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BACKGROUND: Retrobulbar hemangioblastomas involving the optic apparatus in patients with von Hippel-Lindau disease (VHL) are rare, with only 25 reported cases in the literature. OBJECTIVE: To analyze the natural history of retrobulbar hemangioblastomas in a large cohort of VHL patients in order to define presentation, progression, and management. METHODS: Clinical history and imaging of 250 patients with VHL in an ongoing natural history trial and 1774 patients in a neurosurgical protocol were reviewed. The clinical course, magnetic resonance images, treatment, and outcomes were reviewed for all included patients. RESULTS: A total of 18 patients with retrobulbar hemangioblastoma on surveillance magnetic resonance imaging met the inclusion criteria for this study. Of the 17 for whom clinical information was available, 10 patients presented with symptoms related to the hemangioblastoma, and 7 were asymptomatic. The mean tumor volume was larger for symptomatic (810.6 ± 545.5 mm(3)) compared to asymptomatic patients (307.6 ± 245.5 mm(3); P

Background The origin of syrinx fluid is controversial. Objective To elucidate the mechanisms of syringomyelia associated with cerebrospinal fluid pathway obstruction and with intramedullary tumors, contrast transport from the spinal subarachnoid space (SAS) to syrinx was evaluated in syringomyelia patients. Methods We prospectively studied patients with syringomyelia: 22 with Chiari I malformation and 16 with SAS obstruction-related syringomyelia before and 1 wk after surgery, and 9 with tumor-related syringomyelia before surgery only. Computed tomography-myelography quantified dye transport into the syrinx before and 0.5, 2, 4, 6, 8, 10, and 22 h after contrast injection by measuring contrast density in Hounsfield units (HU). Results Before surgery, more contrast passed into the syrinx in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia than in tumor-related syringomyelia, as measured by (1) maximum syrinx HU, (2) area under the syrinx concentration-time curve (HU AUC), (3) ratio of syrinx HU to subarachnoid cerebrospinal fluid (CSF; SAS) HU, and (4) AUC syrinx/AUC SAS. More contrast (AUC) accumulated in the syrinx and subarachnoid space before than after surgery. Conclusion Transparenchymal bulk flow of CSF from the subarachnoid space to syrinx occurs in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia. Before surgery, more subarachnoid contrast entered syringes associated with CSF pathway obstruction than with tumor, consistent with syrinx fluid originating from the subarachnoid space in Chiari I malformation and spinal obstruction-related syringomyelia and not from the subarachnoid space in tumor-related syringomyelia. Decompressive surgery opened subarachnoid CSF pathways and reduced contrast entry into syringes associated with CSF pathway obstruction.

Background Cauda equina hemangioblastomas in von Hippel-Lindau (VHL) disease can cause significant neurological signs and symptoms. Despite their associated morbidity, the management of these tumors remains incompletely defined. Objective To determine optimal management, we analyzed the functional outcomes after resection of these tumors. Methods VHL patients who underwent surgical resection of cauda equina hemangioblastomas at the National Institutes of Health and the University of Virginia were included. Clinical and radiological follow-up was performed at 6- to 12-month intervals after surgery. Results Fifteen patients underwent 18 operations for 21 cauda equina hemangioblastomas (median follow-up 5.9 years). Patients often presented with multiple symptoms, including pain (67%), numbness (50%), urinary complaints (33%), and weakness (11%). Median preoperative tumor volume was 1.2 cm 3 . Four tumors at 3 operations were not resected due to a motor nerve root origin. Gross total resection was achieved in 14 surgeries (93% of operations when resection was attempted). New mild (non-function limiting) neurological symptoms were noted after 11 operations (61%), which most often (64%) resolved within 2 weeks of surgery. At 6-month follow-up, 15 patients (83%) were stable, 2 (11%) were improved, and 1 (6%) was worse. Histological analysis revealed that all tumors originated from within the involved nerve fascicle. Conclusions VHL-associated cauda equina hemangioblastomas have an intrafascicular origin and require interruption of the rootlet of origin for complete resection. Motor nerve root involvement may preclude complete resection but strategies including bony decompression and/or interruption of vascular supply may provide a therapeutic option. Nevertheless, most VHL patients with symptom-producing lesions improve with resection.

