Introduction Hydrocephalus is a common neurosurgical problem often treated with ventriculoperitoneal shunt. Assessing shunt function involves clinical presentation, radiological findings and physical examination of the patient and the shunt reservoir, which often may include a shunt tap. ShuntCheckTM is an non-invasive transcutaneous thermal convection system that is used to detect cerebrospinal fluid (CSF) flow through shunts. In this study we have used ShuntCheckTM to evaluate patients with suspected shunt malfunction, and report our early findings. Methods Patients were screened per IRB protocol and enrolled in the study. Patients were evaluated with appropriate examination and radiological studies based on patient’s history and presentation. ShuntCheckTM was used to assess shunt flow per trained protocol. Patients were followed for 7 days of the initial ShuntCheckTM test. Results Eight patients were enrolled in the study. Four of them had surgery to explore and revise the shunt; two had a ventricular catheter obstruction,two had poor flow through the valve or the peritoneal catheter. None of the patients had any adverse reactions to the ShuntCheck device. ShuntCheck accurately diagnosed poor flow in 100% of the operative cases. In one of the nonoperative cases, ShuntCheck showed no flow, but a nuclear medicine study showed a patent shunt system. Conclusions Assessing patients for possible shunt malfunction involves a multimodal approach including clinical history, physical examination and radiological evaluation. ShuntCheckTM may prove a useful non-invasive tool to accurately assist in the shunt evaluation process, to help speed the diagnosis and potentially defer other more invasive diagnostic procedures.

BACKGROUND CONTEXT: Tethered cord syndrome (TCS) is frequently associated with scoliosis in the pediatric population. Following spinal cord untethering, many patients continue to experience progression of spinal deformity. However, incidence, time course, and risk factors for scoliosis progression following tethered cord release remain unclear.

The following review of the literature describes the ganglioglioma, an uncommon mixed glioneuronal neoplasm, most often of low-grade histology, with a small, albeit well-documented, malignant potential. These tumors exhibit a strong epileptogenic propensity and most often present as new onset seizures or are discovered after a long history of refractory epilepsy. Despite their indolent course, the importance of gross total resection is well recognized to prevent anaplastic and malignant degeneration. Morphologically, the neoplasm is often cystic with an enhancing mural nodule, but can also be entirely solid. They are most often found in the temporal lobe but have been found throughout the neuraxis. An exceedingly rare location of the ganglioglioma is within the lateral ventricle. A systematic literature search revealed only eight reports documenting the occurrence of a ganglioglioma within the lateral ventricle. We describe an illustrative case of an intraventricular ganglioglioma with a prominent cystic component and enhancing mural nodule, which represents the classic radiographic appearance of gangliogliomas described in other locations. A superior parietal lobule approach offered excellent surgical access for tumor removal and the patient has remained free of neurological deficits following surgery. Regardless of location within the central nervous system, ganglioglioma should be on the differential diagnosis for any cystic mass with a mural nodule, particularly in the setting of epilepsy.

Treatment failure for Chiari decompression is frequently associated with scarring, intradural adhesions, and recurrent loss of hindbrain space. While autograft has been our standard for hindbrain duraplasty, we investigated whether introducing anti-adhesive synthetic GORE PRECLUDE® MVP® Dura Substitute (expanded polytetrafluoroethylene [ePTFE] graft) was associated with improved patient outcomes.

