Predictive Value of Clinical, CSF and Vessel Wall MRI Variables in Diagnosing Primary Angiitis of the CNS.

Background and Objectives: Without brain biopsy, there are limited diagnostic predictors to differentiate primary angiitis of the CNS (PACNS) from intracranial atherosclerotic disease (ICAD). We examined the utility of clinical, CSF, and quantitative vessel wall magnetic resonance imaging (VWMRI) variables in predicting PACNS from ICAD. Methods: In this cross-sectional design, observational study, we reviewed electronic medical records to identify patients (18 years and older) who presented to our medical center between January 2015 and December 2021 for ischemic stroke due to intracranial vasculopathy. Patients with biopsy-proven PACNS, probable PACNS, or ICAD were included. Patients with secondary CNS vasculitis or no VWMRI data were excluded. On VWMRI, for each patient, a total of 20 vessel wall segments were analyzed for percent concentricity, percent irregularity, and concentricity to eccentricity (C/E) ratios. We also collected several clinical and CSF variables. Using logistic regression models, we assessed the diagnostic value of VWMRI, CSF, and clinical variables in predicting PACNS in patients with biopsy-proven disease. We then performed a sensitivity analysis to assess predictors of biopsy-proven and probable PACNS. Results: Thirty-two patients with ICAD (54.2%) and 27 patients with PACNS (45.8%) were included. Of the patients with PACNS, 21 (77.8%) were not biopsied and considered probable PACNS. Twenty-four patients with ICAD (75%) and 6 biopsy-proven patients with PACNS (22.2%) showed large vessel involvement and were included in the primary analysis. Encephalopathy (odds ratio [OR], 7.60; 95% CI 1.07-54.09) and seizure (OR 23.00; 95% CI 1.77-298.45) were significantly associated with PACNS. All patients were included in the sensitivity analysis, in which headache significantly predicted PACNS (OR 7.60; 95% CI 1.07-54.09). In the primary analysis, for every 1 white blood cell/µL increase in CSF, there was a 47% higher odds of PACNS (OR 1.47; 95% CI 1.04-2.07). On VWMRI, a C/E ratio >1 (OR 115.00; 95% CI 6.11-2165.95), percent concentricity ≥50% (OR 55.00; 95% CI 4.13-732.71), and percent irregularity <50% (OR 55.00; 95% CI 4.13-732.71) indicated significantly higher odds of PACNS compared with ICAD. Discussion: Our results suggest that quantitative VWMRI metrics, CSF pleocytosis, and clinical features of encephalopathy, seizure, and headache significantly predict a diagnosis of probable PACNS when compared with ICAD.

Dural arteriovenous fistula in the setting of cerebral venous sinus thrombosis and COVID-19 infection.

OBJECTIVE: The aim of this study was to examine the presence of concurrent venous thrombosis and COVID-19 infections in patients with dural arteriovenous fistulas (dAVFs). METHODS: An analysis of all patients diagnosed with dAVF via cerebral angiography by the senior author was conducted, with special attention given to the presence of cerebral venous sinus thrombosis (CVST) and COVID-19 infection. General demographics, clinical presentation, presence of CVST, and COVID-19 infection status were reported. RESULTS: A total of 30 patients with dAVFs were included in this study. Three patients were diagnosed with COVID-19 (10%), with one of these patients developing CVST (33%) at 6 months postinfection. Of the 27 patients not infected with COVID-19, one was diagnosed with a likely chronic CVST at the time of presentation of dAVF (4%). A total of 11 case reports and 3 retrospective studies describing patients diagnosed with CVST at or after diagnosis of dAVFs have been reported in the literature. The incidence of dAVFs in patients with CVST has been reported as 2.4%, and the incidence of dAVF has reportedly increased five- to tenfold since the COVID-19 pandemic. CONCLUSIONS: COVID-19 infections may pose as an emerging risk factor for the development of CVST and subsequent dAVF development. To the authors' knowledge, this study presents the first cases in the literature describing a temporal relationship between COVID-19 and development of a dAVF with CVST. The effect of both COVID-19 and associated vaccines should be further assessed in future studies to examine its impact as an effect modifier on the association of dAVF and CVST.

