Response to Preoperative Dexamethasone Predicts Postoperative Neurological Improvement of Focal Neurological Deficits in Patients With Brain Metastases.

BACKGROUND: Steroids are used ubiquitously in the preoperative management of patients with brain tumor. The rate of improvement in focal deficits with steroids and the prognostic value of such a response are not known. OBJECTIVE: To determine the rate at which focal neurological deficits respond to preoperative corticosteroids in patients with brain metastases and whether such an improvement could predict long-term recovery of neurological function after surgery. METHODS: Patients with brain metastases and related deficits in language, visual field, or motor domains who received corticosteroids before surgery were identified. Characteristics between steroid responders and nonresponders were compared. RESULTS: Ninety six patients demonstrated a visual field (13 patients), language (19), or motor (64) deficit and received dexamethasone in the week before surgery (average cumulative dose 43 mg; average duration 2.7 days). 38.5% of patients' deficits improved with steroids before surgery, while 82.3% of patients improved by follow-up. Motor deficits were more likely to improve both preoperatively ( P = .014) and postoperatively ( P = .010). All 37 responders remained improved at follow-up whereas 42 of 59 (71%) of nonresponders ultimately improved ( P < .001). All other clinical characteristics, including dose and duration, were similar between groups. CONCLUSION: A response to steroids before surgery is highly predictive of long-term improvement postoperatively in brain metastasis patients with focal neurological deficits. Lack of a response portends a somewhat less favorable prognosis. Duration and intensity of therapy do not seem to affect the likelihood of response.

Treatment of L5-S1 spondyloptosis with stand-alone anterior lumbar interbody fusion in a patient with neurofibromatosis.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystem disorder that causes multiple tumor formations throughout the nervous system. Common spinal dysplasias seen with NF1, such as dural ectasia (DE), often undergo modulation and predispose these patients to spondylolisthesis, making surgical treatment challenging. CASE DESCRIPTION: A patient with NF1 presented with a 12-year-history of back and left lower extremity radicular pain. Lumbar spine magnetic resonance imaging revealed developmental anomalies with severe DE and associated scalloping of the L4-S1 vertebral bodies and severe L5-S1 Meyerding grade 4 spondylolisthesis. During surgery, post-positioning x-rays demonstrated a grade 5 spondyloptosis. The patient underwent an L5-S1 stand-alone anterior lumbar interbody fusion (ALIF). The final construct was an ALIF cage with one screw into S1, without an anterior plate. By 3-months post-operative, there was complete resolution of preoperative symptoms and at 2 year follow-up the patient was asymptomatic with stable hardware and solid bony fusion. To the authors' knowledge, this is the first report of spondyloptosis treated with a stand-alone ALIF in a patient with NF1 and severe DE.

Updates on techniques and technology to optimize external ventricular drain placement: A review of the literature.

External ventricular drainage is a common and invaluable neurosurgical procedure and is one of the first procedures learned and performed independently by neurosurgical residents. As accuracy and precision are paramount to EVD placement, attention to technique is paid early in a resident's training. With the advancement of virtual technology, it has become increasingly possible to move away from traditional training situations and human error, and towards automated assistance and superior cyber learning environments. Although there is significant room for improvement, there are promising results with computerized placement guides and virtually augmented practice. Here, we provide a review of the updates on EVD placement techniques, technology and training, all of which serve to improve the precision, accuracy and efficiency of EVD placement.

Changing Hands: A Rising Role of the Tumor Surgeon in Teaching Sylvian Fissure Dissection.

OBJECTIVE: The landscape of microneurosurgery has changed considerably over the past 2 decades, with a decline in indications for open surgery on cerebrovascular pathology and ever-increasing indications for open resection of brain tumors. This study investigated how these trends in case volume affected residents' training experiences in microsurgery and, specifically, Sylvian fissure dissection. METHODS: Resident case logs were reviewed, identifying open cerebrovascular operations and craniotomies for tumor. Operations involving Sylvian fissure dissection were identified through operative reports. Changes in case number by resident were plotted over time, and linear regression was applied. RESULTS: Among 23 chief residents, 3045 operations were identified, 1071 of which were for cerebrovascular pathology and 1974 for tumor. Open cerebrovascular experience decreased (P < 0.0001) while tumor volume remained unchanged (P = 0.221). The number of Sylvian fissure dissections per resident did not change over time overall (P = 0.583) or within cerebrovascular operations (P = 0.071). The number of Sylvian fissure dissections in tumor operations increased (P = 0.004). This effect was predominated by an increase in intraaxial tumors approached via Sylvian fissure dissection (P = 0.003). The proportion of Sylvian fissure dissections in tumor surgery increased from 15% in 2009 to 34% by 2019 (P = 0.003). CONCLUSIONS: Residents are seeing an increasing proportion of their Sylvian fissure dissection experience during tumor operations. The distribution of this experience will continue to evolve as surgical indications change but suggests a growing role for tumor surgeons in resident training in microsurgery.

Combined magnetic field results in higher fusion rates than pulsed electromagnetic field bone stimulation after thoracolumbar fusion surgery.

