Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain.

The neurophysiological footprint of brain activity after cardiac arrest and during near-death experience (NDE) is not well understood. Although a hypoactive state of brain activity has been assumed, experimental animal studies have shown increased activity after cardiac arrest, particularly in the gamma-band, resulting from hypercapnia prior to and cessation of cerebral blood flow after cardiac arrest. No study has yet investigated this matter in humans. Here, we present continuous electroencephalography (EEG) recording from a dying human brain, obtained from an 87-year-old patient undergoing cardiac arrest after traumatic subdural hematoma. An increase of absolute power in gamma activity in the narrow and broad bands and a decrease in theta power is seen after suppression of bilateral hemispheric responses. After cardiac arrest, delta, beta, alpha and gamma power were decreased but a higher percentage of relative gamma power was observed when compared to the interictal interval. Cross-frequency coupling revealed modulation of left-hemispheric gamma activity by alpha and theta rhythms across all windows, even after cessation of cerebral blood flow. The strongest coupling is observed for narrow- and broad-band gamma activity by the alpha waves during left-sided suppression and after cardiac arrest. Albeit the influence of neuronal injury and swelling, our data provide the first evidence from the dying human brain in a non-experimental, real-life acute care clinical setting and advocate that the human brain may possess the capability to generate coordinated activity during the near-death period.

Cost-effectiveness analysis in patients with an unruptured cerebral aneurysm treated with observation or surgery.

OBJECTIVE: The main goal of preventive treatment of unruptured intracranial aneurysms (UIAs) is to avoid the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage. A comparison between the conservative approach and the surgical approach combining endovascular treatment and microsurgical clipping is currently lacking. This study aimed to conduct an updated evaluation of cost-effectiveness comparing the two approaches in patients with UIA. METHODS: A decision tree with a Markov model was developed. Quality-adjusted life-years (QALYs) associated with living with UIA before and after treatment were prospectively collected from a cohort of patients with UIA at a tertiary center. Other inputs were obtained from published literature. Using Monte Carlo simulation for patients aged 55, 65, and 75 years, the authors modeled the conservative management in comparison with preventive treatment. Different proportions of endovascular and microsurgical treatment were modeled to reflect existing practice variations between treatment centers. Outcomes were assessed in terms of QALYs. Sensitivity analyses to assess the model's robustness and completed threshold analyses to examine the influence of input parameters were performed. RESULTS: Preventive treatment of UIAs consistently led to higher utility. Models using a higher proportion of endovascular therapy were more cost-effective. Models with older cohorts were less cost-effective than those with younger cohorts. Treatment was cost-effective (willingness to pay < 100,000 USD/QALY) if the annual rupture risk exceeded a threshold between 0.8% and 1.9% in various models based on the proportion of endovascular treatment and cohort age. A higher proportion of endovascular treatments and younger age lowered this threshold, making the treatment of aneurysms with a lower risk of rupture more cost-effective. CONCLUSIONS: Preventive treatment of aneurysms led to higher utility compared with conservative management. Models with a higher proportion of endovascular treatment and younger patient age were most cost-effective.

Basilar Apex Aneurysm: Case Series, Systematic Review, and Meta-analysis.

BACKGROUND: A lower rate of aneurysmal recanalization in stent assisted coiling versus coiling alone has been observed in aneurysms overall. This study aims to primarily stratify and compare degree of occlusion per treatment modality in basilar apex aneurysms. Secondary outcomes were retreatment, posttreatment hemorrhage, and procedure-related complications. METHODS: Medical literature including MEDLINE and EMBASE database was searched. We performed metaregressions, bias analysis, and fail-safe N. We controlled for the quality of the studies. RESULTS: Data from eligible studies (N = 12) and study center patients (n = 117) were pooled for a total of 396 nonduplicated patients. Stent-assisted coiling had a lower rate of retreatment (17% vs. 24%) and higher rate of posttreatment hemorrhage (5% vs. 3%) compared with coiling. Stent-assisted coiling had a higher rate of complete occlusion (55% vs. 45%) and a lower rate of residual aneurysm (15% vs. 23%) compared with coiling. Comparative analyses were performed. Microsurgical technique remained the most morbid treatment modality with the best rate of complete occlusion (93%) and lowest rates of rehemorrhage (2%) and retreatment (5%). CONCLUSIONS: This is the first and largest meta-analysis focused on patients treated for basilar apex aneurysm. We report higher rehemorrhage rates with stent-assisted coiling. This study provides benchmark data to guide clinicians in future treatment decision making and encourages future research to stratify outcomes.

Cannabis use and outcomes after aneurysmal subarachnoid hemorrhage: A nationwide retrospective cohort study.

