Negative MRI and a seizure onset zone close to eloquent areas in FCD type II: Application of MRg-LiTT after a SEEG re-evaluation in pediatric patients with a previous failed surgery

OBJECTIVE

Negative MRI and an epileptogenic zone (EZ) adjacent to eloquent areas are two main issues that can be encountered during pre-surgical evaluation for epilepsy surgery. Focal Cortical Dysplasia type II (FCD type II) is the most common aetiology underlying a negative MRI. The objective of this study is to present three cases of pediatric patients exhibiting negative MRI and a seizure onset zone close to eloquent areas, who previously underwent traditional open surgery or SEEG-guided radiofrequency thermocoagulations (RF-TC). After seizure seizure recrudescence, pre-surgical SEEG was re-evaluated and Magnetic Resonance-guided laser interstitial thermal therapy (MRg-LiTT) was performed. We discuss the SEEG patterns, the planning of laser probes trajectories and the outcomes one year after the procedure.

METHODS

Pediatric patients who underwent SEEG followed by MRg-LiTT for drug-resistant epilepsy associated with FCD type II at our Centre were included. Pre-surgical videoEEG (vEEG), stereoEEG (sEEG), and MRI were reviewed. Post-procedure clinical outcome (measured by Engel score) and complications rates were evaluated.

RESULTS

Three patients underwent 3 MRg-LiTT procedures from January 2022 to June 2022. Epileptogenic zone was previously studied via SEEG in all the patients. All the three patients pre-surgical MRI was deemed negative. Mean age at seizure onset was 47 months (21-96 months), mean age at MRg-LiTT was 12 years (10 years 10 months - 12 years 9 months). Engel class Ia outcome was achieved in patients #2 and #3, Engel class Ib in patient #1. Mean follow-up length was of 17 months (13 months - 20 months). Complications occurred in one patient (patient #2, extradural hematoma).

CONCLUSIONS

The combined use of SEEG and MRg-LiTT in complex cases can lead to good outcomes both as a rescue therapy after failed surgery, but also as an alternative to open surgery after a successful SEEG-guided Radiofrequency Thermocoagulation (RF-TC). Specific SEEG patterns and a previous good outcome from RF-TC can be predictors of a favourable outcome.

Clinical and oncological outcomes in single-stage versus staged surgery for pediatric craniopharyngiomas: a multicenter retrospective study

PURPOSE

Craniopharyngiomas (CPGs) are aggressive brain tumors responsible of severe morbidity in children. The best treatment strategies are under debate. Our study evaluates surgical, pituitary, and hypothalamic outcomes of a tailored staged-surgical approach compared to a single-stage radical approach in children with CPGs.

METHODS

Multicenter retrospective study enrolling 96 children treated for CPGs in the period 2010-2022. The surgical management was selected after a multidisciplinary evaluation. Primary endpoint includes the inter-group comparison of preservation/improvement of hypothalamic-pituitary function, the extent of resection, and progression-free survival (PFS). Secondary endpoints include overall survival (OS), morbidity, and quality of life (QoL).

RESULTS

Gross Total Resection (GTR) was reached in 46.1% of cases in the single-stage surgery group (82 patients, age at surgery 9 ± 4.7 years) and 33.3% after the last operation in the staged surgery group (14 patients age 7.64 ± 4.57 years at first surgery and 9.36 ± 4.7 years at the last surgery). The PFS was significantly higher in patients addressed to staged- compared to single-stage surgery (93.75% vs 70.7% at 5 years, respectively, p = 0.03). The recurrence rate was slightly higher in the single-stage surgery group. No significant differences emerged in the endocrinological, visual, hypothalamic outcome, OS, and QoL comparing the two groups.

CONCLUSIONS

In pediatric CPGs' surgical radicality and timing of intervention should be tailored considering both anatomical extension and hypothalamic-pituitary function. In selected patients, a staged approach offers a safer and more effective disease control, preserving psychophysical development.

