Neurosurgical management of proton beam therapy-induced moyamoya syndrome.

OBJECTIVE: Proton beam therapy (PBT) is an increasingly used treatment modality for pediatric patients with brain tumors. Moyamoya syndrome (MMS) is well recognized as a complication of traditional photon radiotherapy, however its association with PBT is less well described. The authors discuss their initial experience with the neurosurgical management of MMS secondary to PBT in a large-volume pediatric neurovascular service. METHODS: The authors performed a retrospective case review of consecutive children referred for neurosurgical management of MMS after PBT between 2009 and 2022. Patient demographic characteristics, oncological history and treatment, interval between PBT and MMS diagnosis, and MMS management were recorded. Clinical outcome at last review was classified as good if the modified Rankin Scale (mRS) score was ≤ 2 and/or the patient attended mainstream education without additional assistance. Poor outcome was defined as mRS score ≥ 3 and/or the patient received additional educational support. The recorded radiological outcomes included angiographic analysis of stenosis, evidence of brain ischemia/infarction on MRI, and postsurgical angiographic revascularization. RESULTS: Ten patients were identified. Oncological diagnosis included craniopharyngioma (n = 6), optic pathway glioma (1), ependymoma (1), Ewing sarcoma (1), and rhabdosarcoma (1). The median (interquartile range [IQR]) age at PBT was 5.1 (2.7-7.9) years. The median (IQR) age at MMS diagnosis was 7.8 (5.7-9.3) years. The median time between PBT and diagnosis of MMS was 20 (15-41) months. Six patients had poor functional status after initial oncological treatment and prior to diagnosis of MMS. All 10 patients had endocrine dysfunction, 8 had visual impairment, and 4 had behavioral issues prior to MMS diagnosis. Four patients had a perioperative ischemic event: 2 after tumor surgery, 1 after MMS surgical revascularization, and 1 after receiving a general anesthetic for an MRI scan during oncological surveillance. Seven children were treated with surgical revascularization, whereas 3 were managed medically. The incidence of ischemic events per cerebral hemisphere was reduced after surgical revascularization: only 1 patient of 7 had an ischemic event during the follow-up period after surgery. No children moved from good to poor functional status after MMS diagnosis. CONCLUSIONS: MMS can occur after PBT. Magnetic resonance angiography sequences should be included in surveillance MRI scans to screen for MMS, and families should be counseled about this complication. Management at a high-volume pediatric neurovascular center, including selective use of revascularization surgery, appears to maintain functional status in these children.

3-Dimensional Morphometric Outcomes After Endoscopic Strip Craniectomy for Unicoronal Synostosis.

BACKGROUND: Endoscopic strip craniectomy with postoperative helmeting (ESCH) for unicoronal synostosis has shown to be a less morbid procedure when compared with fronto-orbital remodeling (FOR). We aim in this pilot study to report objective methods and quantitative morphologic outcomes of endoscopically treated unicoronal synostosis using 3-dimensional surface scans. METHODS: Our electronic records were reviewed for ophthalmological, neurodevelopmental outcomes, and helmet-related complications. For morphologic outcomes, the following parameters were used: Cranial Index, Cranial Vault Asymmetry Index, Anterior Symmetry Ratio (ASR), and Root Mean Square between the normal and synostotic sides of the head. Three-dimensional stereophotogrammetry scans were evaluated at 3 time points preoperative, 6 months post-op, and at the end of the treatment, which was compared with age-matched scans of normal controls and FOR patients. Nonparametric tests were used for statistical analysis. RESULTS: None of the ESCH cases developed strabismus, major neurodevelopmental delay, or helmet complications. All morphologic parameters improved significantly at 6 months post-op except for the Cranial Vault Asymmetry Index. The ASR was the only parameter to change significantly between 6 months post-op and final scans. At end of helmet treatment, ASR and Root Mean Square differed significantly between the ESCH and both FOR and control groups. CONCLUSIONS: Endoscopic strip craniectomy with postoperative helmeting for single unicoronal synostosis had excellent clinical outcomes. Most of the improvement in head morphology occurred in the first 6 months of treatment. Despite the normalization of the overall head shape, there was residual asymmetry in the frontal and temporal regions of the head.

Transtemporal approach to hypothalamic hamartomas in children: report of 3 cases.

The surgical approach to hypothalamic hamartomas (HHs) associated with medically refractory epilepsy is challenging because of these lesions' deep midline or paramedian location. Whether the aim is resection or disconnection, the surgical corridor dictates how complete a procedure can be achieved. Here, the authors report a transtemporal approach suitable for Delalande type I, inferior extraventricular component of type III, and type IV lesions. This approach provides optimal visualization of the plane between the hamartoma and the hypothalamus with no manipulation to the pituitary stalk and brainstem, allowing for extensive disconnection while minimizing injury to adjacent neurovascular structures.Through a 1-cm corticectomy in the middle temporal gyrus, a surgical tract is developed under neuronavigational guidance toward the plane of intended disconnection. On reaching the mesial temporal pia-arachnoid margin, it is opened, providing direct visualization of the hamartoma, which is then disconnected or resected as indicated. Critical neurovascular structures are generally not exposed through this approach and are preserved if encountered.Three patients (mean age 4.9 years) with intractable epilepsy were treated using this technique as part of the national Children's Epilepsy Surgery Service. Following resection, the patient in case 1 (Delalande type I) is seizure free off medication at 3 years' follow-up (Engel class IA). The patient in case 2 (Delalande type III) initially underwent partial disconnection through a transcallosal interforniceal approach and at first had significant seizure improvement before the seizures worsened in frequency and type. Complete disconnection of the residual lesion was achieved using the transtemporal approach, rendering this patient seizure free off medication at 14 months postsurgery (Engel class IA). The patient in case 3 (Delalande type IV) underwent incomplete disconnection with a substantial reduction in seizure frequency at 3 years' follow-up (Engel class IIIC). There were no surgical complications in any of the cases.The transtemporal approach is a safe and effective alternative to more conventional surgical approaches in managing HHs with intractable epilepsy.

