Publications

A 72-year-old woman was admitted for elective L4/L5 laminectomy. The operative procedure was extradural, and a Jackson-Pratt (JP) drain was placed in the tissue bed and set to wall suction during skin closure. During closure, the patient developed a 15 s period of asystole. The patient was haemodynamically stable, but was comatose for 3 days postoperatively. Cardiac enzymes and EEG were unrevealing. Head CT showed traces of subarachnoid haemorrhage and signs suggestive of cerebral anoxia. JP drain at the incision produced 170-210 mL/day of fluid, positive for β-2 transferrin, indicating cerebrospinal fluid (CSF). The patient fully returned to baseline on hospital day 10. MRI on hospital day 8 normalised. The reversible coma and radiographic findings were most consistent with acute intracranial hypotension relating to acute loss of CSF. Because radiographic findings can mimic hypoxic-ischaemic injury, acute intracranial hypotension should be considered in the differential diagnosis of postoperative coma after cranial or spinal surgery.

Previous studies of cocaine use and stroke have focused on acute effects of cocaine in perceived high-risk populations. We characterized mechanisms and risk factors for cocaine use among ischemic stroke patients from a broad range of socioeconomic backgrounds to inform medical management decisions and prevention efforts. We studied consecutive adults admitted with acute ischemic stroke to our institution between January 2007 and December 2010 with a history or laboratory confirmation of cocaine use. Age, sex, and race-matched cocaine-negative controls were derived from the same study population. Demographics, risk factors, clinical and imaging data were compared between groups. Among 4073 acute ischemic stroke patients, 91 (2.2%) had a history of cocaine use and/or a positive toxicology screen (cases). Cocaine abusers did not differ from controls by occupation, income, or educational level (P > 0.5). Active tobacco use independently increased the odds of cocaine use among stroke patients (odds ratio 3.9, 95% confidence interval 2.0-7.5), as did the history of migraine (odds ratio 2.5, 95% confidence interval 1.1-5.9). Stroke subtype also predicted cocaine use among stroke patients (odds ratio 0.73, 95% confidence interval 0.58-0.93). Stroke patients with current or past cocaine use could not be distinguished from non-users by socioeconomic factors. Liberal use of toxicology screening among a much broader population of patients is needed for proper identification and management. Further study of causal mechanisms for cardioembolism in cocaine-associated stroke is warranted.

Severe traumatic brain injury is associated with both acute and delayed neuro- logical injury. Cerebral vasospasm is commonly associated with delayed neurological decline in aneurysmal subarachnoid hemorrhage patients. However, the role played by vasospasm in traumatic brain injury is less clear. Vasospasm occurs earlier, for a shorter duration, and often without significant neurological consequence among traumatic brain injury patients. Detection and management strategies for vasospasm in aneurysmal subarachnoid hemorrhage are not easily transferrable to traumatic brain injury patients. We present a patient with a severe traumatic brain injury who had dramatic improvement following emergent decompressive hemicraniectomy. Two weeks after initial presentation he suffered a precipitous decline despite intensive surveillance. This case illustrates the distinct challenges of diagnosing cerebral vasospasm in the setting of severe traumatic brain injury.

BACKGROUND: Transcranial Doppler ultrasound (TCD) has been used as a confirmatory test for the diagnosis of brain death (BD), but may be inaccurate in patients with a skull defect or extraventricular drain (EVD).

METHODS AND RESULTS: We report three cases of patients with a skull defect or EVD in whom TCD supported a diagnosis of BD but in which the clinical examination later refuted the diagnosis.

CONCLUSION: We caution against the use of TCD to confirm the diagnosis of BD in the presence of a skull defect or EVD.

BACKGROUND: Whether brain imaging can identify patients who are most likely to benefit from therapies for acute ischemic stroke and whether endovascular thrombectomy improves clinical outcomes in such patients remains unclear.

METHODS: In this study, we randomly assigned patients within 8 hours after the onset of large-vessel, anterior-circulation strokes to undergo mechanical embolectomy (Merci Retriever or Penumbra System) or receive standard care. All patients underwent pretreatment computed tomography or magnetic resonance imaging of the brain. Randomization was stratified according to whether the patient had a favorable penumbral pattern (substantial salvageable tissue and small infarct core) or a nonpenumbral pattern (large core or small or absent penumbra). We assessed outcomes using the 90-day modified Rankin scale, ranging from 0 (no symptoms) to 6 (dead).