Structural Brain Injury on Brain Magnetic Resonance Imaging in Acute Respiratory Distress Syndrome.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is an acute inflammatory respiratory failure condition that may be associated with brain injury. We aimed to describe the types of structural brain injuries detected by brain magnetic resonance imaging (MRI) among patients with ARDS. METHODS: We retrospectively reviewed and collected data on brain injuries as detected by brain MRI during index hospitalization of all patients with ARDS at a single tertiary center in the United States from January 2010 to October 2018 (pre-COVID era). Structural brain injuries were classified as cerebral ischemia (ischemic infarct and hypoxic-ischemic brain injury) or cerebral hemorrhage (intraparenchymal hemorrhage, cerebral microbleeds, subarachnoid hemorrhage, and subdural hematoma). Descriptive statistics were conducted. RESULTS: Of the 678 patients with ARDS, 66 (9.7%) underwent brain MRI during their ARDS illness. The most common indication for brain MRI was encephalopathy (45.4%), and the median time from hospital admission to MRI was 10 days (interquartile range 4-17). Of 66 patients, 29 (44%) had MRI evidence of brain injury, including cerebral ischemia in 33% (22 of 66) and cerebral hemorrhage in 21% (14 of 66). Among those with cerebral ischemia, common findings were bilateral globus pallidus infarcts (n = 7, 32%), multifocal infarcts (n = 5, 23%), and diffuse hypoxic-ischemic brain injury (n = 3, 14%). Of those with cerebral hemorrhage, common findings were cerebral microbleeds (n = 12, 86%) and intraparenchymal hemorrhage (n = 2, 14%). Patients with ARDS with cerebral hemorrhage had significantly greater use of rescue therapies, including prone positioning (28.6% vs. 5.8%, p = 0.03), inhaled vasodilator (35.7% vs. 11.5%, p = 0.046), and recruitment maneuver (14.3% vs. 0%, p = 0.04). CONCLUSIONS: Structural brain injury was not uncommon among selected patients with ARDS who underwent brain MRI. The majority of brain injuries seen were bilateral globus pallidus infarcts and cerebral microbleeds.

Cerebral microbleeds in acute respiratory distress syndrome.

BACKGROUND: Cerebral microbleeds (CMB) have been observed in patients with critical illness. We sought to examine the frequency of CMB in patients with acute respiratory distress syndrome (ARDS) and association with neurologic complications including acute cerebral ischemia and seizures. METHODS: A retrospective review of patients with ARDS from January 2010 to October 2018 was performed. Patients with brain MRIs with susceptibility weighted imaging or gradient echo sequences were included. We compared neurologic complications and intensive care unit outcomes between patients with and without CMB. Cerebral small vessel disease (CSVD) was defined as the presence of CMB, lacunar infarcts, enlarged perivascular spaces, and white matter hyperintensities. RESULTS: Of 678 patients with ARDS, 61 met inclusion criteria. Median age was 54 years (IQR 42-63) and 28 were males. Of 12 (20%) with CMB, 10 had lobar CMB. Four patients had CMB in the corpus callosum, all involving the splenium. Neurologic complications were more common in those with CMB including acute cerebral ischemia (41.7% versus 10.2%, p=0.008) and seizures (33.3% versus 8.2%, p=0.021). ARDS rescue therapies were more commonly used in patients with CMB (p=0.005). There was no difference in hospital mortality (41.7% versus 34.7%, p=0.652). Patients with CMB did not have a higher CSVD score than those without CMB when accounting for the presence of CMB (median=1 versus 0, p=0.891). CONCLUSION: CMB were present in twenty percent of patients with ARDS who had MRI and were more commonly seen in patients requiring ARDS rescue therapies.

Outcomes of heart transplant recipients with prior left ventricular assist device associated stroke.

