Absent Brainstem Reflexes Research Articles

Role of Clinical and Multimodality Neuroimaging in the Evaluation of Brain Death/Death by Neurologic Criteria and Recent Highlights from 2023 Updated Guidelines.

Purpose of Review: This review aims to provide a comprehensive overview of the diagnosis of brain death/death by neurologic criteria (BD/DNC) by emphasizing the clinical criteria established by the American Academy of Neurology (AAN) in light of their updated guidelines released in 2023. In this review, we will focus on the current implementation of ancillary tests including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler, which provide support in diagnoses when clinical examination and apnea tests are inconclusive. Finally, we will also provide examples to discuss the implementation of certain imaging studies in the context of diagnosing BD/DNC. Recent Findings: Recent developments in the field of neurology have emphasized the importance of clinical criteria for diagnosing BD/DNC, with the AAN providing clear updated guidelines that include coma, apnea, and the absence of brainstem reflexes. Current ancillary tests, including the catheter cerebral angiogram, nuclear scintigraphy, and transcranial Doppler play a crucial role in confirming BD/DNC when the clinical assessment is limited. The role of commonly used imaging studies including computed tomography and magnetic resonance angiographies of the brain as well as CT/MR perfusion studies will also be discussed in the context of these new guidelines. Summary: BD/DNC represents the permanent cessation of brain functions, including the brainstem. This review article provides the historical context, clinical criteria, and pathophysiology that goes into making this diagnosis. Additionally, it explores the various ancillary tests and selected imaging studies that are currently used to diagnose BD/DNC under the newly updated AAN guidelines. Understanding the evolution of how to effectively use these diagnostic tools is crucial for healthcare professionals who encounter these BD/DNC cases in their practice.

Intracranial Hypertension Syndrome Secondary to Intraventricular Hemorrhage: A Case Report

Introduction: Acute intracranial hypertension (ICH) syndrome is a neurosurgical emergency. Timely diagnosis of ICH is imperative for potential reversibility of the neurological condition. We report the case of a child with bleeding and hydrocephalus secondary to lateral ventricle injury, with an emphasis on the outcome secondary to ICH. Case Report: A 10-year-old girl presented to the emergency department with a history of progressive holocranial headache and vomiting for 1 day. She progressed with a progressive decrease in the level of consciousness. A computed tomography scan of the head was performed only 12 hours after admission, revealing intraventricular hemorrhage associated with calcifications and ventricular dilation. Upon admission to a specialized service, she had bilateral fixed mydriasis and the absence of brainstem reflexes. Emergency ventriculostomy was performed, but the patient developed brain death the following day. Conclusion: Besides the delay in diagnosis, the time between diagnosis and emergency neurosurgical treatment also constituted a significant factor in the unfavorable outcome described. In many ICH situations, a simple procedure like ventriculostomy can prevent an unfavorable outcome. Therefore, proper evaluation of pediatric patients and early recognition of clinical signs indicating intracranial hypertension are crucial for preventing an unfavorable and potentially fatal outcome.

Abstract 245: A Validated Score to Predict Poor Neurological Outcome After 72 Hours of Refractory VF/VT in Out of Hospital Cardiac Arrest Patients Requiring Extracorporeal Cardiopulmonary Resuscitation

