Could Radiographs Be More Helpful in the Removal of an Intraorbital Foreign Body Than a Surgical Navigation System? A Neurosurgical Case Report.

Intraorbital foreign body (IOFB) is a vision-threatening condition that requires careful management. IOFB can manifest clinically from asymptomatic up to severe inflammation and blindness. Diagnosis and treatment are determined by the nature of the IOFB. The type, location, and complications related to the IOFB are taken into consideration when planning the surgery. Here, we report the case of a male in his 20s who was admitted to our clinic with a computed tomography (CT) scan which verified the presence of an IOFB. The patient underwent surgery and the IOFB was removed. Using a surgical navigation system (SNS), it was difficult to pinpoint the IOFB precisely during surgery. We took radiographs with a C-arm to improve our orientation and locate the IOFB. The patient recovered uneventfully, and no issues were noticed one month following surgery. This case report highlights the selection of treatment methods and demonstrates when radiographs can be more helpful than an SNS in the removal of the IOFB.

A rare cause of low back pain in adolescence - Bertolotti syndrome: A case report.

Background: Bertolotti syndrome (BS) is defined as a congenital anomaly of the spine that includes sacralization of the lowest lumbar vertebra or lumbarization of the first sacral vertebra (i.e., lumbosacral transitional vertebra- LSTV) and the pain associated with this condition. The incidence of BS in adolescence is rare; we found only three such case reports of patients under the age of 18 in the literature, here will add a fourth. Case Description: A 17-year-old female presented with a 2-month history of low back pain exacerbated by physical activity. Her neurological examination was normal, except for pain elicited when applying pressure over the sacroiliac joints bilaterally, and over the spinous process of the L5 vertebra. The computed tomography scan documented BS: (i.e., LSTV - Castellvi classification: Type IIa on the left side). She was successfully treated with nonsteroidal anti-inflammatory drugs (NSAIDs) alone. Conclusion: Here, we report a 17-year-old female who was symptomatic from BS and was successfully treated with NSAIDs.

Extracranial Glioblastoma Metastasis: A Neuropathological Case Report.

Glioblastoma (GBM) is a central nervous system (CNS) high-grade glioma with a dismal patient prognosis. Classical concepts surrounding GBM development and progression indicate its ability to produce metastasis within the CNS, one of the few primary tumors with such capabilities. While classical concepts state that no primary CNS tumor produces extracranial metastasis, there have been multiple reports of such occurrences over the previous two decades. Here, we report a case of a male in his forties who presented to our institution with complaints of progressive headache and a history of right temporal craniotomy one month prior with a histologically verified GBM performed at another institution. Neuroradiology confirmed a residual tumor in the areas of the previous craniotomy, and gross total excision confirmed the diagnosis of GBM, although based on the presence of connective tissue amidst the tumor stroma, gliosarcoma could not be ruled out. The patient initiated treatment, and his condition remained stable for four calendar years until he again presented to our institution with a rapidly growing tumor mass in the right lateral neck region. Excision of the neck mass showed histopathological features of a tumor comprised of atypical cells with pronounced polymorphism, some with spindle cell morphology and a tendency for fascicular growth and focal palisade necrosis. Immunohistochemistry with a broad set of markers disproved epithelial, mesenchymal, melanocytic, and lymphoid genesis, with some markers of glial genesis present; hence, metastatic GBM was established. The patient reinitiated treatment and is currently stable. The steadily increasing amount of similar reported cases, together with the steady, albeit small, increase in GBM patient survival and improvement of neurooncological healthcare distribution and follow-up, challenge the classical concepts of GBM and other primary CNS tumors being unable to produce metastasis and swaying this perception towards the biological capabilities of these tumors to produce metastasis, while such rarely develop due to the short patient survival.

Not All Monstrous Cells Indicate Glioblastoma: A Neuropathological Case Report of Pleomorphic Xanthoastrocytoma Misdiagnoses As Giant Cell Glioblastoma.

