A case series of atypical features of patients with biopsy-proven isolated IgG4-related hypophysitis and normal serum IgG4 levels.

BACKGROUND: IgG4-related hypophysitis is a rare clinical entity that forms part of an emerging group of multi-organ IgG4-related fibrosclerotic systemic diseases. The rare prevalence of the disease, presenting features that overlap with other sellar pathologies, and variable imaging features can make preoperative identification challenging. PURPOSE AND METHODS: We report three cases of isolated IgG4-related hypophysitis with atypical clinical and imaging features that mimicked those of pituitary apoplexy and other sellar lesions. Additionally, we review the literature of IgG4-related hypophysitis to provide context for individual patient data described herein. RESULTS: All patients presented with symptoms that mimicked those of pituitary apoplexy and visual disturbance, and MRI findings suggestive of pituitary macroadenoma, Rathke's cleft cyst and craniopharyngioma. The clinical presentation warranted surgical decompression, resulting in rapid symptomatic improvement. Preoperative high-dose followed by postoperative low-dose glucocorticoid replacement therapy was administered in all cases. Histopathology showed dense infiltrate of IgG4 cells. Post-operative follow-up monitoring for 12-26 months revealed normal serum IgG4 levels with no other organ involvement, while endocrinological testing revealed persistent pituitary hormone deficiencies. CONCLUSIONS: Our cases highlight the importance of considering IgG4-related hypophysitis in the differential diagnosis of solid and cystic sellar lesions presenting acutely with pituitary apoplexy symptoms. Existing diagnostic criteria may not be sufficiently precise to permit rapid and reliable identification, or avoidance of surgery in the acute setting. In contrast to other reports of the natural history of this condition, despite the severity of presenting features, the disease in our cases was pituitary-restricted with normal serum IgG4 levels.

The utility of high-resolution intraoperative MRI in endoscopic transsphenoidal surgery for pituitary macroadenomas: early experience in the Advanced Multimodality Image Guided Operating suite.

OBJECTIVE: Endoscopic skull base surgery has become increasingly popular among the skull base surgery community, with improved illumination and angled visualization potentially improving tumor resection rates. Intraoperative MRI (iMRI) is used to detect residual disease during the course of the resection. This study is an investigation of the utility of 3-T iMRI in combination with transnasal endoscopy with regard to gross-total resection (GTR) of pituitary macroadenomas. METHODS: The authors retrospectively reviewed all endoscopic transsphenoidal operations performed in the Advanced Multimodality Image Guided Operating (AMIGO) suite from November 2011 to December 2014. Inclusion criteria were patients harboring presumed pituitary macroadenomas with optic nerve or chiasmal compression and visual loss, operated on by a single surgeon. RESULTS: Of the 27 patients who underwent transsphenoidal resection in the AMIGO suite, 20 patients met the inclusion criteria. The endoscope alone, without the use of iMRI, would have correctly predicted extent of resection in 13 (65%) of 20 cases. Gross-total resection was achieved in 12 patients (60%) prior to MRI. Intraoperative MRI helped convert 1 STR and 4 NTRs to GTRs, increasing the number of GTRs from 12 (60%) to 16 (80%). CONCLUSIONS: Despite advances in visualization provided by the endoscope, the incidence of residual disease can potentially place the patient at risk for additional surgery. The authors found that iMRI can be useful in detecting unexpected residual tumor. The cost-effectiveness of this tool is yet to be determined.

The future of practice science: challenges and opportunities for neurosurgery.

Outcomes-directed approaches to quality improvement have been adopted by diverse industries and are increasingly the focus of government-mandated reforms to health care education and delivery. The authors identify and review current reform initiatives originating from agencies regulating and funding graduate medical education and health care delivery. These reforms use outcomes-based methodologies and incorporate principles of lifelong learning and patient centeredness. Important new initiatives include the Accreditation Council for Graduate Medical Education Milestones; the pending adoption by the American Board of Neurological Surgery of new requirements for Maintenance of Certification that are in part outcomes based; initiation by health care systems and consortia of public reporting of patient outcomes data; institution by the Centers for Medicare & Medicaid Services of requirements for comparative effectiveness research and the physician quality reporting system; and linking of health care reimbursement in part to patient outcomes data and quality measures. Opportunities exist to coordinate and unify patient outcomes measurement throughout neurosurgical training and practice, enabling effective patient-centered improvements in care delivery as well as efficient compliance with regulatory mandates. Coordination will likely require the development of a new science of practice based in the daily clinical environment and utilizing clinical data registries. A generation of outcomes science and quality experts within neurosurgery should be trained to facilitate attainment of these goals.

