Chiari I malformation and acute acquired comitant esotropia: case report and review of the literature.

The authors describe a rare case of a Chiari I malformation presenting with acute acquired comitant esotropia (AACE) in a 5-year-old boy. A posterior fossa decompression with duraplasty and a C1-2 laminectomy were performed. There was an immediate postoperative improvement in the esotropia, which completely resolved by 7 months following surgery. The pertinent literature is discussed and reasons are presented for recommending posterior fossa decompression in certain patients, rather than strabismus surgery, as the initial treatment for esotropia. The authors suggest that in patients with AACE, even subtle symptoms and signs of Chiari I malformation should prompt imaging of the posterior fossa. Strong consideration should be given to performing posterior fossa decompression in patients with Chiari I malformation and AACE before strabismus surgery because the esotropia may completely resolve with decompression.

Percutaneous vertebroplasty and kyphoplasty performed at a cancer center: refuting proposed contraindications.

OBJECT: The purpose of this study was to examine a group of patients with cancer who underwent a vertebroplasty or a kyphoplasty for a vertebral body (VB) fracture, even though the procedure may have been considered contraindicated based on previous reports in the literature. METHODS: The electronic database maintained by the Departments of Neurosurgery and Anesthesiology-Pain Management at the University of Texas M. D. Anderson Cancer Center was searched for patients who underwent vertebroplasty or kyphoplasty between January 2001 and July 2003. The criteria defining a contraindicated procedure were based on a review of the literature. Group I consisted of patients who did not undergo a contraindicated vertebroplasty or kyphoplasty, whereas Group II consisted of patients who underwent one of these procedures even though it may have been considered contraindicated. There were 53 patients with fractures at 132 levels who met the criteria for the study. Of these, 17 patients with fractures at 18 levels (14% of total) were considered to have undergone a contraindicated vertebroplasty or kyphoplasty (Group II). There were 12 complications (11%) in the 114 levels in Group I and seven complications (39%) in the 18 levels in Group II (p = 0.03). The most common complication was cement extrusion from the anterior VB that did not involve the venous system. No patient required an open surgical procedure to remove extruded cement. CONCLUSIONS: Vertebroplasty and kyphoplasty appear to be safe and effective in the setting of severe back pain caused by VB fracture that is unresponsive to other therapies, even in the presence of relative contraindications to the procedures.

En bloc resection of primary sacral tumors: classification of surgical approaches and outcome.

OBJECT: En bloc resection with adequate margins is associated with the highest probability of long-term tumor control or cure in most cases of primary sacral malignancies. The authors present their experience with a systematic approach to these lesions. They provide a novel classification of surgical techniques based on the level of nerve root sacrifice and evaluate the functional and oncological outcomes. METHODS: Seventy-eight consecutive patients underwent 94 resections of sacral neoplasms at The University of Texas M. D. Anderson Cancer Center in Houston between August 1993 and June 2002. The records of 29 consecutive patients who underwent en bloc resection of primary sacral tumors were retrospectively reviewed. The median follow-up period was 55 months (range 1-103 months). Chordoma was the most frequent tumor type (16 cases). Midline sacral amputation was performed in 25 patients (eight low, four middle, seven high, and five total sacrectomies; one hemicorporectomy). Lateral sacrectomy was undertaken in four patients (two unilateral excisions of the sacroiliac joint and two hemisacrectomies). The surgical margins were wide in 19 cases, marginal in nine, and contaminated in one. The type of sacrectomy correlated with characteristic outcomes with respect to bladder, bowel, and ambulatory functions. Duration of hospital stay was related to the extent of sacrectomy (p = 0.003, Wilcoxon signed-rank test). The median Kaplan-Meier disease-free survival for patients with chordoma was 68 months (95% confidence interval 46-90 months). CONCLUSIONS: Classification of en bloc sacral resection techniques by the level of nerve root transection is useful in predicting postoperative function and the potential for morbidity. Adequate surgical margins should not be compromised to preserve function when they are necessary to affect tumor control.

Expression of the splicing regulator polypyrimidine tract-binding protein in normal and neoplastic brain.