Pleomorphic xanthoastrocytoma (PXA) is a rare central nervous system malignant neoplasm with a relatively favorable prognosis. As PXA histologically presents with large, multinucleated neoplastic cells, its principal differential diagnosis is giant cell glioblastoma (GCGBM). While there is a significant overlap between the two histologically and the neuropathological diagnosis can be challenging, as well as having some overlap neuroradiologically, the patient prognosis differs significantly, with PXA having a more favorable one. Herein we present a case report of a male patient in his thirties diagnosed with GCGBM and presenting again six years later with thickening of the wall of the porencephalic cyst suggestive of disease recurrence. Histopathology revealed neoplastic spindle, small lymphocyte-like, large epithelioid-like, some with foamy cytoplasm, and scattered large multinucleated cells with bizarre nuclei. For the most part, the tumor had a distinct border to the surrounding brain parenchyma, except for a single zone of invasion. As per the depicted morphology, with a lack of pathognomic features of GCGBM, the diagnosis of PXA was defined, and the oncologic committee reevaluated the patient with treatment reinitiation. Based on the close morphological profile of these neoplasias, it is likely that in the case of limited material, multiple PXA cases are diagnosed as GCGBM, resulting in misdiagnosed long survivors.

Posterior Fossa Dysembryoplastic Neuroepithelial Tumor: A Neuropathological Report.

Dysembryoplastic neuroepithelial tumors (DNTs) are rare neoplastic entries of the central nervous system. Conventionally DNTs are with cortical location and predominantly occur in the temporal lobe associated with epilepsy. Subtentorial DNTs are rare entries. Herein we report a case of a two-year-old female with a DNT located in the cerebellum. The patient presented clinically with new onset gait instability, headaches and strabismus. Neuroradiology revealed a heterogenous, predominantly cystic lesion in the cerebellar vermis and left cerebellar hemisphere, which was interpreted as possible medulloblastoma based on the patient profile. Frozen section neuropathology was more suggestive of a low-grade glial tumor, with conventional histology and immunohistochemistry showing an admixture of glial and neuronal cells - a complex variety of DNT. Due to the histological appearance, differential diagnosis was required with other neuroglial tumors native to the posterior fossa, such as Lhermitte-Duclos disease. There have been several such published case reports, which, although of older patients, present with similar symptoms and neuropathological findings. The complexity of the neuropathological finding in posterior fossa DNTs can lead to future separation of this entry from conventional DNT, as was seen in the past with septum pellucidum DNT, now referred to as myxoid glioneuronal tumor.

Paraganglioma in the spinal cord histologically mimicking ependymoma - a case report.

Paraganglioma is a tumour lesion of neuroectodermal origin that occurs at various places in the human body, but is rarely observed in the spinal cord. Usually, it presents in the lumbar region (cauda equine and filum terminal) as a slow-growing painless tumour mass that causes local compression.

Sexual discrimination in neurosurgery: a questionnaire-based nationwide study amongst women neurosurgeons in Bulgaria.

BACKGROUND: The aim of this qualitative, descriptive, cross-sectional study was to identify potential factors influencing the progression of female neurosurgeons in Bulgaria. METHODS: The study was conducted nationally, by sending out an online (SurveyMonkey®) questionnaire with 30 questions over a 3-month period to 15 registered female neurosurgeons in practice including residents/trainees and specialists from state universities, private universities and regional hospitals in Bulgaria. The questionnaire covered basic demographics, level of academic achievement and aspects of personal and professional experience, along with questions on the perceived barriers that female neurosurgeons nationally encountered during their clinical and academic career. These results were compared with similar studies conducted in other countries following a literature search on PubMed. RESULTS: Eleven out of fifteen respondents returned the completed survey, covering 10 institutions which included 8 university clinics and two regional clinics, achieving a response rate of 73.3%. No questionnaires were excluded. The factors negatively influencing the clinical and academic professional development and progression in the field included lack of mentors and other female role models, perceived bias regarding remuneration and leave, as well as a lack of support with regards to work-life balance and difficulty progressing in the academic fields. CONCLUSIONS: Although there is an ever increasing and growing awareness of the factors negatively impacting women progression in neurosurgery worldwide, there are still significant gaps and biases that hinder career progression amongst female neurosurgical communities and highlight a need for potential practices to be established in the workplace to counteract this.

Minimising radiation exposure to the surgeon in minimally invasive spine surgeries: A systematic review of 15 studies.

