Evaluating the efficacy and safety of single-agent etoposide intra-CSF chemotherapy in children and young people with relapsed/refractory central nervous system tumours.

PURPOSE: The aim of the project was to evaluate intra-CSF etoposide administration in a palliative setting for children and young people with relapsed/refractory central nervous system (CNS) tumours, with the primary endpoints being overall survival and progression-free survival time. A safety endpoint was to assess the side effect profile and complications of intra-CSF etoposide. METHODS: Thirty-five patients under the age of 30 years (median age: 5.33 years) were enrolled onto the project. The cross-centre study was a service evaluation, with a data collection spreadsheet designed in Nottingham and completed by both Nottingham and Oxford centres. Data was analysed using SPSS, assessing the overall survival and progression-free survival times, as well as the 6-month and 1-year survival rates. RESULTS: The median overall survival and progression-free survival times were 10.97 and 5.91 months, respectively. The 6-month and 1-year overall survival rates were 67% and 48%, and the progression-free survival rates were 50% and 22%. Age at the start of intra-CSF therapy was significantly associated with overall survival (P = 0.046), with the 6 + age group having improved overall survival. Treatment type was significantly associated with overall survival (P = 0.012), with etoposide intra-CSF treatment being associated with improved overall survival. Treatment duration was significantly associated with both overall survival (P < 0.001) and progression-free survival (P < 0.001). CONCLUSION: Intra-CSF etoposide treatment has shown to increase both overall and progression-free survival significantly, whilst having few side effects and maintaining a good quality of life for patients, reflecting it as a beneficial therapy in the palliative setting.

Clinical utility of circulating miR-371a-3p for the management of patients with intracranial malignant germ cell tumors.

BACKGROUND: The current biomarkers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) have limited sensitivity/specificity for diagnosing malignant germ cell tumors (GCTs) and "marker-negative" patients require histological confirmation for diagnosis. However, GCTs at intracranial sites are surgically relatively inaccessible and biopsy carries risks. MicroRNAs from the miR-371~373 and miR-302/367 clusters are over-expressed in all malignant GCTs and, in particular, miR-371a-3p shows elevated serum levels at diagnosis for testicular disease. METHODS: Using our robust preamplified qRT-PCR methodology, we quantified miR-371a-3p levels in serum and cerebrospinal fluid (CSF) in a series of 4 representative clinical cases, 3 with intracranial malignant GCT and 1 with Langerhans cell histiocytosis (LCH), compared with appropriate control cases. RESULTS: Serum and/or CSF miR-371a-3p levels distinguished those with intracranial malignant GCTs from LCH and, if known in real time, could have helped clinical management. The benefits would have included (1) the only confirmatory evidence of an intracranial malignant GCT in 1 case, supporting clinical decision making; (2) early detection of intracranial malignant GCT in another, where an elevated CSF miR-371a-3p level preceded the histologically confirmed diagnosis by 2 years; and (3) confirmation of an intracranial malignant GCT relapse with an elevated serum miR-371a-3p level, where serum and CSF AFP and HCG levels were below thresholds for such a diagnosis. CONCLUSIONS: This series highlights the potential for microRNA quantification to assist the noninvasive diagnosis, prognostication, and management for patients with intracranial malignant GCTs. Serum and CSF should be collected routinely as part of future studies to facilitate the extension of these findings to larger patient cohorts.

Feasibility of awake craniotomy in the pediatric population.

