Safety and reliability of artificial CO2 augmentation method in comparison with standard apneic oxygenation method for brain death determination.

INTRODUCTION: The most commonly used apnea test for determination of brain death is the apneic oxygenation method. While all the commonly used apnea tests have associated complications, artificial CO2 augmentation has been reported to have fewer complications. However, data supporting the use of the latter method is limited. METHODS: We identified 102 patients who underwent brain death testing during the last ten years. Artificial CO2 augmentation apnea testing was used in 50 of these patients while 52 patients underwent standard apneic oxygenation apnea testing. RESULTS: No significant differences between the two groups were noted in any previously considered clinical outcomes, including hypoxemia, acidemia, or shock. However, shorter duration of apnea testing was observed in the artificial CO2 augmentation method suggesting its feasibility to the standard apneic oxygenation method in terms of convenience and reduction of the risk surrounding prolonged hypercapnia and hypoxemia. CONCLUSION: This retrospective cohort study provides further observational evidence to support the safety of alternate apnea testing techniques with the standard apnea method for determination of brain death in adults.

Use of Arterial Spin-Labeling in Patients with Aneurysmal Sub-arachnoid hemorrhage.

Delayed cerebral ischemia (DCI) due to cerebral vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) has long been recognized as a major source of morbidity and mortality. Early detection of cerebral vasospasm and identification of patients who are likely to become symptomatic is crucial to guide aggressive medical and/or endovascular interventions. Magnetic resonance imaging using arterial spin-label (ASL) is a noninvasive mean for assessing cerebral blood flow and is based on direct magnetic labeling of arterial blood water protons. The diagnostic role of ASL in acute ischemic stroke, epilepsy, and neurodegenerative disorders has been explained in multiple studies but its ability to predict vasospasm in aSAH has not been published before. The purpose of this study is to highlight the diagnostic implications of different perfusion patterns of ASL in patients with aSAH which can be utilized to prevent DCI in such patients when other commonly used modalities are not available, contraindicated, or fail to detect vasospasm.

Good Outcomes with the Intraventricular Vancomycin Therapy in a Patient with Ruptured Brain Abscesses.

Brain abscesses are associated with high morbidity and mortality rates. In particular, patients with intraventricular rupture of brain abscess (IVROBA) exhibit mortality rates up to 85%. Treatment options are lacking for IVROBA, once patients become refractory to intravenous antibiotics and surgical drainage. Limited data exist regarding the risks and benefits of intraventricular therapy in such a scenario. We report a patient with IVROBA, who deteriorated while on systemic antibiotics; once intraventricular vancomycin was employed, the patient demonstrated remarkable improvement without perceivable side effects. This case suggests that intraventricular vancomycin may be a safe, effective, and viable option for the treatment of IVROBA, especially for patients becoming refractory to systemic antibiotics.

Seizure Prophylaxis in the Immediate Post-Hemorrhagic Period in Patients with Aneurysmal Subarachnoid Hemorrhage.

INTRODUCTION: Seizures are a well-known complication of aneurysmal subarachnoid hemorrhage (aSAH) and occur most commonly in the immediate posthemorrhagic period. Most commonly used antiepileptic drugs (AEDs) for seizure prophylaxis in aSAH include phenytoin and levetiracetam. There is no reliable data available on the safety and efficacy of restricting AED prophylaxis only till the aneurysm is secured. METHODS: We retrospectively chart reviewed patients admitted to our neurosciences intensive care unit (NICU) with aSAH during the past two years. Seizure incidence was studied in patients treated with phenytoin versus levetiracetam and in patients treated for 3-7 days vs. those where AED was discontinued immediately after aneurysm was secured. RESULTS: In 28 patients, AED prophylaxis was discontinued immediately after the aneurysm was secured, and in 21 patients, it was continued for 3-7 days. Of the 28 patients who received AED prophylaxis for less than or equal to two days, phenytoin was used in 20 patients and levetiracetam was used in eight patients. In patients receiving AED prophylaxis for 3-7 days, phenytoin was used in eight cases and levetiracetam was used in 13 cases. None of these patients had seizures reported during hospitalization or at three-month follow-up. CONCLUSION: Stopping the AED prophylaxis immediately after aneurysm coiling is not associated with increased risk of seizures. Seizures at presentation in patients with aSAH are not associated with development of epilepsy at three months. Both phenytoin and levetiracetam are well tolerated in patients with aSAH when limited to the immediate posthemorrhagic period.

