Neurosurgery Training in Greece

OBJECTIVE

The structure and specifics of neurosurgery residency training vary substantially across programs and countries, potentially leading to differences in clinical reasoning, surgical skills, and professionalism. The Greek neurosurgical training system is unique in numerous respects. This manuscript delineates the current state of neurosurgical residency training in Greece and outlines future directions.

METHODS

A narrative review was conducted to describe the Greek neurosurgical residency training structure. The perspectives of the authors regarding challenges in training and future directions were synthesized.

RESULTS

This manuscript describes the neurosurgery residency curriculum and board certification process, existing training programs, and key challenges in neurosurgery residency training in Greece. The authors propose future directions to reform neurosurgical training in Greece.

CONCLUSIONS

Neurosurgery residency training in Greece has been largely unchanged for many years. This review leads to suggested modification of the existing training process may improve the quality of training and equip neurosurgeons to respond to the rapidly changing landscape of the field.

Localization of Vestibular Cortex Using Electrical Cortical Stimulation: A Systematic Literature Review

The vestibular system plays a fundamental role in body orientation, posture control, and spatial and body motion perception, as well as in gaze and eye movements. We aimed to review the current knowledge regarding the location of the cortical and subcortical areas, implicated in the processing of vestibular stimuli. The search was performed in PubMed and Scopus. We focused on studies reporting on vestibular manifestations after electrical cortical stimulation. A total of 16 studies were finally included. Two main types of vestibular responses were elicited, including vertigo and perception of body movement. The latter could be either rotatory or translational. Electrical stimulation of the temporal structures elicited mainly vertigo, while stimulation of the parietal lobe was associated with perceptions of body movement. Stimulation of the occipital lobe produced vertigo with visual manifestations. There was evidence that the vestibular responses became more robust with increasing current intensity. Low-frequency stimulation proved to be more effective than high-frequency in eliciting vestibular responses. Numerous non-vestibular responses were recorded after stimulation of the vestibular cortex, including somatosensory, viscero-sensory, and emotional manifestations. Newer imaging modalities such as functional MRI (fMRI), Positron Emission Tomography (PET), SPECT, and near infra-red spectroscopy (NIRS) can provide useful information regarding localization of the vestibular cortex.

Giant aneurysm arising from a cortical middle cerebral artery branch presenting as an extra-axial tumour: a case report

The size and anatomical complexity make giant intracranial aneurysms challenging surgical lesions. There is limited literature available for those arising from distal branches. The cases that have been reported in the literature have all presented with symptoms from a rupture leading to an intracranial haemorrhage. In this case report, the authors present a case of a giant aneurysm arising from a cortical branch of the middle cerebral artery presenting as an extra-axial tumour. A 76-year-old gentleman presented with a 2-day history of subjective left arm numbness. Imaging revealed a large conical right-sided parietal lesion. Intraoperatively, it was found that the lesion was being supplied by a single vascular pedicle. Histology was consistent with an aneurysm. In this case, that patient did not have any evidence of a rupture unlike all reported cases of cortical giant aneurysms. This case highlights the myriad location and presentation of giant intracranial aneurysms.

SURG-09. EXTRAOPERATIVE CORTICAL MAPPING VIA IMPLANTED SUBDURAL AND DEPTH ELECTRODES FOR MAXIMIZING ELOQUENT AREA GLIOMA RESECTION

OBJECTIVE

Aggressive, even supramarginal, resection without compromising the neurological status of the patient remains a great challenge in the management of glioma cases. Accurate cortical and subcortical functional mapping allows more radical glioma resection. Numerous imaging, electrophysiological, and hybrid methodologies have been employed in the cortical mapping of patients with gliomas in eloquent areas. Despite the recent advances of these non-invasive modalities, direct electrical cortical and subcortical stimulation and mapping through an awake craniotomy remains the gold standard for maximal glioma resection and preservation of eloquent cortex functions. Extraoperative stimulation and mapping via implanted subdural and/or depth electrodes may be a valid alternative mapping method in these cases that an awake procedure is not feasible. The role of this mapping method is examined in our current study.

MATERIAL & METHODS

In a retrospective study, 51 patients undergoing extraoperative stimulation and mapping for glioma resection were included. The demographic data, the clinical characteristics, the stimulation parameters and complications, the extent of resection, the perioperative complications, and the tumor histological grade were analyzed. Shapiro-Wilk test, as well as uni- and multi-variate regression analysis was used for our statistical analysis.