BACKGROUND: Intraoperative imaging in minimally invasive spinal surgeries is associated with significant radiation exposure to surgeons, which overtime can lead to serious health hazards including malignancy. In this study, the authors conducted a systematic review to evaluate the efficacy of navigation assisted fluoroscopy methods on radiation exposure to the surgeon in minimally invasive spine surgeries, percutaneous endoscopic lumbar discectomy/percutaneous endoscopic transforaminal discectomy versus minimally invasive spine transforaminal lumbar interbody fusion (PELD/PETD versus MIS-TLIF). METHODS: A systematic literature search was conducted using PUBMED/MEDLINE on 20th July, 2020. Inclusion criteria were applied according to study design, surgical technique, spinal region, and language. Data extracted included lumbar segment, average operation time (min), fluoroscopic time (s), and radiation dose (µSV), efficacy of modified navigation versus conventional techniques; on reducing operation, fluoroscopy times and effective radiation dose. RESULTS: Fifteen studies (ten prospectives, and five retrospectives) were included for quantitative analysis. PELD recorded a shorter operation time (by 126.3min, p<0.001) and fluoroscopic time (by 22.9s, p=0.3) than MIS-TLIF. The highest radiation dose/case (µSV) for both techniques were recorded at the surgeon's: finger, chest, neck and eye. The effective dose for MIS-TLIF was 30µSV higher than PELD. Modified navigation techniques recorded a shorter operation time (by 15.9min, p=0.3); fluoroscopy time (by 289.8s, p=0.3); effective radiation dose (by 169.5µSV, p=0.3) than conventional fluoroscopy methods. DISCUSSION: This systematic literature review showed that although navigation assisted fluoroscopy techniques are superior to conventional methods in minimising radiation exposure, lack of statistical significance warrants future randomised controlled trials, to solidify their efficacy in reducing radiation related hazards.

Prevalence of non-reporting of hospital medical errors in the Islamic Republic of Iran.

BACKGROUND: Medical errors frequently occur in health care facilities, jeopardizing patient safety and increasing associated costs. AIMS: This cross-sectional investigation examined the rates of and reasons for non-reporting of medical errors at Nemazee Hospital, Shiraz, Islamic Republic of Iran. METHODS: Self-administered questionnaires were completed by 283 staff members, including physicians, nurses and medical students. One-way analysis of variance, Fisher's least significant difference post hoc, Spearman correlation coefficient and intraclass correlation tests were used for statistical analyses. RESULTS: Almost all (95.8%) participants had observed at least 1 medical error during the previous year, with over half (50.5%) observing 3-10 errors. The preferred method for reporting medical errors among physicians and medical students was verbal and informal (40.3% and 41.8% respectively), while nurses preferred written forms (45.7%). The results indicated significant differences between groups concerning individual and organizational barriers in general, and among all sub-categories (P < 0.001). CONCLUSION: Concerns of legal entanglements and confidentiality issues were recognized as the main barriers to reporting medical errors.

Is fusion the most suitable treatment option for recurrent lumbar disc herniation? A systematic review.

OBJECTIVE: Recurrent lumbar disc herniation (rLDH) is a common issue after primary discectomy and can cause severe pain, morbidity, and reoperation. The purpose of this systematic review was to evaluate the surgical management of recurrent lumbar disc herniation. METHODS: A systematic literature search was conducted using Pubmed and Embase databases on 18thAugust, 2019. The inclusion and exclusion criteria were applied according to study design, surgical approach, language, number of patients; and spinal level. Data extracted included patient demographics, and clinical outcomes (patients with excellent/good outcomes; VAS back and leg score improvement, complication and recurrence rates). RESULTS: Sixteen studies, (comprising of seven prospective and nine retrospective) met the inclusion criteria. Ten studies evaluated discectomy only; four analysed fusion, and two analysed both discectomy only and fusion approaches. Fusion approaches recorded a superior success rate (8.3 % higher, p>0.05); postoperative VAS back score improvement (5 % higher, p>0.05) than discectomy alone.  However, discectomy alone approaches recorded a more favourable postoperative VAS leg score improvement (4.2 % higher p>0.05), and complication rate (3.2% lower, p>0.05) than fusion techniques. CONCLUSION: There is significant heterogeneity in clinical outcomes reported for studies after surgical intervention in rLDH patients. Neither discectomy nor fusion's superiority was statistically significant. Despite fusion yielding longer operative times, and length of stay (adding to the expense), it is superior in minimising mechanical instability and recurrence. Finally, we conclude that both approaches are equally efficacious in rLDH cases, and choice should be based on a case by case basis.

