Faculty Bibliography

PURPOSE OF REVIEW/OBJECTIVE:This article describes the prerequisites for brain death/death by neurologic criteria (BD/DNC), clinical evaluation for BD/DNC (including apnea testing), use of ancillary testing, and challenges associated with BD/DNC determination in adult and pediatric patients. RECENT FINDINGS/RESULTS:Although death determination should be consistent among physicians and across hospitals, states, and countries to ensure that someone who is declared dead in one place would not be considered alive elsewhere, variability exists in the prerequisites, clinical evaluation, apnea testing, and use of ancillary testing to evaluate for BD/DNC. Confusion also exists about performance of an evaluation for BD/DNC in challenging clinical scenarios, such as for a patient who is on extracorporeal membrane oxygenation or a patient who was treated with therapeutic hypothermia. This prompted the creation of the World Brain Death Project, which published an international consensus statement on BD/DNC that has been endorsed by five world federations and 27 medical societies from across the globe. SUMMARY/CONCLUSIONS:The World Brain Death Project consensus statement is intended to provide guidance for professional societies and countries to revise or develop their own protocols on BD/DNC, taking into consideration local laws, culture, and resource availability; however, it does not replace local medical standards. To that end, pending publication of an updated guideline on determination of BD/DNC across the lifespan, the currently accepted medical standards for BD/DNC in the United States are the 2010 American Academy of Neurology standard for determination of BD/DNC in adults and the 2011 Society of Critical Care Medicine/American Academy of Pediatrics/Child Neurology Society standard for determination of BD/DNC in infants and children.

BACKGROUND:To enhance knowledge about religious objections to brain death/death by neurologic criteria (BD/DNC), we surveyed hospital chaplains about their experience with and beliefs about BD/DNC. METHODS:We distributed an online survey to five chaplaincy organizations between February and July 2019. RESULTS:There were 512 respondents from all regions of the USA; they were predominantly Christian (450 of 497; 91%), board certified (413 of 490; 84%), and employed by community hospitals (309 of 511; 61%). Half (274 of 508; 56%) of the respondents had been involved in a case in which a family objected to BD/DNC on the basis of their religious beliefs. In 20% of cases involving a religious objection, the patient was Buddhist, Hindu, Jewish, or Muslim. Most respondents believed that a person who is declared brain dead in accordance with the American Academy of Neurology standard is dead (427 of 510; 84%). A minority of respondents believed that a family should be able to choose whether an assessment for determination of BD/DNC is performed (81 of 512; 16%) or whether organ support is discontinued after BD/DNC (154 of 510; 30%). These beliefs were all significantly related to lack of awareness that BD/DNC is the medical and legal equivalent of cardiopulmonary death throughout the USA and that organ support is routinely discontinued after BD/DNC, outside of organ donation. CONCLUSIONS:Hospital chaplains, who work at the intersection between religion and medicine, commonly encounter religious objections to BD/DNC. To prepare them for these situations, they should receive additional education about BD/DNC and management of religious objections to BD/DNC.

BACKGROUND:Evolution of brain magnetic resonance imaging (MRI) findings in critically ill patients with coronavirus disease 2019 (COVID-19) is unknown. METHODS:We retrospectively reviewed 4530 critically ill patients with COVID-19 admitted to three tertiary care hospitals in New York City from March 1 to June 30, 2020 to identify patients who had more than one brain MRI. We reviewed the initial and final MRI for each patient to (1) measure the percent change in the bicaudate index and third ventricular diameter and (2) evaluate changes in the presence and severity of white matter changes. RESULTS:Twenty-one patients had two MRIs separated by a median of 22 [Interquartile range (IQR) 14-30] days. Ventricle size increased for 15 patients (71%) between scans [median bicaudate index 0.16 (IQR 0.126-0.181) initially and 0.167 (IQR 0.138-0.203) on final imaging (p < 0.001); median third ventricular diameter 6.9 mm (IQR 5.4-10.3) initially and 7.2 mm (IQR 6.4-10.8) on final imaging (p < 0.001)]. Every patient had white matter changes on the initial and final MRI; between images, they worsened for seven patients (33%) and improved for three (14%). CONCLUSIONS:On serial imaging of critically ill patients with COVID-19, ventricle size frequently increased over several weeks. White matter changes were often unchanged, but in some cases they worsened or improved, demonstrating there is likely a spectrum of pathophysiological processes responsible for these changes.

