Background: Ventricular shunt infections lead to significant morbidity and mortality. This study aimed to identify risk factors for 30-day postoperative infection outcomes of ventricular shunts for pediatric hydrocephalus. Methods: A retrospective cohort study using the National Surgical Quality Improvement Program (NSQIP) Pediatric database for years 2016-2021 was conducted. Patients under 18 years undergoing ventricular shunt surgery were included. The primary outcome was 30-day postoperative shunt infection. A multivariable logistic regression analysis of fourteen prognostic variables was performed. Results: A total of 10,878 patients (mean age 3.1 years, 44.2% female) were included. The 30-day postoperative shunt infection rate was 3.7%. Infection risk increased with nutritional support, longer operating room duration, and congenital hydrocephalus. Risk decreased with increasing age, intraoperative intraventricular antibiotics, and first-time shunt placement. Variables not significantly affecting infection risk included sex, BMI, ostomy, tracheostomy, neuromuscular disease, structural pulmonary/airway abnormality, steroid use, antibiotic-impregnated shunts, and endoscopic catheter placement. Conclusions: Postoperative shunt infections in pediatric patients are influenced by both modifiable and non-modifiable factors. Identifying and addressing modifiable risks can significantly reduce infection rates, minimize the need for surgical revisions, and enhance therapeutic outcomes and overall quality of life.

Background: Diffusion tensor imaging (DTI) tractography enables detailed visualization of white matter tracts (WMT) relevant to surgical planning. Head-to-head performance of clinically available DTI software has not been assessed. We retrospectively compared Synaptive’s Modus Plan™(vers. 2.0.1.1743) and Medtronic’s StealthViz™(vers. 1.4) software, focusing on workflow, usability, stability, and capacity to generate WMT reconstructions. Methods: Retrospective evaluation of patients (n=13) with intrinsic brain lesions (01/2021-12/2023) with MP and SV software. Corticospinal and optic radiation WMT reconstruction was attempted according to the manufacturers specifications and was rated as clinically useful or not, based on anatomic plausibility. Duration of each analysis step (image importing, post-processing, segmentation, fine-tuning and tract export) was recorded. Ease of use, degree of clinician input, program stability, and tract output type were also assessed. Results: 13 patients (31±;19 yrs; 6F) were included. Mean workflow duration was significantly longer for MP (22:51 min) versus SV (7:35 min) (p<0.0001). Successful WMT reconstruction occurred in 9/13 (69.2%) with MP, versus 5/13 (38.5%) for SV. MP was rated to have superior usability, stability and required less clinician input but technical parameters (e.g. FA) or export object type was inflexible. Conclusions: Synaptive’s MP permitted more robust WMT reconstruction with enhanced usability and stability but with significantly longer workflow.

Background: There are few published reports on the safety and efficacy of stereoelectroencephalography (SEEG) in the presurgical evaluation of pediatric drug-resistant epilepsy. Our objective was to describe institutional experience with pediatric SEEG in terms of (1) insertional complications, (2) identification of the epileptogenic zone and (3) seizure outcome following SEEG-tailored resections. Methods: Retrospective review of 29 patients pediatric drug resistant epilepsy patients who underwent presurgical SEEG between 2005 – 2018. Results: 29 pediatric SEEG patients (15 male; 12.4 ± 4.6 years old) were included in this study with mean follow-up of 6.0 ± 4.1 years. SEEG-related complications occurred in 1/29 (3%)—neurogenic pulmonary edema. A total of 190 multi-contact electrodes (mean of 7.0 ± 2.5per patient) were implanted across 30 insertions which captured 437 electrographic seizures (mean 17.5 ± 27.6 per patient). The most common rationale for SEEG was normal MRI with surface EEG that failed to identify the EZ (16/29; 55%). SEEG-tailored resections were performed in 24/29 (83%). Engel I outcome was achieved following resections in 19/24 cases (79%) with 5.9 ± 4.0 years of post-operative follow-up. Conclusions: Stereoelectroencephalography in presurgical evaluation of pediatric drug-resistant epilepsy is a safe and effective way to identify the epileptogenic zone permitting SEEG-tailored resection.

Background: Diffusion-tensor imaging (DTI) tractography is commonly used in neurosurgical practice, but is largely limited to the preoperative setting. This is due primarily to image degradation caused by susceptibility artifact when conventional single-shot (SS) echo-planar imaging DTI is acquired for open cranial, surgical position intraoperative DTI (iDTI). A novel, artifact-resistant, readout-segmented (RS) DTI has not yet been evaluated in the intraoperative MRI (iMRI) environment. Our objective was to evaluate the performance of RS-DTI versus SS-DTI for intraoperative white matter imaging. Methods: Pre- and intraoperative 3T, T1-weighted and DTI (RS-iDTI and SS-iDTI) in 22 adults undergoing intraaxial iMRI resections (low-grade glioma: 14, 64%; high-grade glioma: 7, 32%; cortical dysplasia: 1). Regional susceptibility artifact, anatomical deviation relative to T1WI, and tractographic output were compared between iDTI sequences. Results: RS-iDTI resulted in less regional susceptibility artifact and mean anatomic deviation (RS-iDTI: 2.7±0.2 mm versus SS-iDTI 7.5±0.4 mm; p<0.0001). Tractographic failure occurred in 8/22 (36%) patients for SS-iDTI whereas RS-iDTI permitted successful reconstruction in 4 of these 8. Maximal tractographic differences between DTI sequences were substantial (mean 9.7±5.7 mm). Conclusions: Readout-segmented EPI enables higher quality and more accurate DTI for surgically relevant tractography of major white matter tracts in intraoperative, open cranium, neurosurgical applications at 3T.