Objective Many patients with symptomatic Chiari I malformation experience symptom recurrence after surgical decompression. Improved radiographic predictors of outcome are needed to better select patients most likely to benefit from surgical intervention. We examined whether ventral or dorsal cerebrospinal fluid (CSF) flow dynamics assessed by cine phase-contrast MRI scans could predict response to posterior fossa decompression for Chiari I malformation.Methods Forty-four consecutive pediatric patients undergoing pre-operative cine phase-contrast MRI followed by posterior fossa decompression for Chiari I malformation were retrospectively reviewed. The association of pre-operative ventral or dorsal CSF flow abnormalities at the foramen magnum with symptom-free survival after surgical decompression was assessed via Kaplan-Meier plots and log-rank analysis.Results Mean +/- SD age at time of surgery was 8 +/- 6 years. Sixteen (36%) patients demonstrated decreased CSF flow dorsal to the cervico-medullary brainstem alone. Fourteen (32%) patients demonstrated abnormal CSF flow both ventral and dorsal to the cervico-medullary brainstem. Fourteen (32%) had normal hindbrain CSF flow. Overall, 13 (30%) patients experienced some degree of symptom recurrence by last follow-up (mean of 27 +/- 16 months post-operatively). Symptom recurrence did not differ as a function of degree of tonsilar ectopia (p=0.55). Abnormal CSF flow dorsal to the cervico-medullary brainstem was not associated with symptom recurrence after surgical decompression (p=0.10). However, combined pre-operative ventral and dorsal CSF flow abnormality was associated with a significant reduction (2.6-fold) in the risk of post-operative symptom recurrence (p < 0.05). Only one patient (7%) with pre-operative ventral and dorsal CSF flow pathology experienced symptom recurrence 3.5 years after surgery versus 12 (40%) patients without ventral CSF flow pathology. There were otherwise no differences in baseline clinical, radiological, or operative variables between patients with abnormal versus normal ventral CSF flow.Conclusion The presence of decreased CSF flow both ventral and dorsal to the cervico-medullary brainstem was associated with improved response to hindbrain decompression for Chiari I malformation in children. Cine phase-contrast MRI may be a useful tool for surgical risk stratification and identifying patients that may be optimal surgical candidates. Combined ventral and dorsal hindbrain CSF flow pathology may better predict response to posterior fossa decompression compared to dorsal CSF flow pathology alone.

Objective Symptom recurrence remains a problem for some patients after surgical decompression for Chiari I malformation. We set out to identify variables at presentation that could identify subgroups most likely to experience incomplete symptom relief after hindbrain decompression for Chiari I malformation.Materials and methods We retrospectively reviewed the records of all pediatric patients undergoing first-time suboccipital decompression for Chiari I malformation over a 10-year period. Measured outcomes included (1) persistence or recurrence of symptoms regardless of severity and (2) need for revision decompression.Results Two hundred fifty-six children (10 5years old) underwent surgery for Chiari I malformation and were followed up for a mean of 27months. Presenting symptoms included headache in 192 (75%) patients and brainstem or cranial nerve symptoms in 68 (27%) patients. Fifty-seven (22%) patients experienced mild to moderate symptom recurrence. Nineteen (7%) patients required revision decompression for significant symptom recurrence. Headache was 70% more likely to persist or recur versus cranial nerve or brainstem symptoms (relative risk 1.70, p < 0.05). Vertigo and frontal headache independently increased the odds of symptom recurrence 2.9- and 1.5-fold, respectively. Each increasing year of preoperative headache duration was independently associated with 15% increase in likelihood of symptom persistence (p < 0.05). Severe tonsilar ectopia (caudal to C2 lamina) was twice as likely to require revision decompression (14% versus 6%).Conclusion In our experience, recurrence of mild symptomatology not severe enough to justify revision surgery may occur in nearly a fifth of patients after surgery. Headache was more likely to recur than objective cranial nerve or brainstem symptoms. Increasing duration of headaches, frontal headaches, and vertigo may be more refractory symptoms of Chiari I malformation.

OBJECT Chiari malformation Type I (CM-I) is often associated with scoliosis. It remains unclear which subgroups of patients are most likely to experience progression of spinal deformity after cervicomedullary decompression. The authors' goal was to determine the time frame of curvature progression and assess which patient subgroups are at greatest risk for progression of spinal deformity after surgery. METHODS The authors retrospectively reviewed the records of all pediatric patients with significant scoliosis in whom suboccipital decompression was performed to treat for CM-I during a 10-year period at a single academic institution. Clinical, radiological, and operative variables were assessed as independent factors for failure (worsening of scoliosis) by using a univariate regression analysis. RESULTS Twenty-one children (mean age 9 +/- 3 years; 4 male) underwent hindbrain decompression for CM-I-associated scoliosis and were followed for a mean of 39 months. All patients harbored a syrinx. Eight patients (38%) experienced improvement in scoliosis curvature, whereas 10 (48%) suffered a progression. Thoracolumbar junction scoliosis (p = 0.04) and failure of the syrinx to improve (p = 0.05) were associated with 5- and 4-fold respective increases in the likelihood of deformity progression. Each increasing degree of preoperative Cobb angle was associated with an 11% increase in the likelihood of scoliotic curve progression (p < 0.05). CONCLUSIONS Over one third of patients with CM-I-associated scoliosis will improve after cervicomedullary decompression alone. Cervicomedullary decompression is a good first-line option, particularly in children with concordant posterior fossa symptoms. Patients presenting with more severe scoliosis (increasing Cobb angle) or scoliosis that crosses the thoracolumbar junction may benefit from earlier orthopedic involvement and should be monitored regularly for curvature progression after cervicomedullary decompression. In cases in which there is a failure of the syrinx to show improvement after suboccipital decompression, the patients are also more likely to develop curvature progression.