Introduction: The challenge with neuroprognostication is finding a multimodal prediction model that yields the lowest false positive rate for a poor outcome. Objectives: To develop and validate a score that accurately predicts poor neurological outcome after 72 hours of ECPR initiation. Methods: Single-center, retrospective cohort study included 361 OHCA patients who underwent ECPR at the University of Minnesota between December 2015-January 2023. In a 50% random modeling sample, we obtained a derivation (n=180) and validation sample (n=181). The primary outcome was poor neurological outcome (defined as CPC 3-5) at hospital discharge. Neurological predictors were neuro specific enolase (NSE)>3ULN on day 1, myoclonus status epilepticus on day 1-3, neurological pupillary index (NPI)<2 on day 3-6, Glasgow motor=3 on day 3-6, highly malignant pattern on EEG (hmEEG) on day 3-6, CT with anoxic brain injury on day 3, and absent of brainstem reflexes on day 3-6. Univariate and multivariate analysis were performed on each predictor. A simple prediction score tool was constructed and evaluated through ROC analysis. A youden index was used for optimal cut-off. Results: Of 361 patients, 170 (47%) survived to hospital discharge. Of these, 85% (145/170) survived with favorable neurological outcome. The final multivariate logistic regression model in the derivation sample retained eight predictors: Absence of witnessed status and bystander CPR; downtime≥ 7min, lactate≥ 9mmol, low flow≥ 55min, NSE>3ULN, hmEEG, CT with anoxic brain injury and absence of brainstem reflexes, which were combined to develop an 8-point risk scoring model Minnesota OHCA using ECPR (MECPR). Model discrimination had an AUC of 0.87 [95%CI 0.82-0.92] in the derivation sample and 0.86 [95% CI 0.85-0.92] in the validation sample, and calibration (goodness of fit p=0.04). MECPR≥6 predicted poor neurological outcome with a sensitivity ~21%, specificity 100% and a FPR 0%. A MECPR ≥4 and ≥6 had an 89% and 97% probability of poor neurological outcome, respectively. Conclusions: A simple, accurate prediction scoring tool (MECPR) based on a multimodal approach after 72hrs of refractory cardiac arrest provides estimates of probability of poor neurological outcome among patients treated with ECPR.

Paediatric organ donation following neurological determinants of death in intensive care units in Saudi Arabia: a retrospective cross-sectional study

ObjectivesThe aim of this retrospective cross-sectional study was to assess the performance of paediatric organ donation in intensive care units following neurological determinants of death in Saudi Arabia.DesignRetrospective cross-sectional study.SettingPaediatric...

Diagnostic Value of Computed Tomography Angiography in Confirmation of Brain Death

Accurate and on-time confirmation of brain death (BD) is necessary to prevent unnecessary treatments and allow for well-timed organ harvesting for transplantation. While clinical criteria for BD are legally reliable in some countries, others may prefer complementary ancillary tests to assess the brain's electrical activity and/or blood circulation. This study aims to define the sensitivity and specificity of CT-Angiography based on four-, seven-, and ten-score tests compared to the clinical criteria and electroencephalography in patients with BD. A total of 32 patients with a confirmed diagnosis of BD according to their clinical criteria (cases) along with 18 patients with GCS=3 and absent brain stem and papillary reflexes who had spontaneous respiration (controls), all with blood pressure > 90 mmHg, diuresis > 100 ml/h, and CVP > 6-8 mmHg, underwent CT-angiography. The 4-, 6-, and 10-score criteria were used according to the opacity/lack of opacity of the brain vessels in CTA evaluation scales for the diagnosis of BD. The two groups were homogeneous in terms of age, gender distribution, and the etiology of coma. All patients in the control group received zero in 4-, 7-, and 10-scores; while, the average values for 4-score, 7-score, and 10-score in patients with confirmed BD were 3.75±0.67, 6.4±1.36, and 9.06±2.2, respectively. Of patients with BD, 28 (87.5%), 26 (81.25%), and 25 (78.12%) received full 4-, full 7-, and full 10-scores. The sensitivity and specificity as well as negative and positive predictive values for all three scores were found to be 100%. Also, the sensitivities for various cerebral vessels were as: ICV: 100%, GCV: 96.9%, P2: 90.6%, M4: 87.5%, BA: 84.4%, and A3: 84.4%. Also, the specificity of lack of opacification in all these vessels for the diagnosis of BD was 100%. According to our findings, the CTA-based four-point scoring system with 100% specificity can be used along with clinical examinations to confirm BD.

Challenges in determining death by neurologic criteria in extracorporeal membrane oxygenation - A single center experience.

Apnea test (AT) in patients on extracorporeal membrane oxygenation (ECMO) support is challenging, leading to variation in determining death by neurologic criteria (DNC). We aim to describe the diagnostic criteria and barriers for DNC in adults on ECMO in a tertiary care center. A retrospective review of a prospective observational standardized neuromonitoring study was conducted in adult VA- and VV-ECMO patients at a tertiary center from June 2016 to March 2022. Brain death was defined according to the 2010 American Academy of Neurology guidelines and following the 2020 World Brain Death Project recommendations for performing AT in ECMO patients. Eight (2.7%) ECMO patients (median age = 44years, 75% male, 50% VA-ECMO) met criteria for DNC, six (75%) of whom were determined with AT. In the other two patients who did not undergo AT due to safety concerns, ancillary tests (transcranial doppler and electroencephalography) were consistent with DNC. An additional seven (2.3%) patients (median age = 55years, 71% male, 86% VA-ECMO) were noted to have absent brainstem reflexes but failed to complete determination of DNC as they underwent withdrawal of life-sustaining treatment (WLST) before a full evaluation was completed. In these patients, AT was never performed, and ancillary tests were inconsistent with either neurological exam findings and/or neuroimaging supporting DNC, or with each other. AT was used safely and successfully in 6 of the 8 ECMO patients diagnosed with DNC and was always consistent with the neurological exam and imaging findings, as opposed to ancillary tests alone.

