Jeffrey S. Raskin

Brainstem Opioidergic System Is Involved in Early Response to Experimental SAH

Subarachnoid hemorrhage (SAH) is a form of stroke with high rates of mortality and permanent disability for patients who survive the initial event. Previous research has focused on delayed cerebral vasospasm of large conduit arteries as the cause of poor long-term outcomes after SAH. New evidence suggests that acute failure to restore cerebral blood flow (CBF) after SAH may be setting the stage for delayed ischemic neurological deficits. Our lab previously demonstrated that the rostral ventromedial medulla (RVM), an autonomic and sensorimotor integration center, is important for maintaining CBF after experimental SAH. In this study, we have demonstrated that ablation of μ-opioid receptor containing cells with dermorphin conjugates in the RVM results in a high mortality rate after experimental SAH and, in survivors, causes a dramatic decrease in CBF. Further, locally blocking the μ-opioid receptor with the antagonist naltrexone attenuated the reduction in CBF secondary to experimental SAH. Saturating μ-opioid receptors with the agonist [d-Ala(2),NMe-Phe(4),Gly-ol(5)]-encephalin (DAMGO) had no effect. Taken together, these results suggest that SAH activates opioidergic signaling in the RVM with a resultant reduction in CBF. Further, cells in the RVM that contain μ-opioid receptors are important for survival after acute SAH. We propose that failure of the RVM μ-opioid receptor cells to initiate the compensatory CBF response sets the stage for acute and delayed ischemic injury following SAH.

Case comparison and literature review of glioblastoma: A tale of two tumors

Background: Diagnosis of glioblastoma multiforme (GBM) includes a heterogeneous group of tumors. We describe two cases with histopathologically and molecularly similar tumors, but very different outcomes. We attempt to illustrate the need for improved prognostic markers for GBM. Case Description: Two patients with similar molecular profiles were retrospectively identified. The following markers were assessed: O6-methylguanine DNA methyltransferase (MGMT) methylation, isocitrate dehydrogenase (IDH) 1 and 2 status, epidermal growth factor receptor (EGFR) amplification, phosphatase and tensin homolog (PTEN) status, Ki-67, p53, and 1p/19q status. Each patient was assigned a Karnofsky performance score at presentation. Case 1 (62-year-old male) was a right temporal lobe glioblastoma with a molecular profile of amplified EGFR, normal PTEN, no IDH1/2 mutation, 28.7% MGMT promoter methylation, 5-20% Ki-67, 1p deletion, and 19q intact. The patient underwent resection followed by radiation therapy and 2 years of chemotherapy, and was asymptomatic and tumor free 5 years post diagnosis. Tumor eventually recurred and the patient expired 72 months after initial diagnosis. Case 2 (63-year-old male) was a right frontal white matter mass consistent with glioblastoma with a molecular profile of amplified EGFR, absent PTEN, no IDH1/2 mutation, 9.9% MGMT promoter methylation, 5-10% Ki-67, and 1p/19q status inconclusive. A radical subtotal resection was performed; however, 2 weeks later symptoms had returned. Subsequent imaging revealed a tumor larger than at diagnosis. The patient expired 3 months after initial diagnosis. Conclusion: The need for formulating more robust means to classify GBM tumor subtypes is paramount. Standard histopathologic and molecular analyses are costly and did not provide either of these patients with a realistic appraisal of their prognosis. Individualized whole genome testing similar to that being reported for medulloblastoma and other tumors may be preferable to the array of tests as currently utilized.

Correlation of preoperative MRI with the long-term outcomes of dorsal root entry zone lesioning for brachial plexus avulsion pain.

OBJECT Lesioning of the dorsal root entry zone (DREZotomy) is an effective treatment for brachial plexus avulsion (BPA) pain. The role of preoperative assessment with MRI has been shown to be unreliable for determining affected levels; however, it may have a role in predicting pain outcomes. Here, DREZotomy outcomes are reviewed and preoperative MRI is examined as a possible prognostic factor. METHODS A retrospective review was performed of an institutional database of patients who had undergone brachial plexus DREZ procedures since 1995. Preoperative MRI was examined to assess damage to the DREZ or dorsal horn, as evidenced by avulsion of the DREZ or T2 hyperintensity within the spinal cord. Phone interviews were conducted to assess the long-term pain outcomes. RESULTS Between 1995 and 2012, 27 patients were found to have undergone cervical DREZ procedures for BPA. Of these, 15 had preoperative MR images of the cervical spine available for review. The outcomes were graded from 1 to 4 as poor (no significant relief), good (more than 50% pain relief), excellent (more than 75% pain relief), or pain free, respectively. Overall, DREZotomy was found to be a safe, efficacious, and durable procedure for relief of pain due to BPA. The initial success rate was 73%, which declined to 66% at a median follow-up time of 62.5 months. Damage to the DREZ or dorsal horn was significantly correlated with poorer outcomes (p = 0.02). The average outcomes in patients without MRI evidence of DREZ or dorsal horn damage was significantly higher than in patients with such damage (3.67 vs 1.75, t-test; p = 0.001). A longer duration of pain prior to operation was also a significant predictor of treatment success (p = 0.004). CONCLUSIONS Overall, the DREZotomy procedure has a 66% chance of achieving meaningful pain relief on long-term follow-up. Successful pain relief is associated with the lack of damage to the DREZ and dorsal horn on preoperative MRI.