OBJECTIVEChiari I malformation is complicated by syringomyelia in many cases. Hindbrain decompression remains first-line surgical treatment; however, the incidence, time course, and predictors of syrinx resolution remain unclear. We set out to determine predictors of syrinx improvement after hindbrain decompression for Chiari I- associated syringomyelia. METHODSForty-nine consecutive pediatric patients undergoing posterior fossa decompression for Chiari I-associated syringomyelia were followed with serial magnetic resonance imaging evaluations postoperatively. Clinical, radiological, and operative variables were assessed as predictors of syrinx improvement as a function of time using Kaplan-Meier plots and log-rank analysis. RESULTSMean patient age was 11 ± 5 years. Syringomyelia was symptomatic in 39 (80%) and asymptomatic in 10 (20%) cases. Twenty-one (54%) patients experienced symptom resolution (median, 4 mo postoperatively). Twenty-seven (55%) patients experienced radiographic improvement in syringomyelia (median, 14 mo postoperatively). After hindbrain decompression, motor symptoms were associated with a 2.35 increased hazard ratio for symptom improvement (P = 0.031) versus all other symptoms. Among patients with sensory deficits, dysesthesia was associated with a 3.12 increased hazard ratio for symptom improvement (P = 0.032) versus symptoms of paresthesia or anesthesia. CONCLUSIONIn our experience, just more than one-half of patients with Chiari- associated syringomyelia demonstrated clinical and radiographic improvement after hindbrain decompression. Median time to radiographic improvement lagged behind clinical improvement by 10 months. Motor symptoms were more likely to improve with hindbrain decompression. Paresthesia or anesthesia symptoms were less likely to improve with hindbrain decompression. These findings may help guide surgical decision making and aid in patient education.

OBJECT Indications for duraplasty in treatment of Chiari malformation Type I (CM-I) remain unclear. In the present study, the authors evaluate their surgical experience to determine whether intraoperative ultrasonography is effective in the selection of patients with CM-I who can be adequately treated with craniectomy alone without duraplasty. METHODS The authors reviewed the records of 256 children who underwent first-time hindbrain decompression for CM-I. Craniectomy alone (without duraplasty) was performed when intraoperative ultrasonography suggested adequate decompression of the subarachnoid spaces ventral and dorsal to the tonsils after suboccipital craniectomy alone. Duraplasty was performed if intraoperative ultrasonography demonstrated persistent dural compression of the tonsils following craniectomy. Symptom recurrence as a function of time was compared between cases of duraplasty versus suboccipital decompression alone stratified by extent of tonsillar herniation. RESULTS Duraplasty was performed in 140 patients (55%), and suboccipital decompression alone was performed in 116 patients (45%). Patients underwent follow-up for 29 +/- 15 months. Symptoms included headache in 192 patients (75%) and lower cranial nerve and brainstem dysfunction in 68 (27%). In 38 patients (15%) there was tonsillar herniation rostral to the C-1 lamina, in 195 (76%) it extended between the C-1 and C-2 lamina, and in 23 patients (9%) there was herniation caudal to the lower border of the C-2 lamina. In children with tonsillar herniation caudal to C-1, ultrasonography-guided suboccipital decompression alone was associated with a 2-fold increase in the risk of symptom recurrence compared with those who also underwent duraplasty (p = 0.01). In children with tonsillar herniation rostral to C-1, outcome was equivalent between suboccipital decompression alone and duraplasty (p = 0.41). CONCLUSIONS In the setting of moderate-to-severe tonsillar CM-I, intraoperative ultrasonography demonstrating decompression of the subarachnoid spaces ventral and dorsal to the tonsils may not effectively select patients in whom bone decompression alone is sufficient. Duraplasty may be warranted in cases of tonsillar herniation that extends below the C-1 lamina regardless of intraoperative ultrasonography findings. More objective cerebrospinal fluid flow or volumetric measures may be needed intraoperatively to guide duraplasty in patients with more pronounced tonsillar herniation.

