed by a semiautomated volumetric analysis on T2 fluid attenuated inversion recovery–magnetic resonance imaging. Outcomes included the rate of any intracerebral hemorrhage, 90-day modified Rankin Score (mRS), the rate of good outcome (discharge mRS ⩽2), and the rate of successful reperfusion (thrombolysis in cerebral ischemia score 2b or 3). Results— Between June 2012 and December 2015, 56 patients with acute ischemic stroke met the study criteria. Median WMH volume was 6.76 cm3 (4.84–16.09 cm3). Increasing WMH volume did not significantly affect the odds of good outcome (odds ratio [OR], 0.811; 95% confidence interval [CI], 0.456–1.442), intracerebral hemorrhage (OR, 1.055; 95% CI, 0.595–1.871), parenchymal hematoma (OR, 0.353; 95% CI, 0.061–2.057), successful recanalization (OR, 1.295; 95% CI, 0.704–2.383), or death (OR, 1.583; 95% CI, 0.84–2.98). Conclusions— Mechanical thrombectomy using stentrievers seems to be safe in selected patients with acute ischemic stroke with large vessel occlusion, nonwithstanding the severity of WMH burden in this population. Larger prospective studies are warranted to validate these findings.

Safety and outcomes of simultaneous vasospasm and endovascular aneurysm treatment (SVAT) in subarachnoid hemorrhage

Background Simultaneous vasospasm and endovascular aneurysm treatment (SVAT) has been shown to be effective with good clinical outcomes in small series, but these studies have not examined predictive factors for clinical outcome after treatment. Objective To identify the safety and efficacy of SVAT in a large multicenter patient cohort and evaluate prognostic markers of clinical outcome following SVAT. Methods This study retrospectively enrolled 50 consecutive patients undergoing SVAT at 11 different centers. We analyzed Hunt and Hess and Fisher grades, aneurysm location, angiographic vasospasm grade, Glasgow Outcome Scale (GOS) at discharge, and 90-day modified Rankin Scale (mRS) scores. Results A total of 50 patients undergoing SVAT between the years 2003 and 2009 were identified. Patients presented, on average, 6.48±4.45 days after subarachnoid hemorrhage. Hunt and Hess and Fisher grades were 1 (n=7), 2 (n=12), 3 (n=14), 4 (n=15), 5 (n=2), and 3 and 4 (n=33), respectively. Aneurysm location was distributed as follows: anterior (n=32), posterior (n=16), anterior and posterior (n=2). Patients with good clinical condition (Hunt and Hess score 1–3) had significantly higher odds of surviving (OR=17.5, 95% CI 1.9 to 161.5), favorable GOS (OR=4.2, 95% CI 1.2 to 14.8), and favorable 90-day mRS (OR=4.2, 95% CI 1.2 to 14.8). Conclusions SVAT is safe, with the majority of patients achieving good clinical outcome. Patients with lower Hunt and Hess grades have higher odds of surviving and favorable clinical prognosis.

Osmotic demyelination syndrome: plasmapheresis versus intravenous immunoglobulin?

A 63-year-old man with a past medical history of nonalcoholic steatohepatitis cirrhosis complicated by hepatic encephalopathy and non-bleeding esophageal varices presented for orthotopic liver transplantation. The patient had no acute complications in the immediate post-operative period, and was extubated on post-operative day (POD) 1. At that time, he was neurologically intact, alert and oriented and with no focal neurological deficits. On POD 3, he became lethargic and quadriplegic (Medical Research Council Scale Grade 0), and developed right-sided focal seizures with secondary generalization. His serum sodium was 128 mmol/L. He was re-intubated, and treated for his seizures with lorazepam 4 mg and levetiracetam 2 g, and then continued on levetiracetam 1 g two times a day. The following day, he was unresponsive and had no motor response to painful stimuli. His serum sodium had corrected without additional exogenous intervention to 135 mmol/L. On post symptom onset day (PSOD) 3, an MRI brain without contrast showed chronic small vessel ischemic changes but no other abnormality (Fig. 1a). The EEG did not show any seizure or epileptiform discharges. Serum chemistry and cerebrospinal fluid analysis did not show any significant abnormalities. On PSOD 13, his presentation remained the same. An MRI brain was repeated showing DWI restriction and high T2 signal in the central pons, suggestive of ODS (Fig. 1b). On PSOD 19, he was started on both IVIG and PP for a total of 5 days. Approximately 3 weeks after treatment with IVIG and Plasmapheresis, a repeat MRI showed similar prominence of T2 hyperintensity in the central pons with sparing of the periphery as compared to prior, findings consistent with central pontine myelinolysis/osmotic demyelination syndrome (Fig. 1c). Over the next 90 days the patient improved, becoming fully alert, regaining spontaneous muscle flicker in all four extremities (Medical Research Council Scale Grade 1), full eye movements and the ability to swallow. Osmotic demyelination syndrome (ODS) is a disorder characterized by the destruction of neuronal myelin sheaths in either the central area of the pons as in central pontine myelinolysis (CPM), or in other susceptible areas such as the basal ganglia, hippocampi or cerebellum known as external pontine myelinolysis (EPM). CPM can present with T2 hyperintensities on MRI in a classic trident-shape pattern. ODS usually presents as a complication of rapid correction of hyponatremia. Although no specific treatment has been described, plasmapheresis (PP) and intravenous immunoglobulin (IVIG) have been suggested as possible options for the management of ODS [1]. A clear association has been established between rapid correction of hyponatremia and the development of ODS. Although not completely understood, the pathophysiology of ODS classically described is the reduced extracellular osmolality causing brain cells to release osmotically-active substances in an attempt to achieve osmotic equilibrium. These osmotic substances cannot be reabsorbed rapidly, and when sodium levels are increased, they create an osmotic stress that leads to a disruption in the blood brain barrier, leading to myelinolysis. In addition, the death of oligodendrocytes via apoptosis from osmotic shifts has also been suggested & Andrew C. Berry aberry5555@gmail.com