Polypyrimidine tract-binding protein (PTB) is a nuclear factor that binds to the polypyrimidine tract of pre-mRNA introns, where it is associated with negative regulation of RNA splicing and with exon silencing. We have previously demonstrated that PTB expression is increased during glial cell transformation and that this increase correlates brain and in glial and neuronal tumors. Paraffin sections were stained by using a primary monoclonal antibody against PTB. Tissues that were analyzed included normal with changes in the RNA splicing of the fibroblast growth factor receptor 1. In this paper we examine the specific cellular distribution of PTB expression in normal brain (n = 2) and tumors of various types (low-grade astrocytoma, n = 2; anaplastic astrocytoma, n = 2; glioblastoma, n = 4; medulloblastoma, n = 4; central neurocytoma, n = 2; dysplastic gangliocytoma, n = 1; ganglioglioma, n = 1; paraganglioma, n = 1). In glial cell populations the majority of astrocytes and oligodendrocytes were negative, but occasional positively staining cells were observed. Strongly positive PTB staining was observed in ependymocytes, choroid plexus epithelium, microglia, arachnoid membrane, and adenohypophysis, and weak staining was found in the neurohypophysis. In all cases vascular endothelium and smooth muscle stained strongly. In tumor samples, intense positive nuclear staining was observed in transformed cells of low-grade astrocytoma, anaplastic astrocytoma, glioblastoma multiforme, medulloblastoma, paraganglioma, and the glial population of both ganglioglioma and dysplastic gangliocytoma (the neuronal cells of both were negative). In medulloblastoma, neoplastic neuronal cells were positive, as were other cell lineages. In normal brain, all neuron populations and pineocytes were negative for PTB. We conclude that although glial cells show derepression of PTB expression, a similar mechanism is absent in both nonneoplastic neurons and in most neuronally derived tumor cells. Strong upregulation of PTB expression in tumor cells of glial or primitive neuroectodermal origin suggests involvement of this protein in cellular transformation. Whether PTB affects splicing of RNAs critical to cellular transformation or proliferation is an important question for future research.

Metastatic prostate carcinoma to the intradural extramedullary spinal compartment. Case report.

Despite the relatively high incidence of prostate carcinoma involving the spinal column, those that are associated with spinal intradural extramedullary metastases are rare. The role of surgery for metastases to this spinal compartment is limited and palliative because presentation tends to be late in the course of the disease, particularly for prostate carcinoma. It is also considered to be part of the spectrum of leptomeningeal carcinomatosis and is associated with a high incidence of brain metastases. The authors review a rare case of prostate carcinoma metastatic to the spinal intradural extramedullary space and discuss its clinical presentation, imaging features, and surgical management.

Subarachnoid-pleural fistula after resection of thoracic tumors.

OBJECT: Little has been written about the appropriate diagnosis, investigation, and management of subarachnoid-pleural fistula (SPF). The authors report a series of patients with SPF that developed after resection of spinal tumor and discuss the diagnosis and treatment of this entity. METHODS: Between 1993 and 2002, nine patients with SPF observed after spinal surgery at the M. D. Anderson Cancer Center were prospectively followed. In all patients the tumors were located in the thoracic region, and the most common entity was vertebral body metastasis (six cases), with renal cell carcinoma being the most common form of the disease (three cases). All but one patient underwent surgery via a transthoracic approach; in only one patient an intradural approach was performed. The most common presentation was overt cerebrospinal fluid (CSF) leakage, manifesting as chest tube drainage (four cases) or as leakage through the wound (one case). A definitive diagnosis of SPF was established in four patients, with evidence of extraspinal leakage on an 111In-radionuclide CSF study. Although all patients initially underwent a trial of lumbar CSF drainage, all but one required open repair, including creation of intercostal muscle (three cases) and omental (one case) flaps. CONCLUSIONS: After spinal surgery in which the thorax is entered, a diagnosis of SPF should be considered in any patient with abnormal chest tube output, persistent pleural effusion, or clinical evidence of intracranial hypotension. The diagnosis should be confirmed by performing a radionuclide-labeled CSF study. Definitive open repair is required in most cases and preferentially consists of a vascularized tissue graft, which is most easily obtained from an intercostal muscle flap.

Craniofacial resections in the elderly: an outcome study.