Thoracoabdominal normothermic regional perfusion in donation after circulatory death does not restore brain blood flow

Use of thoracoabdominal normothermic regional perfusion (TA-NRP) during donation after circulatory death (DCD) is an important advance in organ donation. Prior to establishing TA-NRP, the brachiocephalic, left carotid, and left subclavian arteries are ligated, thereby eliminating anterograde brain blood flow via the carotid and vertebral arteries. While theoretical concerns have been voiced that TA-NRP after DCD may restore brain blood flow via collaterals, there have been no studies to confirm or refute this possibility. We evaluated brain blood flow using intraoperative transcranial Doppler (TCD) in two DCD TA-NRP cases. Pre-extubation, anterior and posterior circulation brain blood flow waveforms were present in both cases, similar to the waveforms detected in a control patient on mechanical circulatory support undergoing cardiothoracic surgery. Following declaration of death and initiation of TA-NRP, no brain blood flow was detected in either case. Additionally, there was absence of brainstem reflexes, no response to noxious stimuli and no respiratory effort. These TCD results demonstrate that DCD with TA-NRP did not restore brain blood flow.

Acute Loss Of Brain Stem Reflexes Following Intracranial Hemorrhage (P5-7.004)

<h3>Objective:</h3> The objective of this case report is to present a case of acute immune mediate demyelinating polyneuropathy (AIDP) triggered by an intracranial hemorrhage (ICH), which was identified by early loss of brainstem reflexes. <h3>Background:</h3> AIDP is a phagocytic attack on Schwann cells and/or myelin in the peripheral nervous system, resulting in decreased nerve conduction and acute denervation. AIDP has rarely been observed with intracranial hemorrhage or ischemic stroke. Moreover, a diagnosis of fulminant AIDP with a clinical picture of brain death has only been previously described in few case reports, and never in the setting of intracranial hemorrhage. <h3>Design/Methods:</h3> This is a case report, where we describe a patient who underwent ICH evacuation which progressed to fulminant AIDP with loss of brainstem reflexes. <h3>Results:</h3> A 79-year-old female who presented with acute onset left hemiparesis was admitted to the ICU after evacuation of a right frontal-parietal ICH. Two weeks after, the patient’s neurological exam showed an acute loss of corneal, gag and cough reflexes, bilateral mydriasis and flaccid quadriplegia with areflexia. Repeat imaging did not reveal injury that would explain the change in clinical status. A lumbar puncture revealed albumino-cytologic dissociation. Serum studies returned positive for anti-GM1 and TPO antibodies. EMG revealed multiple absent motor and sensory conduction responses and decreased amplitude and conduction velocity. She was treated with intravenous immunoglobulin and plasma exchange therapy. Over the course of one week, she gradually recovered her reflexes, motor strength and became responsive to medical care. <h3>Conclusions:</h3> While the patient’s apparent comatose state and absent brainstem reflexes was suspicious for brain death, the severity of her hemorrhage was not consistent with it. Our diagnosis of fulminant AIDP was based on a combination of neurological examination, lumbar puncture and EMG studies and allowed for effective treatment and recovery of a patient showing signs of apparent brain death. <b>Disclosure:</b> Dr. Malerba has nothing to disclose. Dr. Davitz has nothing to disclose. Dr. Patterson has nothing to disclose. Dr. Nelson has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Spark Healthcare. Dr. Nelson has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Healthcare. Dr. Nelson has received publishing royalties from a publication relating to health care. Dr. Tsetsou has nothing to disclose.

