Middle temporal gyrus approach to mesial temporal lobe tumours in children.

AIM OF THE STUDY: To assess whether the middle temporal gyrus (MTG) approach to mesial temporal lobe (MTL) tumours is an effective procedure for the treatment of epilepsy in children. CLINICAL RATIONALE FOR THE STUDY: MTL tumours are a common cause of drug-resistant epilepsy in children. There is as yet no consensus regarding their treatment. One possibility is resection via a MTG approach. MATERIAL AND METHODS: We assessed the medical records of patients treated at the Department of Neurosurgery, Children's Memorial Health Institute,Warsaw, Poland between 2002 and 2020. A prospectively maintained database including clinical, laboratory, and radiographic presentation, as well as pre- and post-operative course, was analysed. Patients with at least a one- -year follow-up were included. RESULTS: There were 14 patients aged 4-18 years who underwent a MTG approach for a MTL tumour. All presented with epileptic seizure, and none had neurological deficit on admission to hospital. Median follow-up was 2.5 years. Neuronavigation was used to adjust the approach, localise the temporal horn, and achieve radical resection of the tumour and the hippocampus. Gross total resection was performed in all cases. In most patients, histopathological examination revealed ganglioglioma. One patient had transient aphasia. Two patients developed hemiparesis after surgery, which later improved. One of them also experienced visual disturbances. Acute complications were more frequent in younger patients (p = 0.024). In all cases, MRI confirmed complete resection and there was no tumour recurrence during the follow-up period. 13/14 patients remained seizure-free (Engel class I). CONCLUSIONS AND CLINICAL IMPLICATIONS: The MTG approach to MTL tumours is an effective procedure for the treatment of epilepsy in children. It avoids removal of the lateral temporal lobe and poses only a minor risk of permanent neurological complications.

Recommendations of the Polish Association of Neuropathologists on performing post-mortem examination of the brain and spinal cord.

Neuropathological central nervous system (CNS) post-mortem examination is a highly specialistic element of the autopsy procedure with methodological specificity. Herein we propose updated recommendations for CNS autopsy for pathologists and neuropathologists. The protocol includes the compendium of neuroanatomy with current nomenclature, consecutive steps of gross examination, as well as appropriate sampling algorithms in different clinical and pathological settings. The significance of pathoclinical cooperation in differential diagnosis is exposed. We believe it is essential to create and promote the guidelines to improve the quality of CNS post-mortem examination at the national level.

Comparative genomic analysis of intracranial germ cell tumors - the preliminary study focused on Sonic Hedgehog signaling pathway.

AIM OF THE STUDY: Examination of copy number changes in a group of intracranial germ cell tumors (GCTs) with particular focus on putative aberrations of the main genes coding SHh pathway proteins. MATERIAL AND METHODS: The study was performed on DNA isolated from fresh-frozen tumor tissue samples from eight GCTs, including six intracranial GCTs. The intracranial group consisted of three germinomas, two mature teratomas and one mixed germ cell tumor. Comparative genomic profiling analysis was carried out using microarray-CGH method (Cytosure ISCA UPD 4×180k, OGT). The results were analyzed with Feature Extraction (Agilent Technologies) and Nexus Copy Number (BioDiscovery) softwares. RESULTS AND CONCLUSIONS: Chromosomal aberrations were found in two intracranial germinomas. These tumors were characterized by complex genomic profiles encompassing chromosomes 7, 8, 9, 10, 11, 12, 16, 17 and 19. Common findings were gain at 12p13.33p11.1 of 35 Mbp and gain at 17q11.1q25.3 of 55 Mbp. In one tumor, also SHh (7q36.3), SMO (7q32.1) and GLI3 (7p14.1) copy gains occurred together with 9q21.11q34.3 loss, including PTCH1, all being elements of SHh signaling pathway. Moreover, both tumors showed various copy gain of genes being ligands, regulators, receptors or target genes of SHh (MTSS1; PRKACA and FKBP8) as well as gain of genes of SHh coopting WNT pathway (WNT3, WNT5B, WNT9B in both tumors; WNT16, WNT2 in pineal lesion). Further studies on larger group are needed to characterize SHh-related gene alterations in intracranial GCTs and for searching genotype-phenotype relations.