OBJECT: The elderly population is increasing in number and is healthier now than in the past. The purpose of this study was to examine complications and outcomes following craniofacial resection (CFR) in elderly patients and to compare findings with those of a matched younger cohort. METHODS: All patients 70 years of age or older undergoing CFR at the M.D. Anderson Cancer Center (elderly group) between December 1992 and July 2003 were identified by examining the Department of Neurosurgery database. A random cohort of 28 patients younger than 70 years of age (control group) was selected from the overall population of patients who underwent CFR. There were 28 patients ranging in age from 70 to 84 years (median 74 years). Major local complications occurred in seven elderly patients (25%) and in six control patients (21%) (p = 0.75), and major systemic complications occurred in nine elderly patients (32%) and in three control patients (11%) (p = 0.05). There was one perioperative death in both groups of patients. The median duration of disease-specific survival for the elderly patients was not reached (mean 6.8 years); however, it was 8.3 years for control patients (p = 0.24). Predictors of poorer overall survival from a multivariate analysis of the elderly group included presence of cardiac disease (p = 0.005), a major systemic perioperative complication (p = 0.03), and a preoperative Karnofsky Performance Scale score less than 100 (p = 0.04). CONCLUSIONS: In this study of elderly patients who underwent CFR, there was no difference in disease-specific survival when compared with a matched cohort of younger patients. There was, however, an increased incidence of perioperative major systemic complications in the elderly group.

Jugular bulb oximetry for prediction of vasospasm following subarachnoid hemorrhage.

BACKGROUND: Cerebral vasospasm adversely impacts the outcome of those suffering aneurysmal subarachnoid hemorrhage (SAH). Prediction of vasospasm could improve outcomes. We hypothesized that preclinical vasospasm would be heralded by an increase in cerebral oxygen extractions (AVDO2) which could be detected by jugular bulb oximetry. A pilot study was conducted to address this hypothesis. METHODS: Fourteen consenting patients with aneurysmal SAH, undergoing early surgery, were entered into the study. Four patients were withdrawn from the study secondary to failure of catheters or religious belief. At the time of craniotomy, a jugular bulb catheter was placed. Post-operatively, arterial and jugular bulb blood samples were taken every 12 hours to calculate AVDO2. As this was an observational study, no change in management occurred based on measurements. RESULTS: Four of 10 patients had clinical vasospasm. These patients had a significant rise in AVDO2 approximately one day prior to the onset of neurologic deficits (P<0.001). Symptoms resolved along with a significant improvement in AVDO2 on instituting hypertensive, hemo-dilutional, and hypervolemic therapy in these patients. The six patients who did not exhibit clinical vasospasm did not demonstrate significant rise in AVDO2. CONCLUSIONS: Jugular bulb oximetry is simple and cost effective. Increases in AVDO2 using this technique were predictive of clinically evident vasospasm in the subsequent hours to days. This investigation supports a larger study to assess the utility of jugular bulb oximetry in predicting vasospasm in aneurysmal SAH.

P53 and MIB-1 immunohistochemistry as predictors of the clinical behavior of nonfunctioning pituitary adenomas.

BACKGROUND: P53 expression and increased MIB-1 proliferation index have been shown to correlate with invasive behavior in pituitary adenomas. The purpose of this study was to determine whether these indices could be used to predict a higher likelihood of recurrence in clinically nonfunctional pituitary adenomas and thus guide adjuvant therapy. METHODS: Fifty-one clinically nonfunctional pituitary adenomas were selected from the database at the Vancouver Hospital and Health Sciences Center between the years 1990-1998. Included were 32 nonrecurrent and 19 recurrent adenomas. RESULTS: The mean initial labelling index for p53 in nonrecurrent tumours was 0.38% (0-1.58%), while it was 0.46% (0-3.65%) for recurrent adenomas. The mean initial MIB-1 index for nonrecurrent tumours was 1.63% (0.08-9.36%), while for recurrent tumours it was 1.92% (0-7.76%). The percentage of p53 positive adenomas was 66% for nonrecurrent tumours and 68% for recurrent tumours. None of the differences in the labelling indices between the recurrent and nonrecurrent groups was statistically significant. As 12 patients (38%) in the nonrecurrent group had undergone radiotherapy as initial adjuvant therapy after surgery and none of the recurrent group had done so, patients who did not receive radiotherapy in the nonrecurrent group were analyzed separately. Again, none of the differences in the labelling indices between the recurrent and nonrecurrent groups was statistically significant when the effect of radiotherapy was removed from the analysis. CONCLUSIONS: The results demonstrate no statistical difference in the p53 or MIB-1 labelling indices between recurrent and nonrecurrent nonfunctional pituitary adenomas. Concern should be raised in attaching too much clinical significance to these labelling indices, especially with respect to p53 as a predictor of the clinical behavior of nonfunctional pituitary adenomas.

Stereotactic radiosurgery for Cushing disease.