RESULTS: Among 118 eligible patients, the mean age was 65.5 years, the mean time to enrollment was 5.5 hours, and 58% had a favorable penumbral pattern. Revascularization in the embolectomy group was achieved in 67% of the patients. Ninety-day mortality was 21%, and the rate of symptomatic intracranial hemorrhage was 4%; neither rate differed across groups. Among all patients, mean scores on the modified Rankin scale did not differ between embolectomy and standard care (3.9 vs. 3.9, P=0.99). Embolectomy was not superior to standard care in patients with either a favorable penumbral pattern (mean score, 3.9 vs. 3.4; P=0.23) or a nonpenumbral pattern (mean score, 4.0 vs. 4.4; P=0.32). In the primary analysis of scores on the 90-day modified Rankin scale, there was no interaction between the pretreatment imaging pattern and treatment assignment (P=0.14).

CONCLUSIONS: A favorable penumbral pattern on neuroimaging did not identify patients who would differentially benefit from endovascular therapy for acute ischemic stroke, nor was embolectomy shown to be superior to standard care. (Funded by the National Institute of Neurological Disorders and Stroke; MR RESCUE ClinicalTrials.gov number, NCT00389467.).

OBJECT: Decompressive craniectomy mandates subsequent cranioplasty. Complications of cranioplasty may be independent of the initial craniectomy, or they may be contingent upon the craniectomy. Authors of this study aimed to identify surgery- and patient-specific risk factors related to the development of surgical site infection and other complications following cranioplasty.

METHODS: A consecutive cohort of patients of all ages and both sexes who had undergone cranioplasty following craniectomy for stroke or trauma at a single institution in the period from May 2004 to May 2012 was retrospectively established. Patients who had undergone craniectomy for infectious lesions or neoplasia were excluded. A logistic regression analysis was performed to model and predict determinants related to infection following cranioplasty.

RESULTS: Two hundred thirty-nine patients met the study criteria. The overall rate of complication following cranioplasty was 23.85% (57 patients). Complications included, predominantly, surgical site infection, hydrocephalus, and new-onset seizures. Logistic regression analysis identified previous reoperation (OR 3.25, 95% CI 1.30-8.11, p = 0.01) and therapeutic indication for stroke (OR 2.45, 95% CI 1.11-5.39, p = 0.03) as significantly associated with the development of cranioplasty infection. Patient age, location of cranioplasty, presence of an intracranial device, bone flap preservation method, cranioplasty material, booking method, and time interval > 90 days between initial craniectomy and cranioplasty were not predictive of the development of cranioplasty infection.

CONCLUSIONS: Cranioplasty complications are common. Cranioplasty infection rates are predicted by reoperation following craniectomy and therapeutic indication (stroke). These variables may be associated with patient-centered risk factors that increase cranioplasty infection risk.

OBJECTIVE: To examine the American Academy of Neurology (AAN)'s prevention and limitation of conflicts of interest (COI) related to relationships with pharmaceutical and medical device manufacturers and other medically related commercial product and service companies (industry).

METHODS: We reviewed the AAN's polices governing its interactions with industry, mechanisms for enforcement, and the recent findings of the board-appointed COI task force, in the context of the 2009 David Rothman and colleagues' article in JAMA, the Council of Medical Specialty Societies (CMSS) Code for Interactions with Companies (Code), efforts of the American Medical Association in this area, and increased public and Congressional scrutiny of physician/physician organizations' relationships with industry.

RESULTS: The AAN's Policy on Conflicts of Interest provides 4 mechanisms for addressing COI: avoidance, separation, disclosure, and regulation. The AAN's Principles Governing Academy Relationships with External Sources of Support, including recent amendments proposed by the COI task force, regulate industry interaction with AAN programming, products, and leadership. With the Policy, Principles, and other methods of COI prevention, the AAN meets or exceeds all recommendations of the CMSS Code.

CONCLUSIONS: With its adherence to the Principles since 2004, the AAN has been a leader among professional medical associations in appropriately managing COI related to interactions with industry. Recent amendments to the Principles maintain the AAN's position as a leader in a time of increased public scrutiny of physicians' and professional medical associations' relationships with industry. The AAN is responsive to the recommendations of the COI task force, and has adopted the CMSS Code.

BACKGROUND: Beginning in the 1930s, the Canadian asbestos industry created and advanced the idea that chrysotile asbestos is safer than asbestos of other fiber types.

METHODS: We critically evaluate published and unpublished studies funded by the Quebec Asbestos Mining Association (QAMA) and performed by researchers at McGill University.

RESULTS: QAMA-funded researchers put forth several myths purporting that Quebec-mined chrysotile was harmless, and contended that the contamination of chrysotile with oils, tremolite, or crocidolite was the source of occupational health risk. In addition, QAMA-funded researchers manipulated data and used unsound sampling and analysis techniques to back up their contention that chrysotile was "essentially innocuous."

CONCLUSIONS: These studies were used to promote the marketing and sales of asbestos, and have had a substantial effect on policy and occupational health litigation. Asbestos manufacturing companies and the Canadian government continue to use them to promote the use of asbestos in Europe and in developing countries. Am. J. Ind. Med. 44:540-557, 2003.