BACKGROUND: Left ventricular assist devices (LVADs) improve survival in patients with end-stage heart failure but are associated with ischemic stroke and intracranial hemorrhage (ICH). The impact of LVAD-associated stroke on transplant candidacy and outcomes has not been characterized. METHODS: Adult patients undergoing LVAD implantation at Cleveland Clinic between 2004 to 2021 were reviewed and patients who developed ischemic stroke or ICH were identified. Post-transplant survival analysis was performed between patients with LVAD-associated stroke vs. without. RESULTS: 917 patients had an LVAD implantation of whom 244 (median age 57, 79% male) underwent subsequent transplant including 25 with prior LVAD-associated stroke. The 1- and 2-year survival after transplant in patients with LVAD-associated stroke were 100% and 95% respectively, compared with 92% and 90% in patients without stroke (p=0.156; p=0.323) Similarly, there was no difference in stroke incidence at 1- and 2 years after transplant between patients with LVAD-associated stroke (4% and 5%) and those without prior stroke (5% and 6%, p = 0.884; p=0.744). CONCLUSIONS: In this single-center retrospective study, patients with LVAD-associated stroke were significantly less likely to undergo heart transplant, but those who underwent heart transplant had similar post-transplant outcomes as patients without history of LVAD-associated stroke. Given the similar outcomes seen in this population, history of LVAD-associated stroke should not be viewed as an absolute contraindication to subsequent heart transplant.

Neurologic Complications in Patients With Left Ventricular Assist Devices.

Left ventricular assist device (LVAD) use has revolutionised the care of patients with advanced heart failure, allowing more patients to survive until heart transplantation and providing improved quality for patients unable to undergo transplantation. Despite these benefits, improvements in device technology, and better clinical care and experience, LVADs are associated with neurologic complications. This review provides information on the incidence, risk factors, and management of neurologic complications among LVAD patients. Although scant guidelines exist for the evaluation and management of neurologic complications in LVAD patients, a high index of suspicion can prompt early detection of neurologic complications which may improve overall neurologic outcomes. A better understanding of the implications of continuous circulatory flow on systemic and cerebral vasculature is necessary to reduce the common occurrence of neurologic complications in this population.

Pearls & Oy-sters: Seronegative Eastern Equine Encephalitis in an Immunocompromised Stem Cell Transplant Recipient.

Altered mental status in immunosuppressed patients has a wide differential diagnosis. In this case, a 27-year-old man presented with encephalopathy, nausea, vomiting, and fevers. His medical history was significant for acute myeloid leukemia in remission after allogenic hematopoietic stem cell transplantation 17 months prior complicated by graft vs host disease affecting his skin treated with sirolimus. A lumbar puncture was performed with a lymphocytic pleocytosis, mildly elevated protein, and negative Gram-stain and bacterial and fungal cultures. His examination deteriorated, and he became comatose with loss of pupillary and corneal reflexes. An MRI of his brain demonstrated T2/fluid-attenuated inversion recovery signal abnormality involving the bilateral basal ganglia, mesial temporal lobes, and entire brainstem along with bilateral temporal parenchymal and leptomeningeal enhancement. Ultimately, diagnosis was made through metagenomic PCR sequencing from his CSF. This case highlights diagnostic challenges in immunosuppressed patients because antibodies against the causative antigen were negative (potentially related to decreased antibody production in the setting of immunosuppression).

MRI of Cerebrovascular Injury Associated With COVID-19 and Non-COVID-19 Acute Respiratory Distress Syndrome: A Matched Case-Control Study.

OBJECTIVES: Cerebrovascular injury associated with COVID-19 has been recognized, but the mechanisms remain uncertain. Acute respiratory distress syndrome (ARDS) is a severe pulmonary injury, which is associated with both ischemic and hemorrhagic stroke. It remains unclear if cerebrovascular injuries associated with severe COVID-19 are unique to COVID-19 or a consequence of severe respiratory disease or its treatment. The frequency and patterns of cerebrovascular injury on brain MRI were compared among patients with COVID-19 ARDS and non-COVID-19 ARDS. DESIGN: A case-control study. SETTING: A tertiary academic hospital system. PATIENTS: Adult patients (>18 yr) with COVID-19 ARDS (March 2020 to July 2021) and non-COVID-19 ARDS (January 2010-October 2018) who underwent brain MRI during their index hospitalization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cerebrovascular injury on MRI included cerebral ischemia (ischemic infarct or hypoxic ischemic brain injury) and intracranial hemorrhage (intraparenchymal, subarachnoid, or subdural, and cerebral microbleed [CMB]).Twenty-six patients with COVID-19 ARDS and sixty-six patients with non-COVID ARDS underwent brain MRI during the index hospitalization, resulting in 23 age- and sex-matched pairs. The frequency of overall cerebrovascular injury (57% vs 61%), cerebral ischemia (35% vs 43%), intracranial hemorrhage (43% vs 48%), and CMB (52% vs 41%) between COVID-19 ARDS and non-COVID-19 ARDS patients was similar (all p values >0.05). However, four of 26 patients (15%) with COVID-19 and no patients with non-COVID-19 ARDS had disseminated leukoencephalopathy with underlying CMBs, an imaging pattern that has previously been reported in patients with COVID-19. CONCLUSIONS: In a case-control study of selected ARDS patients with brain MRI, the frequencies of ischemic and hemorrhagic cerebrovascular injuries were similar between COVID-19 versus non-COVID-19 ARDS patients. However, the MRI pattern of disseminated hemorrhagic leukoencephalopathy was unique to the COVID-19 ARDS patients in this cohort.