Minimal Access Posterior Approach for Extrapleural Thoracic Sympathectomy: A Cadaveric Study and Cases.

OBJECTIVE Operatively, video-assisted thoracoscopic sympathectomy (VATS) involves pleural entry and poses risk in small children and patients with pulmonary disease. A conventional posterior sympathectomy is more invasive than VATS. We investigated a cadaveric feasibility study of a minimal access posterior approach for endoscopic extrapleural sympathectomy and discuss this minimal approach in children with cardiac sympathectomy. METHODS A posterior endoscopic extrapleural approach for thoracic sympathectomy was performed using lightly embalmed cadavers; surgical corridor depth, width, and associated pleural violation were recorded. Two pediatric cases undergoing secondary prevention for breakthrough cardiac dysrhythmias using this approach are discussed: case 1, a 9-year-old girl with refractory long QT syndrome; and case 2, a 13-year-old boy with hypertrophic cardiomyopathy. RESULTS The cadaveric study supported 100% identification of a craniocaudal-oriented sympathetic chain using an 18-mm tubular retractor, and a 10% pleural violation rate. There were no clinically significant pneumothoracies in either proof of concept cases. CONCLUSIONS Minimal access posterior extrapleural sympathectomy is feasible to expose the sympathetic chain in the thoracic region with good visualization using either endoscopic or microscopic magnification. Single-position bilateral thoracic sympathectomy can be performed in pediatric patients with life-threatening ventricular arrhythmias. Based on the cadaveric study and the 2 preliminary cases, we believe that a posterior minimal access approach allows safe and effective access to the thoracic sympathetic chain for causes requiring sympathectomy using single positioning, with minimal risk of pneumothorax or Horner syndrome.

World Neurosurgery: Case Reports Surgical Management of Trigeminal Neuralgia in Children

BACKGROUND Trigeminal neuralgia (TN) is a well-recognized facial pain syndrome. Discrete forms with disparate pain symptoms include classic and atypical. However, atypical facial pain includes neuralgiform pain along a spectrum. Most cases of TN are diagnosed in the adult population. Case reports and series of children have presented TN as a similar entity, with treatment similar to that for adults. We reviewed the pertinent data and present 2 pediatric TN cases successfully treated with microvascular decompression (MVD). CASE DESCRIPTION Two pediatric patients (age 12 and 15 years) with TN refractory to previous medical therapy were identified. Both patients were deemed appropriate surgical candidates and underwent MVD to manage their TN. TN compression was arterial in both cases and involved portions of the anterior inferior cerebellar artery. Patient 1 was pain free 6 months after the procedure. Patient 2 was pain free immediately after the procedure and had been weaned off preoperative symptomatic management at the latest follow-up visit. The most recent follow-up examination was 12 and 8 months for patients 1 and 2, respectively, with both experiencing continued freedom from pain. CONCLUSIONS Few studies have reported on the effectiveness of MVD in the pediatric population for the management of TN. The supporting data and our 2 cases have demonstrated that MVD is effective for pediatric patients to treat their TN. Furthermore, the side effects appear to be minimal, with excellent pain relief after MVD in this patient population.

Improving Efficiency and Mapping Surgical Procedures Using Lean Methods

Abstract The delivery of high-value and low-cost health care is an increasingly urgent directive of public health institutions. As national health expenditure becomes an increasingly higher proportion of the gross domestic product, governments and health care systems are trying to find ways to reduce the cost of health care without reducing the overall health of the population. Recently, Lean methodologies have been borrowed and adapted from automobile assembly lines to health care delivery. These methods have been used in places ranging from the clinic, to ambulatory surgery centers, to high-volume hospital operating rooms to improve the quality and efficiency of health care delivery while reducing costs.

Eliminating Unnecessary Diagnostic Imaging and Labs

Abstract In the era of value-based health care, reducing waste and decreasing cost is a priority for health care systems. A primary challenge in improving health care value is to maintain or improve outcomes while reducing the cost of care. Lean Production, widely used in manufacturing industries, aims to reduce cost and eliminate waste and can be used to achieve similar ends in medicine. By assimilating these principles, health care systems can identify wasteful processes to further the Triple Aim (improve outcomes, reduce costs, and improve patient experience). At Oregon Health & Science University, an initiative was created to evaluate the efficacy of imaging obtained by the neuroscience service line and limit nonessential images. A single standardized procedure, retrosigmoid craniectomy for microvascular decompression, was analyzed. Retrospective analyses of institutional data were performed prior to prospective changes in clinical practice. Data collected after implementation of the clinical changes demonstrated similar outcomes and reduced cost, thereby increasing value.