Cerebrospinal fluid and plasma oxytocin concentrations are positively correlated and negatively predict anxiety in children

The neuropeptide oxytocin (OXT) exerts anxiolytic and prosocial effects in the central nervous system of rodents. A number of recent studies have attempted to translate these findings by investigating the relationships between peripheral (e.g., blood, urinary and salivary) OXT concentrations and behavioral functioning in humans. Although peripheral samples are easy to obtain in humans, whether peripheral OXT measures are functionally related to central OXT activity remains unclear. To investigate a possible relationship, we quantified OXT concentrations in concomitantly collected cerebrospinal fluid (CSF) and blood samples from child and adult patients undergoing clinically indicated lumbar punctures or other CSF-related procedures. Anxiety scores were obtained in a subset of child participants whose parents completed psychometric assessments. Findings from this study indicate that plasma OXT concentrations significantly and positively predict CSF OXT concentrations (r=0.56, P=0.0064, N=27). Moreover, both plasma (r=-0.92, P=0.0262, N=10) and CSF (r=-0.91, P=0.0335, N=10) OXT concentrations significantly and negatively predicted trait anxiety scores, consistent with the preclinical literature. Importantly, plasma OXT concentrations significantly and positively (r=0.96, P=0.0115, N=10) predicted CSF OXT concentrations in the subset of child participants who provided behavioral data. This study provides the first empirical support for the use of blood measures of OXT as a surrogate for central OXT activity, validated in the context of behavioral functioning. These preliminary findings also suggest that impaired OXT signaling may be a biomarker of anxiety in humans, and a potential target for therapeutic development in individuals with anxiety disorders.

MRI surrogates for molecular subgroups of medulloblastoma

BACKGROUND AND PURPOSE

Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups.

MATERIALS AND METHODS

All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (wingless, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes.

RESULTS

Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), wingless tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%-100%), and sonic hedgehog tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%-100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%-98%). When we used the MR imaging feature-based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort.

CONCLUSIONS

Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing.

Time-dependent structural changes of the dentatothalamic pathway in children treated for posterior fossa tumor

BACKGROUND AND PURPOSE

Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway.

MATERIALS AND METHODS

Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline.

RESULTS

The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia.

CONCLUSIONS

Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.

Cerebrovascular disease in childhood cancer survivors: A Children's Oncology Group Report

BACKGROUND

Curative therapy for childhood cancer has dramatically improved over past decades. Therapeutic radiation has been instrumental in this success. Unfortunately, irradiation is associated with untoward effects, including stroke and other cerebrovascular disease (CVD). The Children's Oncology Group (COG) has developed guidelines for screening survivors at risk for persistent or late sequelae of cancer therapy.

OBJECTIVES

This review summarizes the pathophysiology and relevant manifestations of radiation-induced CVD and outlines the specific patient groups at risk for early-onset stroke. The reader will be alerted to the availability of the COG recommendations for monitoring, and, when applicable, specific screening and treatment recommendations will be highlighted.

METHODS

A multidisciplinary task force critically reviewed the existing literature and scored the evidence to establish the current COG guidelines for monitoring health of survivors treated with head and neck irradiation.

RESULTS

Previous head and neck exposure to therapeutic radiation is associated with latent CVD and increased risk for stroke in some patient groups. Common manifestations of radiation-induced CVD includes steno-occlusive disease, moyamoya, aneurysm, mineralizing microangiopathy, vascular malformations, and strokelike migraines.

CONCLUSION

Risk for stroke is increased in survivors of pediatric CNS tumors, Hodgkin lymphoma, and acute lymphoblastic leukemia who received radiation to the brain and/or neck. As the population of survivors ages, vigilance for stroke and cerebrovascular disease needs to continue based on specific exposures during curative cancer therapy.

Efficacy and tolerability of intrathecal liposomal cytarabine for central nervous system embryonal tumors

2064

Background: Liposomal cytarabine (DepoCyt) is a sustained-release intrathecal (IT) preparation of cytarabine, formulated by encapsulating the drug in spherical aqueous chambers within a lipid matrix. While proven effective in lymphomatous meningitis, this drug has shown some activity in medulloblastoma (MB) with spinal metastases in limited pediatric phase I study. Methods: We reviewed all patients at our institution treated with liposomal cytarabine for primary central nervous system (CNS) embryonal tumors-MB, primitive neuroectodermal tumor (PNET), and atypical teratoid rhabdoid tumor (ATRT). Results: A cohort of 17 patients were treated with liposomal cytarabine at diagnosis of CNS embryonal tumor (2 PNET, 3 ATRT) or relapse (12 MB [7 average-risk, 5 high-risk]); nine had leptomeningeal metastases. Drug was dosed at 2 mg/kg up to 50, every 2 weeks to monthly, along with dexamethasone. Concurrent systemic chemotherapy was given in 16 patients. Median age at first dose was 10.8 years (range 0.9 to 27.9 years). A total of 102 doses were administered (lumbar IT 76, Ommaya intraventricular 36) with a mean of six treatments (range 1–16). Only three administrations were associated with adverse effects of arachnoiditis or headache; no dose reductions were required. Median overall survival from relapse was 11.8 months. All six evaluable patients with malignant cerebrospinal fluid (CSF) cytology and treated with at least two doses cleared their spinal fluid (mean 3 doses, range 1–5). No patient developed malignant CSF cytology while receiving liposomal cytarabine. Ten patients developed progressive disease and died, with only one later recurrence in the spinal fluid. Seven patients remain alive (4 initial and 3 relapse) with five in continuous complete remission (2 ATRT) for a median 13.7 months from first liposomal cytarabine. Conclusions: Liposomal cytarabine was well tolerated and easily administered. All patients with neoplastic meningitis cleared malignant cells from their spinal fluid after treatment with IT liposomal cytarabine and systemic chemotherapy. One-third of our cohort remains in remission from otherwise fatal diagnoses. Our findings warrant a phase II trial of liposomal cytarabine in newly diagnosed or recurrent CNS embryonal tumors.

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