Expanding the mutational spectrum associated to neural tube defects: literature revision and description of novel VANGL1 mutations

BACKGROUND

Neural Tube Defects (NTD) are a common class of birth defects that occur in approximately 1 in 1000 live births. Both genetic and nongenetic factors are involved in the etiology of NTD. Planar cell polarity (PCP) genes plays a critical role in neural tube closure in model organisms. Studies in humans have identified nonsynonymous mutations in PCP pathway genes, including the VANGL genes, that may play a role as risk factors for NTD.

METHODS

Here, we present the results of VANGL1 and VANGL2 mutational screening in a series of 53 NTD patients and 27 couples with a previous NTD affected pregnancy.

RESULTS

We identified three heterozygous missense variants in VANGL1, p.Ala187Val, p.Asp389His, and p.Arg517His, that are absent in controls and predicted to be detrimental on the protein function and, thus, we expanded the mutational spectrum of VANGL1 in NTD cases. We did not identify any new variants having an evident pathogenic effect on protein function in VANGL2. Moreover, we reviewed all the rare nonsynonymous or synonymous variants of VANGL1 and VANGL2 found in patients and controls so far published and re-evaluated them for their pathogenic role by in silico prediction tools. Association tests were performed to demonstrate the enrichment of deleterious variants in reviewed cases versus controls from Exome Variant Server (EVS).

CONCLUSION

We showed a significant (p = 7.0E-5) association between VANGL1 rare genetic variants, especially missense mutations, and NTDs risk.

Glioneuronal tumors and epilepsy in children: seizure outcome related to lesionectomy

AIM

Glioneuronal tumors (especially gangliogliomas and dysembryoplastic neuroepithelial tumors) are an increasingly recognised cause of drug-resistant epilepsy in children. The optimal surgical strategy (lesionectomy vs. extended resection of epileptogenic peritumoral areas) to obtain seizure control has not been fully established. Our aim was to analyze the post-surgical seizure outcome in children with epileptogenic glioneuronal tumors related to lesionectomy.

METHODS

The clinical data were collected through a database. Video-EEG and MRI were performed in all patients pre-operatively and at the follow-up.

RESULTS

Our series included 22 patients. The age range at surgery was 10 months-16 years (mean: 6.5±4.5 years). Epilepsy duration ranged 1-78 months (mean: 11.6±17.0). There were complex partial seizures in 14 cases, simple partial seizures in 6 patients and generalized epilepsy in 2. Gross-total surgical removal was achieved in 15 (68.2%) patients. At the last follow-up (mean 4.7 years), 20 (90.9%) patients were seizure-free (Engel Class I) and two (9.1%) were Engel Class III. Six out of seven (85.7%) patients with subtotal removal were Engel Class I. Statistical analysis failed to detect any difference between seizure outcome (Engel Class) and tumor type (DNT vs. GG; P=1.00) or location (temporal vs. non temporal; P=0.51), and extension of the resection (total vs. subtotal; P=1.00).

CONCLUSION

Primary aim of the surgery for epileptogenic glioneuronal tumors is to remove the lesion and to obtain a complete seizure control. However, if a complete tumor resection cannot be carried out, a subtotal removal of the lesion can equally provide satisfactory results.

Sciatic schwannoma spanning the sciatic notch: removal by an anterior, transabdominal approach

We describe a sciatic schwannoma spanning the sciatic notch in a 39-year-old woman with persistent pelvic pain after caesarean delivery. The tumour was detected by pelvic CT scan and MRI. Anterior transabdominal surgery allowed the en bloc removal of both the pelvic and the buttock component of the tumour.

Voriconazole proves effective in long-term treatment of a cerebral cryptococcoma in a chronic nephropathic HIV-negative patient, after fluconazole failure

Although being a rare occurrence, brain cryptococcoma may represent an emerging issue, because of its relationship with a broadening range of risk factors, including malignancies, neutropenia, end-organ failure, bone marrow and solid-organ transplantation, and multiple underlying causes of primary-secondary immunodeficiency. A cerebral cryptococcoma in a chronic nephropathic HIV-negative subject with homocystinuria, completely cured with neurosurgery and voriconazole after fluconazole failure, is described.

Endoscope-controlled microneurosurgery for the treatment of intracranial fluid cysts

OBJECTIVE

This study assessed the role of endoscope-controlled microneurosurgery (ECM) in the treatment of intracranial cerebrospinal fluid (CSF) cysts.

