Gregory M. Weiner

Cervical and cervicomedullary spinal cord stimulation for chronic pain: efficacy and outcomes.

BACKGROUND The role for spinal cord stimulation (SCS) in the management of chronic spinal cord forms of pain involving cervical dermatomes or the cervicomedullary junction (CMJ) for facial pain remains largely uncharted. OBJECTIVE To review outcomes with cervical and CMJ SCS performed by a single surgeon, with particular emphasis on complications and efficacy. METHODS All patients that underwent cervical or CMJ SCS by the lead author were identified and follow-up obtained by telephone questionnaires. Patient demographics, surgical details, outcomes and complications for all patients identified were critically reviewed. RESULTS Of 121 patients identified that underwent at least trial SCS, 100 underwent permanent lead implantation. Indications for cervical SCS included brachial plexus lesions (8), complex regional pain syndrome (33), degenerative disc disease (4), failed neck surgery syndrome (23), chronic radiculopathy (6) and post-herpetic neuralgia (PHN) (1); for CMJ SCS, indications included trigeminal deafferetiation pain (10), trigeminal neuropathic pain (4), PHN (4) and occipital neuralgia (7). Pain relief was greater along the extremities than axially, and less in the occipital area than in the head or face. Mean pain reduction averaged 56.6% at a mean follow-up of 4.2 years. Of 24 revision surgeries required, 8 were for presumed lead migration or fracture. Complications included 4 CSF leaks, 5 wound infections, and 4 cases of persistent numbness or pain. Pain relief lasted an average of 3.6 years. CONCLUSION Cervical and CMJ SCS are safe and efficacious and may provide greater relief along the upper extremities than axially, and in the head rather than in the occipital region.

Ommaya reservoir with ventricular catheter placement for chemotherapy with frameless and pinless electromagnetic surgical neuronavigation

BACKGROUND Accuracy in Ommaya reservoir catheter placement is critical to chemotherapy infusion. Most frameless image guidance is light emitting diode (LED) based, requiring a direct line of communication between instrument and tracker, limiting freedom of instrument movement within the surgical field. Electromagnetic neuronavigation may overcome this challenge. OBJECTIVE To compare Ommaya reservoir ventricular catheter placement using electromagnetic neuronavigation to LED-based optical navigation, with emphasis on placement accuracy, operative time and complication rate. METHODS Twenty-eight patients who underwent placement of Ommaya reservoirs at our institution between 2010 and 2014 with either electromagnetic (12 patients) or optical neuronavigation (16 patients) were retrospectively reviewed. RESULTS Half of the patients were male. Their mean age was 56 years (range 28-87 years). Accuracy and precision in catheter tip placement at the target site (foramen of Monro) were both higher (p=0.038 and p=0.043, respectively) with electromagnetic neuronavigation. Unintended placement of the distal catheter contralateral to the target site occurred more frequently with optical navigation, as did superior or inferior positioning by more than 5 mm. Mean operative times were shorter (p=0.027) with electromagnetic neuronavigation (43.2 min) than with optical navigation (51.0 min). There were three complications (10.7%)--one case each of cytotoxic edema, post-operative wound infection, and urinary tract infection. The rate of complication did not differ between groups. CONCLUSION In contrast with optical neuronavigation, frameless and pinless electromagnetic image guidance allows the ability to track instrument depth in real-time. It may increase ventricular catheter placement accuracy and precision, and decrease operative times.

The early days of hemostasis in neurosurgery.

Two key discoveries in the 19th century--infection control and the development of general anesthesia--provided an impetus for the rapid advancement of surgery, especially within the field of neurosurgery. Yet the field of neurosurgery would not have existed in the modern sense without the development and advancement of techniques in hemostasis. Improvement in intraoperative hemostasis came more gradually but was no less important to enhancing neurosurgical outcomes. The history of hemostasis in neurosurgery is often overlooked. Herein, the authors briefly review the historical progression of hemostatic techniques since the beginning of the early modern era of neurosurgery.