BACKGROUND: Bone growth stimulators have been used as an adjunct to spinal fusion surgery in efforts to increase fusion rates. METHODS: The authors retrospectively reviewed the medical records of patients who underwent thoracolumbar fusion surgeries by a single surgeon. Patients were then separated into three groups; pulsed electromagnetic field stimulation (PEMF), combined magnetic field stimulation (CMF) or no stimulation (NS), and computed tomography radiographic results at least 1 year after surgery were compared (solid fusion, stable nonunion, and pseudarthrosis). RESULTS: A total of 60 patients were included; 16 (26.7%) used PEMF, 24 (40.0%) used CMF, and 20 (33.3%) had NS. There were no significant differences in patient demographics. There was no difference in the mean fusion levels (p = 0. 477). Solid fusion was achieved in 11/16 (68.8%) PEMF, 21/24 (87.5%) CMF, and 20/20 (100.0%) NS patients. Stable nonunion was displayed in 2/24 (8.3%) CMF, and zero PEMF and NS patients. There were 5/16 (31.3%) PEMF, 1/24 (4.2%) CMF, and zero NS patients demonstrating radiologic pseudarthrosis. There was a statistically significant difference between PEMF and CMF (p = 0.017) and between PEMF and NS (p = 0.006) groups. No statistical difference was found between CMF and NS (p = 1.000). CONCLUSION: This is the first study to compare PEMF and CMF bone growth stimulators in patients with degenerative pathologies who underwent thoracolumbar spinal fusions. Overall, the addition of these bone growth stimulators does not improve fusion outcomes, although CMF appears superior to PEMF.

PEEK interbody devices for multilevel anterior cervical discectomy and fusion: association with more than 6-fold higher rates of pseudarthrosis compared to structural allograft.

OBJECTIVE: Common interbody graft options for anterior cervical discectomy and fusion (ACDF) include allograft and polyetheretherketone (PEEK). PEEK has gained popularity due to its radiolucent properties and a modulus of elasticity similar to that of bone. PEEK devices also result in higher billing costs than allograft, which may drive selection. A previous study found a 5-fold higher rate of pseudarthrosis with the use of PEEK devices compared with structural allograft in single-level ACDF. Here the authors report on the occurrence of pseudarthrosis with PEEK devices versus structural allograft in patients who underwent multilevel ACDF. METHODS: The authors retrospectively reviewed 81 consecutive patients who underwent a multilevel ACDF and had radiographic follow-up for at least 1 year. Data were collected on age, sex, BMI, tobacco use, pseudarthrosis, and rate of reoperation for pseudarthrosis. Logistic regression was used for data analysis. RESULTS: Of 81 patients, 35 had PEEK implants and 46 had structural allograft. There were no significant differences between age, sex, smoking status, or BMI in the 2 groups. There were 26/35 (74%) patients with PEEK implants who demonstrated radiographic evidence of pseudarthrosis, compared with 5/46 (11%) patients with structural allograft (p < 0.001, OR 22.2). Five patients (14%) with PEEK implants required reoperation for pseudarthrosis, compared with 0 patients with allograft (p = 0.013). CONCLUSIONS: This study reinforces previous findings on 1-level ACDF outcomes and suggests that the use of PEEK in multilevel ACDF results in statistically significantly higher rates of radiographic pseudarthrosis and need for revision surgery than allograft. Surgeons should consider these findings when determining graft options, and reimbursement policies should reflect these discrepancies.

Sympathectomy via a posterior approach after a failed trans-thoracic approach: a case of its use for arrhythmia.

OBJECTIVE: Congenital long QT syndrome (LQTS) provides an opportunity for neurosurgical intervention. Medication and implantable cardiac defibrillator (ICD)-refractory patients often require left cardiac sympathetic denervation (LCSD) via anterior video-assisted thoracoscopic surgery (VATS). However, this approach has major pulmonary contraindications and risks, with a common concern in children being their inability to tolerate single-lung ventilation. At Oregon Health & Science University, the authors have developed a posterior approach-extrapleural, minimally invasive, T1-5 LCSD-that minimizes this risk. METHODS: A 9-year-old girl with LQTS type III presented to the emergency department while experiencing ventricular tachycardia (VT) and ventricular fibrillation (VF) with multiple ICD firings. Medical management failed to resolve the VF/VT. VATS was attempted but could not be safely performed due to respiratory insufficiency. The patient was reintubated for dual-lung ventilation and repositioned prone. Her respiratory insufficiency resolved. Using METRx serial dilating tubes under the microscope, the left T1-5 sympathetic ganglia were sectioned and removed. RESULTS: Postoperatively, the patient had no episodes of VF/VT, pneumothorax, hemothorax, or Horner syndrome. With mexiletine and propranolol, she has remained largely VF/VT free, with only one VT episode during the 2-year follow-up period. CONCLUSIONS: Minimally invasive, posterior, extrapleural, T1-5 LCSD is safe and effective for treating congenital LQTS in children, while minimizing the risks associated with VATS.