INTRODUCTION:The use of programmable shunt valves has increased dramatically in the practice of pediatric hydrocephalus. Despite theoretical advantages, it remains unclear if the use of programmable vs set-pressure valves affects shunt outcome.MATERIALS AND METHODS:The clinical and radiological records of all pediatric patients undergoing ventriculoperitoneal (VP), ventriculopleural (VPl), and ventriculoatrial (VA) shunt surgery from 2001 to 2004 at an academic institution were reviewed. The association of programmable vs set-pressure valves with subsequent shunt revision was assessed by Kaplan-Meier shunt survival plots and log-rank analysis.RESULTS:A total of 279 VP, VPl, and VA shunt surgeries were performed on patients with median (interquartile range) age of 4 (1-14) years (161 male, 118 female; 158 communicating, 122 obstructive hydrocephalus). Programmable valves were used in 76 (27%) cases and set-pressure valves in 203 (73%). At mean+/-SD follow-up of 17 +/- 13 months, programmable vs set-pressure valves were associated with reduced risk of both overall shunt revision [26 (35%) vs 109 (54%); relative risk (RR) (95% CI); 0.61 (0.41-0.91), p = 0.016] and proximal obstruction [9 (12%) vs 58 (28%); RR (95% CI); 0.39 (0.27-0.80), p = 0.006]. There was no difference in distal obstruction [3 (4%) vs 11 (5%) cases], infection [6 (8%) vs 12 (6%) cases], valve obstruction [0 (0%) vs 4 (2%)], or shunt disconnection [2 (3%) vs 1 (1%)] between adjustable and set-pressure valves, respectively.CONCLUSION:In our experience, the use of programmable vales was associated with a decreased risk of proximal shunt obstruction and shunt revision. Programmable valves may be preferred in patients frequently experiencing proximal shunt failure. A prospective, controlled study is warranted to evaluate the potential value of adjustable vs set-pressure valve systems.

INTRODUCTION: Treatment failure remains a problem for many patients after surgical decompression Chiari I malformation. Identification of predictors of outcome are needed to better select patients most likely to benefit from surgical intervention. We set out to identify clinical and radiographic variables at presentation that could identify subgroups most likely to fail surgical intervention for Chiari I malformation. METHODS: We retrospectively reviewed the records of all pediatric patients undergoing suboccipital decompression for Chiari I malformation during a 10-year period at a single academic institution. Clinical, radiological, and operative variables were assessed as independent risk factors for treatment failure via multivariate proportional-hazards regression analysis. RESULTS: Two hundred seventy-nine children (10 ± 5 yr, 130 boys) underwent surgery for Chiari I malformation and were followed for a mean of 27 months. Symptoms included headache in 211 (76%) and posterior fossa and lower cranial nerve dysfunction in 93 (33%) children. Mean duration of...

OBJECT:Antibiotic-impregnated shunt (AIS) systems may decrease the incidence of cerebrospinal fluid (CSF) shunt infections. However, there is a reluctance to use AIS components because of their increased cost. In the present study the authors evaluated factors contributing to the medical costs associated with the treatment of CSF shunt infections in a hydrocephalic pediatric population, those implanted with AIS systems compared with those implanted with standard shunt systems.METHODS:The authors retrospectively reviewed data obtained in all pediatric patients who had undergone CSF shunt insertion at their institution over a 3-year period. All patients were followed up for 12 months after surgery. The independent association between AIS catheter use and subsequent shunt infection was assessed by performing a multivariate proportional hazards regression analysis. Factors contributing to the medical costs associated with shunt infection were evaluated.RESULTS:Two hundred eleven pediatric patients underwent 353 shunting procedures. Two hundred eight shunts (59%) were placed with nonimpregnated catheters and 145 shunts (41%) were placed with AIS catheters. Twenty-five patients (12%) with non-AIS catheters experienced shunt infection, whereas only two patients (1.4%) with AIS catheters had a shunt infection within the 6-month follow-up period (p < 0.01). Among infected patients, infected patients with standard shunt components had a longer average hospital stay, more inpatient complications related to infection treatment, and more multiple organism infections and multiple antibiotic regimens, compared with those with AIS components.CONCLUSIONS:Although individual AIS components are more expensive than standard ones, factors contributing to medical costs are fewer in pediatric patients with infected shunts when the components are antibiotic-impregnated rather than standard.

Antibiotic-impregnated shunt (AIS) systems have been designed to prevent the colonization of shunt components by skin flora that occurs at surgery. Although such systems may decrease the incidence of early shunt infections (those occurring within 6 months of shunt placement), it is unclear if such exposure to prolonged antibiotics leads to an increased incidence or virulence of late shunt infections (those occurring later than 6 months after shunt placement). In this study, the authors evaluate the incidence of late shunt infection after the introduction of an AIS system in a pediatric hydrocephalus population.

