Tene A. Cage

Treatment-related morbidity and the management of pediatric craniopharyngioma: a systematic review.

OBJECT Craniopharyngiomas are benign tumors but their close anatomical relationship with critical neurological, endocrine, and vascular structures makes gross-total resection (GTR) with minimal morbidity difficult to achieve. Currently, there is controversy regarding the extent, timing, and modality of treatment for pediatric craniopharyngioma. METHODS The authors performed a systematic review of the published literature on pediatric craniopharyngioma to determine patterns of clinical practice and the reported outcomes of standard treatment strategies. This yielded 109 studies, which contained data describing extent of resection for a total of 531 patients. Differences in outcome were examined based upon extent of resection and choice of radiation treatment. RESULTS Gross-total resection was associated with increased rates of new endocrine dysfunction (OR 5.4, p < 0.001), panhypopituitarism (OR 7.8, p = 0.006), and new neurological deficits (OR 9.9, p = 0.03) compared with biopsy procedures. Subtotal resection (STR) was not associated with an increased rate of new neurological deficits. Gross-total was associated with increased rates of diabetes insipidus (OR 7.7, p = 0.05) compared with the combination of STR and radiotherapy (RT). The addition of RT to STR was associated with increased rates of panhypopituitarism (OR 9.9, p = 0.01) but otherwise similar rates of morbidities. CONCLUSIONS Although subject to the limitations of a literature review, this report suggests that GTR is associated with increased rates of endocrinopathies compared with STR + RT, and this should be considered when planning goals of surgery.

A systematic review of treatment outcomes in pediatric patients with intracranial ependymomas

OBJECT Ependymoma is the third most common primary brain tumor in children. Tumors are classified according to the WHO pathological grading system. Prior studies have shown high levels of variability in patient outcomes within and across pathological grades. The authors reviewed the results from the published literature on intracranial ependymomas in children to describe clinical outcomes as they relate to treatment modality, associated mortality, and associated progression-free survival (PFS). METHODS A search of English language peer-reviewed articles describing patients 18 years of age or younger with intracranial ependymomas yielded data on 182 patients. These patients had undergone treatment for ependymoma with 1 of 5 modalities: 1) gross-total resection (GTR), 2) GTR as well as external beam radiation therapy (EBRT), 3) subtotal resection (STR), 4) STR as well as EBRT, or 5) radiosurgery. Mortality and outcome data were analyzed for time to tumor progression in patients treated with 1 of these 5 treatment modalities. RESULTS Of these 182 patients, 69% had supratentorial ependymomas and 31% presented with infratentorial lesions. Regardless of tumor location or pathological grade, STR was associated with the highest rates of mortality. In contrast, GTR was associated with the lowest rates of mortality, the best overall survival, and the longest PFS. Children with WHO Grade II ependymomas had lower mortality rates when treated more aggressively with GTR. However, patients with WHO Grade III tumors had slightly better survival outcomes after a less aggressive surgical debulking (STR+EBRT) when compared with GTR. CONCLUSIONS Mortality, PFS, and overall survival vary in pediatric patients with intracranial ependymomas. Pathological classification, tumor location, and method of treatment play a role in outcomes. In this study, GTR was associated with the best overall and PFS rates. Patients with WHO Grade II tumors had better overall survival after GTR+EBRT and better PFS after GTR alone. Patients with WHO Grade III tumors had better overall survival after STR+EBRT. Patients with infratentorial tumors had improved overall survival compared with those with supratentorial tumors. Progression-free survival was best in those patients with infratentorial tumors following STR+EBRT. Consideration of all of these factors is important when counseling families on treatment options.

High-resolution ultrasonography and diffusion tensor tractography map normal nerve fascicles in relation to schwannoma tissue prior to resection

The goals of the present study were to demonstrate the ability of high-resolution ultrasonography to delineate normal nerve fascicles within or around peripheral nerve sheath tumors (NSTs). A blinded examiner evaluated 2 patients with symptomatic upper limb NSTs with high-resolution ultrasonography performed in the perioperative suite using a portable ultrasonography system. Ultrasonographic examinations located the tumor mass and identified the normal nerve fascicles associated with the mass. The locations of normal nerve tissue were mapped and correlated with results of MR tractography, operative inspection, and intraoperative electrophysiological monitoring. The study demonstrated a close correlation between normal nerve fascicles identified by ultrasonography, MR tractography, and intraoperative electrophysiological mapping. In particular, ultrasonographic examinations accurately identified the surface regions of the tumor without overlying normal nerve tissue. These preliminary data suggest that preoperative ultrasonographic examinations may provide valuable information, supplementary to the information obtained from intraoperative electrophysiological monitoring. Identification of normal nerve tissue prior to surgery may provide additional information regarding the risk of iatrogenic nerve injury during percutaneous tumor biopsy or open resection of the tumor and may also aid in selecting the optimum surgical approach.

