Frameless robot-assisted stereoelectroencephalography-guided radiofrequency: methodology, results, complications and stereotactic application accuracy in pediatric hypothalamic hamartomas.

Objective: We aimed to investigate the methodology, results, complications and stereotactic application accuracy of electrode implantation and its explanatory variables in stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-RFTC) for pediatric hypothalamic hamartoma. Methods: Children with hypothalamic hamartoma who underwent robot-assisted SEEG-RFTC between December 2017 and November 2021 were retrospectively analyzed. The methodology, seizure outcome, complications, in vivo accuracy of electrode implantation and its explanatory variables were analyzed. Results: A total of 161 electrodes were implanted in 28 patients with 30 surgeries. Nine electrodes not following the planned trajectories due to intraoperative replanning were excluded, and the entry point and target point errors of 152 electrodes were statistically analyzed. The median entry point error was 0.87 mm (interquartile range, 0.50-1.41 mm), and the median target point error was 2.74 mm (interquartile range, 2.01-3.63 mm). Multifactor analysis showed that whether the electrode was bent (b = 2.16, p < 0.001), the length of the intracranial electrode (b = 0.02, p = 0.049), and the entry point error (b = 0.337, p = 0.017) had statistically significant effects on the target error. During follow-up (mean duration 31 months), 27 of 30 (90%) procedures were seizure-free. The implantation-related complication rate was 2.6% (4/152), and the major complication rate in all procedures was 6.7% (2/30). Conclusion: Robot-assisted SEEG-RFTC is a safe, effective and accurate procedure for pediatric hypothalamic hamartoma. Explanatory variables significantly associated with the target point localization error at multivariate analysis include whether the intracranial electrode is bent, the intracranial electrode length and the entry point error.

The prevalence and risk factors of coagulopathy in pediatric patients undergoing surgery for epilepsy.

OBJECTIVE: Hematological consequences of novel antiseizure medications (ASMs) or combined therapies are rarely reported, especially in pediatric patients undergoing surgery for epilepsy. This study aimed to assess the prevalence and risk factors of coagulation dysfunction in this population and evaluate their relationship with intra- and postoperative bleeding. METHODS: Three hundred ninety children who underwent surgery for epilepsy and 104 children without epilepsy who underwent nonepilepsy surgery at the authors' center were included in the study. The authors retrospectively collected and analyzed the following clinical data: sex, age, weight, course of epilepsy, antiseizure therapy, first laboratory data after admission, and transfusion-related data. RESULTS: ASMs were responsible for the higher incidence of coagulation dysfunction in pediatric epilepsy surgery patients. Low body weight (OR 0.95, 95% CI 0.92-0.98) and valproic acid (VPA) therapy (OR 5.13, 95% CI 3.25-8.22) were the most relevant factors leading to coagulation dysfunction. The most common hematological side effects of VPA were thrombocytopenia and hypofibrinogenemia, whereas low body weight was only associated with hypofibrinogenemia. Both VPA and low body weight increased the need for intra- or postoperative transfusion (p < 0.001). CONCLUSIONS: Pediatric epilepsy surgery patients often take multiple ASMs, resulting in an increased incidence of coagulopathy. VPA levels and low body weight were found to be the main influential factors associated with an increased risk of coagulation dysfunction. Platelet and fibrinogen levels were the main indices that were affected. Both VPA and low body weight were relevant to additional surgery-related transfusion, necessitating the need for increased awareness of preoperative coagulopathy before pediatric epilepsy surgery. Clinical trial registration no.: NCT05675254 (ClinicalTrials.gov).

Frameless robot-assisted stereotactic biopsy: an effective and minimally invasive technique for pediatric diffuse intrinsic pontine gliomas.

PURPOSE: Diffuse intrinsic pontine gliomas (DIPGs) are prone to high surgical risks, and they could even lead to death due to their specific sites. To determine the value of frameless robot-assisted stereotactic biopsies of DIPGs, when compared it with microsurgical biopsies. METHODS: We conducted a retrospective study of 71 pediatric patients who underwent biopsies from January 2016 to January 2021. (i) group 1: microsurgical biopsies, and (ii) group 2: frameless robot-assisted stereotactic biopsies. Demographic information, neuroimaging characteristics, pathological diagnoses, operation time, postoperative intensive care unit (ICU) stay time, postoperative hospitalization time, complications, cost, and perioperative mortality rate (POMR) were collected for analyses. RESULTS: 32 Cases underwent microsurgical biopsies (group 1) and 39 cases underwent frameless robot-assisted stereotactic biopsies (group 2). All cases were accurately diagnosed after surgery. There was no significant difference in gender, age, symptom times and tumor volumes between the two groups (p > 0.05); operation time, postoperative ICU, stay time and postoperative hospitalization time were longer in group 1 than in group 2 (p < 0.001); the intraoperative bleeding volumes and cost were higher in group 1 than in group 2 (p < 0.001). Group 1 patients required more perioperative blood transfusion than group 2 (p = 0.001), and the new neurological impairments were more frequent in group 1 than in group 2 (p = 0.003). The POMR was 9.38% (3/32) in group 1 and 0 in group 2 (p = 0.087). CONCLUSIONS: Frameless robot-assisted stereotactic biopsy was an effective and minimally invasive technique for pediatric DIPGs.