BACKGROUND Carney complex (CNC) is a familial neoplasia syndrome that is associated with pituitary-associated hypersecretion of growth hormone (GH) (acromegaly). The underlying cause of pituitary GH hypersecretion and its management have been incompletely defined. OBJECTIVE To provide biological insight into CNC-associated pituitary pathology and improve management, we analyzed findings in CNC patients who underwent transsphenoidal surgery. METHODS Consecutive CNC patients at the National Institutes of Health with acromegaly and imaging evidence of a pituitary adenoma(s) who underwent transsphenoidal resection of tumor(s) were included. Prospectively acquired magnetic resonance imaging and biochemical, surgical, and histological data were analyzed. RESULTS Seven acromegalic CNC patients (2 male, 5 female) were included. The mean age at surgery was 29.7 years (range, 18-44 years). The mean follow-up was 4.7 years (range, 0.2-129 months). Magnetic resonance imaging revealed a single pituitary adenoma in 4 patients and multiple pituitary adenomas in 3 patients. Whereas patients with single discrete pituitary adenomas underwent selective adenomectomy, patients with multiple adenomas underwent selective adenomectomy of multiple tumors, as well as partial or total hypophysectomy. All adenomas were either GH and prolactin positive or exclusively prolactin positive. Pituitary tissue surrounding the adenomas in patients with multiple adenomas revealed hyperplastic GH- and prolactin-positive tissue. CONCLUSION CNC-associated acromegaly results from variable pituitary pathology, including a single GH-secreting adenoma or multiple GH-secreting adenomas and/or GH hypersecretion of the pituitary gland surrounding multiple adenomas. Although selective adenomectomy is the preferred treatment for cases of GH-secreting adenomas, multiple adenomas with associated pituitary gland GH hypersecretion may require partial or complete hypophysectomy to achieve biochemical remission.

In times of fiscal and political uncertainty, philanthropy has become an increasingly important mechanism for building, maintaining, and expanding neurosurgical research programs. Although philanthropy has historically helped launch many hospital systems, scientists and clinicians have generally relied on government grants and industry investment to support research and program infrastructure. However, competition for funds from all sources has increased at the same time as the pipelines for those funds have eroded. Philanthropy can provide salary support to allow neurosurgeons to pursue research and, ultimately, advance the field to improve outcomes for patients. Funds raised can fill financial gaps to recruit and pay for needed research staff, equipment, and facilities. To foster charitable giving, institutions can develop both a culture and processes to promote and support philanthropy. Furthermore, it is essential to ensure that donor relationships are properly nurtured with ongoing stewardship. In addition to cultivating grateful patients, there are numerous creative models of fundraising for research that can be explored, including venture philanthropy, in which voluntary health organizations or individuals partner with academia and industry to invest in early-stage drug development and other innovations. Other approaches include formation of nonprofit foundations and partnerships with other entities to work jointly on shared development goals.

BACKGROUND AND IMPORTANCE We present a unique case of an anterior cranial base von Hippel-Lindau disease (VHL)-associated microcystic neoplasm. To determine the lesion's relationship with VHL and its appropriate management, we discuss its salient clinical, pathological, and molecular features. CLINICAL PRESENTATION A 36-year-old woman with VHL presented with a 3-month history of phantosmia. Serial magnetic resonance imaging studies revealed a lesion within the ethmoid and frontal sinus region that was first evident 18 months before symptom development and demonstrated progressive growth over the interval period. The lesion was resected via a transbasal approach. Histopathological and immunohistochemical analysis revealed a microcystic lesion composed of bland clear cells and underlying endothelial cells consistent with a VHL-associated microcystic neoplasm that are not known to metastasize. Molecular testing demonstrated loss of heterozygosity of the VHL locus, verifying the tumor as a VHL-related neoplasm. CONCLUSION Because primary VHL-associated microcystic tumors in the anterior cranial base have not been described previously, the natural history of these tumors remains unclear. Based on the benign features of these lesions, they can be managed conservatively with close observation and surgical intervention reserved for those that produce symptoms.

OBJECTIVE: Previously, we reported bypass coaptation of the C3 and C4 anterior rami to the upper trunk of the brachial plexus for restoration of the muscles denervated as a result of C5 and C6 nerve root avulsion. This procedure is thought to be superior to the transfer of individual peripheral nerve fibers to the brachial plexus branches. Therefore, the benefits of the bypass coaptation procedures in the treatment of various root avulsions are presented. METHODS: Twenty-six patients were selected as suitable candidates for bypass coaptation procedures. They were divided into 3 groups: 1) Erb-Duchenne palsy due to C5 and C6 root avulsion, 2) Klumpke palsy due to C8 andT1 root avulsion, and 3) the flail arm (or flail upper limb) due to C5 through T1 root avulsion. The surgical techniques are described in detail. RESULTS: The coaptation procedures for the first group resulted in excellent recovery of all the denervated muscles. The patients in the second group showed reinnervation of the finger muscles and finger sensory distributions in infants within the first year after surgery. The flail arm group regained satisfactory proximal muscle function but only mild distal muscle function. One exception was a child who showed significant recovery in proximal and distal motor and sensory function. CONCLUSION: We recommend the bypass coaptation as a useful procedure for the following categories: Erb-Duchenne palsy due to C5 and C6 root avulsion in all ages, Klumpke palsy due to the C8 and T1 avulsion, and the flail arm due to C5 through T1 avulsion in young children. However, bypass procedures for the flail limb in adults require additional innovative methods to facilitate the growth rate of regenerating nerves.