METHODS

Twelve patients affected by symptomatic arachnoid cysts (11 in the sylvian fissure and 1 in the cerebellopontine angle) underwent ECM, in which the endoscope is used to view the operating field while microsurgical instruments can be passed alongside the endoscope for surgical maneuvers. All the cysts were superficially located and could be reached directly through a burr hole on their surface, so that the endoscope was inserted into the cyst without passing through the brain parenchyma. We used a rigid endoscope, performing a wide fenestration of the cyst in the basal cisterns (cystocisternostomy). The excellent endoscopic vision facilitated the surgical procedure with safe maneuvers through a minimally invasive approach. In 11 patients, we observed the resolution of symptoms. A radiological reduction in the cyst was observed in 7 cases. No mortality or major complications were observed.

CONCLUSIONS

Endoscope-controlled microsurgery is a valid minimally invasive procedure for treating superficially located intracranial arachnoid cysts.

Bobble-head doll syndrome due to a suprasellar arachnoid cyst: endoscopic treatment in two cases

OBJECT

We report two cases of bobble-head doll syndrome associated with a large suprasellar arachnoid cyst successfully treated with a minimally invasive endoscopic approach.

METHODS

The clinical history, surgical treatment and results of two children, a 9-year-old boy and a 1-year-old girl, both presenting the clinical features of the bobble-head doll syndrome, are described. As a first procedure, a ventriculo-cystostomy was endoscopically performed in both patients, obtaining either resolution of the symptoms or notable cyst reduction. In the girl, a re-closure of the stoma, with cyst re-expansion, was observed after 18 months. She then underwent a second procedure, a ventriculo-cysto-cisternostomy, with a good result. After 3 years' follow-up, the neurological condition of both patients remains good with complete resolution of abnormal head movement.

CONCLUSION

In our opinion, endoscopic treatment is the procedure of choice for this condition, as it involves few complications and gives good results.

Occipital aneurysmal bone cyst secondary to eosinophilic granuloma

We describe the case of a 2-year-old male patient with an aneurysmal bone cyst (ABC) of the occiput secondary to unifocal eosinophilic granuloma (EG). The lesion presented as a painless mass of the scalp which had grown rapidly over the 2 weeks prior to admission. Radiologically, the lesion was osteolytic and multicystic with fluid-fluid levels. On histology, the cyst wall contained hemosiderin-laden histiocytes, spindle cells, multinucleated giant cells, Langerhans' cells and eosinophils. Surgical treatment consisted of en bloc resection. Fourteen months after surgery, the patient was well with no local recurrence. Association between EG and ABC is rare. To our knowledge, this is the first case involving the skull.

Neurofibromatosis type 2: growth stimulation of mixed acoustic schwannoma by concurrent adjacent meningioma: possible role of growth factors. Case report

The authors report the case of a young man suffering from neurofibromatosis type 2 (NF2) who harbored bilateral acoustic schwannomas and a parasellar meningioma. Neuroimaging studies performed during a 4-year follow-up period showed that the bilateral schwannomas had grown very little and at similar rates. However, after the meningioma had infiltrated the tentorium and approached the ipsilateral schwannoma at the incisura, both Schwann cell tumors started to grow rapidly, particularly the one adjacent to the meningioma, of which the percentage of annual growth rate increased by approximately a factor of 10(2). At the same time, magnetic resonance imaging showed that this tumor also changed its features. During surgery, the acoustic schwannoma was firmly adherent to both meningioma and tentorium. Histological examination revealed meningotheliomatous cells in the schwannoma adjacent to the meningioma. Antiphosphotyrosine immunoblotting of PC12 cells was compatible with the presence of an epidermal growth factor (EGF)-like molecule in the cerebrospinal fluid (CSF) of the patient. This factor was not detected in the CSF of five other NF2 patients, two of whom bore associated bilateral acoustic schwannomas and meningioma in remote locations. It is hypothesized that the meningotheliomatous cells infiltrating the schwannoma triggered an autocrine/paracrine growth-stimulatory mechanism that involved an EGF-like factor.