The ABC's of Spinal Decompression: Pearls and Technical Notes.

OBJECTIVE: The foundation of spine surgery centers on the proper identification, decompression, and stabilization of bony and neural elements. We describe easily reproducible and reliable methods for optimal decompression and release of neural structures to alleviate symptoms and improve patients' quality of life. METHODS: Multiple spinal decompression techniques were described in procedures for which the goal of surgery was decompression alone or decompression and fusion. Eight fundamental techniques were described: inverted U-cut, J-cut, T-cut, L-cut, Z-cut, I-track cuts, C-cut, and O-cut. RESULTS: These foundational cuts may be combined, as needed, to develop an individually tailored approach to the patient's pathology. CONCLUSIONS: After properly identifying the anatomic structures, each of these techniques provides a consistent, reproducible, and efficient means to decompress the spine under various circumstances. These techniques provide surgical trainees with a framework for approaching surgical decompression.

Self-inflicted nail-gun injury with 12 cranial penetrations and associated cerebral trauma. Case report and review of the literature.

In this case report, the authors describe a 33-year-old man who presented with headache due to the presence of 12 nail-gun nails impacted in his cranium and cerebral parenchyma. The authors also review the relevant literature regarding penetrating brain injury. The patient's physical examination revealed a Glasgow Coma Scale score of 15 and impairment of abduction of the right eye and abduction of the jaw producing dysarthria; the remaining results of the neurological examination were normal. Both x-ray films and computerized tomography (CT) scans of the head revealed the presence of 12 nails, the majority of which were located intracranially. A scattering artifact limited the ability of CT scanning to demonstrate any intracranial hemorrhage. Angiography did not demonstrate any evidence of traumatic vascular injury. After general anesthesia had been induced in the patient, the nails were removed in the operating room. Following removal of the final nail, a small left temporal craniotomy was performed to control hemorrhage from a tear in the left middle meningeal artery. Despite the development of a postoperative insular hematoma, the patient was discharged home with minimal deficits. This patient is the only known survivor of the largest number of foreign objects (12) to penetrate the skull intentionally. Overall, self-inflicted nail-gun injuries are less common than accidental discharges. A review of the literature, however, suggests that for penetrating brain injury, self-infliction is the more common mechanism. For those patients who survive such an injury, clinical decision making must focus on preventing further cortical or vascular damage. A rational management strategy should permit these patients to be discharged with no additional injury.

Magnetic resonance approaches to brain aging and Alzheimer disease-associated neuropathology.

The noninvasive, nonradioactive, quantitative nature of magnetic resonance techniques has propelled them to the forefront of neuroscience and neuropsychiatric research. In particular, recent advances have confirmed their enormous potential in patients with Alzheimer disease (AD). Structural and functional magnetic resonance (MR) imaging have demonstrated significant correlation with clinical outcomes and underlying pathology and are used increasingly in the AD clinic. This review will highlight the role of high-resolution structural MR imaging and functional magnetic resonance imaging in the identification of atrophic and hemodynamic changes in AD and their potential as diagnostic biomarkers and surrogates of therapeutic response. Advanced MR techniques based on diffusion, perfusion, and neurochemical abnormalities in the aging brain will be presented briefly. These newer techniques continue to expand our understanding of neuropathology in the aging brain and are likely to play an important clinical role in the future.

Preservation of functional hearing after gamma knife surgery for vestibular schwannoma.

