Brainstem cavernous malformations (CMs) are complex lesions associated with hemorrhage and neurological deficit. In this review, the authors describe the anatomical nuances relating to the operative techniques for these challenging lesions. The resection of brainstem CMs in properly selected patients has been demonstrated to reduce the risk of rehemorrhage and can be achieved relatively safely in experienced hands.
Wael F. Asaad, Brian P. Walcott, Brian V. Nahed and Christopher S. Ogilvy
Manuel Ferreira Jr., Brian P. Walcott, Brian V. Nahed and Laligam N. Sekhar
Hemifacial spasm (HFS) is caused by arterial or venous compression of cranial nerve VII at its root exit zone. Traditionally, microvascular decompression of the facial nerve has been an effective treatment for posterior inferior and anterior inferior cerebellar artery as well as venous compression. The traditional technique involves Teflon felt or another construct to cushion the offending vessel from the facial nerve, or cautery and division of the offending vein. However, using this technique for severe vertebral artery (VA) compression can be ineffective and fraught with complications. The authors report the use of a new technique of VA pexy to the petrous or clival dura mater in patients with HFS attributed to a severely ectatic and tortuous VA, and detail the results in a series of patients.
Six patients with HFS due to VA compression underwent a retrosigmoid craniotomy, combined with a far-lateral approach in some patients. On identification of the site of VA compression, the vessel was mobilized adequately for the decompression. Great care was taken to avoid kinking the perforating vessels arising from the VA. Two 8-0 nylon sutures were passed through to the wall of the VA and then through the clival or petrous dura, and then tied to alleviate compression on cranial nerve VII.
Patients were followed for at least 1 year postoperatively (mean 2.7 years, range 1–4 years). All 6 patients had complete resolution of their HFS. Facial function was tested postoperatively, and was stable when compared with the preoperative baseline. Two of the 3 patients with preoperative tinnitus had resolution of this symptom after the procedure. Postoperative imaging demonstrated VA decompression of the facial nerve and no evidence of stroke in all patients. One patient suffered from hearing loss, another developed a postoperative transient unilateral vocal cord paralysis, and a third patient developed a pseudomeningocele that resolved with the placement of a lumbar drain.
Hemifacial spasm and other neurovascular syndromes are effectively treated by repositioning the compressing artery. Careful study of the preoperative MR images may identify a select group of patients with HFS due to an ectatic VA. Rather than traditional decompression with only pledget placement, these patients may benefit from a VA pexy to provide an effective, safe, and durable resolution of their symptoms while minimizing surgical complications.
Jean-Valery Coumans, Brian P. Walcott, William E. Butler, Brian V. Nahed and Kristopher T. Kahle
Resolution of syringomyelia is common following hindbrain decompression for Chiari malformation, yet little is known about the kinetics governing this process. The authors sought to establish the volumetric rate of syringomyelia resolution.
A retrospective cohort of patients undergoing hindbrain decompression for a Chiari malformation Type I with preoperative cervical or thoracic syringomyelia was identified. Patients were included in the study if they had at least 3 neuroimaging studies that detailed the entirety of their preoperative syringomyelia over a minimum of 6 months postoperatively. The authors reconstructed the MR images in 3 dimensions and calculated the volume of the syringomyelia. They plotted the syringomyelia volume over time and constructed regression models using the method of least squares. The Akaike information criterion and Bayesian information criterion were used to calculate the relative goodness of fit. The coefficients of determination R 2 (unadjusted and adjusted) were calculated to describe the proportion of variability in each individual data set accounted for by the statistical model.
Two patients were identified as meeting inclusion criteria. Plots of the least-squares best fit were identified as 4.01459e −0.0180804 x and 13.2556e −0.00615859 x. Decay of the syringomyelia followed an exponential model in both patients (R2 = 0.989582 and 0.948864).