Implications of Causes of Intracranial Hemorrhage During Left Ventricular Assist Device Support.

BACKGROUND: Intracranial hemorrhage (ICH) is a frequent complication in patients with an implanted left ventricular assist device (LVAD) for advanced heart failure. Bloodstream infection is known to be associated with ICH in patients with LVAD, but its effects on ICH-associated mortality are unknown. We compared characteristics and mortality of infection-associated, traumatic, and spontaneous hemorrhages. METHODS: Patients in an LVAD registry at a tertiary care center were reviewed for this cohort study. ICH included intraparenchymal hemorrhage, subarachnoid hemorrhage, and subdural hemorrhage. Hemorrhages were categorized into infectious, traumatic, and spontaneous by the presence or absence of concurrent device-associated infection or antecedent trauma. RESULTS: Of 683 patients with an LVAD, 73 experienced ICH (10.7%). Intraparenchymal hemorrhage was the most prevalent (72%), followed by subarachnoid hemorrhage (27%) and subdural hemorrhage (23%), with multiple concurrent hemorrhage subtypes in 16 patients (22%). Median time from implantation to ICH was shorter in spontaneous ICH than in infection-associated ICH (100 days vs. 252 days, p = 0.048). The prevalence of the different subtypes of ICH were similar between spontaneous and infection-associated ICH, and no differences were seen in mortality between the different causes of ICH. CONCLUSIONS: Although spontaneous ICH occurred earlier after LVAD implantation than infection-associated ICH, no difference in mortality was seen between the different causes of ICH.

Does Targeted Temperature Management Improve Neurological Outcome in Extracorporeal Cardiopulmonary Resuscitation (ECPR)?

PURPOSE: Targeted temperature management (TTM) is a standard of care in patients after cardiac arrest for neuroprotection. Currently, the effectiveness and efficacy of TTM after extracorporeal cardiopulmonary resuscitation (ECPR) is unknown. We aimed to compare neurological and survival outcomes between TTM vs non-TTM in patients undergoing ECPR for refractory cardiac arrest. METHODS: We searched PubMed and 5 other databases for randomized controlled trials and observational studies reporting neurological outcomes or survival in adult patients undergoing ECPR with or without TTM. Good neurological outcome was defined as cerebral performance category <3. Two independent reviewers extracted the data. Random-effects meta-analyses were used to pool data. RESULTS: We included 35 studies (n = 2,643) with the median age of 56 years (interquartile range [IQR]: 52-59). The median time from collapse to ECMO cannulation was 58 minutes (IQR: 49-82) and the median ECMO duration was 3 days (IQR: 2.0-4.1). Of 2,643, 1,329 (50.3%) patients received TTM and 1,314 (49.7%) did not. There was no difference in the frequency of good neurological outcome at any time between TTM (29%, 95% confidence interval [CI]: 23%-36%) vs. without TTM (19%, 95% CI: 9%-31%) in patients with ECPR (P = 0.09). Similarly, there was no difference in overall survival between patients with TTM (30%, 95% CI: 22%-39%) vs. without TTM (24%, 95% CI: 14%-34%) (P = 0.31). A cumulative meta-analysis by publication year showed improved neurological and survival outcomes over time. CONCLUSIONS: Among ECPR patients, survival and neurological outcome were not different between those with TTM vs. without TTM. Our study suggests that neurological and survival outcome are improving over time as ECPR therapy is more widely used. Our results were limited by the heterogeneity of included studies and further research with granular temperature data is necessary to assess the benefit and risk of TTM in ECPR population.

Determination of Brain Death in Patients Undergoing Short-Term Mechanical Circulatory Support Devices.