A rare spinal reflex in brain death: Bilateral plantar flexion in nuchal rigidity examination

A 74-year-old female patient, who developed a hypoxic brain injury after cardiopulmonary arrest, was diagnosed with brain death on the 4th day of the clinical onset depending on the absence of brainstem reflexes and the intracranial blood circulation in magnetic resonance angiography, and positive apnea test. Bilateral plantar flexion response to the neck flexion was observed while lifting the head for the examination of oculocephalic reflex during the in-service nurse training. The plantar flexion response was observed every time the neck flexion was performed. This finding was interpreted primarily in favor of spinal reflex and the repeated brain death tests confirmed the diagnosis. Regarding the literature, spinal reflexes may emerge in patients with brain death and plantar flexion is among the most common reflexes. These reflexes are usually observed following painful stimuli, during the apnea test or when the patient is taken off the mechanical ventilation. Although the nuchal rigidity examination is not included in the routine diagnosis procedure of brain death, in this paper we report bilateral plantar flexion as a response to the neck flexion in a patient with brain death in the light of the studies found in the literature. We conclude that the introduction of the above-mentioned examination to the diagnosis of brain death will contribute to the improvement of the diagnosis procedure and prevent delays in the preparation of the potential donors.

Abstract Number ‐ 137: Delayed aneurysmal rupture of a giant fusiform vertebrobasilar aneurysm after flow‐diversion embolization with adjunctive coiling

Introduction Vertebrobasilar aneurysms carry a high risk of operative morbidity and high mortality risk with rupture. Treatment with flow diversion embolization has gained popularity. While adjunctive coiling may lower the risk of delayed aneurysm rupture (DAR), DAR can occur during stent endothelialization. describe a case of DAR following flow diversion with adjunctive coil embolization of a giant vertebrobasilar aneurysm and review the literature to further characterize this phenomenon. Methods PubMed was queried using search terms: “delayed,” “aneurysm,” “rupture,” “flow diverter,” “flow diversion,” and “flow diverting stent” yielding 220 results. There were 47 studies describing 89 patients with DAR after flow diversion. Results A forty‐five‐year‐old male presented with posterior fossa compression symptoms secondary to a 30‐mm fusiform basilar artery aneurysm, which grew during short‐interval follow‐up to 35 mm. The patient consented to endovascular embolization. Tri‐axial catheter access system was used to deploy seven telescoping flow diverters from the basilar tip to the intradural left vertebral artery, and nine coils were subsequently deployed in the aneurysm dome. The right vertebral artery was coil embolized. The procedure was uncomplicated and the patient was continued on dual‐antiplatelet therapy. Four weeks later, the patient became unresponsive with absent brainstem reflexes, workup revealed diffuse subarachnoid hemorrhage with intraventricular hemorrhage. Digital subtraction angiography demonstrated contrast extravasation at the aneurysm neck. He succumbed to his neurological injury two days later. Out of 89 patients with DAR after flow diversion, only 3 occurred in fusiform basilar aneurysms treated with adjunctive coil embolization. Only one case, a 37.1‐mm aneurysm treated with 3 flow diverters with adjunctive embolization, occurred at greater than 30 days post‐intervention. Conclusions This case highlights the need to better characterize the role of adjunctive coiling with flow diversion for large or giant aneurysms, and to better understand risk factors related to delayed aneurysm rupture.

3D EEG and Clinical Evidence of Brain Dying. Preliminary Report

Determination of brain dying means reversible or irreversible injury to the brain, including the brainstem. Current guidelines rely on clinical examination including the proof of coma, absent brain stem reflexes, and apnoea test. Neurophysiological testing using electroencephalography and evoked potentials — somatosensory evoked potentials and brainstem auditory evoked potential could have been helpful in the final diagnostic brain death conclusion, but the diagnostic accuracy of these methods in the last years has revealed controversies. Here, we present data on quantitative EEG signal evaluation (qEEG) by a 3-dimensional brain mapping (3D BM) as developing tool to clarify whether the transverse and anterior posterior coherences such as connectivity indices may demonstrate connection in transversal or anterior posterior dimensions with «wavelet transformation» and if the 3D BM visualization of the of representative EEG signals may improve informative value of EEG signals quantification when evaluating the brain dying.The purpose of our work is to provide an update on the evidence and controversies on the use of EEG for determining brain dying and raise discussion on EEG applications to improve the transplantation program.Results. We analyzed the EEG records of 10 patients admitted for cardiopulmonary resuscitation (CPR) during September, 2017 — August, 2018. Data from one patient, ŽM, 33 years old, after haemorrhagic shock (August 2018) were analyzed in details. Quantitative EEG dynamics by images and clinical course of brain dying were monitored prior and after the amantadine sulfate intravenous administration for brain revival. Data demonstrated the ability of brain to survive; the cause of final brain death was heart failure.Conclusion. Data confirm the hope for survival of the brain in a coma and demonstrate brain capability to keep functionally optimal state as a potential for a good social adaptation.