BACKGROUND: Awake craniotomy with direct cortical stimulation and mapping is the gold standard for resection of lesions near eloquent brain areas, as it can maximize the extent of resection while minimizing the risk of neurological damage. In contrast to the adult population, only small series of awake craniotomies have been reported in children. AIMS: The aim of our study is to establish the feasibility of awake craniotomy in the pediatric population. METHODS: We performed a retrospective observational study of children undergoing a supratentorial awake craniotomy between January 2009 and April 2019 in a pediatric tertiary care center. Our primary outcome was feasibility of awake craniotomy, defined as the ability to complete the procedure without conversion to general anesthesia. Our secondary outcomes were the incidence of serious intraoperative complications and the mapping completion rate. RESULTS: Thirty procedures were performed in 28 children: 12 females and 16 males. The median age was 14 years (range 7-17). The primary diagnosis was tumor (83.3%), epilepsy (13.3%), and arterio-venous malformation (3.3%). The anesthetic techniques were asleep-awake-asleep (96.7%) and conscious sedation (3.3%), all cases supplemented with scalp block and pin-site infiltration. Awake craniotomy was feasible in 29 cases (96.7%), one patient converted to general anesthesia due to agitation. Serious complications occurred in six patients: agitation (6.7%), seizures (3.3%), increased intracranial pressure (3.3%), respiratory depression (3.3%), and bradycardia (3.3%). All complications were quickly resolved and without major consequences. Cortical mapping was completed in 96.6% cases. New neurological deficits occurred in six patients (20%)-moderate in one case and mild in 5-being all absent at 6 months of follow-up. CONCLUSION: Awake craniotomy with intraoperative mapping can be successfully performed in children. Adequate patient selection and close cooperation between neurosurgeons, anesthesiologists, neuropsychologists, and neurophysiologists is paramount. Further studies are needed to determine the best anesthetic technique in this population group.

Phosphorus spectroscopy in acute TBI demonstrates metabolic changes that relate to outcome in the presence of normal structural MRI.

Metabolic dysfunction is a key pathophysiological process in the acute phase of traumatic brain injury (TBI). Although changes in brain glucose metabolism and extracellular lactate/pyruvate ratio are well known, it was hitherto unknown whether these translate to downstream changes in ATP metabolism and intracellular pH. We have performed the first clinical voxel-based in vivo phosphorus magnetic resonance spectroscopy (31P MRS) in 13 acute-phase major TBI patients versus 10 healthy controls (HCs), at 3T, focusing on eight central 2.5 × 2.5 × 2.5 cm3 voxels per subject. PCr/γATP ratio (a measure of energy status) in TBI patients was significantly higher (median = 1.09) than that of HCs (median = 0.93) (p < 0.0001), due to changes in both PCr and ATP. There was no significant difference in PCr/γATP between TBI patients with favourable and unfavourable outcome. Cerebral intracellular pH of TBI patients was significantly higher (median = 7.04) than that of HCs (median = 7.00) (p = 0.04). Alkalosis was limited to patients with unfavourable outcome (median = 7.07) (p < 0.0001). These changes persisted after excluding voxels with > 5% radiologically visible injury. This is the first clinical demonstration of brain alkalosis and elevated PCr/γATP ratio acutely after major TBI. 31P MRS has potential for non-invasively assessing brain injury in the absence of structural injury, predicting outcome and monitoring therapy response.

The role of surgery in refractory epilepsy secondary to polymicrogyria in the pediatric population.

OBJECTIVE: Polymicrogyria (PMG) is a common malformation of cortical development. Many patients with PMG will have medically refractory epilepsy but the role of epilepsy surgery is unclear. The objective of this study was to assess the efficacy of surgical resection/disconnection in achieving seizure control in pediatric patients with PMG. METHODS: A retrospective review of children undergoing epilepsy surgery for PMG between 2002 and 2017 at The Hospital for Sick Children in Toronto, Canada, was performed. RESULTS: A total of 12 children aged 6 months to 17.8 years (median 8.8 years) underwent resective surgery (7 children) or functional hemispherectomy (5 children). Gross total resection or complete disconnection of PMG was carried out in 7 of 12 children. Follow-up duration was between 1 and 9 years (median 2.1 years). Nine children remained seizure-free at last follow-up. Complete resection or disconnection of PMG led to seizure freedom in 6 of 7 patients (86%), whereas subtotal resection produced seizure freedom in 3 of 5 patients (60%). SIGNIFICANCE: We present one of the largest surgical series of pediatric PMG patients. Seizure outcomes were best with complete resection/disconnection of PMG. However, tailored resections based on electroclinical and neuroradiologic data can produce good outcomes and remain an appropriate strategy for patients with extensive PMG.

The effect of succinate on brain NADH/NAD+ redox state and high energy phosphate metabolism in acute traumatic brain injury.