OBJECT: The goal of this retrospective study was to define the rates of preservation of functional hearing and growth control of vestibular schwannomas (VS) treated by gamma knife surgery (GKS) involving a consistent 12-Gy prescription dose. METHODS: One hundred thirty-four patients with unilateral VS underwent GKS between 1994 and 2000. The mean magnetic resonance (MR) imaging follow-up period was 31.7 months (maximum 72 months), and the mean audiometry follow-up interval was 26.3 months (maximum 60 months). The mean marginal dose was 12 +/- 0.6 Gy. The mean maximum dose delivered to the tumor center was 25.4 Gy (range 17.4-34.3 Gy). The tumor control rate, defined as no change or a reduction in size at last follow up, was 96.7%. Of the patients studied, 97.7% remained free from the need to undergo tumor resection. Overall functional hearing preservation was 61.7%; the preservation rate for intracanalicular tumors was 63.6%, for those with an intracranial diameter less than 1.5 cm it was 54.5%, for those between 1.5 and 3 cm it was 68.2%, and for those larger than 3 cm it was 33.3%. Early in the series, three patients (2.2%) developed temporary facial weakness (House-Brackmann Grade II-III) in the posttreatment period, but this resolved within a few weeks. No case of facial weakness occurred after 1996. CONCLUSIONS: The authors demonstrated the efficacy, safety, and in many ways, the advantage of GKS over microsurgery for VS. Patients harboring tumors 3 cm or smaller in intracranial diameter, regardless of their age and medical condition, should be given the option of undergoing GKS as primary treatment.

Dura splitting decompression for Chiari I malformation in pediatric patients: clinical outcomes, healthcare costs, and resource utilization.

BACKGROUND: Dural splitting decompression may be an effective and safe treatment for Chiari I malformation. OBJECTIVE: To compare clinical outcomes, complications, and resource utilization for patients undergoing Chiari I decompression with or without duraplasty. METHODS: Between 2000 and 2009, the senior author performed 113 Chiari I decompression operations with dural splitting or duraplasty in children less than 18 years of age; 110 were included in a retrospective cohort analysis of safety, efficacy, and treatment cost. Patients without significant syringomyelia underwent dural splitting decompression, and patients with syringomyelia underwent duraplasty. RESULTS: : Sixty-three patients without significant syringomyelia (57%) underwent dural splitting decompression. They were significantly younger than patients undergoing duraplasty (8.3 ± 4.9 years vs 10.4 ± 4.4 years; P < .05). Headaches improved or resolved in most patients in both groups (90.5% vs 93.6%; P = .59). Dysphagia, long tract signs, cranial nerve, and bulbar symptoms also improved similarly in both groups. Three duraplasty patients were treated medically for aseptic meningitis; one underwent reoperation for a symptomatic pseudomeningocele. No patient undergoing dural splitting decompression experienced a cerebrospinal fluid-related complication. Extradural decompression required less operative time than duraplasty (105.5 vs 168.9 minutes, P < .001), a shorter length of stay (2.4 vs 2.8 days, P = .011), and lower total cost for the primary hospitalization ($26 837 vs $29 862, P = .015). CONCLUSION: In this retrospective cohort study, dural splitting decompression was equally effective, safer, and lower cost for treatment of Chiari I malformation without syringomyelia. A multicenter trial with groups balanced for the presence of syringomyelia is necessary to determine whether these results are generalizable.

Indocyanine green fluorescence endoscopy for visual differentiation of pituitary tumor from surrounding structures.

OBJECT: As demonstrated by histological and neuroimaging studies, pituitary adenomas have a capillary vascular density that differs significantly from that of surrounding structures. The authors hypothesized that intraoperative indocyanine green (ICG) fluorescence endoscopy could be used to visually differentiate tumor from surrounding tissues, including normal pituitary gland and dura. METHODS: After institutional review board approval, 16 patients undergoing endoscopic transsphenoidal surgery for benign pituitary lesions were prospectively enrolled in the study. A standard endoscopic endonasal approach to the sella was completed. Each patient then underwent endoscopic examination of the sellar dura and then the exposed pituitary adenoma after ICG bolus injection (12.5-25 mg). This examination was performed using a custom endoscope with a near-infrared light source and excitation wavelength filter. RESULTS: The authors successfully recorded ICG fluorescence from sellar dura, pituitary, and surrounding structures in 12 of 16 patients enrolled. There were 3 technical failures of intraoperative ICG endoscopy, and 1 patient was excluded following discovery of a dye cross-allergy. A standard dose of 25 mg of ICG in 10 ml of aqueous solution optimized visualization of sellar region microvasculature within 45 seconds of peripheral bolus injection. Adenoma was less fluorescent than normal pituitary gland. Dural invasion by tumor was identifiable by a marked increase in fluorescence compared with native dura. The ICG endoscopic examination added 15-20 minutes of operative time under general anesthesia. There were no complications that resulted from use of ICG or the fluorescent light source. CONCLUSIONS: Indocyanine green fluorescence endoscopy shows promise as an intraoperative modality to visually distinguish pituitary tumors from normal tissue and to visually identify areas of dural invasion, thereby facilitating complete tumor resection and minimizing injury to surrounding structures. These results support the continued development of fluorescence endoscopic resection techniques.