Reversible Brain Death

Snakebite is a serious public health problem and one of the priorities in WHO's list of neglected tropical diseases. It significantly increases morbidity and mortality associated with envenomation in India. A neurotoxic snakebite can present in the form of symptoms ranging from asymptomatic presentation, ptosis, and complete external and internal ophthalmoplegia to complete respiratory failure. This is a case report of a 22-year-old male, who presented with bilateral ptosis and impending respiratory failure. He soon became deeply comatose, with absent brain stem reflexes (mute plantar, fixed pupils, and the absence of the doll's eye reflex) which were suggestive of brain death. He was treated with polyvalent anti-snake venom, anticholinesterases, and supportive therapy and recovered completely with an excellent outcome.

Brain death/death by neurologic criteria determination: an update.

Brain death, also known as death by neurologic criteria (DNC), is a well-established concept. In this article, we present a short history of the concept and give an overview of recent changes and a practical update on diagnosis and definitions of brain death/DNC. Unresolved issues will be discussed. There is variability in brain death/DNC determination worldwide. In recent years, successful attempts have been made to harmonize these criteria and, consequently, to improve public trust in the process and diagnosis. An international multidisciplinary collaboration has been created and it has published minimum criteria, provided guidance for professionals and encouragement to revise or develop guidelines on brain death/DNC worldwide. There are two sets of criteria for declaration of death. First, if there is neither cardiac output nor respiratory effort, then cardiopulmonary criteria are used. Second, if both the cerebrum and brainstem have completely and permanently lost all functions, and there is a persistent coma, absent brainstem reflexes and no spontaneous respiratory effort, death can be declared on the basis of brain death/DNC. Although attempts to formulate uniform criteria are ongoing, consensus has been reached on the minimum criteria. Some inconsistencies and questions remain.

Cases Abusing Brain Death Definition in Organ Procurement in China.

Organ donation after brain death has been practiced in China since 2003 in the absence of brain death legislation. Similar to international standards, China's brain death diagnostic criteria include coma, absence of brainstem reflexes, and the lack of spontaneous respiration. The Chinese criteria require that the lack of spontaneous respiration must be verified with an apnea test by disconnecting the ventilator for 8min to provoke spontaneous respiration. However, we have found publications in Chinese medical journals, in which the donors were declared to be brain dead, yet without an apnea test. The organ procurement procedures started with initiating "intratracheal intubation for mechanical ventilation after brain death," indicating that a brain death diagnosis was not performed. The purpose of the intubation was not to resuscitate the patient but rather was directly related to facilitating the explantation of organs. Moreover, it was unmistakably stated in two of these publications that the cardiac arrest was induced in these patients without brain death determination by cold St. Thomas cardioplegic solution or other cold myocardial protection solutions. This means that the condition of these donors neither met the criteria of brain death nor that of cardiac death. In other words, the "donor organs" may well have been procured in these cases from living human beings. Thus, brain death definition is abused in China by some individuals for organ harvesting, and a systematic investigation is needed to clarify the situation of organ donation after brain death in China.

A New Spinal Reflex Movement in Brain Death: Undulating Axial Trunk Torsion.

