Hippocampal resection during hemispherotomy: is it needed?

PURPOSE: Hemispherotomy is an effective surgery for intractable pediatric hemispheric epilepsy. Over the years, the surgical goal has shifted from a complete hemispheric resection (anatomical hemispherectomy) to a disconnective hemispherotomy (DH). Multiple techniques for DH have been described, and often, anterior temporal lobectomy (ATL, with hippocampal resection) is performed. The goal of the current study is to assess the role of hippocampal resection in DH. METHODS: We retrospectively collected all clinical data of children (< 18 years old) who underwent DH between 2001 and 2022 at two tertiary large centers. Epilepsy status and surgical outcome were compared, based on whether the hippocampus was resected (as part of an ATL) or disconnected at the amygdala and atrial segment of the fornix (with no ATL). RESULTS: A total of 86 patients (32 females) were included. The most common epilepsy etiologies were stroke (31), Rasmussen's encephalitis (16), cortical dysplasia (10), and hemimegaloencephaly (9). The mean age at surgery was 7 (± 4.9) years. The average number of anti-seizure medications (ASMs) at surgery was 3 (± 1.2). Hemispherotomy techniques included peri-insular (54), vertical (23 [19 endoscopic + 4 parasagittal]), and trans-sylvian (9). The mean follow-up was 41.5 (± 38) months. Forty-three patients had hippocampal resection, and 43 patients had a hippocampal disconnection. Both groups had similar Engel outcome scores (p = 0.53). CONCLUSIONS: Disconnective hemispherotomy is highly effective for pediatric intractable hemispheric epilepsy. Our data suggest that the inclusion of hippocampal resection does not provide additional benefit.

Filum terminale lipomas-the role of intraoperative neuromonitoring.

BACKGROUND: Filum terminale lipomas (FTL) represent a sub-type of spinal lipomas, where there is fatty infiltration of the filum. It becomes a surgical entity when it manifests as clinical or radiological tethered cord syndrome. Intraoperative neuromonitoring (IONM) has been suggested as a valuable tool in children for tethered cord surgeries. FTL is distinct and cannot be compared with complex tethered cord syndrome (TCS). Untethering an FTL is a relatively straightforward microsurgical exercise, usually based on anatomical findings. Neurological morbidity in FTL untethering is extremely low. The necessity of IONM in FTL has not been evaluated. The objective of this study was to identify the role of IONM in untethering an FTL METHODS: Available electronic data and case files were interrogated to identify children (0-18 years) who underwent an untethering of FTL between 2008 and 2019. We had a shift in our policy and tried to use IONM as often as possible in all tethered cord surgery from 2014. All children were categorised under 'IONM implemented' or 'no IONM' group. Outcomes analysed were as follows: (1) Clinical status on short-term and long-term follow-up, (2) alteration of surgical course by IONM and (3) complications specifically associated with IONM RESULTS: Among 80 children included in this study, IONM was implemented in 37 children and 43 children underwent untethering without IONM. 32.5% of children were 'syndromic'. Seventy-five percent of children were under age 3 years during surgery. Both groups (No IONM vs. IONM implemented) were well matched in most variables. Majority of 'no IONM' surgeries were performed prior to 2014. There was no neurological morbidity in the entire cohort. Mean duration of follow-up was 49.10 (± 33.67) months. Short-term and long-term clinical status remained stable in both cohorts. In 16 children, the filum was stimulated. Based on our protocol, majority had a negative response. One child showed a positive response, contradicted by thorough microscopic inspection. Despite a positive response, the filum was untethered. IONM was not associated with any complication in this study. CONCLUSION: FTL untethering is an inherently low-risk microsurgery in experienced hands with rarely reported neurological morbidity. IONM may not be required for all FTL and may be used more judiciously.

The Role of 3D Reconstruction of the Skull in Patients with Suspected Shunt Malfunction.

BACKGROUND: Mechanical shunt malfunction may lead to significant morbidity and mortality. Shunt series assessments help evaluate shunt integrity; however, they are of limited value in the area of the skull due to skull curvature, thickness, and air sinuses. We describe the role of 3D bone reconstruction CT (3DCT) in demonstrating the shunt integrity over the skull, comparing this technique to skull X-rays (SXR). METHODS: Data were collected retrospectively for shunted patients with concurrent SXR and 3DCT and for patients presenting with shunt failures at the region of the skull, including clinical course and radiological findings. We compared the SXR and 3DCT findings. The 3DCT was reconstructed from standard diagnostic CT protocols performed during evaluation of suspected shunt malfunction and not thin-slice CT protocols. RESULTS: Forty-eight patients with 57 shunts underwent SXR and 3DCT. Interobserver agreement was high for most variables. Both SXR and 3DCT had a high sensitivity, specificity, and accuracy identifying tubing disconnections (between 0.83 and 1). Full valve type and setting were significantly more accurate based on SXR versus 3DCT (>90 vs. <20%), and valve integrity was significantly more readily verified on 3DCT versus SXR (100 vs. 52%). CONCLUSIONS: 3DCT and SXR complement each other in diagnosing mechanical shunt malfunctions over the skull. The main limitation of 3DCT is identification of valve type and settings, which are clearer on SXR, while the main limitation of SXR is a less ability to evaluate valve integrity. 3DCT also enables an intuitive 3D understanding of the shunt tubing over the skull.