The most common cause of Cushing syndrome is Cushing disease, in which hypercortisolism is produced by a functional adrenocorticotropic hormone-producing adenoma of the anterior pituitary gland. The common therapies available include microsurgical resection, conventional fractionated radiotherapy, and stereotactic radiosurgery (SRS). In this article the authors review the indications, results, and complications associated with SRS in the treatment of Cushing disease. In as many as 90% of patients SRS results in disease remission, which is defined as a normal 24-hour urinary free cortisol level and a normal or subnormal morning serum cortisol level. Although in most patients who are subsequently cured a marked decrease in the serum cortisol level is demonstrated within 3 months after treatment, a biochemical cure may be delayed up to 3 years in some cases. Complications following SRS for pituitary adenomas are uncommon, particularly in patients with microadenomas, which are most commonly seen in Cushing disease. The most common complication is hypopituitarism, which occurs in up to 50% of patients with a mean latency period of 5 years. Radiation-induced optic neuropathy has been reported in less than 2% of cases and induction of a secondary neoplasm in less than 1% of cases. For patients with Cushing disease, the rate of endocrinological cure following SRS appears to be similar to that attained using microsurgical resection. In contrast to surgery, SRS has the benefit of being noninvasive and associated with a very low incidence of diabetes insipidus, although hypopituitarism may be more common with SRS. With continued follow-up patient reviews and additional experience with SRS, it may become possible to make more definitive statements regarding SRS as the initial treatment for patients with Cushing disease.

Olfactory groove meningiomas.

OBJECT: Olfactory groove meningiomas (OGMs) arise over the cribriform plate and may reach very large sizes prior to presentation. They can be differentiated from tuberculum sellae meningiomas because OGMs arise more anterior in the skull base and displace the optic nerve and chiasm inferiorly rather than superiorly. METHODS: The authors searched the neurosurgery database at the M. D. Anderson Cancer Center for cases of OGM treated between 1993 and 2003. The records of these patients were then reviewed retrospectively for details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status. Thirteen patients, (12 women and one man, mean age 56 years) harbored OGMs (mean size 5.7 cm). All patients underwent bifrontal craniotomies and biorbital osteotomies. There were 11 complete resections (including the hyperostotic bone and dura of the cribriform plate and any extension into the ethmoid sinuses) and two subtotal resections with minimal residual tumor left in patients with recurrent lesions. No complication directly due to the surgery occurred in any patient. There were no recurrences in a mean follow-up period of 2 years (range 0-5 years). CONCLUSIONS: With current microsurgical techniques, the results of OGM resection are excellent, with a high rate of total resection and a low incidence of complications. All hyperostotic bone should be removed with the dura of the anterior skull base to minimize the risk of recurrence.

Ventricular catheter exchange using a peel-away outer catheter.

Ventricular catheter replacement can be challenging, especially in patients with small ventricles. Shunt malfunction due to ventricular catheter obstruction can occur without ventricular enlargement, such as in the setting of slit-ventricle syndrome or benign intracranial hypertension. The authors describe a simple technique for ventricular catheter exchange using a peel-away catheter. In the limited initial experience of the senior author (G.S.C.), this technique appears to be safe and effective. To the authors' knowledge, this method has not been described in the neurosurgical literature before.

Malignant tumors of the anterolateral skull base.