We report a 4-year-old girl with a complicated Enterococcus faecalis ventriculoperitoneal shunt infection who failed vancomycin therapy. We demonstrate linezolid's high CSF penetration and its CSF bacteriostatic activity against E. faecalis. Linezolid may be a good alternative for treatment of ventriculoperitoneal shunt infections in cases of vancomycin-resistant organisms or apparent treatment failures.

BACKGROUND:Ventriculoperitoneal (VP) shunts are widely used for treating hydrocephalus. These devices are prone to malfunction with up to 70% requiring revision. Shunt infection and obstruction comprise the majority of malfunctions and usually present dramatically. However, rare presentations occur.METHODS/RESULTS:We report a rare case of VP shunt malfunction presenting with pleuritic chest pain. A 13-year-old girl with a VP shunt placed at birth for congenital hydrocephalus presented on multiple occasions with pleuritic chest pain, cough, and fever. She was diagnosed with an upper respiratory tract infection and discharged home. She returned with respiratory compromise, and chest x-ray depicted the shunt catheter in the pleural space with an associated pleural effusion and infiltrate. The patient fully recovered with intravenous antibiotics, thoracentesis, and placement of a new shunt system.CONCLUSIONS:VP shunt malfunction usually presents with signs and symptoms of increased intracranial pressure and/or infection. However, unusual presentations of malfunction may occur with signs and symptoms which appear unrelated to the shunt. Thus, all patients with VP shunts warrant a comprehensive evaluation.

Auditory processing of speech and nonspeech sounds was studied prospectively in two hemidecorticectomy patients (ages 10-11 years) with Rasmussen's syndrome. We tested auditory word recognition under four listening conditions: in quiet, in noise, after acoustic filtering, and dichotically. Recognition of environmental sounds and discrimination of tones and digitized syllables were also tested. Presurgical testing confirmed normal processing of speech and nonspeech, for both patients, under all listening conditon. One year after surgery, both patients demonstrated intact recognition of words and environmental sounds in quiet but impaired word recognition in noise. The left hemidecorticectomy patient also demonstrated impaired recognition of low-pass filtered words. These findings suggest that either hemisphere can process speech or nonspeech sounds in quiet, whereas both hemispheres are needed to process speech in background noise. Hemispheric contributions to processing speech in noise appear to differ, with the left hemisphere compensating for loss of phonologic information and the right hemisphere compensating for increased attention demands.

More than 100 years after its identification, type I Chiari malformation remains poorly understood. Despite impressive advances in clinical diagnosis, neuroradiology, and neurosurgery, central questions about the pathogenesis, natural history, and prevalence of this condition remain unanswered. Although not common, Chiari malformation should be considered in any patient with signs and symptoms localized to the brain stem or cerebellum, particularly if signs and symptoms coexist with headache and signs of central cord involvement. More importantly, tonsillar ectopia always must be considered in the context of a thorough history and patient evaluation, with recognition that even patients with significant degrees of tonsillar ectopia may remain asymptomatic for extended periods, Craniocervical decompression is the preferred surgical treatment in most cases of type I Chiari malformation with or without syringohydromyelia.

Thirty-three meningeal neoplasms were karyotyped, and the results were compared with histologic features. Thirteen neoplasms had no discernible abnormality or sex chromosome loss only; nine had monosomy or structural abnormality involving only chromosome 22; and 11 had other chromosome abnormalities with or without chromosome 22 involvement. Histologic evidence of invasion was not associated with an abnormal karyotype in the three angioblastic tumors examined. All seven fibroblastic meningiomas had abnormal karyotypes, with monosomy 22 the most common change. Abnormal karyotypes were detected in 76% of syncytial and 55% of transitional meningiomas. When these results were combined with those from 259 meningeal tumors reported since 1987, abnormal karyotypes were detected in at least half of all histologic types. Chromosome changes secondary to those involving chromosome 22 may indicate additional areas of the genome that play a role in tumor progression. In the combined series, chromosome losses were most frequently observed in meningiomatous and transitional histologies; chromosomes 1, 6, 14, 18, and Y each were lost in 10 or more meningiomas, whereas only chromosome 20 was gained at the same frequency. Structural abnormalities most frequently involved chromosome 1. These changes are distinctly different from those observed in other common intracranial neoplasms, specifically astrocytic neoplasms.