Physiological significance of R-fMRI indices: Can functional metrics differentiate structural lesions (brain tumors)?

Resting-state functional MRI (R-fMRI) research has recently entered the era of "big data", however, few studies have provided a rigorous validation of the physiological underpinnings of R-fMRI indices. Although studies have reported that various neuropsychiatric disorders exhibit abnormalities in R-fMRI measures, these "biomarkers" have not been validated in differentiating structural lesions (brain tumors) as a concept proof. We enrolled 60 patients with intracranial tumors located in the unilateral cranialcavity and 60 matched normal controls to test whether R-fMRI indices can differentiate tumors, which represents a prerequisite for adapting such indices as biomarkers for neuropsychiatric disorders. Common R-fMRI indices of tumors and their counterpart control regions, which were defined as the contralateral normal areas (for amplitude of low frequency fluctuations (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo) and degree centrality (DC)) and ipsilateral regions surrounding the tumors (for voxel-mirrored homotopic connectivity (VMHC)), were comprehensively assessed. According to robust paired t-tests with a Bonferroni correction, only VMHC (Fisher's r-to-z transformed) could successfully differentiate substantial tumors from their counterpart normal regions in patients. Furthermore, ALFF and DC were not able to differentiate tumor from normal unless Z-standardization was employed. To validate the lower power of the between-subject design compared to the within-subject design, each metric was calculated in a matched control group, and robust two-sample t-tests were used to compare the patient tumors and the normal controls at the same place. Similarly, only VMHC succeeded in differentiating significant differences between tumors and the sham tumor areas of normal controls. This study tested the premise of R-fMRI biomarkers for differentiating lesions, and brings a new understanding to physical significance of the Z-standardization.

The correlation between accumulation of amyloid beta with enhanced neuroinflammation and cognitive impairment after intraventricular hemorrhage.

OBJECTIVE: Intraventricular hemorrhage (IVH) is found in approximately 40% of intracerebral hemorrhages and is associated with increased mortality and poor functional outcome. Cognitive impairment is one of the complications and occurs due to various pathological changes. Amyloid beta (Aß) accumulation and neuroinflammation, and the Alzheimer disease-like pathology, may contribute to cognitive impairment. Iron, the degradation product of hemoglobin, correlates with Aß. In this study, the authors investigated the correlation between Aß accumulation with enhanced neuroinflammation and cognitive impairment in a rat model of IVH. METHODS: Nine male Sprague-Dawley rats underwent an intraventricular injection of autologous blood. Another 9 rats served as controls. Cognitive function was assessed by the Morris water maze and T-maze rewarded alternation tests. Biomarkers of Aß accumulation, neuroinflammation, and c-Jun N-terminal kinase (JNK) activation were examined. RESULTS: Cognitive function was impaired in the autologous blood injection group compared with the control group. In the blood injection group, Aß accumulation was observed, with a co-located correlation between iron storage protein ferritin and Aß. Beta-site amyloid precursor protein cleaving enzyme-1 (BACE1) activity was elevated. Microgliosis and astrogliosis were observed in hippocampal CA1, CA2, CA3, and dentate gyrus areas, with elevated proinflammatory cytokines tumor necrosis factor-α and interleukin-1. Protein levels of phosphorylated JNK were increased after blood injection. CONCLUSIONS: Aß accumulation and enhanced neuroinflammation have a role in cognitive impairment after IVH. A potential therapeutic method requires further investigation.

Effectiveness of deferoxamine on ferric chloride-induced epilepsy in rats.

Iron overload has been regarded as a common cause for refractory epilepsies in patients after hemorrhagic strokes. This study is to examine the potential epilepsy control effect of deferoxamine (DFO), an iron chelator, on a ferric chloride-induced epilepsy rat model. Twenty four rats were divided into 4 groups: group I is blank control group, group II is sham group with intracortical injection of saline, group III is epilepsy group with intracortical injection of iron and saline treatment, group IV is treatment group with intracortical injection of iron and DFO treatment. For the DFO intervention group, a daily dose of 100mg/kg DFO via peritoneal injection was applied for 14days. Outcomes were evaluated by behavioral study, electroencephalography (EEG), magnetic resonance imaging (MRI) scan and tissue analysis. Epilepsies according to behavioral observations and EEG analysis were significantly suppressed after intervention of DFO. Reduction of iron content in the brain cortex was proved by diminished low signal area on T2-MRI images (p=0.006) and tissue analysis (p<0.001), simultaneously the superoxide dismutase (SOD) activity increased (p<0.001). Western blot analysis demonstrated the decreasing of local transferrin after DFO treatment. DFO is efficient at Fe clearance, thus helpful in epilepsy control. This finding implies potential therapeutic value of DFO in patients with refractory epilepsy after hemorrhagic stroke.