OBJECTIVE: Malignancies of the anterolateral skull base are clinically and pathologically distinct from those of the central anterior skull base and the temporal bone. The purpose of this report is to describe the outcomes and complications after skull base surgery and multimodality therapy in a group of patients with anterolateral skull base malignancies. PATIENT DATA AND METHODS: The mean duration of follow-up for living patients was 57.2 months (median, 56.8 months). The median age of the 52 patients who met the inclusion criteria for this study was 47 years (range, 1-81 years). The most common presenting feature was cranial nerve palsy (60%). Of these cranial nerve palsies, trigeminal neuropathies causing facial numbness were the most common, with V2 being affected in 35%, V3 affected in 33%, and V1 affected in 17%. Abducens neuropathy was present in 14% of patients. The most frequently occurring pathologies after the various sarcomas were squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) in 23% and 14% of patients, respectively. Of the 30 sarcomas, 16 were classified as low grade and 14 were classified as high grade. RESULTS: Complications of treatments were identified in 16 patients (31%). Ten patients had a single complication, whereas 6 patients experienced multiple complications. The most common complications were a new or worsened cranial nerve deficit (n = 4), pneumonia (n = 4), and flap necrosis (n = 3). Recurrence after the treatment associated with the index surgery occurred in 37 patients (71%). The recurrence was local in 30 patients (58%), both local and distant (metastatic) in 4 patients (8%), and only distant in 3 patients (12%). The median progression-free survival (PFS) was 2.1 years (range, 1.2-3.0 years). Median PFS times of 0.6 and 1.6 years were noted for patients with high-grade sarcoma (HGS) and low-grade sarcoma (LGS), respectively. The mean PFS (median not reached) for the patients with SCC was 4.6 years, whereas the median PFS for patients with ACC was 3.3 years. The overall 2- and 5-year survivals for all patients were 81% and 53% (median, 5.0 years; 95% confidence interval, 3.9-6.1 years), respectively. The median survival for patients with nonsarcomas was 6.9 years, the 2-year survival was 82%, and the 5-year survival was 55%. Patients with HGS survived the shortest time (median, 3.3 years; 2-year, 64%; 5-year, 27%), whereas those patients with LGS had an intermediate survival (median, 5.3 years; 2-year, 94%, 5-year, 72%). CONCLUSION: It is our belief that anterolateral skull base malignancies comprise a distinct group of tumors. These lesions should be analyzed separately from central anterior skull base lesions and temporal bone malignancies. With a multimodality treatment protocol, acceptable survivals may be obtained that are comparable to results that have been reported for tumors involving less difficult areas of the skull base.

Surgical resection of intrinsic insular tumors.

This report, with an accompanying videotape, details the authors' technique for performing radical resections of tumors intrinsic to the insular lobe. The resection technique takes advantage of the fact that many intrinsic insular tumors grow within the confines of the insula, usually without violating pial borders or invading the medial structures. The method described is based on an anatomic dissection of the insula that uses the internal boundaries of the region, particularly the peri-insular sulci, as guides for resection. The videotape provides a visual description of this method.

Current surgical management of glioblastoma.

Surgical resection is a critical aspect of the management of a patient with a glioblastoma (GBM). An intimate knowledge of the anatomy of a GBM, as well as familiarity with particular surgical techniques and adjunctive technologies is required for safe surgical resection. The goals of resection include diagnosis, relief of mass effect, and cytoreduction. A recent study showed that resection of 98% or more of the tumor mass can result in a statistically significant survival advantage. Even in functionally critical areas, "gross total" resections are possible if proper techniques are employed. It is recommended that a "gross total" resection of the enhancing portion of a GBM be performed whenever possible. With this philosophy, the mortality rate is 3% and the rate of major neurologic morbidity is less than 10%.

Optimizing outcomes with maximal surgical resection of malignant gliomas.

BACKGROUND: Aggressive surgical resection of malignant gliomas is a controversial issue in neurosurgery. Studies with rigorous methodology that fully address this issue have only recently become available. METHODS: The controversy regarding the role of maximal surgical resection of malignant gliomas is reviewed. The authors discuss surgical techniques and adjunctive technologies that can be utilized to assist in resection of these lesions. RESULTS: Using current microneurosurgical techniques, it is possible to resect malignant gliomas in gross total fashion. An aggressive approach in which 98% or more of the tumor mass is resected results in a statistically significant survival advantage. CONCLUSIONS: An aggressive surgical procedure for malignant gliomas can result in increased survival duration for selected groups of patients.

Percutaneous vertebroplasty in vertebra plana secondary to metastasis.

Severe vertebral body collapse secondary to metastatic disease is considered a contraindication to vertebroplasty by most authors. Resolution of radicular pain after vertebroplasty is also not well reported. A case of successful vertebroplasty of a severe T7 collapse secondary to metastatic thymic carcinoma with an associated posterior cortical fracture of the body that resulted in resolution of axial and radicular pain is described. The patient had near-complete relief of severe axial and radicular pain. Postoperative imaging revealed anterior placement of the cement without leak into the spinal canal or the intervertebral foramen. The objectives are to describe the clinical and radiographic features of the case to support the idea that vertebra plana secondary to metastatic disease may not be a contraindication to vertebroplasty in selected patients. Simple techniques to avoid leak of cement into the spinal canal are also described. Severe vertebral collapse secondary to metastatic fractures may not be a contraindication to vertebroplasty, provided that appropriate measures are taken to place the trocars and to avoid extrusion of cement into the spinal canal.