Brain death is defined as the irreversible cessation of function of the brain, brain stem, and medulla oblongata, despite the persistent respiration and circulation supported by mechanical ventilation. The determination of brain death is important with outcome prediction and organ transplantations. Spinal reflexes can be seen in patients with brain death and created confusion about the diagnosis of brain death for patients’ families, which cause delay or refusal of deceased-donor organ donation. We present here a new dramatic spinal movement after tapping stimulation which should be recognized to avoid unnecessary testing and confusion for clinicians and family members. A 31-year-old woman presented with sudden severe headache to our hospital. Brain computed tomography (CT) revealed acute intraventricular hemorrhage. Her CT angiography showed a pseudoaneurysm at the end of left posterior pericallosal artery, puff-of-smoke collaterals at the M1 segment of right middle cerebral artery and at end of left internal carotid artery. A lumbar drainage was placed on the admission day. Two days later, her headache remained severe, and brain CT showed that her ventricular system was still filled with blood. An external ventricular drain was placed at the anterior horn of her right lateral ventricle. Six days later, she developed coma, and all her brain stem reflexes became absent. Brain CT showed increased intraventricular hemorrhage. Twenty days later, transcranial doppler and electroencephalogram proved brain death, and she passed the apnea test as well. All the procedures of brain death determination (clinical assessments and ancillary examinations) were conducted twice at an interval of 24 hours to confirm the death of brain. The timeline of her disease course and the results of relevant ancillary examinations were provided in Figures S1 through S3 and Table S1, SDC, https://links.lww.com/TP/C308. She was noted to have dramatic undulating axial trunk torsion and myoclonus in response to tapping stimulation at right shoulder (Figure 1). After tapping stimulation, the patient undulatingly twisted her abdomen towards the right with her chest and head moving to the left, and then she twisted her abdomen towards the left with her chest and head moving to the right. Myoclonus occurred after it and lasted for several seconds. Movements of undulating axial trunk torsion recurred in the end. The whole motor response to tapping stimulation lasted for about 10 seconds. This spinal reflex movement was seen for 8 days, from the 10th day after the absence of brain stem reflexes until 4 days after the confirmation of brain death when the patient was discharged upon request of family members.FIGURE 1.: Movement pattern. After tapping stimulation, the patient undulatingly twisted her abdomen towards the right with her chest and head moving to the left (①), and then she twisted the torso in the opposite way (②). Subsequently, myoclonus occurred (③), and movements of undulating axial trunk torsion repeated in the end.The exact mechanism for spinal reflexes in brain death remains unclear. These basic spinal reflex movements have been thought to be caused by modulatory afferents to these spinal cord centers and the absence of cortical inhibition.1 Some reflex movements evoked during the apnea test, such as Lazarus sign, might be due to hypoxic stimulation of cervical spinal cord neurons functionally isolated from rostral brain areas.2 Plantar flexion, myoclonus, triple flexion reflex, and pronator extension reflex are the common spinal reflexes in brain death.3 Lazarus sign is a rare complex movement consisting of bilateral arm flexion to chest, shoulder adduction, and hand crossing, which can be seen in 1.5% of brain-dead patients.4 Here, we reported another dramatic complex spinal movement of undulating axial trunk torsion which involves deep back muscles. The organ donation did not occur after determination of brain death due to the concern and refusal of family members. This reflex movement was not reported before and should be recognized to avoid uncertainty for families and failure in organ donation.5,6

Severe cerebral edema in substance-related cardiac arrest patients

BackgroundStudies of neurologic outcomes have found conflicting results regarding differences between patients with substance-related cardiac arrests (SRCA) and non-SRCA. We investigate the effects of SRCA on severe cerebral edema development, a neuroimaging intermediate endpoint for neurologic injury. Methods327 out-of-hospital comatose cardiac arrest patients were retrospectively analyzed. Demographics and baseline clinical characteristics were examined. SRCA categorization was based on admission toxicology screens. Severe cerebral edema classification was based on radiology reports. Poor clinical outcomes were defined as discharge Cerebral Performance Category scores > 3. ResultsSRCA patients (N = 86) were younger (P < 0.001), and more likely to have non-shockable rhythms (P < 0.001), be unwitnessed (P < 0.001), lower Glasgow Coma Scale scores (P < 0.001), absent brainstem reflexes (P < 0.05) and develop severe cerebral edema (P < 0.001) than non-SRCA patients (N = 241). Multivariable analyses found younger age (P < 0.001), female sex (P = 0.008), non-shockable rhythm (P = 0.01) and SRCA (P = 0.05) to be predictors of severe cerebral edema development. Older age (P < 0.001), non-shockable rhythm (P = 0.02), severe cerebral edema (P < 0.001), and absent pupillary light reflexes (P = 0.004) were predictors of poor outcomes. SRCA patients had higher proportion of brain deaths (P < 0.001) compared to non-SRCA patients. ConclusionsSRCA results in higher rates of severe cerebral edema development and brain death. The absence of statistically significant differences in discharge outcomes or survival between SRCA and non-SRCA patients may be related to the higher rate of withdrawal of life-sustaining treatment (WLST) in the non-SRCA group. Future neuroprognostic studies may opt to include neuroimaging markers as intermediate measures of neurologic injury which are not influenced by WLST decisions.

