ABCG2 Expression as a Potential Survival Predictor in Human Gliomas.

Gliomas are notably challenging to treat due to their invasive nature and resistance to conventional therapies. The ABCG2 protein has attracted attention for its role in multidrug resistance, complicating treatment effectiveness. This study scrutinized the relationship between ABCG2 expression and glioma grade and the role of ABCG2 in the process of glioma progression, aiming to evaluate ABCG2 expression as a predictive factor of tumor progression and patient survival. Conducted at Dubrava University Hospital, Zagreb, Croatia, the study analyzed 152 glioma specimens from 2013 to 2022, assessing ABCG2 expression alongside standard clinical markers. A significant association was found between patients' survival and the ABCG2 profile (p = 0.003, r = 0.24), separately for patients who underwent chemotherapy (p = 0.0004, r = 0.32) and radiotherapy (p = 0.003, r = 0.29). Furthermore, the ABCG2 profile was significantly associated with disease progression (p = 0.007, r = 0.23), tumor grade (p = 0.0002, r = 0.31), and Ki67 expression (p = 0.0004, r = 0.31). ABCG2-positive tumor cells only showed association with Ki67 expression (p = 0.002, r = 0.28). The ABCG2 profile was found to affect the overall patient survival (p = 0.02) and represent a moderate indicator of tumor progression (p = 0.01), unlike the percentage of ABCG2-positive tumor cells. ABCG2 may serve as a marker of angiogenesis and vascular abnormalities within tumors, predicting glioma progression and treatment response. Targeting ABCG2 could enhance chemoradiotherapy efficacy and improve patient outcomes, which highlights its value in assessing tumor aggressiveness and designing treatment strategies.

FORAMEN OVALE AND FORAMEN ROTUNDUM: CHARACTERIZATION OF POSTNATAL DEVELOPMENT.

The sphenoid bone development occurs in both prenatal and postnatal periods. Sphenoid bone openings are used as surgical landmarks and are of great importance for neurosurgeons in everyday practice. The aim of this study was to identify morphological characteristics, postnatal development and remodeling, as well as clinical aspect of the sphenoid bone openings and to investigate their relationship and difference in size. The macerated sphenoid bones analyzed in this study were scanned by micro-computed tomography. Areas and distance in-between foramen ovale and foramen rotundum were measured. In addition, different shapes of foramen ovale were described. The most common shape of foramen ovale on both sides was oval, followed by the round, almond and elongated shapes. Modest to strong positive correlations between all foramina and age for the whole sample and both subsamples were presented, except for the right foramen rotundum area in the male subsample, which did not show significant correlation with age. Our study revealed changes in postnatal development and anatomy of foramen ovale and foramen rotundum, primarily in the aspects of size and shape, and should contribute to reducing the risk of damage to neurovascular structures during surgical procedures.

Clinical application of the RONNA G4 system - preliminary validation of 23 robotic frameless brain biopsies.

AIMS: To report the outcomes of robot-assisted brain biopsies performed using a novel RONNA G4 system. The system was developed by a research group from the Faculty of Mechanical Engineering and Naval Architecture and a team of neurosurgeons from Dubrava University Hospital, University of Zagreb School of Medicine. METHODS: This prospective study included 49 biopsies analyzed during one year: 23 robotic frameless and 26 frame-based Leksell stereotactic biopsies. We analyzed the presenting symptoms, tumor range and location, postoperative complications, pathohistological diagnosis, diagnostic yield, as well as operation and hospitalization duration. The target point error was calculated to assess the accuracy of the RONNA system. RESULTS: No postoperative mortality, morbidity, or infections were observed. In the frameless robotic biopsy group, only one pathohistological diagnosis was inconclusive. Therefore, the diagnostic yield was 95.6% (22/23), similar to that of the framebased Leksell stereotactic biopsy group (95.1% or 25/26). The average target point error in the frameless robotic biopsy group was 2.15±1.22 mm (range 0.39-5.85). CONCLUSION: The RONNA G4 robotic system is a safe and accurate tool for brain biopsy, although further research warrants a larger patient sample, comparison with other robotic systems, and a systematic analysis of the entry and target point errors.

The vicious interplay between disrupted sleep and malignant brain tumors: a narrative review.

Malignant brain tumors are among the most aggressive human neoplasms. One of the most common and severe symptoms that patients with these malignancies experience is sleep disruption. Disrupted sleep is known to have significant systemic pro-tumor effects, both in patients with other types of cancer and those with malignant brain lesions. We therefore provide a review of the current knowledge on disrupted sleep in malignant diseases, with an emphasis on malignant brain tumors. More specifically, we review the known ways in which disrupted sleep enables further malignant progression. In the second part of the article, we also provide a theoretical framework of the reverse process. Namely, we argue that due to the several possible pathophysiological mechanisms, patients with malignant brain tumors are especially susceptible to their sleep being disrupted and compromised. Thus, we further argue that addressing the issue of disrupted sleep in patients with malignant brain tumors can, not just improve their quality of life, but also have at least some potential of actively suppressing the devastating disease, especially when other treatment modalities have been exhausted. Future research is therefore desperately needed.

DOES THE TYPE OF SURGERY IN BRAIN ABSCESS PATIENTS INFLUENCE THE OUTCOME? ANALYSIS BASED ON THE PROPENSITY SCORE METHOD.

