A systematic review on the assessment of cerebral autoregulation in patients with Large Vessel Occlusion.

As the majority of large vessel occlusion (LVO) patients are not treated with revascularization therapies or efficiently revascularized, complementary management strategies are needed. In this article we explore the importance of cerebral autoregulation (CA) assessment in the prediction and/or modification of infarct growth and hemorrhagic transformation. In patients with LVO, these are important factors that affect prognosis. A systematic search of the PubMed, EMBASE databases and a targeted Google search was conducted, resulting in the inclusion of 34 relevant articles. There is an agreement that CA is impaired in patients with LVO; several factors have been identified such as time course, revascularization status, laterality, disease subtype and location, some of which may be potentially modifiable and affect outcomes. The personalized CA assessment of these patients suggests potential for better understanding of the inter-individual variability. Further research is needed for the development of more accurate, noninvasive techniques for continuous monitoring and personalized thresholds for CA.

Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension.

BACKGROUND: Medically refractory idiopathic intracranial hypertension (IIH) is frequently treated with venous sinus stenosis stenting with high success rates. Patient selection has been driven almost exclusively by identification of supraphysiological venous pressure gradients across stenotic regions based on theoretical assessment of likelihood of response. OBJECTIVE: To explore the possibility of benefit in low venous pressure gradient patients. METHODS: Using a single-center, prospectively maintained registry of patients with IIH undergoing venous stenting, we defined treatment groups by gradient pressures of ≤4, 5 to 8, and >8 mmHg based on the most frequently previously published thresholds for stenting. Baseline demographics, clinical, and neuro-ophthalmological outcomes (including optical coherence tomography and Humphrey visual fields) were compared. RESULTS: Among 53 patients, the mean age was 32 years and 70% female with a mean body mass index was 36 kg/m 2 . Baseline characteristics were similar between groups. The mean change in lumbar puncture opening pressure at 6 months poststenting was similar between the 3 groups (≤4, 5-8, and >8 mmHg; 13.4, 12.9, and 12.4 cmH 2 O, P = .47). Papilledema improvement was observed across groups at 6 months (100, 93, and 86, P = .7) as were all clinical symptoms. The mean changes in optical coherence tomography retinal nerve fiber layer (-30, -54, and -104, P = .5) and mean deviation in Humphrey visual fields (60, 64, and 67, P = .5) at 6 weeks were not significantly different. CONCLUSION: Patients with IH with low venous pressure gradient venous sinus stenosis seem to benefit equally from venous stenting compared with their higher gradient counterparts. Re-evaluation of our restrictive criteria for this potentially vision sparing intervention is warranted. Future prospective confirmatory studies are needed.

Disparities among neurointerventionalists suggest further investigation of conscious sedation versus general anesthesia during thrombectomy for acute stroke.

INTRODUCTION: Prior retrospective and case-control studies have shown that the use of general anesthesia (GA) during endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) was independently associated with poor clinical outcomes compared with cases performed under conscious sedation (CS). Conversely, recent small randomized clinical trials (RCT) demonstrated a trend toward better outcome in cases performed under GA. METHODS: We submitted an online survey to 193 Society of Vascular Interventional Neurology and 78 American Association of Neurological Surgeons and Congress of Neurological Surgeons - Cerebrovascular Section neuroendovascular practitioners. Questions were aimed at understanding the current state of anesthesia practice during EVT, and to determine if there is clinical equipoise for a large multicenter RCT comparing GA versus CS during EVT. RESULTS: Between March and May of 2017, we received 116 (43%) responses. Anesthesiologists were responsible for managing 96% of the GA cases as compared to only 51% of the CS cases (P < 0.0001). Notable 56% of providers reported performing less than a quarter of their cases under GA. Only 7% performed all cases under GA compared with 17% who used solely CS (P = 0.048). More than half of respondents thought a new RCT was necessary, of whom 61% were interested in participating. Among interested responders, 59% were located in centers with 3 or more neurointerventionalists. CONCLUSION: The significant variation among neuroendovascular providers, added with the lack of consensus among recent trials and meta-analyses, demonstrate clinical equipoise for further studies to explore the effects of anesthesia during EVT in AIS-LVO.

Use of single versus multiple vasodilator agents in the treatment of cerebral vasospasm: is more better than less?