A key pathophysiological process and therapeutic target in the critical early post-injury period of traumatic brain injury (TBI) is cell mitochondrial dysfunction; characterised by elevation of brain lactate/pyruvate (L/P) ratio in the absence of hypoxia. We previously showed that succinate can improve brain extracellular chemistry in acute TBI, but it was not clear if this translates to a change in downstream energy metabolism. We studied the effect of microdialysis-delivered succinate on brain energy state (phosphocreatine/ATP ratio (PCr/ATP)) with 31P MRS at 3T, and tissue NADH/NAD+ redox state using microdialysis (L/P ratio) in eight patients with acute major TBI (mean 7 days). Succinate perfusion was associated with increased extracellular pyruvate (+26%, p < 0.0001) and decreased L/P ratio (-13%, p < 0.0001) in patients overall (baseline-vs-supplementation over time), but no clear-cut change in 31P MRS PCr/ATP existed in our cohort (p > 0.4, supplemented-voxel-vs-contralateral voxel). However, the percentage decrease in L/P ratio for each patient following succinate perfusion correlated significantly with their percentage increase in PCr/ATP ratio (Spearman's rank correlation, r = -0.86, p = 0.024). Our findings support the interpretation that L/P ratio is linked to brain energy state, and that succinate may support brain energy metabolism in select TBI patients suffering from mitochondrial dysfunction.

Glycolysis and the pentose phosphate pathway after human traumatic brain injury: microdialysis studies using 1,2-(13)C2 glucose.

Increased 'anaerobic' glucose metabolism is observed after traumatic brain injury (TBI) attributed to increased glycolysis. An alternative route is the pentose phosphate pathway (PPP), which generates putatively protective and reparative molecules. To compare pathways we employed microdialysis to perfuse 1,2-(13)C2 glucose into the brains of 15 TBI patients and macroscopically normal brain in six patients undergoing surgery for benign tumors, and to simultaneously collect products for nuclear magnetic resonance (NMR) analysis. (13)C enrichment for glycolytic 2,3-(13)C2 lactate was the median 5.4% (interquartile range (IQR) 4.6-7.5%) in TBI brain and 4.2% (2.4-4.4%) in 'normal' brain (P<0.01). The ratio of PPP-derived 3-(13)C lactate to glycolytic 2,3-(13)C2 lactate was median 4.9% (3.6-8.2%) in TBI brain and 6.7% (6.3-8.9%) in 'normal' brain. An inverse relationship was seen for PPP-glycolytic lactate ratio versus PbtO2 (r=-0.5, P=0.04) in TBI brain. Thus, glycolytic lactate production was significantly greater in TBI than 'normal' brain. Several TBI patients exhibited PPP-lactate elevation above the 'normal' range. There was proportionally greater PPP-derived lactate production with decreasing PbtO2. The study raises questions about the roles of the PPP and glycolysis after TBI, and whether they can be manipulated to achieve a better outcome. This study is the first direct comparison of glycolysis and PPP in human brain.

Giant intracranial hemangioma in a neonate.

In this report we detail the case of an infant presenting with a giant intracranial congenital hemangioma and describe the clinical features and surgical management. Congenital hemangiomas are benign vascular tumors that typically present as skin lesions in neonates and infants. On rare occasions they present as intracranial tumors. The possibility that these tumors may undergo spontaneous regression poses a treatment dilemma.

Spinal intradural haemorrhage in a patient with Wegener's Granulomatosis.

We describe the case of a patient with known Wegener's Granulomatosis who developed a spontaneous intradural haematoma in the thoracic spine against a background of a recent relapse in her vasculitis. Decompression resulted in a rapid recovery of lower limb function. We propose involvement of the spinal meninges in the systemic vasculitis as the cause of haemorrhage.

Reactivation and centripetal spread of herpes simplex virus complicating acoustic neuroma resection.

BACKGROUND: Herpes simplex is a common human pathogen that has rare but severe manifestations including encephalitis. CASE DESCRIPTION: A 44-year-old man underwent uneventful resection of an acoustic neuroma. Postoperatively, he developed swinging pyrexia, vomiting, and episodic confusion. Analysis of cerebrospinal fluid showed a lymphocytosis, and polymerase chain reaction revealed herpes simplex DNA. After treatment of herpes encephalitis with acyclovir, the patient made a good recovery. CONCLUSION: Herpes encephalitis is a rare complication of neurosurgical procedures, and the most likely etiology is reactivation of latent infection from manipulation of cranial nerves.