Appearance of intracranial cottonoids on intraoperative magnetic resonance imaging.

To our knowledge, this is a unique report of intraoperative magnetic resonance imaging (iMRI) of an intracranial cottonoid. The current literature describes images of cottonoids as a post-operative finding in the setting of an unintentionally retained foreign body; however, the iMRI images we present are important as the use of iMRI in the resection of complex tumors and epilepsy foci increases. This series of images was obtained during a craniotomy for tumor resection of a patient with dysembryoplastic neuroepithelial tumor. To determine both the degree of tumor resection and the amount of residual tumor, cottonoids were left in our patient's resection cavity and underwent iMRI. The ability to distinguish cottonoids in these images is important for intraoperative localization of resection margins and to prevent the retention of cottonoids.

Does subtotal resection ameliorate hypothalamic morbidity in pediatric craniopharyngioma? A 30-year retrospective cohort study.

OBJECTIVE: The optimal extent of resection of craniopharyngiomas to minimize the long-term risks of hypothalamic and endocrine dysfunction (obesity and panhypopituitarism) in children remains uncertain. The purpose of this study was to report long-term outcomes of pediatric patients with craniopharyngioma undergoing surgical treatment and to study rates of endocrinological and hypothalamic dysfunction in association with extent of resection. METHODS: This retrospective study was performed in a cohort of children who underwent resection for craniopharyngioma at Children's of Alabama between 1990 and 2020. The primary outcome was hypothalamic dysfunction defined as a 0.5 increase in body mass index (BMI) Z-score and as a BMI > 2 SDs with or without psychiatric disturbances. Univariable analysis was performed using ANOVA, Wilcoxon rank-sum test, Pearson's chi-square test, and Fisher's exact test as appropriate. Missing data on the primary outcome were handled via multiple imputations. Relative risks were estimated using a multivariable generalized linear model with a priori variables selected using a modified Poisson regression approach with robust error variance to estimate risk ratios. RESULTS: The cohort includes 39 patients (24 girls and 15 boys; age range 1 month-16 years) who underwent resection of craniopharyngioma at the authors' center between 1990 and 2020. The preoperative goal of treatment was cyst decompression (CD) in 5, subtotal resection (STR) in 13, and gross-total resection (GTR) in 21 patients. The median long-term follow-up after surgery was 8.11 years (average 8.21, range 0.4-24.33 years). Univariate analysis demonstrated a statistically significant increase in hypothalamic dysfunction in patients undergoing GTR when compared to those undergoing STR or CD at 1 month postoperatively (p = 0.006) and 6-11 months postoperatively (p = 0.010), but with this difference not persisting beyond 1 year. Multivariable analysis showed patients older than 10 years at time of surgery to be the most affected and at highest risk of developing significant hypothalamic dysfunction. There was no significant difference in pituitary or neurological function between the STR/CD and GTR groups at 12-24 months or at most recent follow-up. There was no significant difference in BMI Z-scores between the STR/CD and GTR groups at 6-12 months or at most recent follow-up. CONCLUSIONS: Both STR and GTR of craniopharyngioma were associated with significant endocrinological sequelae after 1 year. These potential complications should be discussed with patients and their families, and postoperative protocols should include early nutritional and endocrinological interventions with endocrinologist consultation.

Hydrocephalus surveillance following CSF diversion: a modified Delphi study.

OBJECTIVE: Long-term follow-up is often recommended for patients with hydrocephalus, but the frequency of clinical follow-up, timing and modality of imaging, and duration of surveillance have not been clearly defined. Here, the authors used the modified Delphi method to identify areas of consensus regarding the modality, frequency, and duration of hydrocephalus surveillance following surgical treatment. METHODS: Pediatric neurosurgeons serving as institutional liaisons to the Hydrocephalus Clinical Research Network (HCRN), or its implementation/quality improvement arm (HCRNq), were invited to participate in this modified Delphi study. Thirty-seven consensus statements were generated and distributed via an anonymous electronic survey, with responses structured as a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). A subsequent, virtual meeting offered the opportunity for open discussion and modification of the statements in an effort to reach consensus (defined as ≥ 80% agreement or disagreement). RESULTS: Nineteen pediatric neurosurgeons participated in the first round, after which 15 statements reached consensus. During the second round, 14 participants met virtually for review and discussion. Some statements were modified and 2 statements were combined, resulting in a total of 36 statements. At the conclusion of the session, consensus was achieved for 17 statements regarding the following: 1) the role of standardization; 2) preferred imaging modalities; 3) postoperative follow-up after shunt surgery (subdivided into immediate postoperative imaging, delayed postoperative imaging, routine clinical surveillance, and routine radiological surveillance); and 4) postoperative follow-up after an endoscopic third ventriculostomy. Consensus could not be achieved for 19 statements. CONCLUSIONS: Using the modified Delphi method, 17 consensus statements were developed with respect to both clinical and radiological follow-up after a shunt or endoscopic third ventriculostomy. The frequency, modality, and duration of surveillance were addressed, highlighting areas in which no clear data exist to guide clinical practice. Although further studies are needed to evaluate the clinical utility and cost-effectiveness of hydrocephalus surveillance, the current study provides a framework to guide future efforts to develop standardized clinical protocols for the postoperative surveillance of patients with hydrocephalus. Ultimately, the standardization of hydrocephalus surveillance has the potential to improve patient care as well as optimize the use of healthcare resources.

Cerebellar tonsil ectopia measurement in type I Chiari malformation patients show poor inter-operator reliability.