Objective Proteins are the primary components of cells and are vital constituents of any living organism. The proteins that make up an organism (proteome) are constantly changing and are intricately linked to neurological disease processes. The study of proteins, or proteomics, is a relatively new but rapidly expanding field with increasing relevance to neurosurgery. Methods We present a review of the state-of-the-art proteomic technology and its applications in central nervous system diseases. Results The technique of "selective microdissection" allows an investigator to selectively isolate and study a pathological tissue of interest. By evaluating protein expression in a variety of central nervous system disorders, it is clear that proteins are differentially expressed across disease states, and protein expression changes markedly during disease progression. Conclusion Understanding the patterns of protein expression in the nervous system has critical implications for the diagnosis and treatment of neurological disease. As gatekeepers in the diagnosis, evaluation, and treatment of central nervous system diseases, it is important for neurosurgeons to develop an appreciation for proteomic techniques and their utility.

Objective Bilateral endolymphatic sac tumors (ELSTs) are associated with von Hippel-Lindau disease and often underlie significant audiovestibular morbidity, including hearing loss. Patient This 44-year-old female von Hippel-Lindau disease patient presented with tinnitus, vertigo, and binaural hearing loss. Magnetic resonance and computed tomography imaging demonstrated bilateral ELSTs, and audiometry confirmed bilateral hearing loss. Intervention The patient underwent staged resection of the ELSTs (left then right). After resection of the left ELST and during the same operation, a cochlear implant was placed. Main outcome measures Clinical, audiometric, and imaging data. Results Postoperatively, the patient had resolution of tinnitus and vertigo with a significant implant-aided improvement in hearing. Conclusion Because of their unique anatomic and biologic features, resection of bilateral tumors and cochlear implantation in deaf ELST patients is a potential option to improve hearing and quality of life.

Objective: To determine if convection-enhanced delivery (CED) of glucocerebrosidase could be used to treat targeted sites of disease progression in the brain and brainstem of a patient with neuronopathic Gaucher disease while monitoring enzyme distribution using MRI. Methods: A CED paradigm in rodents (n = 8) and primates (n = 5) that employs co-infusion of a surrogate MRI tracer (gadolinium diethylenetriamine penta-acetic acid [Gd-DTPA]) with glucocerebrosidase to permit real-time monitoring of distribution was developed. The safety and feasibility of this delivery and monitoring paradigm were evaluated in a patient with type 2 Gaucher disease. Results: Animal studies revealed that real-time, T1-weighted, MRI of Gd-DTPA accurately tracked enzyme distribution during CED. Targeted perfusion of clinically affected anatomic sites in a patient with neuronopathic Gaucher disease (frontal lobe and brainstem) with glucocerebrosidase was successfully performed. Real-time MRI revealed progressive and complete filling of the targeted region with enzyme and Gd-DTPA infusate. The patient tolerated the infusions without evidence of toxicity. Conclusions: Convection-enhanced delivery can be used to safely perfuse large regions of the brain and brainstem with therapeutic levels of glucocerebrosidase. Co-infused imaging surrogate tracers can be used to monitor and control the distribution of therapeutic agents in vivo. Patients with neuronopathic Gaucher disease and other intrinsic CNS disorders may benefit from a similar treatment paradigm.

Because Pseudallescheria boydii vertebral osteomyelitis is rare and frequently resistant to available antifungal agents, the proper treatment of this lesion has not been defined. To better determine the best treatment of this lesion, the authors evaluated a case P. boydii vertebral osteomyelitis and reviewed the literature. A 48-year-old man had isolated thoracic vertebral osteomyelitis resulting from P. boydii and associated severe thoracic back pain and proximal lower extremity pain and weakness. Magnetic resonance imaging studies revealed continued collapse of the T6--T7 vertebrae despite previous posterior debridement and appropriate antifungal chemotherapy. On admission to the authors' institution, the patient underwent a right thoracotomy, anterior debridement with transthoracic T6--T7 corpectomies and strut grafting, followed by posterior fusion and stabilization with pedicle screws. After operation, the patient's pain, hyperalgesia, and lower extremity symptoms resolved. He was treated with a 12-month course of itraconazole. Imaging and laboratory studies show no evidence of recurrence. P. boydii vertebral osteomyelitis can have devastating neurologic sequelae if not treated properly. The frequent lack of response of this unusual fungal infection to systemic therapy requires frequent serial follow-up examinations. Patients with evidence of progression on imaging studies or neurologic findings should undergo early and aggressive surgical debridement.