COVID 19-Depression and Neurosurgeons.

OBJECTIVE: The goal of this survey was to determine factors associated with anxiety/depression among neurosurgeons during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: An online survey was performed of neurosurgeons worldwide, conducted over 3 weeks. Depression in neurosurgeons was assessed by Self-Reporting Questionnaire-20. RESULTS: A total of 375 responses were received from 52 countries. Among all neurosurgeons, 34% felt tense, 32.5% were unhappy, 25% experienced insomnia, almost 20% had headaches, and 5% had suicidal ideation during the pandemic. Of participants, 14% had a score on Self-Reporting Questionnaire-20 consistent with depression. The likelihood of depression was significantly higher among those who did not receive guidance about self-protection from their institutions (odds ratio [OR], 2.47), those who did not feel safe with provided personal protective equipments (OR, 3.13), and those whose families considered their workplace unsafe (OR, 2.29). Depression was less likely in neurosurgeons who had minor concerns, compared with those with significant health concerns for their families (OR, 0.36). In multivariate analysis after controlling for effects of other covariates, odds of depression were significantly higher among neurosurgeons who did not feel safe with the provided personal protective equipment (OR, 2.43) and who were exposed to a COVID-19-positive colleague (OR, 2.54). Participants who had moderate concerns for their families had lesser odds of anxiety/depression than did those with significant concerns (OR, 0.28). CONCLUSIONS: Based on the modifiable risk factors of depression in this study, it is recommended that the safety of neurosurgeons be ensured by providing appropriate safety measures for them to regain their confidence and hence reduce the incidence of depression.

A Comparative Review of Demographics, Incidence, and Epidemiology of Histologically Confirmed Intracranial Tumors in Brazil and Bulgaria.

Intracranial tumors (ICTs) attract numerous scientific teams and tremendous financial resources worldwide. These lesions of the central nervous system (CNS) can be both benign and malignant in biological behavior as well as local or metastatic in origin. We compared data from two studies on primary and metastatic ICTs from Brazil and Bulgaria, based on histopathologically confirmed ICTs from tertiary health centers. Primary ICTs significantly outweigh the frequency of metastatic ICTs. Primary ICTs represent 86.45% in Brazil and 69.17% in Bulgaria, with around 60% of their totals being malignant. There is a statistical dominance of tumors from the neuroepithelial origin, with the most common entry being glioblastoma multiforme. The second-most common primary ICT group comprises tumors of meningeal origin. Metastatic ICTs show great variance; 13.55% in Brazil and 31.38% in Bulgaria of all ICT cases being attributed to them. However, metastatic ICTs are even a more diverse group than neuroepithelial tumors, with the majority of this group comprising metastatic colorectal adenocarcinoma (almost exclusively in males), metastatic breast adenocarcinoma in females, metastatic pulmonary carcinomas (primarily from the non-small cell group with a male predominance), and metastatic melanoma with an even gender ratio.

Cell biology of glioblastoma multiforme: from basic science to diagnosis and treatment.

First described in the 1800s, glioblastoma multiforme (GBM), a class IV neoplasm with astrocytic differentiation, as per the revised 2016 World Health Organization classification of tumors of the central nervous system (CNS) is the most common malignant tumor of the CNS. GBM has an extremely wide set of alterations, both genetic and epigenetic, which yield a great number of mutation subgroups, some of which have an established role in independent patient survival and treatment response. All of those components not only represent a closed cycle but are also relevant to the tumor biological behavior and resistance to treatment as they form the pathobiological behavior and clinical course. The presence of different triggering mutations on the background of the presence of key mutations in the GBM stem cells (GBMsc) further separates GBM as primary arising de novo from neural stem cell precursors developing into GBMsc and secondary, by means of aggregated mutations. Some of the change in cellular biology in GBM can be observed via light microscope as they form the cellular and tissue hallmarks of the condition. Changes in genetic information, resulting in alteration, suppression and expression of genes compared to their physiological levels in healthy astrocytes lead to not only cellular, but also extracellular matrix reorganization. These changes result in a multiform number of micromorphological and purely immunological/biochemical forms. Therefore, in the twenty-first century the term multiforme, previously outcast from nomenclatures, has gained new popularity on the background of genotypic diversity in this neoplastic entry.

Interaction between transcription factors PAX6/PAX6-5a and specific members of miR-183-96-182 cluster, may contribute to glioma progression in glioblastoma cell lines.