Visualizing axon regeneration after peripheral nerve injury with magnetic resonance tractography

Diffusion tensor imaging (DTI) with tractography is an MRI technique that can visualize nerve pathways by taking advantage of anisotropy of water diffusion in tracts with longitudinally oriented fibers. To date, no study in humans has shown that DTI and tractography can follow regeneration of axons during recovery from traumatic peripheral nerve injury. We show that tractography is able to identify regenerating axons advancing through a graft repair of an injured nerve, and demonstrate correlation with evidence of recovery on serial clinical, electrodiagnostic, and muscle MRI assessments.

Self-reported functional outcome after surgical intervention in patients with idiopathic normal pressure hydrocephalus

The goal of this study was to characterize long-term social and functional outcomes in adults treated for idiopathic normal pressure hydrocephalus (NPH). Data for 252 patients treated medically or surgically for idiopathic NPH were obtained through the Hydrocephalus Association Database Project. Data on post-surgical outcomes including improvement in symptoms, the need for in-home care, ability to drive, and employment status were analyzed. Most patients (73.7%) surveyed were treated with a shunt, an endoscopic third ventriculostomy (ETV), or both. More patients who underwent surgery reported driving and being employed compared to those who did not have surgery. Most shunt patients had improvements in gait (81.1%), urinary incontinence (55.9%), and dementia (64.4%). Overall, shunt patients reported more dramatic improvements in quality of life as compared to ETV patients (72.2% versus 55.6%). Treating idiopathic NPH with cerebrospinal fluid diversion facilitates a return to independence through improved functional and social outcomes.

High-Grade Gliomas in Children

High-grade gliomas (HGGs) are malignant tumors and typically include glioblastoma multiforme and anaplastic astrocytoma subtypes. Brainstem gliomas and ependymomas are separate entities with respect to clinical presentation, treatment, prognosis, and outcome in comparison with supratentorial HGGs. In children, these tumors account for 3% to 7% of newly diagnosed brain tumors and 20% of all diagnoses of pediatric supratentorial brain tumors. These neoplasms are highly proliferative and mitotically active and of glial origin. This article reviews clinical, diagnostic, and pathologic features of HGG and current treatments and potential future therapies specific to pediatric patients with HGGs.

Prospective comparison of long-term pain relief rates after first-time microvascular decompression and stereotactic radiosurgery for trigeminal neuralgia

OBJECTIVE Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD), stereotactic radiosurgery (SRS), and radiofrequency ablation (RFA). Although the efficacy of each procedure has been described, few studies have directly compared these treatment modalities on pain control for TN. Using a large prospective longitudinal database, the authors aimed to 1) directly compare long-term pain control rates for first-time surgical treatments for idiopathic TN, and 2) identify predictors of pain control. METHODS The authors reviewed a prospectively collected database for all patients who underwent treatment for TN between 1997 and 2014 at the University of California, San Francisco. Standardized collection of data on preoperative clinical characteristics, surgical procedure, and postoperative outcomes was performed. Data analyses were limited to those patients who received a first-time procedure for treatment of idiopathic TN with > 1 year of follow-up. RESULTS Of 764 surgical procedures performed at the University of California, San Francisco, for TN (364 SRS, 316 MVD, and 84 RFA), 340 patients underwent first-time treatment for idiopathic TN (164 MVD, 168 SRS, and 8 RFA) and had > 1 year of follow-up. The analysis was restricted to patients who underwent MVD or SRS. Patients who received MVD were younger than those who underwent SRS (median age 63 vs 72 years, respectively; p < 0.001). The mean follow-up was 59 ± 35 months for MVD and 59 ± 45 months for SRS. Approximately 38% of patients who underwent MVD or SRS had > 5 years of follow-up (60 of 164 and 64 of 168 patients, respectively). Immediate or short-term (< 3 months) postoperative pain-free rates (Barrow Neurological Institute Pain Intensity score of I) were 96% for MVD and 75% for SRS. Percentages of patients with Barrow Neurological Institute Pain Intensity score of I at 1, 5, and 10 years after MVD were 83%, 61%, and 44%, and the corresponding percentages after SRS were 71%, 47%, and 27%, respectively. The median time to pain recurrence was 94 months (25th-75th quartiles: 57-131 months) for MVD and 53 months (25th-75th quartiles: 37-69 months) for SRS (p = 0.006). A subset of patients who had MVD also underwent partial sensory rhizotomy, usually in the setting of insignificant vascular compression. Compared with MVD alone, those who underwent MVD plus partial sensory rhizotomy had shorter pain-free intervals (median 45 months vs no median reached; p = 0.022). Multivariable regression demonstrated that shorter preoperative symptom duration (HR 1.005, 95% CI 1.001-1.008; p = 0.006) was associated with favorable outcome for MVD and that post-SRS sensory changes (HR 0.392, 95% CI 0.213-0.723; p = 0.003) were associated with favorable outcome for SRS. CONCLUSIONS In this longitudinal study, patients who received MVD had longer pain-free intervals compared with those who underwent SRS. For patients who received SRS, postoperative sensory change was predictive of favorable outcome. However, surgical decision making depends upon many factors. This information can help physicians counsel patients with idiopathic TN on treatment selection.