Three-dimensional analysis of syringomyelia resolution over time enables the kinetics to be estimated. This technique is yet to be validated in a large cohort. Because syringomyelia is the final common pathway for a number of different pathological processes, it is possible that this exponential only applies to syringomyelia related to treatment of Chiari malformation Type I.
Brandyn Castro, Brian P. Walcott, Navid Redjal, Jean-Valery Coumans and Brian V. Nahed
Frontal sinus fractures are heterogeneous, and management of these fractures is often modified based on injury pattern and institutional experience. The optimal initial treatment of frontal sinus fractures is controversial. Treatment strategies are aimed at correcting cosmetic deformity, as well as at preventing delayed complications, including CSF fistulas, mucocele formation, and infection. Existing treatment options include observation, reconstruction, obliteration, cranialization, or a combination thereof. Modalities for treatment encompass both open surgical approaches and endoscopic techniques. In the absence of Class I data, the authors review the existing literature related to treatment strategies of frontal sinus fractures, particularly as they relate to CSF fistulas, to provide recommendations based on the best available evidence.
Brian P. Walcott, Brian V. Nahed, Kristopher T. Kahle, Navid Redjal and Jean-Valery Coumans
Previous methods to determine stroke prevalence, such as nationwide surveys, are labor-intensive endeavors. Recent advances in search engine query analytics have led to a new metric for disease surveillance to evaluate symptomatic phenomenon, such as influenza. The authors hypothesized that the use of search engine query data can determine the prevalence of stroke.
The Google Insights for Search database was accessed to analyze anonymized search engine query data. The authors' search strategy utilized common search queries used when attempting either to identify the signs and symptoms of a stroke or to perform stroke education. The search logic was as follows: (stroke signs + stroke symptoms + mini stroke − heat) from January 1, 2005, to December 31, 2010.
The relative number of searches performed (the interest level) for this search logic was established for all 50 states and the District of Columbia. A Pearson product-moment correlation coefficient was calculated from the statespecific stroke prevalence data previously reported.
Web search engine interest level was available for all 50 states and the District of Columbia over the time period for January 1, 2005–December 31, 2010. The interest level was highest in Alabama and Tennessee (100 and 96, respectively) and lowest in California and Virginia (58 and 53, respectively). The Pearson correlation coefficient (r) was calculated to be 0.47 (p = 0.0005, 2-tailed).
Search engine query data analysis allows for the determination of relative stroke prevalence. Further investigation will reveal the reliability of this metric to determine temporal pattern analysis and prevalence in this and other symptomatic diseases.
Aaron A. Cohen-Gadol, Brian V. Nahed, Jennifer R. Voorhees, Cormac O. Maher and Dennis D. Spencer
✓Although Harvey Cushing is best known for his role in developing surgical treatments for tumors of the central nervous system, he performed diverse neurosurgical procedures throughout his career, both at The Johns Hopkins Hospital (1886–1912) and at the Peter Bent Brigham Hospital (1912–1932). His unique and innovative approach to the treatment of myelomeningoceles associated with hydrocephalus, displayed early in his career, is characteristic of his attempts to circumvent the technical limitations of his time in the management of neurosurgical problems. In this report, the authors discuss the evolution of Cushing's technique in the treatment of myelomeningoceles through two illustrative patient records.
Ahmed J. Awad, Brian P. Walcott, Christopher J. Stapleton, Vijay Yanamadala, Brian V. Nahed and Jean-Valery Coumans
Dabigatran etexilate (Pradaxa) is a novel oral anticoagulant that has gained FDA approval for the prevention of ischemic stroke and systemic embolism in patients with nonvalvular atrial fibrillation. In randomized trials, the incidence of hemorrhagic events has been demonstrated to be lower in patients treated with dabigatran compared with the traditional anticoagulant warfarin. However, dabigatran does not have reliable laboratory tests to measure levels of anticoagulation and there is no pharmacological antidote. These drawbacks are challenging in the setting of intracerebral hemorrhage. In this article, the authors provide background information on dabigatran, review the existing anecdotal experiences with treating intracerebral hemorrhage related to dabigatran therapy, present a case study of intracranial hemorrhage in a patient being treated with dabigatran, and suggest clinical management strategies. The development of reversal agents is urgently needed given the growing number of patients treated with this medication.
