OBJECTIVE Ivy sign is a radiographic finding on FLAIR MRI sequences and is associated with slow cortical blood flow in moyamoya. Limited data exist on the utility of the ivy sign as a diagnostic and prognostic tool in pediatric patients, particularly outside of Asian populations. The authors aimed to investigate a modified grading scale with which to characterize the prevalence and extent of the ivy sign in children with moyamoya and evaluate its efficacy as a biomarker in predicting postoperative outcomes, including stroke risk. METHODS Pre- and postoperative clinical and radiographic data of all pediatric patients (21 years of age or younger) who underwent surgery for moyamoya disease or moyamoya syndrome at two major tertiary referral centers in the US and Israel, between July 2009 and August 2019, were retrospectively reviewed. Ivy sign scores were correlated to Suzuki stage, Matsushima grade, and postoperative stroke rate to quantify the diagnostic and prognostic utility of ivy sign. RESULTS A total of 171 hemispheres in 107 patients were included. The median age at the time of surgery was 9 years (range 3 months–21 years). The ivy sign was most frequently encountered in association with Suzuki stage III or IV disease in all vascular territories, including the anterior cerebral artery (53.7%), middle cerebral artery (56.3%), and posterior cerebral artery (47.5%) territories. Following surgical revascularization, 85% of hemispheres with Matsushima grade A demonstrated a concomitant, statistically significant reduction in ivy sign scores (OR 5.3, 95% CI 1.4–20.0; p = 0.013). Postoperatively, revascularized hemispheres that exhibited ivy sign score decreases had significantly lower rates of postoperative stroke (3.4%) compared with hemispheres that demonstrated no reversal of the ivy sign (16.1%) (OR 5.5, 95% CI 1.5–21.0; p = 0.008). CONCLUSIONS This is the largest study to date that focuses on the role of the ivy sign in pediatric moyamoya. These data demonstrate that the ivy sign was present in approximately half the pediatric patients with moyamoya with Suzuki stage III or IV disease, when blood flow was most unstable. The authors found that reversal of the ivy sign provided both radiographic and clinical utility as a prognostic biomarker postoperatively, given the statistically significant association with both better Matsushima grades and a fivefold reduction in postoperative stroke rates. These findings can help inform clinical decision-making, and they have particular value in the pediatric population, as the ability to minimize additional radiographic evaluations and tailor radiographic surveillance is requisite.

OBJECTIVE The assessment of hemorrhagic risk is of central importance in the management of pediatric brain arteriovenous malformations (AVMs). A recently published scoring system, the R2eD AVM (race, exclusive deep location or not, AVM size < 3 or ≥ 3, venous drainage exclusively deep or not, and monoarterial feeding or >1 arterial feeders) considers patient race and AVM location, size, venous drainage, and arterial supply and was successfully externally validated for use in adults to predict the risk of AVM hemorrhagic presentation. In this study the authors sought to externally validate the R2eD AVM score for prediction of hemorrhagic risk in the pediatric AVM population. METHODS A pediatric database at Boston Children’s Hospital was retrospectively reviewed for all patients with a diagnosis of intracranial AVM. Exclusion criteria included age > 21 years, multiple AVMs, and incomplete clinical/radiographic data. Demographic data and R2eD AVM score calculations were collected for all patients. Univariate binary logistic regression and multivariate stepwise backward elimination models were used to determine factors associated with hemorrhagic presentation. RESULTS A total of 212 AVMs were identified in 212 patients with vascular anomalies from 1995 to 2021, and 144 patients met the inclusion criteria (74 [51.4%] male, 111 [77.1%] White), of whom 87 (60.4%) patients presented with rupture and 122 (84.7%) underwent resection. The mean age at surgery was 12 years (range 3 months to 20 years). The R2eD AVM scoring system was applied to each patient. The score components of size < 3 cm and exclusive deep venous drainage were significantly associated with rupture risk (p < 0.05). The complete model for the R2eD AVM score had an area under the curve of 0.671 (95% CI 0.586–0.757). CONCLUSIONS This study demonstrated poor external validity of the R2eD AVM score in predicting pediatric AVM rupture risk. The results suggest that future studies are warranted to determine a better scoring method to capture pediatric rupture risk, given the significant differences in clinical presentation in pediatric compared with adult AVM patients.

OBJECTIVE Stereoelectroencephalography (SEEG) and MRI-guided laser interstitial thermal therapy (MRgLITT) have emerged as safe, effective, and less invasive alternatives to subdural grid placement and open resection, respectively, for the localization and treatment of medically refractory epilepsy (MRE) in children. Reported pediatric experience combining these complementary techniques is limited, with traditional workflows separating electrode removal and ablation/resection. The authors describe the largest reported series of pediatric epilepsy patients who underwent MRgLITT following SEEG contrasted with a cohort that underwent craniotomy following SEEG, combining ablation/resection with electrode explantation as standard practice. METHODS The medical records of all patients with MRE who had undergone SEEG followed by MRgLITT or open resection/disconnection at Boston Children’s Hospital between November 2015 and December 2020 were retrospectively reviewed. Primary outcome variables included surgical complication rates, length of hospital stay following treatment, and Engel classification at the last follow-up. RESULTS Of 74 SEEG patients, 27 (median age 12.1 years, 63% female) underwent MRgLITT and 47 (median age 12.1 years, 49% female) underwent craniotomy. Seventy patients (95%) underwent SEEG followed by combined electrode removal and treatment. Eight MRgLITT cases (30%) and no open cases targeted the insula (p < 0.001). Complication rates did not differ, although trends toward more subdural/epidural hematomas, infarcts, and permanent unanticipated neurological deficits were evident following craniotomy, whereas a trend toward more temporary unanticipated neurological deficits was seen following MRgLITT. The median duration of hospitalization after treatment was 3 and 5 days for MRgLITT and open cases, respectively (p = 0.078). Seizure outcomes were similar between the cohorts, with 74% of MRgLITT and craniotomy patients attaining Engel class I or II outcomes (p = 0.386) at the last follow-up (median 1.1 and 1.9 years, respectively). CONCLUSIONS MRgLITT and open resection following SEEG can both effectively treat MRE in pediatric patients and generally can be performed in a two-surgery workflow during a single hospitalization. In appropriately selected patients, MRgLITT tended to be associated with shorter hospitalizations and fewer complications following treatment and may be best suited for focal deep-seated targets associated with relatively challenging open surgical approaches.