Prophylactic Antiepileptics and Seizure Incidence Following Subarachnoid Hemorrhage A Propensity Score–Matched Analysis

Background and Purpose— The utility of prophylactic antiepileptic drug (AED) administration after spontaneous subarachnoid hemorrhage remains controversial. AEDs have not clearly been associated with a reduction in seizure incidence and have been associated with both neurological worsening and delayed functional recovery in this setting. Methods— We retrospectively analyzed a prospectively collected database of subarachnoid hemorrhage patients admitted to our institution between 2005 and 2010. Between 2005 and 2007, all patients received prophylactic AEDs upon admission. After 2007, no patients received prophylactic AEDs or had AEDs immediately discontinued if initiated at an outside hospital. A propensity score–matched analysis was then performed to compare the development of clinical and electrographic seizures in these 2 populations. Results— Three hundred and fifty three patients with spontaneous subarachnoid hemorrhage were analyzed, 43% of whom were treated with prophylactic AEDs upon admission. Overall, 10% of patients suffered clinical and electrographic seizures, most frequently occurring within 24 hours of ictus (47%). The incidence of seizures did not vary significantly based on the use of prophylactic AEDs (11 versus 8%; P=0.33). Propensity score–matched analyses suggest that patients receiving prophylactic AEDs had a similar likelihood of suffering seizures as those who did not (P=0.49). Conclusions— Propensity score–matched analysis suggests that prophylactic AEDs do not significantly reduce the risk of seizure occurrence in patients with spontaneous subarachnoid hemorrhage.

Volumetric response to radiosurgery for brain metastasis varies by cell of origin

OBJECT The aim of this study was to evaluate the imaging response of brain metastases after radiosurgery and to correlate the response with tumor type and patient survival. METHODS The authors conducted a retrospective review of patients who had undergone Gamma Knife radiosurgery for brain metastases from non-small cell lung cancer (NSCLC), breast cancer, or melanoma. The imaging volumetric response by tumor type was plotted at 3-month intervals and classified as a sustained decrease in tumor volume (Type A), a transient decrease followed by a delayed increase in tumor volume (Type B), or a sustained increase in tumor volume (Type C). These imaging responses were then compared with patient survival and tumor type. RESULTS Two hundred thirty-three patients with metastases from NSCLC (96 patients), breast cancer (98 patients), and melanoma (39 patients) were eligible for inclusion in this study. The patients with NSCLC were most likely to exhibit a Type A response; those with breast cancer, a Type B response; and those with melanoma, a Type C response. Among patients with NSCLC, the median overall survival was 11.2 months for those with a Type A response (76 patients), 8.6 months for those with a Type B response (6 patients), and 10.5 months for those with a Type C response (14 patients). Among patients with breast cancer, the median overall survival was 16.6 months in those with a Type A response (65 patients), 18.1 months in those with a Type B response (20 patients), and 7.5 months in those with a Type C response (13 patients). For patients with melanoma, the median overall survival was 5.2 months in those with a Type A response (26 patients) and 6.7 months in those with a Type C response (13 patients). None of the patients with melanoma had a Type B response. The imaging response was significantly associated with survival only in patients with breast cancer. CONCLUSIONS The various types of imaging responses of metastatic brain tumors after stereotactic radiosurgery depend in part on tumor type. However, the type of response only correlates with survival in patients with breast cancer.

Transosseous cerebrospinal fluid fistula 14 years after Chiari decompression: presentation and management

The authors report a unique case of a transosseous CSF fistula that was detected more than 10 years after treatment of a symptomatic Chiari I malformation. This lesion initially presented as an intraosseous cystic lesion involving the C-2 vertebra, which was found to communicate freely with the subarachnoid space through a tiny dural opening. Surgical management involved hemilaminectomy and repair of the dural defect followed by reinforcement of the bony defect with demineralized bone matrix. Following closure of the fistula, symptoms of elevated intracranial pressure developed, necessitating a ventriculoperitoneal shunt for CSF diversion.