Although often overlooked, the diagnosis of adult "tethered cord syndrome" (TCS) is important because the manifestations of this syndrome are readily reversible by untethering. Too often, adult patients with TCS are misdiagnosed as having "failed back syndrome" or other unrelated spinal problems. As a result, many patients are treated with modalities which fail to improve neurological function. The aims of this review are to acquaint readers with the pathophysiology, symptomatology, diagnosis, and treatment of adult TCS based on author's experience in 70 cases. Adult TCS manifested by severe back and leg pain, a subtle onset of motor/sensory changes and musculoskeletal deformities is correlated to TCS pathophysiology and imaging studies. Timely diagnosis of TCS can lead to pain relief and restoration of neurologic function and patient gratification.

In the past, patients with cervical spinal nerve root avulsions were resigned to accept a natural crippling from upper extremity neurological deficits. Recently, bypass coaptation procedures have resulted in functional return of denervated muscles after such avulsions, much to the appreciation of patients. Presented are 12 patients with avulsion of cervical spinal nerve roots that form either the brachial plexus upper trunk (n = 7), lower trunk (n = 1), or all three trunks (n = 4). The patients underwent the new bypass coaptation procedures with complete or partial return of motor and sensory function, which otherwise would be totally nonfunctional. The most dramatic results were noted in those patients who underwent operations within 6 weeks of injury. The results of these procedures offer patients a valid therapeutic modality for an enhanced quality of life after cervical nerve root avulsion.

In the past, stereotactic surgical intervention for Parkinson's disease was considered indicated only in those patients with active motor manifestations that were refractory to pharmacological therapy, manifestations such as tremor, rigidity, dystonia, and dyskinesia. With the reintroduction and refinement of Leksell's posteroventral pallidotomy, both akinetic and hyperkinetic symptoms are now amenable to surgical treatment. We have analyzed the results of 126 patients who underwent either unilateral (n = 58) or bilateral (n = 68) posteroventral pallidotomies. The Unified Parkinson's Disease Rating Scale and Hoehn and Yahr Staging Scale were used for preoperative and postoperative objective assessments. Postoperative follow-up evaluation occurred initially at 1 week and subsequently at intervals between 1 and 12 months (mean = 4.5 months) after surgery. Although individual motor subscores on the Unified Parkinson's Disease Rating Scale were significantly reduced (n = 126, P < or = 0.01), the most dramatic findings were the reversal of akinetic symptoms and the elimination of dyskinesia and profound "off" periods. These clinical results, combined with intraoperative microelectrode records revealing pallidal neuronal hyperactivity, suggest a reconsideration of the pathophysiology of akinesia and point to possible mechanisms of akinesia improvement by posteroventral pallidotomy in some parkinsonian subgroups.

Objective and importance Juxtafacet cysts of the lumbar spine are a recognized cause of back pain, radicular symptoms, neurogenic claudication, and, less often, cauda equina compression syndrome. Hemorrhagic rupture of a juxtafacet cyst and the resulting epidural hematoma may cause chronic and/or acute cauda equina compression. Clinical presentation We report two cases of ruptured hemorrhagic lumbar synovial cysts resulting in epidural hematoma and progressive symptomatic cauda equina compression. Intervention Surgical excision of the epidural hematoma and the associated cyst resulted in complete resolution of symptoms. Conclusion Rarely, juxtafacet cysts of the lumbar spine may rupture and hemorrhage into the epidural space causing symptomatic cauda equina compression. It is important to consider this entity when evaluating the patient with cauda equina compression. The findings of these cases give insight into the clinical presentation, operative treatment, and outcome in these patients.

HEMANGIOBLASTOMAS ARE NOT uncommon intramedullary spinal cord neoplasms. They are highly vascular, benign tumors that occur either sporadically or in the presence of von Hippel-Lindau disease. Despite their exceptionally vascular nature, these lesions can consistently be resected completely and safely with minimal blood loss. We describe a microsurgical method for removal of these tumors from the spinal cord.