BACKGROUND: Type 1 Chiari malformation (CM-I) has been historically defined by cerebellar tonsillar position (TP) greater than 3-5 mm below the foramen magnum (FM). Often, the radiographic findings are highly variable, which may influence the clinical course and patient outcome. In this study, we evaluate the inter-operator reliability (reproducibility) of MRI-based measurement of TP in CM-I patients and healthy controls. METHODS: Thirty-three T2-weighted MRI sets were obtained for 23 CM-I patients (11 symptomatic and 12 asymptomatic) and 10 healthy controls. TP inferior to the FM was measured in the mid-sagittal plane by seven expert operators with reference to McRae's line. Overall agreement between the operators was quantified by intraclass correlation coefficient (ICC). RESULTS: The mean and standard deviation of cerebellar TP measurements for asymptomatic (CM-Ia) and symptomatic (CM-Is) patients in mid-sagittal plane was 6.38 ± 2.19 and 9.57 ± 2.63 mm, respectively. TP measurements for healthy controls was 0.48 ± 2.88 mm. The average range of TP measurements for all data sets analyzed was 7.7 mm. Overall operator agreement for TP measurements was relatively high with an ICC of 0.83. CONCLUSION: The results demonstrated a large average range (7.7 mm) of measurements among the seven expert operators and support that, if economically feasible, two radiologists should make independent measurements before radiologic diagnosis of CM-I and surgery is contemplated. In the future, an objective diagnostic parameter for CM-I that utilizes automated algorithms and results in smaller inter-operator variation may improve patient selection.

Preoperative FMRI Associated with Decreased Mortality and Morbidity in Brain Tumor Patients.

BACKGROUND: Functional Magnetic Resonance Imaging (fMRI) is a presurgical planning technique used to localize functional cortex so as to maximize resection of diseased tissue and avoid viable tissue. In this retrospective study, we examined differences in morbidity and mortality of brain tumor patients who received preoperative fMRI in comparison to those who did not. METHODS: Brain tumor patients (n=206) were selected from a retrospective review of neurosurgical case logs from 2001-2009 at the University of Wisconsin-Madison. RESULTS: Univariate analysis showed improved mortality in the fMRI group and the fMRI+Electrical Cortical Stimulation Mapping (ECM) group compared to the No-fMRI group. Multivariate analyses showed improved mortality of the fMRI group and the fMRI+ECM group compared to the No-fMRI group, with age and tumor grade being the most significant influencers. Overall, the fMRI group showed survival benefits at 3 years; twice that of the No-fMRI group. Furthermore, patients with high-grade tumors showed significant survival benefits in the fMRI group, while patients with low-grade tumors did not (controlling for age and ECM). There was also a significant difference in the two groups with respect to morbidity, with patients receiving fMRI showing improved outcomes in the motor and language domains. CONCLUSIONS: This study analyzing a large retrospective series of brain tumor patients with and without the use of fMRI in the preoperative planning has resulted in improved mortality and morbidity outcomes with the use of fMRI. These results point to the importance of incorporating fMRI in presurgical planning in the clinical management of patients with brain tumors.

Classification and Management of Pediatric Subaxial Cervical Spine Injuries.

Appropriate management of subaxial spine injury in children requires an appreciation for the differences in anatomy, biomechanics, injury patterns, and treatment options compared with adult patients. Increased flexibility, weak neck muscles, and cranial disproportion predispose younger children to upper cervical injuries and spinal cord injury without radiographic abnormality. A majority of subaxial cervical spine injuries can be treated nonoperatively. Surgical instrumentation options for children have significantly increased in recent years. Future studies of outcomes for children with subaxial cervical spine injury should focus on injury classification and standardized outcome measures to ensure continued improvement in quality of care for this patient population.

Two-stage surgical resection of an atypical teratoid rhabdoid tumor occupying the infratentorial and supratentorial compartment in children under two years: Report of two cases.

INTRODUCTION: Atypical teratoid rhabdoid tumors are highly malignant neoplasms that present in young children and can grow to a large size. Maximal safe surgical resection is a mainstay of treatment. PRESENTATION OF CASES: Two cases of children under the age of two with large tumors involving the supratentorial and infratentorial compartments are presented. A two-staged operative approach combining a standard suboccipital approach to the fourth ventricle followed by an infratentorial, supracerebellar approach was utilized for resection. DISCUSSION: Maximal safe surgical resection of large tumors in young children is challenging. A staged approach is presented that affords maximal tumor resection while minimizing perioperative morbidity. CONCLUSION: A staged operative approach appears safe and efficacious when resecting large tumors from both the infratentorial and supratentorial compartments in children less than two years of age.

Selective loss of chromosome 11 in pheochromocytomas associated with the VHL syndrome.

By using comparative genomic hybridization (CGH), we characterized the genetic profiles of 36 VHL-related pheochromocytomas. We then compared the results with those of sporadic and MEN 2-related pheochromocytomas. In 36 VHL-related tumors, loss of chromosome 3 and chromosome 11 were found in 34 tumors (94%) and 31 tumors (86%), respectively. There was significant concordance of deletions in chromosomes 3 and 11 (Kappa=0.64, P=0.0095), suggesting that they are involved in two different but necessary and complementary genetic pathways. The loss of chromosome 11 appeared to be specific for VHL-related pheochromocytoma as it was not present in any of the 10 VHL-related CNS hemangioblastomas studied and was significantly less common when compared with (a) sporadic pheochromocytomas from previously published results (13%; P=<0.0001), and (b) MEN 2-related pheochromocytomas from this and previously published studies (30%; P=0.0012). In summary, this is the first report of a novel consistent genetic alteration that is selected and specific for VHL-related pheochromocytoma, besides the two hits of the VHL gene.