OBJECTIVE: To describe apnoea test (AT) and ancillary study performance for brain death (BD) determination among patients undergoing short-term mechanical circulatory support (MCS) devices, including extracorporeal membrane oxygenation (ECMO) and intra-aortic balloon pump (IABP). METHODS: We retrospectively analysed data regarding use of AT and ancillary study in consecutive adult patients who were diagnosed with BD while on MCS devices (including ECMO and IABP) over a 10-year period. RESULTS: Out of 140 patients, eight were on MCS devices at the time of BD (four ECMO, two ECMO and IABP, two IABP). The most common aetiology of BD was hypoxic ischaemic brain injury (6/8, 75%). In four patients (50%), the AT was not attempted because of haemodynamic instability and ECMO; in the remaining four (50%), both AT and ancillary studies were used. In three patients on ECMO, AT was performed by reducing the ECMO sweep flow rate to a range 0.5-2.7 L/min in order to achieve hypercarbia. One patient underwent AT while on IABP which was complicated by hypotension. All patients underwent ancillary tests, most commonly transcranial Doppler ultrasonography (TCD) (7/8, 88%); among those, cerebral circulatory arrest was confirmed in six of seven patients (86%), all of whom had left ventricular ejection fracture (LVEF) ≥20% and/or were supported with IABP. CONCLUSIONS: There are multiple uncertainties regarding BD diagnosis while on MCS, prompting the need for ancillary studies in most patients. Our study shows that TCD can be used to support BD diagnosis in patients on ECMO who have sufficient cardiac contractility and/or IABP to produce pulsatile flow. TCD use in ECMO patients low LVEF needs further study.

Lupus Cerebellitis Presenting With Ataxia: A Case Report.

We report a case of a woman with a history of systemic lupus erythematosus who developed persistent ataxia and was diagnosis with lupus cerebellitis. Magnetic resonance imaging of the brain showed T2/FLAIR signal hyperintensity within the cerebellar vermis without mass effect. The patient's condition improved with pulse IV methylprednisolone. This case highlights unique imaging findings within the cerebellum, our diagnostic and treatment regimen, and compares this case to previous literature on similar cases.

Timing of Acute Stroke in COVID-19-A Health System Registry Study.

BACKGROUND AND PURPOSE: The association between SARS-CoV-2 infection and stroke remains unknown. We aimed to compare the characteristics of stroke patients who were hospitalized with Coronavirus Disease 2019 (COVID-19) based on the timing of stroke diagnosis. METHODS: We performed a retrospective analysis of adult patients in a health system registry of COVID-19 who were hospitalized and had imaging-confirmed acute stroke during hospitalization. Baseline characteristics and hospital outcomes were collected and analyzed. RESULTS: Out of 882 COVID-19 patients who were hospitalized between March 9 to May 17, 2020, 14 patients (2% of all COVID-19 patients and 21% of those who underwent imaging) presented with stroke or developed stroke during hospitalization. Eleven had acute ischemic stroke (AIS) and 3 had acute hemorrhagic stroke. Six patients (43%) presented to the hospital with acute stroke symptoms and were found to have SARS-CoV-2. Compared to patients who presented with AIS, more patients with AIS during hospitalization were male, of older age, had pneumonia and acute respiratory distress syndrome, were severely ill, and had high inflammatory and thrombotic markers (including C reactive protein, D dimer, ferritin, and fibrinogen). Among all patients, hospital mortality was high (50%) and the majority of patients who were discharged had poor neurological outcome. CONCLUSIONS: A distinction should be made between patients who present with acute stroke with concurrent SARS-CoV-2 infection and those who develop stroke as a complication of severe COVID-19. It is likely that a subset of stroke patients will incidentally test positive for the virus given the widespread pandemic.

Ipsilateral Reversible Cerebral Vasculopathy Secondary to Carotid Artery Revascularization: A Case Report.