A misbalance between proliferation and differentiation of neural stem cells in niches for adult brain neurogenesis is a key mechanism in glioma pathogenesis. In the adult brain, the expression of Pax6 marks stem cells in the forebrain neurogenic niche. We analyzed the expression profile of the two active in vertebrates Pax6 isoforms, Pax6 and Pax6-5a, along with the expression of microRNA cluster miR-183-96-182 in a large set of glioma patient specimens and glioma cell lines which showed opposite expression level, low and high, respectively, with the progression of tumor malignancy. Our results from biochemical and in vitro studies in glioma cell lines disclosed a specific regulation of the PAX6-5a isoform by miR-183. Mechanistically, we show that the downregulation of the lipid kinase SPHK1 by both PAX6 isoforms and the simultaneous induction of CTNDD2 expression, specifically by PAX6-5a, results in reduced glioma cell survival, decreased migration and invasion and increased cell death, in glioma cell lines. Taken together, our findings point towards the important role of PAX6 and define PAX6-5a as a new essential player in glioma development. Finally, we propose that the expression level of TFs PAX6/PAX6-5a and miR-183-96-182 may potentially serve as prognostic markers for the progression of glioma tumors from low- to high-grade with a potential to identify new therapeutic approaches.

JC polyomavirus in the aetiology and pathophysiology of glial tumours.

Glial brain tumours with their poor prognosis, limited treatment modalities and unclear detailed pathophysiology represent a significant health concern. The purpose of the current study was to investigate and describe the possible role of the human polyomavirus JC as an underlying cancerogenic or co-cancerogenic factor in the complex processes of glial tumour induction and development. Samples from 101 patients with glial tumours were obtained during neurosurgical tumour resection. Small tissue pieces were taken from several areas of the histologically verified solid tumour core. Biopsies were used for DNA extraction and subsequent amplification reactions of sequences from the JC viral genome. Real-time polymerase chain reaction was used for detection and quantification of its non-coding control region (NCCR) and gene encoding the regulatory protein Large T antigen (LT). An average of 37.6% of all patients was found to be LT positive, whereas only 6.9% tested positive for NCCR. The analysis of the results demonstrated significant variance between the determined LT prevalence and the rate for NCCR, with a low starting copy number in all positive samples and threshold cycles in the range of 36 to 42 representing viral load in the range from 10 to 1000 copies/µl. The results most probably indicate incomplete JC viral replication. Under such conditions, mutations in the host cell genome may be accumulated due to interference of the virus with the host cell machinery, and eventually malignant transformation may occur.

Checklists in Neurosurgery to Decrease Preventable Medical Errors: A Review.

Neurosurgery represents a zero tolerance environment for medical errors, especially preventable ones like all types of wrong site surgery, complications due to the incorrect positioning of patients for neurosurgical interventions and complications due to failure of the devices required for the specific procedure. Following the excellent and encouraging results of the safety checklists in intensive care medicine and in other surgical areas, the checklist was naturally introduced in neurosurgery. To date, the reported world experience with neurosurgical checklists is limited to 15 series with fewer than 20,000 cases in various neurosurgical areas. The purpose of this review was to study the reported neurosurgical checklists according to the following parameters: year of publication; country of origin; area of neurosurgery; type of neurosurgical procedure-elective or emergency; person in charge of the checklist completion; participants involved in completion; whether they prevented incorrect site surgery; whether they prevented complications due to incorrect positioning of the patients for neurosurgical interventions; whether they prevented complications due to failure of the devices required for the specific procedure; their specific aims; educational preparation and training; the time needed for checklist completion; study duration and phases; number of cases included; barriers to implementation; efforts to implementation; team appreciation; and safety outcomes. Based on this analysis, it could be concluded that neurosurgical checklists represent an efficient, reliable, cost-effective and time-saving tool for increasing patient safety and elevating the neurosurgeons' self-confidence. Every neurosurgical department must develop its own neurosurgical checklist or adopt and modify an existing one according to its specific features and needs in an attempt to establish or develop its safety culture. The world, continental, regional and national neurosurgical societies could promote safety checklists and their benefits.

Ultrasound-based neuronavigation and spinal cord tumour surgery - marriage of convenience or notified incompatibility?