BACKGROUND: Cannabis is the most consumed recreational drug in the world. It is possible that cannabis has an association with an increased risk of vasospasm-related strokes and delayed cerebral ischemia (DCI), which are major causes of morbidity and mortality in aneurysmal subarachnoid hemorrhage (aSAH). Hence, this study aimed to explore the independent relationship between cannabis use and outcomes after aSAH using the 2016 United States Nationwide Inpatient Sample. METHODS: This study was conducted using the 2016 National Inpatient Sample with ICD-10 codes. Multivariate logistic regression was used to examine the association between cannabis use, the primary (inpatient mortality) and secondary outcomes. RESULTS: There were 42,394 patients identified with aSAH, of whom 925 were identified as cannabis users. Cannabis users and non-users were similar in terms of severity of aSAH. Although the unadjusted mortality rate was lower among cannabis users (16%) than non-users (22%), (p = 0.04), both the age-adjusted odds ratio (OR) (0.83, 95% confidence interval (CI): 0.56; 1.24) and the multivariate-adjusted OR (0.87, 95% CI: 0.54; 1.42) did not reach statistical significance. Secondary outcomes did not reach statistical significance. CONCLUSION: In this nationwide cohort, cannabis users with aSAH had similar outcomes compared to nonusers. However, these results are likely limited by underreporting of cannabis use. Future prospective studies are needed to elucidate the pathophysiology and association between cannabis and outcomes following aSAH.

Headache Outcomes After Treatment of Unruptured Intracranial Aneurysm: A Systematic Review and Meta-Analysis.

Background and Purpose- While unruptured intracranial aneurysms may be discovered incidentally in the workup of chronic headache, it remains unclear whether their treatment ultimately impacts headache severity. We aim to conduct a systematic review and meta-analysis assessing headache severity after treatment of unruptured intracranial aneurysm. Methods- MEDLINE and EMBASE were systematically reviewed. Results- Data from 7 studies met inclusion criteria (309 nonduplicated patients). The standard mean difference in pre- and post-intervention headache severity was estimated at -0.448 (95% CI, -0.566 to -0.329) under a random effects model. No significant heterogeneity was noted nor was any significant publication bias demonstrated. Conclusions- This is the first systematic review assessing postoperative headache severity following treatment of unruptured intracranial aneurysm. While a significant reduction in headache severity was observed, further investigation into this phenomenon is recommended before it influences clinical practice. Future study should stratify headache outcomes by aneurysm size, location, and treatment modality.

Midline cerebellar medulloblastoma in a seventy-one-year-old patient.

BACKGROUND: Medulloblastoma is the most common malignant central nervous system tumour in children but, in contrast, quite rare in adults. Hemispheric, rather than midline, cerebellar medulloblastomas are more common in older children and adults. We present the unusual case of a 71-year-old man who presented with a fourth ventricular mass that proved to be a medulloblastoma. METHODS: A 71-year-old man presented with progressive balance problems, slurred speech and double vision. A CT scan of the brain revealed a hyperattenuating, partially calcified, avidly enhancing mass within the fourth ventricle. Diffusion weighted MRI showed restricted diffusion within the mass. The patient underwent a midline suboccipital craniotomy and a subtotal resection was achieved. RESULTS: Histological examination showed a densely cellular neoplasm composed of small cells with a tendency towards neuroblastic rosette formation. Most cells were strongly positive for neuron-specific enolase and synaptophysin. Ultrastructurally, tumour cells showed evidence of neuronal differentiation. These findings were consistent with a classical medulloblastoma. CONCLUSION: Adult medulloblastoma should be considered in the differential diagnosis of a partially calcified hyperattenuating mass within the fourth ventricle.

Complications of embolization of arteriovenous malformations of the brain.

OBJECT: The goal of this study was to determine the rates of mortality and morbidity associated with the embolization of arteriovenous malformations (AVMs) of the brain and to analyze the factors related to embolization-related complications. METHODS: The University of Toronto Brain Vascular Malformation Study Group database was reviewed. Three hundred six patients underwent 513 embolization sessions between November 1984 and September 2002. The combined rate of death and any permanent disabling neurological deficit was 3.9% per patient. Location of the AVM in an eloquent part of the brain, presence of a fistula, and a venous deposition of glue were related to complications. A clinically important reduction in the rate of death and disabling morbidity occurred in the second half of the study period. CONCLUSIONS: Embolization of AVMs in the brain is associated with low overall rates of mortality and disabling morbidity.

Rare intracanalicular ophthalmic aneurysm: endovascular treatment and review of the literature.

This report outlines the diagnosis and endovascular management of a rare intracanalicular ophthalmic aneurysm in a patient presenting with progressive visual loss.