Background: Selective amygdalohippocampectomy (SAH) is a surgical option in well-selected cases of pediatric medically refractory temporal lobe epilepsy (TLE). The objective of this study was to compare the surgical outcome and the rate of reoperation for ongoing or recurrent seizures between SAH and anterior temporal lobectomy (ATL) in pediatric TLE. Methods: Retrospective review of 78 pediatric intractable TLE patients referred to the Comprehensive Epilepsy Program at our institution between 1988 and 2015 treated initially with either a trans-middle temporal gyrus SAH (19) or ATL (59). Patients underwent baseline long-term video electroencephalography and 1.5-Tesla MRI. Neuropsychological testing was performed preoperatively and 12-months postoperatively (including reoperations). Results: The mean follow-up was 64 months (range, 12-186 months). The average age at initial surgery was 10.6±5 years with an average delay of 5.7±4 years between seizure onset and surgery. Ultimately 78% were seizure-free (61/78) at most recent follow-up. Seizure freedom after initial surgical treatment was achieved in 81% of patients who underwent ATL (48 patients) versus 42% in SAH (8 patients; p<0.001). Of patients with ongoing disabling seizures following SAH, reoperation (ATL) was offered in 8 resulting in seizure freedom in 63%, without interval neuropsychological decline. Conclusions: SAH amongst well-selected pediatric TLE results in significantly worse seizure control compared with ATL.

Background: It remains difficult to predict which patients will experience ongoing seizures or neuropsychological deficits following Temporal Lobe Epilepsy (TLE) surgery. MRI allows measurement of brain structures, such as the contralateral (non-resected) hippocampus (cHC) after TLE surgery. Preliminary evidence suggests that the cHC atrophies following surgery, however, the time course of this atrophy, relation to cognitive deficits and seizure outcome remains unclear. Methods: T1-weighted MR imaging and hippocampal volumetry in 26 TLE patients pre- and post-TLE surgery (and 12 controls) as: 1) two-scan group (TSG) (pre- and post-operatively at 5.4 years) and 2) longitudinal group (LG; pre- and on post-operatively on day 1,2,3,6,60,120 and at an average 2.4 years. Seizure outcome and pre- and post-operative neuropsychological assessment was performed. Results: The TSG had significant atrophy by 12% of the unresected cHC (p<0.0001) most pronounced (27%) in the hippocampal body alone. The LG revealed that this atrophy occured rapidly over the first week (1.3%/day; 3%/day cHC body). Significantly greater cHC atrophy was observed in those with ongoing seizures versus the seizure free (p=0.048). Conclusions: Significant cHC atrophy following TLE surgery that begins immediately, progresses over the first week, and remains signficantly depressed. The severity postoperative cHC atrophy may represent an early biomarker of the propensity for delayed seizure recurrence.

Background: Inflicted head injury is a major cause of infant morbidity and mortality. The extent of traumatic brain injury in infants is often best characterized by diffusion weighted magnetic resonance imaging. In this cases series we describe four infants aged 6-19 months, with small unilateral subdural hematomas secondary to abusive head trauma accompanied by extensive areas of restricted diffusion weighted imaging isolated to the cerebral white matter. Methods: Retrospective, single-centre case series of four children with small unilateral subdural hematomas with early and delayed MR imaging with diffusion weighted imaging. Results: In three cases there was acute diffusion restriction ispilateral to the subdural, while in one case diffusion restriction was present bilaterally. All patients had multiple seizures and bilateral multilayered retinal hemorrhages. After non-surgical treatment, all patients survived albeit with significant motor and cognitive deficits and significant cortical atrophy on long-term followup imaging. Conclusions: These four cases highlight that relatively small subdural hematomas following child abuse can manifest with extensive white matter injury only evident at early stages with diffusion weighted imaging. We propose that selective white matter injury as a result of either reperfusion or axonal degeneration in response to the initial insult accounts for this novel pattern of infantile traumatic brain injury.

Background: Temporal Lobe Epilepsy is associated with bilateral gray (GM) and white matter (WM) loss. After surgical treatment progressive bilateral temporal and extra-temporal WM change occur, however, less is known regarding post-operative GM change. We set out to measure contralateral hippocampal volume (CHV) following TLS. Methods: 1.5T-3D-1mm-isotropic-MPRAGE scans in 26 TLE patients and 3 controls in two groups: longitudinal (n=10)(imaged POD1,2,3,6,60,120 and >360d) and single post-operative scan (n=16). Manual volumetry protocols. Results: We find significant CHV atrophy at delayed scan relative to baseline (mean atrophy 26.8%). In the longitudinal group there is significant and progressive atrophy from baseline to POD4-8 (72.6+/-6.5%), POD60-360 (69.7+/-12.3%) and >360 (58.5+/-10.6%). No significant atrophy in either the control group HV or contralateral CV over time. No significant difference in mean HV at the most delayed exam for surgery type (p=0.13) or side (p=0.24). Conclusions: We find a statistically significant CHV atrophy following surgery which is progressive over time. Our longitudinal within-subject design describes the time course and extent more fully than previous work. Caudate analysis indicates that early CHV atrophy is not due to global atrophy following brain surgery but rather may be due to deafferentation and deefferentation. Finally, we find no significant difference in atrophy when analyzed by surgical approach or surgical side.