Visualization of nerve fibers and their relationship to peripheral nerve tumors by diffusion tensor imaging

OBJECT The majority of growing and/or symptomatic peripheral nerve tumors are schwannomas and neurofibromas. They are almost always benign and can usually be resected while minimizing motor and sensory deficits if approached with the proper expertise and techniques. Intraoperative electrophysiological stimulation and recording techniques allow the surgeon to map the surface of the tumor in an effort to identify and thus avoid damaging functioning nerve fibers. Recently, MR diffusion tensor imaging (DTI) techniques have permitted the visualization of axons, because of their anisotropic properties, in peripheral nerves. The object of this study was to compare the distribution of nerve fibers as revealed by direct electrical stimulation with that seen on preoperative MR DTI. METHODS The authors conducted a retrospective chart review of patients with a peripheral nerve or nerve root tumor between March 2012 and January 2014. Diffusion tensor imaging and intraoperative data had been prospectively collected for patients with peripheral nerve tumors that were resected. Preoperative identification of the nerve fiber location in relation to the nerve tumor surface as seen on DTI studies was compared with the nerve fibers intraoperative localization using electrophysiological stimulation and recordings. RESULTS In 23 patients eligible for study there was good correlation between nerve fiber location on DTI and its anatomical location seen intraoperatively. Diffusion tensor imaging demonstrated the relationship of nerve fibers relative to the tumor with 95.7% sensitivity, 66.7% specificity, 75% positive predictive value, and 93.8% negative predictive value. CONCLUSIONS Preoperative DTI techniques are useful in helping the peripheral nerve surgeon to both determine the risks involved in resecting a nerve tumor and plan the safest surgical approach.

Subependymal spread of recurrent glioblastoma detected with the intraoperative use of 5-aminolevulinic acid: case report.

Recurrent glioblastoma (GBM) can occur locally or at distant sites within the brain. Though MRI is the standard imaging modality for primary and recurrent GBM, the full extent of diffuse lesions may not be appreciated on MRI alone. Glioblastomas with ependymal and/or subependymal spread are examples of diffuse infiltrative tumors that are incompletely seen on MRI. Some other adjuvant visualization technique such as intraoperative fluorescence-assisted 5-aminolevulinic acid (5-ALA) could be used to assist the surgeon in localizing the infiltrating tumor. The authors report on a 56-year-old man who presented 7 years after initial resection of an occipital lobe GBM with imaging consistent with distant discrete foci of tumor recurrence. Because these foci were distant from the original resection cavity, there was concern for diffuse, infiltrative tumor elsewhere throughout the brain versus a distant multicentric recurrence. Therefore, the patient was given 5-ALA prior to surgery to aid in tumor detection intraoperatively. Using fluorescent visualization of the resection cavity, it was confirmed that there was subependymal and ependymal spread of the recurrent tumor along the lateral ventricle connecting the recurrence to the previous tumor site. Magnetic resonance imaging may not completely detect the presence of diffuse tumor infiltrating the ependymal or subependymal spaces. Therefore, adjunct intraoperative use of fluorescence-assisted visualization with 5-ALA may be helpful in highlighting and detecting infiltrative tumor to accurately detect tumor burden and distinguish it from a separate multicentric recurrence.

Dual reinnervation of biceps muscle after side-to-side anastomosis of an intact median nerve and a damaged musculocutaneous nerve

Traumatic peripheral nerve injury can lead to significant long-term disability for previously healthy persons. Damaged nerve trunks have been traditionally repaired using cable grafts, but nerve transfer or neurotization procedures have become increasingly popular because the axonal regrowth distances are much shorter. These techniques sacrifice the existing nerve pathway, so muscle reinnervation depends entirely on the success of the repair. Providing a supplemental source of axons from an adjacent intact nerve by using side-to-side anastomosis might reinnervate the target muscle without compromising the function of the donor nerve. The authors report a case of biceps muscle reinnervation after side-to-side anastomosis of an intact median nerve to a damaged musculocutaneous nerve. The patient was a 34-year-old man who had sustained traumatic injury primarily to the right upper and middle trunks of the brachial plexus. At 9 months after the injury, because of persistent weakness, the severely damaged upper trunk of the brachial plexus was repaired with an end-to-end graft. When 8 months later biceps function had not recovered, the patient underwent side-to-side anastomosis of the intact median nerve to the adjacent distal musculocutaneous nerve via epineural windows. By 9 months after the second surgery, biceps muscle function had returned clinically and electrodiagnostically. Postoperative electromyographic and nerve conduction studies confirmed that the biceps muscle was being reinnervated partly by donor axons from the healthy median nerve and partly by the recovering musculocutaneous nerve. This case demonstrates that side-to-side anastomosis of an intact median to an injured musculocutaneous nerve can provide dual reinnervation of the biceps muscle while minimizing injury to both donor and recipient nerves.