AIM: The study aimed to examine the position of three-dimensional (3D) neurosonography and the advantages and disadvantages of ultrasound-based neuronavigation in spinal cord tumour surgery. MATERIAL AND METHODS: During the period July, 2007- February 2011, 28 patients with spinal cord tumours were operated in our neurosurgical clinic. All patients underwent intraoperative 3D neurosonography by means of SonoWandTM and SonoWand InviteTM ultrasound-based neuronavigation systems. RESULTS: Intraoperative 3D neurosonography was used for 6 intramedullary tumours (5 ependymomas and 1 astrocytoma) and 22 extramedullary tumours (8 neurinomas, 10 meningiomas and 4 filum terminale ependymomas). During the performed spinal tumour surgery, snapshots of the 3D images of the surgical situation were obtained. Post-operative results, based on the control MRI findings and the patients' score on Karnofsky Performance Scale, were evaluated during the third month after the surgery. CONCLUSION: Ultrasound-based neuronavigation is a promising tool in extramedullary tumour surgery, especially of meningiomas and neurinomas, ensuring better control on the extent of tumour excision. In patients with intramedullary tumours, however, the use of 3D neurosonography for more precise control on the extent of radical tumour excision is not possible. In general, ultrasound-based neuronavigation has not added much to the surgical management of spinal cord tumors.

Neuronavigational neuroendoscopy--to be or not to be? An international pilot questionnaire-based study.

OBJECTIVE: The almost age-old neuroendoscopy (NE) and neuronavigation (NN) in its twenties independently and indisputably have proved their high value as neurosurgical armamentarium and became even indispensable in some pathologies. However, nowadays the effectiveness of their simultaneous and combined application still is a matter of debate. The purpose of our pilot international, questionnaire-based survey was to assess the position of the opinion leaders in the field of neuroendoscopy worldwide toward the neuronavigational neuroendoscopy (NNNE). METHODS: Within 3 months, a questionnaire with 17 questions was emailed repeatedly to 55 leading academic neuroendoscopic neurosurgeons from 50 institutions in 24 countries. The questionnaire covered aspects of personal and institutional experience in NE, NN, and NNNE, the most frequently treated pathologies by NNNE as well as inquiring the neurosurgeons' opinion for the importance and future of NNNE. RESULTS: Forty-one questionnaires were returned (response rate = 74.6%). Six questionnaires were excluded because of incomplete or incorrect answers, leaving in the survey 35 respondents from 35 institutions in 18 countries. The less experienced neurosurgeons rely in higher degree on NNNE. Most frequently, NNNE is performed for hydrocephalus (procedures other than third ventriculostomy), transsphenoidal surgery, tumor biopsy, and cyst fenestration. Regardless their neurosurgical and NE experience, more than 75% of the respondents state that NNNE extends the range of neuroendoscopic procedures in their neurosurgical departments. CONCLUSION: NNNE represents a valuable operative technique with excellent future prospects. NNNE extends the range of neuroendoscopic procedures, transforming some number of patients from "nonoperable" neuroendoscopically to suitable for neuroendoscopy.

Neuronavigation in cranioorbital neurosurgery - do we really need it?

AIM: The value of neuronavigation in cranioorbital neurosurgery is controversial and relatively unstudied. The aim of this study was to evaluate the application, the usefulness and the reliability of neuronavigation in the neurosurgical treatment of orbital tumours. MATERIAL AND METHODS: A frameless armless infrared-based neuronavigation system was applied in the microsurgical removal of 7 orbital tumors. Image guidance was CT-based in 3 cases, MRI-based in another 3 cases and based on image fusion between CT and MRI image sets in one patient. The extradural fronto-orbital approach was performed in 3 cases, lateral orbitotomy in 2 cases, trans-supraciliar approach in 1 case and inferomedial orbitotomy in 1 case. RESULTS: The surgical procedures were successful in all cases. The procedure-related morbidity and mortality rate in the series was zero. The registration accuracy of the neuronavigation ranged between 1.0 and 1.7 mm, with an average of 1.3 mm. Neuronavigated image guidance was evaluated as useful in all patients. Total tumour removal was achieved in 5 patients and partial tumour excision in 1 case. One patient was only biopsied. CONCLUSION: Neuronavigation is not a substitute for surgical knowledge and experience, but it is a valuable complement with significant intraoperative potential in cranioorbital surgery.