Natalizumab-Associated Primary Central Nervous System Lymphoma.

OBJECTIVE: Natalizumab, a selective adhesion molecule inhibitor binding to an α-4 subunit of integrin, has emerged to be an effective immunomodulator, especially in the treatment of relapsing-remitting multiple sclerosis and Crohn disease. Recent reports documenting the development of primary central nervous system lymphoma (PCNSL) as a result of its administration have been concerning, and they trigger a debate about a possible causal association. In our report, we provide a comprehensive review of the literature on lymphoma development after natalizumab use, and we report an additional case of PCNSL development in a young woman who received natalizumab for her Crohn disease. METHODS: A systematic (qualitative) review of literature on lymphoma development after natalizumab therapy was performed by use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data on patient characteristics, indication for drug therapy, dosages, radiologic findings, potential risk factors for PCNSL, and tumor markers were synthesized. Additionally, we present the findings from the case of a young woman who received natalizumab therapy (4 doses, 300 mg each) for Crohn disease and in whom PCNSL developed. RESULTS: Overall, 8 reports including our index case document lymphoma development after natalizumab use. Our case finding revisits the debate suggesting a remote possibility of association that warrants further evaluation and validation. CONCLUSIONS: Evidence documenting a causal association of natalizumab and PCNSL is weak. Considering the potential benefits of using natalizumab for current indications, we recommend vigilant monitoring of patients receiving the drug for PCNSL outlook.

Placement of C1 Pedicle Screws Using Minimal Exposure: Radiographic, Clinical, and Literature Validation.

BACKGROUND: Traditional C1-2 fixation involves placement of C1 lateral mass screws. Evolving techniques have led to the placement of C1 pedicle screws to avoid exposure of the C1-C2 joint capsule. Our minimal dissection technique utilizes anatomical landmarks with isolated exposure of C2 and the inferior posterior arch of C1. We evaluate this procedure clinically and radiographically through a technical report. METHODS: Consecutive cases of cranial-vertebral junction surgery were reviewed for one fellowship trained spinal surgeon from 2008-2014. Information regarding sex, age, indication for surgery, private or public hospital, intra-operative complications, post-operative neurological deterioration, death, and failure of fusion was extracted. Measurement of pre-operative axial and sagittal CT scans were performed for C1 pedicle width and C1 posterior arch height respectively. RESULTS: 64 patients underwent posterior cranio-vertebral junction fixation surgery. 40 of these patients underwent occipital-cervical fusion procedures. 7/9 (77.8%) C1 instrumentation cases were from trauma with the remaining two (22.2%) from oncologic lesions. The average blood loss among isolated C1-C2 fixation was 160cc. 1/9 patients (11.1%) suffered pedicle breech requiring sub-laminar wiring at the C1 level. On radiographic measurement, the average height of the C1 posterior arch was noted at 4.3mm (range 3.8mm to 5.7mm). The average width of the C1 pedicle measured at 5.3mm (range 2.8 to 8.7mm). The patient with C1 pedicle screw failure had a pedicle width of 2.78mm on pre-operative axial CT imaging. CONCLUSION: Our study directly adds to the literature with level four evidence supporting a minimal dissection of C1 arch in the placement of C1 pedicle screws with both radiographic and clinical validation. CLINICAL RELEVANCE: Justification of this technique avoids C2 nerve root manipulation or sacrifice, reduces bleeding associated with the venous plexus, and leaves the third segment of the vertebral artery unexplored. Pre-operative review of imaging is critical in the placement of C1-C2 instrumentation.

National trends of incidence, treatment, and hospital charges of isolated C-2 fractures in three different age groups.