Successful ventricle to direct heart shunt placement as a salvage cerebrospinal fluid diversion technique. Case report.

The authors report a complex case in a 35-year-old woman who underwent shunt placement at birth for myelomeningocele. She had previously undergone more than 30 shunt revisions, with placement of the distal catheter in the peritoneum multiple times, and also in the pleura, the gall bladder, and the upper venous system. All shunts had failed and the possible placement sites were now anatomically hostile. A median sternotomy was performed as the next option. The catheter was placed directly into the appendage of the right atrium and secured with a pursestring suture. One month postoperatively, the patient presented with a large pericardial effusion after the distal catheter migrated out of the atrium and into the pericardial space. A repeat sternotomy was performed to drain the pericardial CSF collection. The catheter was reinserted into the atrial appendage, and a tunnel was created in the atrial wall to fix the device more securely. At 1 year postoperatively, the patient had no further symptoms of shunt obstruction or cardiac tamponade, and imaging studies suggested that the shunt system was functional. The authors report the first successful ventricle to direct heart shunt in an adult.

Dural augmentation: part I-evaluation of collagen matrix allografts for dural defect after craniotomy.

OBJECTIVE: Primary closure of the dura remains difficult in many neurosurgical cases. One option for dural grafting is the collagen sponge, which is available in multiple forms, namely, monolayer collagen and bilayer collagen. Our primary goal was to assess differences in the incidence of postoperative cerebrospinal fluid (CSF) leak, including fistula and pseudomeningocele, and postoperative infection between monolayer collagen and bilayer collagen grafts. METHODS: A single-center retrospective analysis of 475 consecutive neurosurgical procedures was performed. Primary endpoints were CSF leak and infection, adjusting for the impact of additional nonautologous materials. Multivariate regression analysis was used to identify predictors of postoperative CSF leak and infection. RESULTS: The overall frequency of postoperative CSF leak was 6.7%. There was no significant difference in the incidence of CSF leak based on the type of collagen sponge (monolayer versus bilayer) used (5.5% versus 7.5%, respectively; P = 0.38). The overall frequency of postoperative infection was 4.2%. There was no significant difference in the incidence of infection between groups (4.9% versus 3.8%; P = 0.54). Bilayer sponges were associated with a significantly lower incidence of CSF leak than monolayer sponges (odds ratio, 0.09; 95% confidence interval, 0.01-0.73). CONCLUSION: Bilayer collagen sponges are associated with a reduction in postoperative CSF leak, notably in posterior fossa surgery. The need for additional non-native materials is predictive of postoperative CSF leak, along with location and type of procedure. Intrinsic patient characteristics (e.g., age, diabetes, smoking) do not seem to affect the efficacy of collagen sponge dural grafts.

Neuromonitoring in neurological critical care.

In this article, we review technologies available for direct monitoring of cerebral oxygenation and metabolic status, including jugular venous oxygen saturation, brain tissue oxygen tension, transcranial cerebral oximetry with near-infrared spectroscopy, Positron emission tomography oxidative metabolism, single-photon emission computed tomography/computed tomography perfusion and functional imaging, and cerebral metabolite measurement using microdialysis. We also introduce a novel method of monitoring cerebral perfusion that may substitute for direct monitoring of oxygenation in the future.