A case of vertebral artery duplication at the level of atlas: anatomical description.

PURPOSE: To present case of vertebral artery duplication surrounding the posterior arch of atlas. METHODS: The vertebral artery variation was encountered during dissection of specimen from the body of a 62-year-old man. RESULTS: The vertebral artery formed a circle located extraduraly, surrounding the posterior arch of atlas vertebra. Topography and morphometry of the finding is described. Embryology and clinical significance based on literature review are discussed. CONCLUSIONS: Precise diagnostic imaging is necessary before surgical interventions at the level of cranio-spinal junction in order to avoid conflict with rare vascular variations.

A case of atlas assimilation: description of bony and soft structures.

A case of atlas assimilation revealed during serial study of suboccipital region is presented. The specimen was harvested from the body of 31-year-old woman. Images of the computed tomography scans are correlated with classic dissection. Asymmetrical bony assimilation is accompanied by asymmetrical development of the suboccipital musculature. In the presented case, the atlantic segments of both vertebral arteries preserved their usual course between bony elements derived from the atlas and proatlas. Development of the soft tissues must be influenced by similar factors as development of the skeleton. Detailed radiologic studies, possibly with volumetric reconstructions, are necessary in cases of atlas assimilation before surgical interventions in the region of craniovertebral junction.

H2A.Z histone variants facilitate HDACi-dependent removal of H3.3K27M mutant protein in pediatric high-grade glioma cells.

Diffuse intrinsic pontine gliomas (DIPGs) are deadly pediatric brain tumors, non-resectable due to brainstem localization and diffusive growth. Over 80% of DIPGs harbor a mutation in histone 3 (H3.3 or H3.1) resulting in a lysine-to-methionine substitution (H3K27M). Patients with DIPG have a dismal prognosis with no effective therapy. We show that histone deacetylase (HDAC) inhibitors lead to a significant reduction in the H3.3K27M protein (up to 80%) in multiple glioma cell lines. We discover that the SB939-mediated H3.3K27M loss is partially blocked by a lysosomal inhibitor, chloroquine. The H3.3K27M loss is facilitated by co-occurrence of H2A.Z, as evidenced by the knockdown of H2A.Z isoforms. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis confirms the occupancy of H3.3K27M and H2A.Z at the same SB939-inducible genes. We discover a mechanism showing that HDAC inhibition in DIPG leads to pharmacological modulation of the oncogenic H3.3K27M protein levels. These findings show the possibility of directly targeting the H3.3K27M oncohistone.

Germinoma Mimicking Brain Inflammation: A Case Report.

The authors report a case of a germinoma of the brain in the child with symptoms restricted to central nervous system. Ten-year-old girl presented initially with sight deterioration, learning difficulties, abnormal behavior, polydipsia, and polyuria. Brain magnetic resonance examination revealed T2 hyperintensity of the corpus callosum, anterior commissure, and caudate nuclei. Brain biopsy revealed extensive macrophage infiltration. Given these results and positive antinuclear antibodies in the blood, immunosuppressive and immunomodulatory treatment was implemented but it was not effective. The patient developed progressive quadriparesis, sleep disturbances, and dementia. Second brain biopsy was performed and it revealed germinoma cells. Chemotherapy was administered, but the girl died due to disseminated intravascular coagulation syndrome. The reported case shows an unusual coexistence of germinoma with prominent inflammation in the brain and highlights the importance of brain biopsy in such complex cases.

[Topography and morphometry of the porus trigeminus]. / Topografia i morfometria otworu jamy nerwu trójdzielnego.