Endovascular Treatment of Tandem Common Carotid Artery Origin and Distal Intracranial Occlusion in Acute Ischemic Stroke

BACKGROUND Tandem occlusion resulting in acute ischemic stroke is associated with high morbidity and mortality and a poor response to thrombolytic therapy. The use of endovascular strategies for tandem stroke cases results in an improved outcome for this subgroup of patients. We present 2 cases with a pattern of tandem occlusion consisting of proximal obstruction at the origin of the common carotid artery (CCA) with concomitant intracranial occlusion treated by endovascular techniques. METHODS The 2 patients presented each with occlusion at the left CCA origin and ipsilateral intracranial vessel (left middle cerebral artery and carotid terminus, respectively). A transfemoral anterograde approach was used to deliver a balloon-mounted stent across the proximal CCA origin occlusion to gain access to the distal cerebral vasculature. Subsequently, a stent retriever assisted mechanical aspiration thrombectomy was used to revascularize the intracranial occlusion. RESULTS Complete revascularization with Thrombolysis in Cerebral Infarction scores of 2b and improvement in neurologic deficits occurred in both cases. Good clinical outcome was achieved for both patients at 3-month follow-up. CONCLUSIONS An anterograde transfemoral approach should be considered in cases of tandem occlusion of the proximal CCA and middle cerebral artery.

Aneurysmal subarachnoid hemorrhage with concomitant posterior communicating artery fenestration

Fenestrations of the posterior communicating artery (PCoA) are extremely rare. Associated aneurysms have only been documented three times in the literature, and none associated with a subarachnoid hemorrhage. We describe a 52-year-old female who presented with a subarachnoid hemorrhage secondary to a ruptured saccular aneurysm at the proximal limb of a fenestrated right PCoA. The patient was also found to have bilateral middle cerebral artery (MCA) aneurysms. Surgical management included surmising the etiology of the subarachnoid hemorrhage with subsequent clipping of both the right PCoA and MCA aneurysm. The potential embryological mechanisms leading to a PCoA fenestration are discussed.

Conservative management vs intervention for unruptured brain arteriovenous malformations.

Author Affiliations: Department of Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands (Kusters, Avis, Kastelein); Department of Imagelabonline and Imagelabcardiovascular, University of Amsterdam, Amsterdam, the Netherlands (de Groot); Department of Pediatrics, Academic Medical Center, Amsterdam, the Netherlands (Wijburg, Wiegman); Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam, the Netherlands (Hutten).

Diagnostic Accuracy of Somatosensory Evoked Potential Monitoring in Evaluating Neurological Complications During Endovascular Aneurysm Treatment

BACKGROUND Somatosensory evoked potential (SSEP) monitoring is used extensively for early detection and prevention of neurological complications in patients undergoing many different neurosurgical procedures. However, the predictive ability of SSEP monitoring during endovascular treatment of cerebral aneurysms is not well detailed. OBJECTIVE To evaluate the performance of intraoperative SSEP in the prediction postprocedural neurological deficits (PPNDs) after coil embolization of intracranial aneurysms. METHODS This population-based cohort study included patients ≥18 years of age undergoing intracranial aneurysm embolization with concurrent SSEP monitoring between January 2006 and August 2012. The ability of SSEP to predict PPNDs was analyzed by multiple regression analyses and assessed by the area under the receiver operating characteristic curve. RESULTS In a population of 888 patients, SSEP changes occurred in 8.6% (n = 77). Twenty-eight patients (3.1%) suffered PPNDs. A 50% to 99% loss in SSEP waveform was associated with a 20-fold increase in risk of PPND; a total loss of SSEP waveform, regardless of permanence, was associated with a greater than 200-fold risk of PPND. SSEPs displayed very good predictive ability for PPND, with an area under the receiver operating characteristic curve of 0.84 (95% CI 0.76-0.92). CONCLUSION This study supports the predictive ability of SSEPs for the detection of PPNDs. The magnitude and persistence of SSEP changes is clearly associated with the development of PPNDs. The utility of SSEP monitoring in detecting ischemia may provide an opportunity for neurointerventionalists to respond to changes intraoperatively to mitigate the potential for PPNDs.