BACKGROUND: The emergence of neurologic symptoms after carotid revascularization is not uncommon and typically caused by perioperative ischemic stroke or hyperperfusion. Postoperative vasculopathy, including reversible cerebral vasoconstriction syndrome (RCVS) is a rare complication of carotid intervention and may be an under-identified cause of neurologic deficit after revascularization. We report a case of reversible postoperative vasculopathy following carotid revascularization as well as its management. CASE PRESENTATION: A 74 year old right-handed woman presented to the emergency department with sudden onset left arm weakness and episodic shaking while hypotensive. Computed tomography angiography revealed total occlusion of her right internal carotid artery. Transcranial Doppler monitoring demonstrated active embolic events in her right middle cerebral artery raising concern for continued stump embolization. She underwent carotid revascularization with carotid endarterectomy, mechanical thrombectomy, and carotid angioplasty and initially did well postoperatively. On postoperative day 5, she developed a fixed right gaze and left hemiparesis. Computed tomography revealed new right frontal lobe and basal ganglia infarcts, and angiography showed new right internal carotid, middle cerebral, and anterior cerebral artery vasoconstriction consistent with postoperative vasculopathy. Despite treatment with pressure augmentation and vasodilator therapy, her symptoms persisted resulting in left hemiplegia at discharge. DISCUSSION: This case highlights postoperative vasculopathy (including RCVS) as a rare potential complication after carotid revascularization that should be considered in a patient with persistent acute neurologic symptoms. Information regarding incidence and predisposing risk factors is limited. Multiple diagnostic and therapeutic modalities may be necessary in the recognition and treatment of postoperative vasculopathy.

Outcomes, Time-Trends, and Factors Associated With Ancillary Study Use for the Determination of Brain Death.

OBJECTIVES: Brain death determination often requires ancillary studies when clinical determination cannot be fully or safely completed. We aimed to analyze the results of ancillary studies, the factors associated with ancillary study performance, and the changes over time in number of studies performed at an academic health system. DESIGN: Retrospective cohort. SETTING: Multihospital academic health system. PATIENTS: Consecutive adult patients declared brain dead between 2010 and 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 140 brain death patients, ancillary studies were performed in 84 (60%). The false negative rate of all ancillary studies was 4% (5% of transcranial Doppler ultrasounds, 4% of nuclear studies, 0% of electroencephalograms, and 17% of CT angiography). In univariate analysis, ancillary study use was associated with female sex (odds ratio, 2.4; 95% CI, 1.21-5.01; p = 0.013) and the etiology of brain death being hypoxic-ischemic brain injury (odds ratio, 2.9; 95% CI, 1.43-5.88; p = 0.003), nontraumatic intracranial hemorrhage (odds ratio, 0.45; 95% CI, 0.21-0.96; p = 0.039), or traumatic brain injury (odds ratio, 0.22; 95% CI, 0.04-0.8; p = 0.031). In multivariable analysis, female sex (odds ratio, 5.7; 95% CI, 2.56-15.86; p = 0.004), the etiology of brain death being hypoxic-ischemic brain injury (odds ratio, 3.2; 95% CI, 1.3-8.8; p = 0.015), and the neurologists performing brain death declaration (odds ratio, 0.08; 95% CI, 0.004-0.64; p = 0.034) were factors independently associated with use of ancillary studies. Over the study period, the total number of ancillary studies performed each year did not significantly change; however, the number of electroencephalograms significantly decreased with time (odds ratio per 1-yr increase, 0.67; 95% CI, 0.49-0.90; p = 0.014). CONCLUSIONS: A large number of ancillary studies were performed despite a clinical determination of brain death; patients with hypoxic-ischemic brain injury are more likely to undergo ancillary studies for brain death determination, and neurologists were less likely to use ancillary studies for brain death. Recently, the use of electroencephalograms for brain death determination has decreased, likely reflecting significant concerns regarding its validity and reliability.

Neurocritical Care of Mechanical Circulatory Support Devices.

PURPOSE OF REVIEW: Mechanical circulatory support (MCS) devices have demonstrated improved survival outcomes in otherwise refractory cardiopulmonary failure but are associated with significant neurologic morbidity and mortality. This review aims to characterize MCS-associated brain injury and discuss the neurocritical care of this population. RECENT FINDINGS: We found no practice guidelines or specific management strategies for the neurocritical care of patients with MCS devices. Acute brain injury was commonly observed in short-term and durable MCS devices. There is emerging evidence that a standardized neurological monitoring and management algorithm for MCS device-associated brain injury is feasible and potentially improves neurological outcomes. While MCS devices are associated with significant neurologic morbidity and mortality, there is scant evidence regarding optimal neuromonitoring and neurocritical care. With the increase in use of MCS devices for both short-term and durable applications, improved outcomes will depend on early identification and intervention of neurologic complications and further research into their pathophysiology.