BACKGROUND AND PURPOSE: The trigeminal nerve passes from the posterior to the middle cranial fossa above the superior edge of the petrous part and below attachment of the tentorium cerebelli. Behind this place it is surrounded by the dural trigeminal cave which opens posteriorly as the porus trigeminus. The aim of this study was to describe the porus trigeminus along with its relation to the trigeminal nerve and selected structures around. MATERIAL AND METHODS: The study was performed on the material of 20 human, formalin fixed specimens of the cranial base. Measurements were taken with a surgical microscope with an ocular ruler, with precision of 0.2 mm. RESULTS: Mean width of the porus was 7.3 (+/-1.0) mm and height 2.2 (+/-0.4) mm. Dimensions of the trigeminal nerve within the porus were 5.8 (+/-0.8) mm and 2.1 (+/-0.4) mm, respectively. The porus is surrounded by shallow ellipsoid hollow measuring 12.1 (+/-1.8) over 5.1 (+/-1.1) mm. Relation of the porus to the petrous vein was described, as well as to other veins emptying to the dural sinuses in its vicinity. Distances between the porus and venous dural openings were very variable. The following distances were measured from the porus trigeminus to: the internal acustic porus [6.6 (+/-1.7) mm], jugular foramen [16.2 (+/-1.8) mm], jugular tubercle [18.9 (+/-1.8) mm], abducent nerve [5.9 (+/-1.2) mm], trochlear nerve [4.6 (+/-1.4) mm], oculomotor nerve [8.4 (+/-1.9) mm], posterior clinoid process [14.7 (+/-1.8) mm] and median plane [left 13.7 (+/-1.0), and right 13.5 (+/-1.9) mm]. CONCLUSIONS: Obtained results may be helpful during planning surgical approaches to the Meckel's cave and petroclival region.

The choroid plexus of the fourth ventricle and its arteries.

The choroid plexus of the fourth ventricle consists of two symmetrical parts located in the roof of the ventricle and protruding through its openings, the foramina of Luschka and Magendie. The arteries supplying the choroid plexus of the fourth ventricle are difficult to approach because of their deep location within the cerebellopontine angles and the cerebellomedullary fissure. They originate from multiple sites on the cerebellar arteries, and pass near the vital structures of the pons and medulla. The increasing use of the operating microscope and endoscopy during operations in the posterior cranial fossa has created a need for better understanding of the microsurgical anatomy of the plexus and its arteries. The arteries of 15 human brain-stems with cerebelli were injected with coloured gelatine and fixed in 10% formaldehyde solution. The specimens were studied under an operating microscope. The choroids plexus on each side of the midline was divided into four segments, the medial and lateral horizontal segments and the rostral and caudal sagittal segments, in order to facilitate the description of their blood supply. The anterior inferior cerebellar artery (AICA), the posterior inferior cerebellar artery (PICA) and the superior cerebellar artery (SCA) were the main supplying vessels. AICA supplied the portion of the plexus in the cerebellopontine angles and the adjacent part of the lateral recess of the fourth ventricle through the foramina of Luschka. PICA supplied most of the choroid plexus in the roof and the median opening of the fourth ventricle.

Arteries to the proximal part of the olfactory tract.

Destruction of the vascularisation of the olfactory structures during fronto-orbital surgical approaches to the sellar region may result in anosmia as a complication. The goal of this study was to describe the sources of blood supply to the proximal olfactory tract and the macroscopic distribution of these vessels. 20 human brains fixed in formalin with arteries injected with ink-coloured gelatine were studied using a surgical microscope and the micro-dissection technique. The vessels running along the olfactory tract posteriorly and anteriorly on its inferior and superior surface were observed. These arteries and arterioles were most often branches of the constant artery supplying the posterior part of the straight gyrus and orbital gyri (38/40). Similarly, as branches of the medial orbitofrontal artery (7/40), they were found on the superior aspect of the tract. Branches of the distal medial striate artery directed to the olfactory structures were observed on the basal surface of the tract (20/40).