Brain Failure and Brain Death

Brain failure consists of a wide spectrum of central nervous system pathologies with many different neurologic manifestations. The causes of brain failure include several disease processes that result in decreased supply of blood and oxygen to the brain or metabolic derangements that affect the central nervous system. Brain failure usually results in some altered level of consciousness. Brain failure and brain death result in several pathophysiologic changes. The definition of brain death is controversial and evolving. However, clear guidelines to determine brain death have been established. These guidelines state that three cardinal findings be present to establish brain death: (1) coma or unresponsiveness, (2) absence of brainstem reflexes, and (3) apnea. Several clinical parameters must be met when these findings are made. Adjunctive studies such as four-vessel cerebral angiography, electroencephalography, and nuclear brain scintigraphy can help make a diagnosis of brain death. When brain death is established, suitability for organ transplantation should be evaluated. After obtaining consent, potential organ donation should be optimized for possible donation. This review contains 2 figures, 3 tables, and 69 references. Key Words: brain failure, brain death, consciousness, coma, death, delirium, organ donation

Brain Failure and Brain Death

Brain failure consists of a wide spectrum of central nervous system pathologies with many different neurologic manifestations. The causes of brain failure include several disease processes that result in decreased supply of blood and oxygen to the brain or metabolic derangements that affect the central nervous system. Brain failure usually results in some altered level of consciousness. Brain failure and brain death result in several pathophysiologic changes. The definition of brain death is controversial and evolving. However, clear guidelines to determine brain death have been established. These guidelines state that three cardinal findings be present to establish brain death: (1) coma or unresponsiveness, (2) absence of brainstem reflexes, and (3) apnea. Several clinical parameters must be met when these findings are made. Adjunctive studies such as four-vessel cerebral angiography, electroencephalography, and nuclear brain scintigraphy can help make a diagnosis of brain death. When brain death is established, suitability for organ transplantation should be evaluated. After obtaining consent, potential organ donation should be optimized for possible donation. This review contains 2 figures, 3 tables, and 69 references. Key Words: brain failure, brain death, consciousness, coma, death, delirium, organ donation

Brain Failure and Brain Death

Brain failure consists of a wide spectrum of central nervous system pathologies with many different neurologic manifestations. The causes of brain failure include several disease processes that result in decreased supply of blood and oxygen to the brain or metabolic derangements that affect the central nervous system. Brain failure usually results in some altered level of consciousness. Brain failure and brain death result in several pathophysiologic changes. The definition of brain death is controversial and evolving. However, clear guidelines to determine brain death have been established. These guidelines state that three cardinal findings be present to establish brain death: (1) coma or unresponsiveness, (2) absence of brainstem reflexes, and (3) apnea. Several clinical parameters must be met when these findings are made. Adjunctive studies such as four-vessel cerebral angiography, electroencephalography, and nuclear brain scintigraphy can help make a diagnosis of brain death. When brain death is established, suitability for organ transplantation should be evaluated. After obtaining consent, potential organ donation should be optimized for possible donation. This review contains 2 figures, 3 tables, and 69 references. Key Words: brain failure, brain death, consciousness, coma, death, delirium, organ donation

Brain Failure and Brain Death

Brain failure consists of a wide spectrum of central nervous system pathologies with many different neurologic manifestations. The causes of brain failure include several disease processes that result in decreased supply of blood and oxygen to the brain or metabolic derangements that affect the central nervous system. Brain failure usually results in some altered level of consciousness. Brain failure and brain death result in several pathophysiologic changes. The definition of brain death is controversial and evolving. However, clear guidelines to determine brain death have been established. These guidelines state that three cardinal findings be present to establish brain death: (1) coma or unresponsiveness, (2) absence of brainstem reflexes, and (3) apnea. Several clinical parameters must be met when these findings are made. Adjunctive studies such as four-vessel cerebral angiography, electroencephalography, and nuclear brain scintigraphy can help make a diagnosis of brain death. When brain death is established, suitability for organ transplantation should be evaluated. After obtaining consent, potential organ donation should be optimized for possible donation. This review contains 2 figures, 3 tables, and 69 references. Key Words: brain failure, brain death, consciousness, coma, death, delirium, organ donation