Hodgkin lymphoma patients in first remission: routine positron emission tomography/computerized tomography imaging is not superior to clinical follow-up for patients with no residual mass.

There is no consensus regarding optimal follow-up mode for Hodgkin lymphoma (HL) patients that achieve complete remission following chemotherapy or combined chemo- and radiation therapy. Several studies demonstrated high sensitivity of positron emission tomography/computerized tomography (PET/CT) in detecting disease progression; however, these techniques are currently not recommended for routine follow-up. This retrospective study conducted in two Israeli (N = 291) and one New Zealand academic centres (N = 77), compared a group of HL patients, followed-up with routine imaging every 6 months during the first 2 years after achieving remission, once in the third year, with additional dedicated studies performed due to symptoms or physical findings (Group I) to a group of patients without residual masses who underwent clinically-based surveillance with dedicated imaging upon relapse suspicion (Group II). Five-year overall survival (OS) was 94% and median time to relapse was 8·6 months for both modes. Relapse rates in Groups I and II were 13% and 9%, respectively. During the first 3 years of follow-up, 47·5 and 4·7 studies were performed per detected relapse in Groups I and II, respectively. The current study demonstrated no benefit in either progression-free survival (PFS) or OS in HL patients followed by routine imaging versus clinical follow-up. The cost was 10 times higher for routine imaging.

Differentiating spinal pathologies by deep learning approach.

BACKGROUND CONTEXT: Spinal pathologies are diverse in nature and, excluding trauma and degenerative diseases, includes infectious, neoplastic (either extradural or intradural), and inflammatory conditions. The preoperative diagnosis is made with clinical judgment incorporating lab findings and radiological studies. When the diagnosis is uncertain, a biopsy is almost always mandatory since the treatment is dictated by the type of pathology. This is an invasive, timely, and costly process. PURPOSE: The aim of this study was to develop a deep learning (DL) algorithm, based on preoperative MRI and post-operative pathological results, to differentiate between leading spinal pathologies. STUDY DESIGN: We retrospectively collected and analyzed clinical, radiological, and pathological data of patients who underwent spinal surgery or biopsy for various spinal pathologies between 2008 and 2022 at a tertiary center. The patients were stratified according to their pathological reports (the threshold for inclusion was set to 25 patients per diagnosis). METHODS: Preoperative MRI, clinical data, and pathological results were processed by a deep learning model built on the Fast.ai framework on top of the PyTorch environment. RESULTS: A total of 231 patients diagnosed with carcinoma (80), infection (57), meningioma (52), or schwannoma (42), were included in our model. The mean overall accuracy was 0.78±0.06 for the validation, and 0.93±0.03 for the test dataset. CONCLUSION: Deep learning algorithm for differentiation between the aforementioned spinal pathologies, based solely on clinical MRI, proves as a feasible primary diagnostic modality. Larger studies should be performed to validate and improve this algorithm for clinical use. CLINICAL SIGNIFICANCE: This study provides a proof-of-concept for predicting spinal pathologies solely by MRI based DL technology, allowing for a rapid, targeted, and cost-effective work-up and subsequent treatment.

The clinical significance of radiological changes associated with gliadel implantation in patients with recurrent high grade glioma.

Gliadel occasionally induces edema following its implantation. We aimed to correlate such post-surgical radiological changes to its efficacy and subsequent survival. Fifty-six patients with recurrent high grade glioma were treated between 2005 and 2016 with Gliadel implantation. Volumetric measurements of MRI features, including FLAIR abnormalities, tumor bulk (volume of gadolinium enhancement on T1) and resection cavity volumes over time were conducted. To assess dynamics over time, linear regression trendlines for each of these were calculated and examined to correlate with survival. Median follow-up after resection was 21.5 months. Median survival post-Gliadel implantation and overall survival since diagnosis were 12 months and 22 months, respectively. A subgroup of patients (n = 6) with a transient increase in FLAIR changes volume over time survived significantly longer post-Gliadel compared to those who did not demonstrate such change (36 vs 12 months, p = .03). Positive trends, representing overall growth in volume over time, of tumor bulk and resection cavity predicted survival in multivariate analyses (hazard ratios 7.9 and 84, p = .003 and .002, respectively). Increase in tumor bulk and resection cavity over time were associated with decreased survival, while transient FLAIR increase was a favorable prognostic factor. This may represent a transient inflammatory process in the tumor, possibly stemming from a presumed immune-mediated anti-tumor response.

CD68 staining correlates with the size of residual mass but not with survival in classical Hodgkin lymphoma.

The prognostic role of CD68 tumor-associated macrophages in classic Hodgkin lymphoma (cHL) remains controversial. We stained diagnostic biopsies and scored for CD68 using the PGM1 antibody among 98 consecutive patients with cHL from our center followed over a median of 45 months for progression-free survival (PFS). Among 79 patients we assessed interim and post-treatment positron emission tomography-computed tomography (PET-CT). Residual mass (RM) size was based on the greatest diameter of the largest mass seen in post-treatment imaging, and percent reduction was calculated by comparing RM size with its greatest pretreatment diameter. We found a significant association between CD68 positivity and absolute size of initial disease mass (p = 0.014) and residual mass at the end of therapy (p = 0.006) but no association was observed with interim PET-CT results or PFS. Our findings suggest that macrophages may influence tumor size by altering the microenvironment. This study does not support a prognostic role of CD68 positivity in predicting survival.