BACKGROUND: Patients with cerebral vasospasm caused by aneurysmal subarachnoid hemorrhage (aSAH) are often treated with intra-arterial (IA) vasodilator infusion. However, the optimal drug regimen is yet to be elucidated. METHODS: A retrospective review of patients with aSAH and cerebral vasospasm treated with IA vasodilator infusion was performed. Patients in group 1 (2008-2011) were treated with a single agent, either nicardipine or verapamil, and patients in group 2 (2010-2016) were treated with a regimen of nitroglycerin, verapamil, and nicardipine. The post-infusion improvement ratio (PIIR) was compared between groups. Adjusted multivariate logistic regression models were utilized to determine whether patients treated with multiple vasodilators had an improved functional outcome, defined by the modified Rankin Scale, at discharge and 90-day follow-up. RESULTS: Among 116 patients from group 1 (N = 47) and group 2 (N = 69), the median age was 54.5 years [IQR, 46-53 years] and 78% were female. Use of multiple-agent therapy resulted in a 24.36% improvement in vessel diameter over single-agent therapy (median PIIR: group 1, 10.5% [IQR, 5.3-21.1%] vs group 2, 34.9% [IQR, 21.4-66.0%]; p < 0.0001). In the adjusted multivariate logistic regression, the use of multiple-agent therapy was associated with a better functional outcome at discharge (OR 0.15, 95% CI [0.04-0.55]; p < 0.01) and at 90-day follow-up (OR 0.20, 95% CI [0.05-0.77]; p < 0.05) when compared to single-agent therapy. CONCLUSION: In this study, we found that patients treated for cerebral vasospasm with IA infusion of multiple vasodilators had an increased vessel response and better functional outcomes compared to those treated with a single agent.

Exception from informed consent in the era of social media: The SEGA stroke trial experience.

INTRODUCTION: Patients with acute ischemic stroke (AIS) and neurologic deficits are often unable to provide consent and excluded from emergency research participation. Experiences with exception from informed consent (EFIC) to facilitate research on potentially life-saving emergency interventions are limited. Here, we describe our multifaceted approach to EFIC approval for an ongoing randomized clinical trial that compares sedation versus general anesthesia (SEGA) approaches for endovascular thrombectomy during AIS. METHODS: We published a university clinical trial website with EFIC information. We initiated a social media campaign on Facebook within a 50 mile radius of Texas Medical Center. Advertisements were linked to our website, and a press release was issued with information about the trial. In-person community consultations were performed, and voluntary survey information was collected. RESULTS: A total of 193 individuals (65% female, age 46.7 ± 16.6 years) participated in seven focus group community consultations. Of the 144 (75%) that completed surveys, 88.7% agreed that they would be willing to have themselves or family enrolled in this trial under EFIC. Facebook advertisements had 134,481 (52% females; 60% ≥45 years old) views followed by 1,630 clicks to learn more. The website had 1130 views (56% regional and 44% national) with an average of 3.85 min spent. Our Institutional Review Board received zero e-mails requesting additional information or to optout. CONCLUSION: Our social media campaign and community consultation methods provide a significant outreach to potential stroke patients. We hope that our experience will inform and help future efforts for trials seeking EFIC.

Microembolic Signals Detected by Transcranial Doppler Predict Future Stroke and Poor Outcomes.

BACKGROUND AND PURPOSE: Although transcranial Doppler detects microembolic signals (MES) in numerous settings, the practical significance of such findings remains unclear. METHODS: Clinical information from ischemic stroke or transient ischemic attack patients (n = 248) who underwent embolic monitoring from January 2015 to December 2018 was obtained. RESULTS: MES were found in 15% of studies and ischemic recurrence was seen in 11% of patients (over 7 ± 6 days). Patients with MES had more lacunes than those without MES (1 ± 3 vs. 1 ± 2, P = .016), were more likely to have ischemic recurrence (37% vs. 6%, P < .001), undergo a future revascularization procedure (26% vs. 10%, P = .005), have a longer length of stay (9 vs. 4 days, P = .043), and have worse functional disability at discharge (modified Rankin Scale 3-6, 66% vs. 34%, P < .001). After controlling for several relevant cofactors, patients with MES were more likely to have ischemic recurrence (HR 4.90, 95% CI 2.16-11.09, P < .001), worse functional disability (OR 3.31, 95% CI 1.22-8.99, P = .019), and longer length of stays (ß = .202, P < .001). CONCLUSIONS: MES may help to risk stratify patients as their presence is associated with ischemic recurrence and worse outcomes.

Embolization of carotid-cavernous fistulas: A technical note on simultaneous balloon protection of the internal carotid artery.

A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid circulation and the cavernous sinus. Treatment of CCFs often consists of obliteration of the fistula by a transarterial or transvenous endovascular approach using embolic agents. However, fistula embolization is often halted due to the potential embolic complications that may arise from the retrograde flow of the embolic agents into the arterial circulation, which often leads to the development of fistula recurrence. Moreover, retreatment of a CCF recurrence is challenging and more complex approaches may be required. In this technical note, we describe our experience with CCF embolization in 25 patients treated at a single center. We utilized a transvenous approach for CCF embolization with simultaneous balloon occlusion of the internal carotid artery during the infusion of the embolic material into the fistula. In our series, this simultaneous protection of the internal carotid artery showed to be a safe technique to prevent embolic complications and to achieve successful obliteration of the fistula. On follow-up, 2 cases presented a recurrence, one due to technical difficulties and the other related to an undetected vascular injury. In conclusion, this technique provides a safe approach in the treatment of CCFs by decreasing the risk of embolic complications and increasing the effectiveness of the embolic agents in accomplishing the obliteration of the CCF.