RESULTS

The mean age of our participants was 58 (SD: 9.4) years. The location of the glioma was on the left side in 80.4%, while the frontal lobe was affected in 51.0%. Extraoperative cortical and subcortical stimulation and mapping was successful in 94.1%. The median stimulation procedure was 2.0 hours, while the median implantation time was 72 hours. Stimulation-induced seizures occurred in 13.7%, while CSF leakage in 5.9% of our cases. The mean extent of resection was 91.6%, while transient dysphasia occurred in 21.6%, and transient hemiparesis in 5.9% of our cases.

CONCLUSIONS

Extraoperative stimulation and mapping constitutes a valid alternative mapping option in glioma patients, who cannot undergo an awake craniotomy.

Intermediate surgical outcome in patients suffering poor-grade aneurysmal subarachnoid hemorrhage. A single center experience

BACKGROUND

It is known that patients suffering poor-grade aneurysmal subarachnoid hemorrhage (aSAH) have a dismal prognosis. The importance of early intervention is well established in the pertinent literature. Our aim was to assess the functional outcome and overall survival of these patients undergoing surgical clipping.

MATERIAL AND METHODS

In the current retrospective study we included all consecutive poor-grade patients after spontaneous SAH who presented at our institution over an eight-year period. All participants suffering SAH underwent brain CT angiography (CTA) to identify the source of hemorrhage. We assessed the severity of hemorrhage according to the Fisher grade classification scale. All patients were surgically treated. The functional outcome was evaluated six months after the onset with the Glasgow Outcome Scale. Finally, we performed logistic and Cox regression analyses to identify potential prognostic risk factors.

RESULTS

Our study included twenty-three patients with a mean age of 53 years. Five (22%) patients presented with Hunt and Hess grade IV, and eighteen (78%) with grade V. The mean follow-up was 15.8 months, while the overall mortality rate was 48%. The six-month functional outcome was favorable in 6 (26%) patients. The vast majority of our patients died between the 15^th and the 60^th post-ictal days. We did not identify any statistically significant prognostic factors related to the patient's outcome and/or survival.

CONCLUSIONS

Poor-grade aSAH patients may have a favorable outcome with proper surgical management. Large-scale studies are necessary for accurately outlining the prognosis of this entity, and identifying parameters that could be predictive of outcome.

Unusual case of subarachnoid haemorrhage in patient with Fabry's disease: case report and literature review

Fabry's disease is a rare, X linked recessive disease affecting 1 in 40 000 persons. The symptoms result from a lack of or a non-functioning enzyme α galactosidase, which leads to globotriaosylceramide accumulation in the walls of blood vessels. Mortality is generally from cardiac or renal complications and death from subarachnoid haemorrhage is distinctly rare. The authors report a man with Fabry's disease who died after subarachnoid haemorrhage from a progressively enlarging fusiform basilar aneurysm.

Dosimetric evaluation of a new collimator insert system for stereotactic radiotherapy

The prototype of a stereotactic collimator set developed in our department is evaluated for clinical use. This set consists of three cylindrical blocks mounted on a tray which slides in the wedge insert of a Siemens Primus accelerator. Each block has a collimating hole along its long axis to produce radiation fields of circular cross-section at the isocentre plane with diameters of 15 mm, 20 mm and 25 mm. Different geometric and dosimetric quality assurance tests were performed and results are found within the limits set for stereotactic radiotherapy. Dosimetry results measured using Kodak EDR-2 radiographic film and a pinpoint ion chamber also show good agreement with corresponding results calculated by Monte Carlo simulation of the linear accelerator head and the collimators. Measured dosimetry data were used to adapt a conventional PLATO treatment planning system for stereotactic radiotherapy using the prototype collimator set. Treatment planning system calculations and film measurements for treatment of an intracranial lesion in an anthropomorphic head phantom using coplanar 180 degrees arcs are compared and found to agree within 2 mm. This supports the accuracy of dose delivery using the prototype stereotactic collimators. Despite their increased penumbra (2.5-3.5 mm relative to 2-2.5 mm for commercially available collimators) the ease of construction makes the proposed stereotactic collimators an interesting alternative for accomplishing cost effective stereotactic treatments.