Brian P. Walcott, Brian V. Nahed, Kristopher T. Kahle, Ann-Christine Duhaime, Nutan Sharma and Emad N. Eskandar
Generalized dystonic syndromes may escalate into persistent episodes of generalized dystonia known as status dystonicus that can be life-threatening due to dystonia-induced rhabdomyolysis and/or respiratory compromise. Treatment of these conditions usually entails parenteral infusion of antispasmodic agents and sedatives and occasionally necessitates a medically induced coma for symptom control. The authors report a series of 3 children who presented with medically intractable, life-threatening status dystonicus and were successfully treated with bilateral pallidal deep brain stimulation. Bilateral globus pallidus internus stimulation appears to be effective in the urgent treatment of medically refractory and life-threatening movement disorders.
Brian P. Walcott, Jonathan B. Neal, Sameer A. Sheth, Kristopher T. Kahle, Emad N. Eskandar, Jean-Valery Coumans and Brian V. Nahed
Dural closure with synthetic grafts has been suggested to contribute to the incidence of infection and CSF leak. The objective of this study was to assess the contribution of choice of dural closure material, as well as other factors, to the incidence of infection and CSF leak.
A retrospective, consecutive cohort study of adult patients undergoing elective craniotomy was established between April 2010 and March 2011 at a single center. Exclusion criteria consisted of trauma, bur hole placement alone, and temporary CSF fluid diversion.
Three hundred ninety-nine patients were included (mean follow-up 396.6 days). Nonautologous (synthetic) dural substitute was more likely to be used (n = 106) in cases of reoperation (p = 0.001). Seventeen patients developed a surgical site infection and 12 patients developed a CSF leak. Multivariate logistic regression modeling identified estimated blood loss (OR 1.002, 95% CI 1.001–1.003; p < 0.001) and cigarette smoking (OR 2.198, 95% CI 1.109–4.238; p = 0.019) as significant predictors of infection. Synthetic dural graft was not a predictor of infection in multivariate analysis. Infratentorial surgery (OR 4.348, 95% CI 1.234–16.722; p = 0.024) and more than 8 days of postoperative corticosteroid treatment (OR 3.886, 95% CI 1.052–16.607; p = 0.048) were significant predictors for the development of CSF leak. Synthetic dural graft was associated with a lower likelihood of CSF leak (OR 0.072, 95% CI 0.003–0.552; p = 0.036).
The use of synthetic dural closure material is not associated with surgical site infection and is associated with a reduced incidence of CSF leak. Modifiable risk factors exist for craniotomy complications that warrant vigilance and further study.
Benjamin D. Schanker, Brian P. Walcott, Brian V. Nahed, Kristopher T. Kahle, Yan Michael Li and Jean-Valery C. E. Coumans
Chiari malformations (Types I–IV) are abnormalities of the posterior fossa that affect the cerebellum, brainstem, and the spinal cord with prevalence rates of 0.1%–0.5%. Case reports of familial aggregation of Chiari malformation, twin studies, cosegregation of Chiari malformation with known genetic conditions, and recent gene and genome-wide association studies provide strong evidence of the genetic underpinnings of familial Chiari malformation. The authors report on a series of 3 family pairs with Chiari malformation Type I: 2 mother-daughter pairs and 1 father-daughter pair. The specific genetic causes of familial Chiari malformation have yet to be fully elucidated. The authors review the literature and discuss several candidate genes. Recent advances in the understanding of the genetic influences and pathogenesis of familial Chiari malformation are expected to improve management of affected patients and monitoring of at-risk family members.