Nonaneurysmal perimesencephalic subarachnoid hemorrhage on noncontrast head CT: An accuracy, inter-rater, and intra-rater reliability study.

BACKGROUND AND PURPOSE: To evaluate the reliability and accuracy of nonaneurysmal perimesencephalic subarachnoid hemorrhage (NAPSAH) on Noncontrast Head CT (NCCT) between numerous raters. MATERIALS AND METHODS: 45 NCCT of adult patients with SAH who also had a catheter angiography (CA) were independently evaluated by 48 diverse raters; 45 raters performed a second assessment one month later. For each case, raters were asked: 1) whether they judged the bleeding pattern to be perimesencephalic; 2) whether there was blood anterior to brainstem; 3) complete filling of the anterior interhemispheric fissure (AIF); 4) extension to the lateral part of the sylvian fissure (LSF); 5) frank intraventricular hemorrhage; 6) whether in the hypothetical presence of a negative CT angiogram they would still recommend CA. An automatic NAPSAH diagnosis was also generated by combining responses to questions 2-5. Reliability was estimated using Gwet's AC1 (κG), and the relationship between the NCCT diagnosis of NAPSAH and the recommendation to perform CA using Cramer's V test. Multi-rater accuracy of NCCT in predicting negative CA was explored. RESULTS: Inter-rater reliability for the presence of NAPSAH was moderate (κG = 0.58; 95%CI: 0.47, 0.69), but improved to substantial when automatically generated (κG = 0.70; 95%CI: 0.59, 0.81). The most reliable criteria were the absence of AIF filling (κG = 0.79) and extension to LSF (κG = 0.79). Mean intra-rater reliability was substantial (κG = 0.65). NAPSAH weakly correlated with CA decision (V = 0.50). Mean sensitivity and specificity were 58% (95%CI: 44%, 71%) and 83 % (95%CI: 72 %, 94%), respectively. CONCLUSION: NAPSAH remains a diagnosis of exclusion. The NCCT diagnosis was moderately reliable and its impact on clinical decisions modest.

Intraoperative air embolism diagnosis and treatment using hyperbaric oxygen therapy after craniotomy: illustrative case.

BACKGROUND: This report describes the use of hyperbaric oxygen therapy for the acute management of an intraoperative air embolism encountered during a neurosurgical procedure. Furthermore, the authors highlight the concomitant diagnosis of tension pneumocephalus requiring evacuation prior to hyperbaric therapy. OBSERVATIONS: A 68-year-old male developed acute ST-segment elevation and hypotension during elective disconnection of a posterior fossa dural arteriovenous fistula. The semi-sitting position had been used to minimize cerebellar retraction, raising the concern for acute air embolism. Intraoperative transesophageal echocardiography was utilized to establish the diagnosis of air embolism. The patient was stabilized on vasopressor therapy, and immediate postoperative computed tomography revealed air bubbles in the left atrium along with tension pneumocephalus. He underwent urgent evacuation for the tension pneumocephalus followed by hyperbaric oxygen therapy to manage the hemodynamically significant air embolism. The patient was eventually extubated and went on to fully recover; a delayed angiogram revealed complete cure of the dural arteriovenous fistula. LESSONS: Hyperbaric oxygen therapy should be considered for an intracardiac air embolism resulting in hemodynamic instability. In the postoperative neurosurgical setting, care should be taken to exclude pneumocephalus requiring operative intervention prior to hyperbaric therapy. A multidisciplinary management approach facilitated expeditious diagnosis and management for the patient.

Bilateral acute epidural hematoma with good outcome.

Epidural haematomas are one of the most common complicated closed-head injuries, but they, rarely show any bilateral localization. We are reporting here a case of a man found unconscious with Glasgow Coma Scale score; 8/15. Computed tomography of skull revealed bilateral epidural hematoma. Two emergency craniotomies were performed simultaneously, with satisfactory radiological control and neurological outcome. We discussed the aspects of a etiology and treatment about this unusual condition.