Incidence and Risk Factors for Intraoperative Seizures During Elective Craniotomy.

BACKGROUND: Perioperative seizures may affect 1% to 50% of patients undergoing craniotomy and adversely impact outcomes. However, data on intraoperative seizures are limited. This retrospective case-control study investigated the incidence and risk factors for intraoperative seizures during elective supratentorial craniotomy involving evoked potential monitoring. MATERIALS AND METHODS: Patients aged 18 years or above undergoing elective supratentorial craniotomy with evoked potential monitoring who experienced intraoperative seizures at our institution between December 2008 and March 2014 were compared with a control group generated using a random number generator. Six controls were used for each case from among the patients who underwent elective supratentorial craniotomy during the same calendar year. Multivariate analysis was conducted using logistic regression to identify the risk factors for intraoperative seizures. RESULTS: Among the 1916 patients who met the inclusion criteria, 45 (2.3%) had intraoperative seizures. The majority of seizures occurred during burr-hole placement or craniotomy, before lesion manipulation. Timing of seizures relative to motor evoked potential runs and stimulus intensity was variable. Significant risk factors for intraoperative seizures were seizure history (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.07-4.46; P=0.03), diagnosis of brain tumor (OR, 2.41; 95% CI, 1.16-4.19; P=0.02), and temporal craniotomy (OR, 5.18; 95% CI, 2.03-13.25; P=0.001). Intraoperative prophylactic use of phenytoin/fosphenytoin and levetiracetam was protective against seizure (phenytoin/fosphenytoin: OR, 0.12; 95% CI, 0.04-0.35; P<0.001 and levetiracetam: OR, 0.40; 95% CI, 0.17-0.94; P=0.04). Phenytoin/fosphenytoin was more protective than levetiracetam (OR, 0.31; 95% CI, 0.10-0.99; P=0.048). CONCLUSIONS: The overall incidence of intraoperative seizures was 2.3%. Independent risk factors for intraoperative seizures were seizure history, diagnosis of intracranial tumor, and temporal craniotomy. Intraoperative prophylactic anticonvulsant use was protective.

Injury and Liability Associated With Spine Surgery.

BACKGROUND: Although spine surgery is associated with significant morbidity, the anesthesia liability profile for spine surgery is not known. We examined claims for spine procedures in the Anesthesia Closed Claims Project database to evaluate patterns of injury and liability. MATERIALS AND METHODS: A retrospective cohort study was performed. Inclusion criteria were anesthesia claims provided for surgical procedures in 2000 to 2014. We compared mechanisms of injury for cervical spine to thoracic or lumbar spine procedures using χ and the Fisher exact test. Univariate and multivariate logistic regression analyses were used to determine factors associated with permanent disabling injury in spine surgery claims. RESULTS: The 207 spine procedure (73% thoracic/lumbar; 27% cervical) claims comprised >10% of claims. Permanent disabling injuries to nerves, the spinal cord, and the eyes or visual pathways were more common with spine procedures than in nonspine procedures. Hemorrhage and positioning injuries were more common in thoracic/lumbar spine claims, whereas difficult intubation was more common in cervical spine claims. Multiple logistic regression demonstrated prone positioning (odds ratio=3.50; 95% confidence interval, 1.30-9.43) and surgical duration of ≥4 hours increased the odds of severe permanent injury in spine claims (odds ratio=2.73; 95% confidence interval, 1.11-6.72). CONCLUSIONS: Anesthesia claims related to spine surgery were associated with severe permanent disability primarily from nerve and eye injuries. Prone positioning and surgical duration of ≥4 hours were associated with permanent disabling injuries. Attention to positioning, resuscitation during blood loss, and reducing length of surgery may reduce these complications.

Cognitive profiles of neurofibromatosis type 1 patients with minor brain malformations.

Neurofibromatosis type 1 is a genetic condition associated with increased risk of abnormal brain development. The relationship between a specific type of brain malformation and a distinct cognitive sign/deficiency remains unknown. This study investigated the frequency of brain malformations in children with neurofibromatosis type 1, and the impact of those brain malformations on cognitive performance. A retrospective examination was performed of cranial magnetic resonance imaging and clinical records in 604 neurofibromatosis type 1 patients. Eighteen patients with brain malformations and intellectual evaluations were available and compared to a subset of neurofibromatosis type 1 patients (n = 20) without brain malformations. The most common brain malformations included hypothalamic hamartomas and Chiari I malformation. More complex migration disorders were also observed. Comparisons of cognitive profiles between groups revealed differences in patients with hamartomas compared with those manifesting Chiari I malformations or control subjects. As a group, those with hamartomas demonstrated below-average global intellect, whereas patients with Chiari I or no malformations performed in the average range. Disorders in cell organization, expressed as brain malformations (hamartomas or more complex defects), may comprise part of the expression of organizational and developmental defects in patients with neurofibromatosis type 1 and possibly other rat sarcoma gene-mitogen activated protein kinase pathway disorders.