OBJECT: Incidence of C-2 fracture is increasing in elderly patients. Patient age also influences decision making in the management of these fractures. There are very limited data on the national trends of incidence, treatment interventions, and resource utilization in patients in different age groups with isolated C-2 fractures. The aim of this study is to investigate the incidence, treatment, complications, length of stay, and hospital charges of isolated C-2 fracture in patients in 3 different age groups by using the Nationwide Inpatient Sample (NIS) database. METHODS: The data were obtained from NIS from 2002 to 2011. Data on patients with closed fractures of C-2 without spinal cord injury were extracted using ICD-9-CM diagnosis code 805.02. Patients with isolated C-2 fractures were identified by excluding patients with other associated injuries. The cohort was divided into 3 age groups: < 65 years, 65-80 years, and > 80 years. Incidence, treatment characteristics, inpatient/postoperative complications, and hospital charges (mean and total annual charges) were compared between the 3 age groups. RESULTS: A total of 10,336 patients with isolated C-2 fractures were identified. The majority of the patients were in the very elderly age group (> 80 years; 42.3%) followed by 29.7% in the 65- to 80-year age group and 28% in < 65-year age group. From 2002 to 2011, the incidence of hospitalization significantly increased in the 65- to 80-year and > 80-year age groups (p < 0.001). However, the incidence did not change substantially in the < 65-year age group (p = 0.287). Overall, 21% of the patients were treated surgically, and 12.2% of the patients underwent nonoperative interventions (halo and spinal traction). The rate of nonoperative interventions significantly decreased over time in all age groups (p < 0.001). Regardless of treatment given, patients in older age groups had a greater risk of inpatient/postoperative complications, nonroutine discharges, and longer hospitalization. The mean hospital charges were significantly higher in older age groups (p < 0.001). CONCLUSIONS: The incidence of hospitalization for isolated C-2 fractures is progressively increasing in older age groups. Simultaneously, there has been a steadily decreasing trend in the preference for nonoperative interventions. Due to more complicated hospital stay, longer hospitalizations, and higher rates of nonroutine discharges, the patients in older age groups seem to have a higher propensity for greater health care resource utilization.

Traumatic injury to the posterior fossa.

Traumatic injury to the posterior fossa is a complex pathologic condition because of the great heterogeneity of lesions present. Treatment of primary brain injuries and prevention of secondary brain injuries is the mainstay of management. It is imperative to recognize traumatic lesions of the posterior fossa early because of the occurrence of rapid neurologic decline. The decision regarding whether or not to proceed with surgical intervention depends on the patient's clinical condition, neurologic status, and imaging findings. Nonoperative management should be considered only if the patient is fully conscious and the associated posterior fossa lesions are small with little or no mass effect.

The utility and limitations of intraoperative near-infrared indocyanine green videoangiography in aneurysm surgery.

OBJECTIVE: To analyze the clip repositioning rate and the correlation between indocyanine green (ICG) videoangiography and conventional postoperative digital subtraction angiography for completeness of aneurysm occlusion and parent and branching vessel compromise. METHODS: This retrospective study included 112 patients with 126 aneurysms who underwent microsurgical clipping and ICG videoangiography during aneurysm surgery at a single center from January 2008 to June 2013. Age, gender, aneurysm size, location, and rupture status were included in the model for analysis. RESULTS: In 10 patients (8%), ICG videoangiography resulted in clip repositioning during surgery. Discordance between ICG videoangiography and postoperative angiography was observed in 5 patients (4%). There was no significant difference of ICG videoangiography-postoperative angiography discordance between ruptured and unruptured aneurysms (P = 0.56). On multivariate analysis, patient age, gender, aneurysm size, and rupture status did not reach significance. Ophthalmic internal carotid artery aneurysms were more likely to have discordance compared with all other aneurysms (P = 0.04; odds ratio, 10.8; confidence interval, 1.5-75.94). CONCLUSIONS: ICG videoangiography is a very useful modality for intraoperative assessment of the adequacy of aneurysmal obliteration and patency of parent and perforating vessels. However, ICG videoangiography is not absolutely reliable as a stand-alone method during clipping of ophthalmic artery aneurysms and can be complemented with intraoperative digital subtraction angiography. ICG videoangiography can be used either as an alternative or as a complementary technique to intraoperative digital subtraction angiography during aneurysm surgery.

Vagal nerve stimulation for the treatment of medically refractory epilepsy: a review of the current literature.

OBJECT: The authors conducted a study to evaluate the published results of vagal nerve stimulation (VNS) for medically refractory seizures according to evidence-based criteria. METHODS: The authors performed a review of available literature published between 1980 and 2010. Inclusion criteria for articles included more than 10 patients evaluated, average follow-up of 1 or more years, inclusion of medically refractory epilepsy, and consistent preoperative surgical evaluation. Articles were divided into 4 classes of evidence according to criteria established by the American Academy of Neurology. RESULTS: A total of 70 publications were reviewed, of which 20 were selected for review based on inclusion and exclusion criteria. There were 2 articles that provided Class I evidence, 7 that met criteria for Class II evidence, and 11 that provided Class III evidence. The majority of evidence supports VNS usage in partial epilepsy with a seizure reduction of 50% or more in the majority of cases and freedom from seizure in 6%-27% of patients who responded to stimulation. High stimulation with a gradual increase in VNS stimulation over the first 6 weeks to 3 months postoperatively is well supported by Class I and II data. Predictors of positive response included absence of bilateral interictal epileptiform activity and cortical malformations. CONCLUSIONS: Vagal nerve stimulation is a safe and effective alternative for adult and pediatric populations with epilepsy refractory to medical and other surgical management.