Approximately 15% of deaths in developed nations are due to sudden cardiac arrest, making it the most common cause of death worldwide. Though high-quality cardiopulmonary resuscitation has improved overall survival rates, the majority of survivors remain comatose after return of spontaneous circulation secondary to hypoxic ischemic injury. Since the advent of targeted temperature management, neurologic recovery has improved substantially, but the majority of patients are left with neurologic deficits ranging from minor cognitive impairment to persistent coma. Of those who survive cardiac arrest, but die during their hospitalization, some progress to brain death and others die after withdrawal of life-sustaining treatment due to anticipated poor neurologic prognosis. Here, we discuss considerations neurologists must make when asked, "Given their recent cardiac arrest, how much neurologic improvement do we expect for this patient?"

BACKGROUND AND PURPOSE/OBJECTIVE:We reviewed the literature to evaluate cerebrospinal fluid (CSF) results from patients with coronavirus disease 2019 (COVID-19) who had neurological symptoms and had an MRI that showed (1) central nervous system (CNS) hyperintense lesions not attributed to ischemia and/or (2) leptomeningeal enhancement. We sought to determine if these findings were associated with a positive CSF severe acute respiratory syndrome associated coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR). METHODS:We performed a systematic review of Medline and Embase from December 1, 2019 to November 18, 2020. CSF results were evaluated based on the presence/absence of (1) ≥ 1 CNS hyperintense lesion and (2) leptomeningeal enhancement. RESULTS:In 117 publications, we identified 193 patients with COVID-19 who had an MRI of the CNS and CSF testing. There were 125 (65%) patients with CNS hyperintense lesions. Patients with CNS hyperintense lesions were significantly more likely to have a positive CSF SARS-CoV-2 PCR (10% [9/87] vs. 0% [0/43], p = 0.029). Of 75 patients who had a contrast MRI, there were 20 (27%) patients who had leptomeningeal enhancement. Patients with leptomeningeal enhancement were significantly more likely to have a positive CSF SARS-CoV-2 PCR (25% [4/16] vs. 5% [2/42], p = 0.024). CONCLUSION/CONCLUSIONS:The presence of CNS hyperintense lesions or leptomeningeal enhancement on neuroimaging from patients with COVID-19 is associated with increased likelihood of a positive CSF SARS-CoV-2 PCR. However, a positive CSF SARS-CoV-2 PCR is uncommon in patients with these neuroimaging findings, suggesting they are often related to other etiologies, such as inflammation, hypoxia, or ischemia.

Purpose of review: This review summarizes current and emerging treatments for hypoxic-ischemic brain injury (HIBI). Guidance on neuroprognostication after HIBI is also presented. Recent findings: After two 2002 studies demonstrated cooling improved neurologic outcome after HIBI, a 2013 trial found targeting 36 °C was non-inferior to targeting 33 °C. Research is ongoing, but there is no other definitive human data on therapies to prevent secondary brain injury after HIBI. Summary: Guideline-recommended treatment of HIBI includes early, optimal cardiopulmonary resuscitation to prevent primary brain injury, and targeted temperature management to mitigate secondary brain injury. Multiple novel treatment options, including anti-inflammatory agents, anesthetics, and neuroprotective cocktails, are currently being investigated. Additionally, neurostimulants may help promote wakefulness after HIBI. Neuroprognostication after HIBI requires a multimodal approach using the neurologic exam, electroencephalography, somatosensory evoked potentials, neuroimaging, and serum biomarkers. It is important to avoid premature prognostication and nihilism.