Clinical and Radiological Predictors of Malignant Middle Cerebral Artery Infarction Development and Outcomes.

BACKGROUND: Optic nerve sheath diameter (ONSD) can predict intracranial hypertension and outcomes in severe traumatic brain injury. Its utility in middle cerebral artery (MCA) stroke is unknown. AIMS: We reviewed serial radiological measurements, including ONSD, in patients with MCA stroke undergoing decompressive craniectomy (DC) for malignant MCA syndrome and compared demographic, clinical, and radiological data with an age- and gender-matched group of nonmalignant MCA stroke patients. METHODS: Patients admitted to a large tertiary hospital in London, UK, between April 2012 and October 2016 with MCA infarction were identified through 2 data sources. We quantified ONSD, eyeball transverse diameter (ETD), ONSD/ETD ratio, midline shift (MLS), and infarct volume on computed tomography (CT). RESULTS: We identified 19 patients (mean age = 49.8 years [standard deviation = 12.5]) with malignant MCA stroke and 19 patients (47.8 years [16.0]) with nonmalignant MCA stroke. Mean ONSD, ONSD/ETD ratio, MLS, and infarct volume on initial CT all significantly increased after developing malignant MCA syndrome and decreased (except infarct volume, which increased) following DC (all Ps <.05). ONSD and ONSD/ETD ratios in the malignant group did not correlate with functional outcomes but were significantly higher on initial CT compared with the nonmalignant group (mean ONSD: 5.66 mm [.6] versus 4.97 mm [.5], P = .001; mean ONSD/ETD ratio: .25 [.03] versus .22 [.02], P = .002). CONCLUSIONS: ONSD, ONSD/ETD ratio, MLS, and infarct volume change dynamically in patients with malignant MCA infarction who undergo DC. An ONSD of more than 5.25 mm and an ONSD/ETD ratio of more than .232 on initial CT may identify MCA stroke patients at high risk of developing malignant MCA syndrome.

The use of simulation in neurosurgical education and training. A systematic review.

OBJECT: There is increasing evidence that simulation provides high-quality, time-effective training in an era of resident duty-hour restrictions. Simulation may also permit trainees to acquire key skills in a safe environment, important in a specialty such as neurosurgery, where technical error can result in devastating consequences. The authors systematically reviewed the application of simulation within neurosurgical training and explored the state of the art in simulation within this specialty. To their knowledge this is the first systematic review published on this topic to date. METHODS: The authors searched the Ovid MEDLINE, Embase, and PsycINFO databases and identified 4101 articles; 195 abstracts were screened by 2 authors for inclusion. The authors reviewed data on study population, study design and setting, outcome measures, key findings, and limitations. RESULTS: Twenty-eight articles formed the basis of this systematic review. Several different simulators are at the neurosurgeon's disposal, including those for ventriculostomy, neuroendoscopic procedures, and spinal surgery, with evidence for improved performance in a range of procedures. Feedback from participants has generally been favorable. However, study quality was found to be poor overall, with many studies hampered by nonrandomized design, presenting normal rather than abnormal anatomy, lack of control groups and long-term follow-up, poor study reporting, lack of evidence of improved simulator performance translating into clinical benefit, and poor reliability and validity evidence. The mean Medical Education Research Study Quality Instrument score of included studies was 9.21 ± 1.95 (± SD) out of a possible score of 18. CONCLUSIONS: The authors demonstrate qualitative and quantitative benefits of a range of neurosurgical simulators but find significant shortfalls in methodology and design. Future studies should seek to improve study design and reporting, and provide long-term follow-up data on simulated and ideally patient outcomes.

Hyponatremia and brain injury: historical and contemporary perspectives.

Hyponatremia is common in neurocritical care patients and is associated with significant morbidity and mortality. Despite decades of research into the syndrome of inappropriate antidiuretic hormone (SIADH) and cerebral salt wasting (CSW), their underlying pathophysiological mechanisms are still not fully understood. This paper reviews the history behind our understanding of hyponatremia in patients with neurologic injury, including the first reports of CSW and SIADH, and current and future challenges to diagnosis and management in this setting. Such challenges include distinguishing CSW, SIADH, and hypovolemic hyponatremia due to a normal pressure natriuresis from the administration of large volumes of fluids, and hyponatremia due to certain medications used in the neurocritical care population. Potential treatments for hyponatremia include mineralocorticoids and vasopressin 2 receptor antagonists, but further work is required to validate their usage. Ultimately, a greater understanding of the pathophysiological mechanisms underlining hyponatremia in neurocritical care patients remains our biggest obstacle to optimizing patient outcomes in this challenging population.