Granulomatous amebic encephalitis following hematopoietic stem cell transplantation.

BACKGROUND: Granulomatous amebic encephalitis (GAE) is rare, but often fatal. The infection has been documented predominantly among the immunocompromised population or among those with chronic disease. To date, however, there have only been eight cases regarding the infection following hematopoietic stem cell transplantation (HSCT). CASE DESCRIPTION: A 62-year-old female with a history of relapsed diffuse large B-cell lymphoma, recently underwent peripheral blood autologous stem cell transplant after BEAM conditioning (day 0). On day +15, she began to exhibit worsening fatigue, generalized weakness, and fever. Symptoms progressed to nausea, emesis, somnolence, confusion, and frontal headaches over the next few days. Imaging demonstrated multifocal ill-defined vasogenic edema with patchy enhancement. The patient was started on broad antibiotics, antifungals, and seizure prophylaxis. Evaluation for bacterial, fungal, mycobacterial, and viral etiologies was fruitless. Her mental status progressively deteriorated. On day +22, she exhibited severe lethargy and went into pulseless electrical activity arrest, requiring chest compressions. The episode lasted <2 min and her pulse was restored. She was taken to the operating room for a brain biopsy. Postoperatively, her right pupil began to dilate compared to the left; she demonstrated extensor posturing in her upper extremities and withdrawal in her lower extremities. Repeat computed tomography demonstrated progressive edema. Given poor prognosis and poor neurological examination, the family opted for withdrawal of care. Final pathology was consistent with Acanthamoeba GAE. CONCLUSION: The authors report the third case of GAE after autologous stem cell transplant, and the ninth case overall after HSCT. This case is unusual due to its rapid clinical presentation after HSCT compared to prior literature. The case highlights the need for high suspicion of Acanthamoeba infection in this patient population.

Immune mediated neurologic dysfunction as a paraneoplastic syndrome in renal cell carcinoma.

OBJECTIVE: To describe a case of cerebellar ataxia associated with renal cell carcinoma. CASE REPORT: A 53-year-old Caucasian male with a history of Schizophrenia presented with generalized weakness, nausea, vomiting, severe weight loss, and progressively worsening gait difficulty associated with multiple falls. Physical examination revealed profound ataxia with inability to ambulate despite normal strength. The patient also appeared cachectic. A contrast-enhanced CT of the abdomen/pelvis showed a 10.4 x 8.3 cm(2) left renal mass. Histopathology of the tissue revealed morphology consistent with renal cell carcinoma. Paraneoplastic antibodies including anti-Hu, anti-Ma, anti-Ri, and anti-Yo were negative, however, biotinylated serum analysis was positive for hippocampal and cerebellar Purkinje cells. DISCUSSION: The pathogenesis of paraneoplastic neurological syndromes is believed to be associated with antibody and T-cell mediated response to antigens shared between the tumor and neural tissue. Though serum from this patient was negative for well-characterized antibodies, further testing revealed the presence of proteins binding to the hippocampal region of the midbrain and the cerebellum, and to components of the extracellular matrix of the tumor which may suggest partially characterized or as yet uncharacterized antibodies directed against renal cell tumor tissue and the nervous system. This possibility is supported by the observed symptom resolution upon tumor resection. The described case introduces a possible association between an antibody, which may be specific to paraneoplastic neurological syndromes, and renal cell carcinoma.