De novo thalamic arteriovenous malformation in a boy with a brainstem cavernous malformation.

Brain arteriovenous malformations (bAVMs) have long been considered to be congenital, developing between the third and eighth weeks of embryogenesis. However, cases reporting their de novo formation suggest that these lesions can develop after birth and have challenged this concept. We present a case of a 6-year-old boy with a history of a brainstem cavernous malformation diagnosed after birth who later developed a de novo bAVM. The de novo occurrence of this bAVM distant to the site of the cavernous malformation and a prior negative catheter angiography contributes to the uncertainty of the dynamics and pathophysiology of bAVMs.

Pathophysiology and clinical management of moderate and severe traumatic brain injury in the ICU.

Moderate and severe traumatic brain injury (TBI) is the leading cause of morbidity and mortality among young individuals in high-income countries. Its pathophysiology is divided into two major phases: the initial neuronal injury (or primary injury) followed by secondary insults (secondary injury). Multimodality monitoring now offers neurointensivists the ability to monitor multiple physiologic parameters that act as surrogates of brain ischemia and hypoxia, the major driving forces behind secondary brain injury. The heterogeneity of the pathophysiology of TBI makes it necessary to take into consideration these interacting physiologic factors when recommending for or against any therapies; it may also account for the failure of all the neuroprotective therapies studied so far. In this review, the authors focus on neuroclinicians and neurointensivists, and discuss the developments in therapeutic strategies aimed at optimizing intracranial pressure and cerebral perfusion pressure, and minimizing cerebral hypoxia. The management of moderate to severe TBI in the intensive care unit is moving away from a pure "threshold-based" treatment approach toward consideration of patient-specific characteristics, including the state of cerebral autoregulation. The authors also include a concise discussion on the management of medical and neurologic complications peculiar to TBI as well as an overview of prognostication.

Post-partum pituitary insufficiency and livedo reticularis presenting a diagnostic challenge in a resource limited setting in Tanzania: a case report, clinical discussion and brief review of existing literature.

BACKGROUND: Pituitary disorders following pregnancy are an important yet under reported clinical entity in the developing world. Conversely, post partum panhypopituitarism has a more devastating impact on women in such settings due to high fertility rates, poor obstetric care and scarcity of diagnostic and therapeutic resources available. CASE PRESENTATION: A 37 year old African female presented ten years post partum with features of multiple endocrine deficiencies including hypothyroidism, hypoadrenalism, lactation failure and secondary amenorrhea. In addition she had clinical features of an underlying autoimmune condition. These included a history of post-partum thyroiditis, alopecia areata, livedo reticularis and deranged coagulation indices. A remarkable clinical response followed appropriate hormone replacement therapy including steroids. This constellation has never been reported before; we therefore present an interesting clinical discussion including a brief review of existing literature. CONCLUSION: Post partum pituitary insufficiency is an under-reported condition of immense clinical importance especially in the developing world. A high clinical index of suspicion is vital to ensure an early and correct diagnosis which will have a direct bearing on management and patient outcome.

Latent tuberculosis among pregnant mothers in a resource poor setting in Northern Tanzania: a cross-sectional study.

BACKGROUND: Untreated latent TB infection (LTBI) is a significant risk factor for active pulmonary tuberculosis, hence predisposing to adverse pregnancy outcomes and mother to child transmission. The prevalence of latent tuberculosis in pregnancy and its association, if any, with various socio-demographic, obstetric and clinical characteristics was evaluated. METHODS: Northern Tanzania was chosen as the study site. In a cross-sectional study, a total of 286 pregnant women from 12 weeks gestational age to term were assessed. Screening was undertaken using an algorithm involving tuberculin skin testing, symptom screening in the form of a questionnaire, sputum testing for acid fast bacilli followed by shielded chest X-rays if indicated. HIV serology was also performed on consenting participants. RESULTS: Prevalence of latent infection ranged between 26.2% and 37.4% while HIV sero prevalence was 4.5%. After multivariate logistic analysis it was found that age, parity, body mass index, gestational age, and HIV sero status did not have any significant association with tuberculin skin test results. However certain ethnic groups were found to be less vulnerable to LTBI as compared to others (Chi square = 10.55, p = 0.03). All sputum smears for acid fast bacilli were negative. CONCLUSION: The prevalence of latent tuberculosis in pregnant women was found to be relatively high compared to that of the general population. In endemic areas, socio-demographic parameters alone are rarely adequate in identifying women susceptible to TB infection; therefore targeted screening should be conducted for all pregnant women at high risk for activation (especially HIV positive women). As opposed to the current policy of passive case detection, there appears to be an imminent need to move towards active screening. Ethnicity may provide important clues into genetic and cultural differences which predispose to latent tuberculosis, and is worth exploring further.