Coma and Brain Death

Assessing Patients With Altered Level of Consciousness

Patients with alterations in level of consciousness are among the most difficult to assess, so knowledge of how to assess these patients is important for tracking trends and identifying changes. This article discusses methods used to assess patients admitted with an altered level of consciousness and describes the neurological assessment of and potential causes for altered level of consciousness. Identifying and understanding certain examination findings enable faster recognition and intervention for life-threatening neurological events, directly impacting outcomes for neurologically compromised individuals.

Case report: Absent fluorodeoxyglucose uptake in a dog with unexpected brain death

A 5-year-old male Maltese dog was presented with generalized tonic seizures and hypermetria. Multiple nodular subcortical cerebellar enhancements and meningeal enhancement were observed on magnetic resonance imaging. Fluorodeoxyglucose-positron emission tomography/computed tomography was performed due to suspicion of neoplastic disease, and no fluorodeoxyglucose uptake was observed in the intracranial structures. In PET images of this dog, absent fluorodeoxyglucose uptake was identified in the brain indicating no cerebral metabolism, strongly suggested brain death. The dog had no spontaneous breathing and no brainstem reflexes for more than 24 h after the termination of anesthesia. Through these results, this dog was diagnosed with unexpected brain death, and it is presumed that the cause was anesthesia. We report herein a case of brain death in a dog diagnosed using fluorodeoxyglucose-positron emission tomography/computed tomography.

Immunopsychiatry: An Update on Autoimmune Encephalitis for Neuropsychiatrists

INTRODUCTION

Autoimmune encephalitis (AIE) is a group of immune-mediated inflammatory processes of the brain with marked psychiatric features. Although relatively rare, they might offer difficult differential diagnosis with psychiatric conditions, especially catatonia and psychotic syndromes. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is the most common AIE, presenting with psychiatric syndromes in 90% of cases. The associated psychopathology is complex, pleomorphic and best characterized when there is involvement of a psychiatrist in the assessment.

AREAS COVERED

This text will review the main aspects of AIE to psychiatrists and/or neuropsychiatrists.

EXPERT OPINION

Immune system dysfunction has been implicated in the pathophysiology of psychiatric symptoms and disorders. The use of diagnostic criteria of possible AIE, especially when specific antibodies of AIE are not available, allows early diagnosis and prompt treatment which are associated with better clinical outcomes. The study of the psychiatric aspects of AIE can broaden our knowledge of the underlying mechanisms of various psychiatric manifestations.

Las razones para redefinir la muerte y su crítica

A más de cincuenta años del Informe de Harvard, la redefinición propuesta para la muerte continúa siendo problemática y no goza de un consenso internacional. La posibilidad de trasplantar órganos vitales y el avance de los soportes artificiales para el mantenimiento de algunas funciones sustantivas impulsó la necesidad de redefinir la noción de muerte. Al proponer nuevas definiciones surge también un conjunto de interrogantes éticos y técnicos. En este texto exponemos algunas de las principales razones y críticas a la pretensión de definir la muerte encefálica como muerte. Para dicho propósito, realizamos un análisis de las críticas que, sobre este punto, hizo Hans Jonas, así como las refutaciones a su posición. Por otra parte, presentamos algunos de los criterios en que se fundamentan las pruebas diagnósticas y la escasez del consenso en este sentido. De esta manera pretendemos mostrar que los diferentes puntos de vista para definir la muerte, a pesar de no lograr acuerdos entre las diferentes comunidades, requieren un análisis y debate continuos con el fin de dar atención sustentada a los factores que motivaron la redefinición de la muerte.

The clinical and prognostic values of optic nerve sheath diameter and optic nerve sheath diameter/eyeball transverse diameter ratio in comatose patients with supratentorial lesions

Background

The optic nerve sheath diameter (ONSD) and ONSD/eyeball transverse diameter (ETD) ratio have been proven to be correlated with intracranial pressure. This study aimed to evaluate the prognostic roles of ONSD and the ONSD/ETD ratio in comatose patients with supratentorial lesions and to determine the relationship of these two indices with the prognosis of such patients.

Methods

A total of 54 comatose patients with supratentorial lesions and 50 healthy controls were retrospectively included in this study. ONSD and ETD were measured by unenhanced computed tomography (CT). The differences in ONSD and the ONSD/ETD ratio between the two groups were compared. The prognosis of comatose patients was scored using the Glasgow Outcome Scale (GOS) at the 3-month follow-up, and these patients were classified into good (GOS score ≥ 3) and poor (GOS score < 3) prognosis groups. The differences in ONSD and the ONSD/ETD ratio were compared between comatose patients with good prognoses and those with poor prognoses.

Results

The ONSD and ONSD/ETD ratios in the comatose patients were 6.30 ± 0.60 mm and 0.27 ± 0.03, respectively, and both were significantly greater than those in the healthy controls (5.10 ± 0.47 mm, t = 11.426, P < 0.0001; 0.22 ± 0.02, t = 11.468, P < 0.0001; respectively). ONSD in patients with poor prognosis was significantly greater than that in patients with good prognosis (6.40 ± 0.56 vs. 6.03 ± 0.61 mm, t = 2.197, P = 0.032). The ONSD/ETD ratio in patients with poor prognosis was significantly greater than that in patients with good prognosis (0.28 ± 0.02 vs. 0.26 ± 0.03, t = 2.622, P = 0.011). The area under the receiver operating characteristic (ROC) curve, used to predict the prognosis of comatose patients, was 0.650 (95% confidence interval (CI): 0.486–0.815, P = 0.078) for ONSD and 0.711 (95% CI: 0.548–0.874, P = 0.014) for the ONSD/ETD ratio.

Conclusions

The ONSD and ONSD/ETD ratios were elevated in comatose patients. The ONSD/ETD ratio might be more valuable than ONSD in predicting the prognoses of comatose patients with supratentorial lesions.