The effect of incorporating an arterial pH target during apnea test for brain death determination.

BACKGROUND: Persistent apnea despite an adequate rise in arterial pressure of CO2 is an essential component of the criteria for brain death (BD) determination. Current guidelines vary regarding the utility of arterial pH changes during the apnea test (AT). We aimed to study the effect of incorporating an arterial pH target < 7.30 during the AT (in addition to the existing PaCO2 threshold) on brain death declarations. METHODS: We performed retrospective analysis of consecutive adult patients who were diagnosed with BD and underwent AT at the Cleveland Clinic over the last 10 years. Data regarding baseline and post-AT blood gas analyses were collected and analyzed. RESULTS: Ninety-eight patients underwent AT in the study period, which was positive in 89 (91%) and inconclusive in 9 (9%) patients. The mean age was 50 years old (standard deviation [SD] 16) and 54 (55%) were female. The most common etiology BD was hypoxic ischemic brain injury (HIBI) due to cardiac arrest (42%). Compared to those with positive AT, patients with inconclusive AT had a higher post-AT pH (7.24 vs 7.17, p = 0.01), lower PaO2 (47 vs 145, p < 0.01), and a lower PaCO2 (55 vs 73, p = 0.01). Among patients with a positive AT using PaCO2 threshold alone, the frequency of patients with post-AT pH < 7.30 was 95% (83/87). CONCLUSION: Implementing a BD criteria requiring both arterial pH and PaCO2 thresholds reduced the total number of positive ATs; these inconclusive cases would have required longer duration of AT to reach both targets, repeated ATs, or ancillary studies to confirm BD. The impact of this on the overall number BD declarations requires further research.

Brain Injury Is More Common in Venoarterial Extracorporeal Membrane Oxygenation Than Venovenous Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

OBJECTIVES: Despite the common occurrence of brain injury in patients undergoing extracorporeal membrane oxygenation, it is unclear which cannulation method carries a higher risk of brain injury. We compared the prevalence of brain injury between patients undergoing venoarterial and venovenous extracorporeal membrane oxygenation. DATA SOURCES: PubMed and six other databases from inception to April 2020. STUDY SELECTION: Observational studies and randomized clinical trials in adult patients undergoing venoarterial extracorporeal membrane oxygenation or venovenous extracorporeal membrane oxygenation reporting brain injury. DATA EXTRACTION: Two independent reviewers extracted the data from the studies. Random-effects meta-analyses were used to pool data. DATA SYNTHESIS: Seventy-three studies (n = 16,063) met inclusion criteria encompassing 8,211 patients (51.2%) undergoing venoarterial extracorporeal membrane oxygenation and 7,842 (48.8%) undergoing venovenous extracorporeal membrane oxygenation. Venoarterial extracorporeal membrane oxygenation patients had more overall brain injury compared with venovenous extracorporeal membrane oxygenation (19% vs 10%; p = 0.002). Venoarterial extracorporeal membrane oxygenation patients had more ischemic stroke (10% vs 1%; p < 0.001), hypoxic-ischemic brain injury (13% vs 1%; p < 0.001), and brain death (11% vs 1%; p = 0.001). In contrast, rates of intracerebral hemorrhage (6% vs 8%; p = 0.35) did not differ. Survival was lower in venoarterial extracorporeal membrane oxygenation (48%) than venovenous extracorporeal membrane oxygenation (64%) (p < 0.001). After excluding studies that included extracorporeal cardiopulmonary resuscitation, no significant difference was seen in the rate of overall acute brain injury between venoarterial extracorporeal membrane oxygenation and venovenous extracorporeal membrane oxygenation (13% vs 10%; p = 0.4). However, ischemic stroke (10% vs 1%; p < 0.001), hypoxic-ischemic brain injury (7% vs 1%; p = 0.02), and brain death (9% vs 1%; p = 0.005) remained more frequent in nonextracorporeal cardiopulmonary resuscitation venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation. CONCLUSIONS: Brain injury was more common in venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation. While ischemic brain injury was more common in venoarterial extracorporeal membrane oxygenation patients, the rates of intracranial hemorrhage were similar between venoarterial extracorporeal membrane oxygenation and venovenous extracorporeal membrane oxygenation. Further research on mechanism, timing, and effective monitoring of acute brain injury and its management is necessary.