Paediatric developmental venous anomalies (DVAs): how often do they bleed and where?

INTRODUCTION: Developmental venous anomalies (DVAs) are anomalies of venous drainage and considered a low-flow malformation. Studies evaluating natural history and risk factors for intracranial haemorrhage in the paediatric population are rare. We evaluate clinical and radiological features, risk factors and outcomes of paediatric DVAs. METHODS: A retrospective study was conducted over a 10-year period between 2004 and 2014. Medical records, imaging and prospective databases were reviewed. Three-hundred-and-three radiological studies in total were evaluated. RESULTS: Fifty-two children (20 boys and 32 girls [median age: 6 years] were identified with DVAs. Their age distribution was as follows: 1.9% neonates (< 1 month), 11.5% infants (1 month to 1 year), 30.8% 1-5 years, 30.8% 5-12 years and 25% 12-16 years. The majority (92.3%) presented with asymptomatic DVAs identified incidentally. Overall, anatomical distribution revealed predilection for frontal region (42.3%) with other common sites being posterior fossa (17.3%) and basal ganglia (13.5%). Temporal (11.5%), parietal (9.6%) and occipital (5.8%) were the remainder. Associated cavernous malformations (CMs) were present in 3/52 (5.8%), and no DVAs were associated with aneurysms or arteriovenous malformations (AVMs). Three patients had more than one DVA. There were three deaths unrelated to DVAs over median follow-up of 3.8 years. Four patients (7.7%) suffered DVA-related intracranial haemorrhage presenting with neurological deficits. The ages of the children with DVA-related haemorrhages were 21 days, 2 years and 6 months, 7 years and 1 month and 11 years and 7 months. Left-sided DVA haemorrhages predominated (3/4, 75%). The relative risk of a cerebellar DVA haemorrhage compared to its supratentorial counterpart was 5.35 (OR 6.8, 95% CI 0.8-58). DISCUSSION: DVA-related haemorrhage is sevenfold greater in our paediatric cohort compared to adults and is significantly associated with cerebellar location and cavernous malformations. There were no haemorrhages over a median period of 3.8 years of prospective follow-up.

Surgical approaches in pediatric neuro-oncology.

Tumors of the central nervous system comprise nearly a quarter of all childhood cancers and are the most frequent solid tumor in the pediatric population. The most common location is in the posterior fossa, but tumors can occur anywhere intracranially. The spectrum of lesions encountered varies, from being completely benign and requiring surveillance alone to being highly malignant and requiring aggressive treatment in the form of surgery and adjuvant therapy. The extent of resection plays a crucial role in the oncological outcome of many of these tumors. A variety of surgical approaches are available for the spectrum of lesions encountered. This review focuses on summarizing the location, types, and neurosurgical management strategies for pediatric brain intracranial brain tumors. Here, we discuss neurosurgical approaches for a variety of brain tumors and regions, including the management of tumors of the posterior fossa, brainstem, pineal region, intraventricular region, sellar and suprasellar regions, optic pathway and hypothalamus, and supratentorial hemispheres.

Consent in paediatric neurosurgery: adequacy of documentation and parental perspectives.

INTRODUCTION: Consenting paediatric patients for surgical procedures remains inherently unique in that it is underpinned by principles such as parental responsibility, assessment of the child's capacity to consent, and adherence to national/legal guidelines. Quality record keeping is an important objective evidence to demonstrate the highest standards of medical care provided to our patients. The consent form is a crucial medical record encapsulating the attainment of informed consent from a parent/guardian for performing a procedure on their child. We aimed to prospectively evaluate the consenting process in our department to assess adequacy of documentation and parental perspectives. METHODS: A prospective study using qualitative descriptive design was conducted with parents of 50 children requiring neurosurgical procedures over a 3-month period. RESULTS: All patients understood the primary diagnosis and type of surgery. Procedure-specific risks were understood by 98% and 84% could remember the mentioning of general risks of surgery. Only a minority of parents (24%) could recollect that alternative options of management including no treatment were discussed. In cases where relevant, laterality was only documented in 56% of consent forms. All patients felt that an informed decision regarding consent to surgery was made. However, 12% suggested areas where further improvement could be made in the timing of consent and the way information could be better provided. DISCUSSION: Consent is more than a signature on a form. It provides objective evidence of a shared decision-making process between the surgeon, patient, and their parent/guardian. Our initial study highlights multiple areas for improvement.

Multifocal Infratentorial Pilocytic Astrocytoma in an Adult Patient.

BACKGROUND: Pilocytic astrocytoma is a benign glial tumor typically presenting in children. It is rare for adults to present with pilocytic astrocytoma and even less likely to manifest with multiple foci of lesions especially in nonoptic or hypothalamic locations. CASE DESCRIPTION: Our patient was a 37-year old man presenting with varied cranial neuropathies, cerebellar dysfunction, and long tract signs, with imaging demonstrating 3 discrete ill-defined contrast-enhancing lesions affecting the cerebellar peduncles, brainstem, and cervicomedullary junction. Neuronavigation-guided biopsy confirmed World Health Organization grade 1 pilocytic astrocytoma; the patient was treated with radiotherapy. CONCLUSIONS: To our knowledge, we believe this is the first reported case with multifocal infratentorial pilocytic astrocytoma on presentation in an adult patient in the absence of a prior history of associated risk factors such as neurofibromatosis 1 or chemoradiotherapeutic intervention.