Adverse Effects of Grape Seed Extract Supplement: A Clinical Case and Long-Term Follow-Up

ABSTRACT Grape seed extract (GSE) supplement use is becoming more popular today for its potential chemopreventive and chemotherapeutic role. We report a 49-year-old male who presented with recurrent nausea, vomiting, diarrhea, and acute weakness following GSE use. A thorough medical workup ensued and no causes were identified clinically, procedurally, or with imaging. Symptoms resolved after GSE discontinuation and the patient remained symptom-free 5 years later. This case illustrates the paucity of documented detailed clinical cases and lack of controlled trials detailing a thorough and reproducible adverse effect profile of GSE supplement.

Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses

Background: Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. Objective: We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. Methods: This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. Results: From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. Conclusion: In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign.

Cerebrovascular Variants in Posterior Circulation

Ever since the identification of hypertension around 150 years ago, researchers have struggled to find its cause(s) with only minor successes.1 Essential, or primary, or idiopathic hypertension is historically defined as a rise in blood pressure (BP) without any known causes, which still accounts for ≈95% of all hypertension.2 Whereas multiple risk factors for hypertension, including genetic variations, obesity, insulin resistance, high alcohol intake, and stress, have been identified, primary causes for hypertension remain elusive. Also, the predictive factors for its development are unclear.3–5 Given that essential hypertension is one of the major modifiable cardiovascular risk factors, uncovering its possible root causative mechanism(s) would have a tremendous public health impact, including prediction or even prevention of the development of the disease. Furthermore, hypertension is refractory to treatment in ≤20% to 30% of cases despite the availability of numerous classes of antihypertensives, and finding primary cause could improve treatment of refractory hypertension.6 Renovascular disease is a well-described cause of hypertension, which is caused by the increase in renin secretion with subsequent increase in angiotensin and aldosterone but is found to be a primary cause in a minority of cases.7 While there is evidence for the involvement of elevated sympathetic nerve activity, the initiating cause has not been established.8 Early on, one of the proposed pathologic hypotheses has been that the increase in BP is an essential response to thickened and narrowed blood vessels to provide more blood supply to organs. This line of pathologic investigation has been mired in the classic difficulty of determining if …

Target Stroke: Best Practice Strategies Cut Door to Thrombolysis Time to <30 Minutes in a Large Urban Academic Comprehensive Stroke Center

The therapeutic window for acute ischemic stroke with intravenous recombinant tissue plasminogen activator (IV rt-PA) is brief and crucial. The American Heart Association/American Stroke Association Target: Stroke Best Practice Strategies (TSBPS) aim to improve intravenous thrombolysis door-to-needle (DTN) time. We assessed the efficacy of implementation of selected TSBPS to reduce DTN time in a large tertiary care hospital. A multidisciplinary DTN committee assessed causes of delayed DTN time and implemented focused TSBPS in our urban academic medical center. We analyzed door-to-CT time, DTN time, and CT to IV rt-PA time in consecutive patients treated with IV rt-PA over 27 months preimplementation and 13 months postimplementation. One hundred forty-eight patients were included in the preimplementation and 126 in the postimplementation group. We found no significant difference between the groups in demographics, comorbidities, anticoagulation status, prethrombolysis hypertension treatment, arrival by EMS, after-hours arrival, or in stroke etiology. After implementation, median DTN time improved from 59 (interquartile range [IQR]: 52-80) to 29 (IQR: 20-41) minutes (P < .001). Door-to-CT time decreased from 17 (14-21) to 16 (12-19) minutes (P = .016), and CT-to-IV rt-PA time improved from 43 (IQR: 31-59) to 13 (IQR: 6-23) minutes (P < .001). Rates of symptomatic intracranial hemorrhage (2.7% vs 3.2%, P = .82) and treatment of stroke mimics (9% vs 13%, P = .31) were similar in both the groups. Individualized hospital gap analysis identifies targeted interventions that lead to rapid and sustained improvement in treatment times.