There are different options for surgical treatment of brain abscess, mainly standard craniotomy and stereotactic aspiration. It has not yet been established which of these options is associated with a more favorable outcome under similar baseline conditions of patients. Demographic characteristics, microbiology, clinical presentation, and treatment outcome were analyzed for surgically treated adult patients with brain abscess over a 14-year period. A propensity score model was applied to account for baseline conditions that may determine the choice of neurosurgical method. The propensity score was included in the prediction of a favorable outcome, defined as a Glasgow Outcome Scale (GOS) score 4 or 5. We analyzed 91 adult surgically treated patients, of which 53 had standard craniotomy and 38 stereotactic aspiration of brain abscess. Focal neurological deficit was the most common symptom present in 60 (65.9%) patients on admission. Sixty-seven (73.6%) patients had GOS 4 or 5, and seven (7.7%) patients died. The choice of surgery did not influence the outcome (OR 1.181, 95% CI 0.349-3.995), neither did the time elapsed from diagnosis to surgery (OR 0.998, 95% CI 0.981-1.015). Propensity towards standard craniotomy procedure did not influence outcome in brain abscess patients (OR 1.181, 95% CI 0.349-3.995). Worse outcome (GOS below 4) was independently associated with Glasgow Coma Score (GCS) on admission (OR 0.787, CI 0.656-0.944). The choice of neurosurgical procedure did not influence the outcome in patients with brain abscess. Patients with brain abscess who had lower GCS on admission also had worse outcome.

DELAYED EFFECT OF VNS ON INTERICTAL EPILEPTIFORM DISCHARGES AND PHARMACORESISTANCE IN A PATIENT WITH REFRACTORY PERINATAL POSTISCHEMIC EPILEPSY.

A 20-year-old female with refractory perinatal postischemic catastrophic epilepsy and frequent daily generalized atonic, tonic, tonic-clonic and focal seizures was hospitalized in the progressive phase of illness. The diagnosis was confirmed by semiology, interictal electroencephalogram (EEG), long-term video EEG monitoring, and brain magnetic resonance imaging. Repeated interictal EEG findings showed generalized spike and slow wave complexes with a 2-3 Hz frequency. Interictal EEG showed evidence of electroclinical epileptic status on several occasions. She was treated with various antiepileptic drugs without improvement. After verification of her incompetence for normal autonomous living, which resulted in very low quality of life, this patient with refractory epilepsy underwent implantation of vagus nerve stimulator (VNS). In this case report, we present delayed effect of VNS on interictal epileptiform discharges and pharmacoresistance.

HbA1c in patients with intracranial meningiomas WHO grades I and II: A preliminary study.

Meningiomas are among the most common primary brain tumors. There is a growing need for novel ways of differentiating between benign (World Health Organization [WHO] grade I) and atypical (WHO grade II) meningiomas as well as for novel markers of the tumor's future behavior. A difference between glucose metabolism in atypical and benign meningiomas is well known. However, a significant correlation between the systemic metabolic status of the patient and the meningioma WHO grade has not yet been established. Our aim was to compare the WHO grades of intracranial meningiomas with the patient's HbA1c levels as a more reliable marker of the chronic systemic metabolic status than the fasting blood glucose value, which is usually looked at. We retrospectively analyzed 15 patients and compared their meningioma WHO grade with their preoperative HbA1c values. Our results show that patients with benign intracranial meningiomas have significantly lower HbA1c value. Conversely, patients with atypical intracranial meningiomas have higher HbA1c values. Furthermore, we showed that the proliferation factor Ki67 was statistically strongly correlated with the HbA1c value (p < .001. These results imply a possible positive correlation between meningioma cell proliferation and the chronic systemic glycemia. Further research in this area could not only lead to better understanding of meningiomas but could have significant clinical application.

Intraoperative identification of the corticospinal tract and dorsal column of the spinal cord by electrical stimulation.

OBJECTIVES: Anatomical identification of the corticospinal tract (CT) and the dorsal column (DC) of the exposed spinal cord is difficult when anatomical landmarks are distorted by tumour growth. Neurophysiological identification is complicated by the fact that direct stimulation of the DC may result in muscle motor responses due to the centrally activated H-reflex. This study aims to provide a technique for intraoperative neurophysiological differentiation between CT and DC in the exposed spinal cord. METHODS: Recordings were obtained from 32 consecutive patients undergoing spinal cord tumour surgery from July 2015 to March 2017. A double train stimulation paradigm with an intertrain interval of 60 ms was devised with recording of responses from limb muscles. RESULTS: In non-spastic patients (55% of cohort) an identical second response was noted following the first CT response, but the second response was absent after DC stimulation. In patients with pre-existing spasticity (45%), CT stimulation again resulted in two identical responses, whereas DC stimulation generated a second response that differed substantially from the first one. The recovery times of interneurons in the spinal cord grey matter were much shorter for the CT than those for the DC. Therefore, when a second stimulus train was applied 60 ms after the first, the CT-fibre interneurons had already recovered ready to generate a second response, whereas the DC interneurons were still in the refractory period. CONCLUSIONS: Mapping of the spinal cord using double train stimulation allows neurophysiological distinction of CT from DC pathways during spinal cord surgery in patients with and without pre-existing spasticity.

Monoamine Neurotransmitter Metabolite Concentration as a Marker of Cerebrospinal Fluid Volume Changes.

OBJECTIVE: In our previous papers we demonstrated that changes in blood and cerebrospinal fluid (CSF) osmolarity have a strong influence on CSF pressure and volume, which is in accordance with a new proposed hypothesis of CSF physiology. Thus, acute changes in CSF volume should be reflected in the CSF concentration of different central nervous system (CNS) metabolites. METHODS: In anesthetized cats (n = 4) we measured the outflow volume of CSF by cisternal free drainage at a negative CSF pressure (-10 cmH2O) before and after the intraperitoneal (i.p.) application of a hypo-osmolar substance (distilled water). In samples of CSF collected at different time intervals (30 min) we measured the concentration of homovanillic acid (HVA). RESULTS: In spite of fact that constant CSF outflow volume was obtained after a 30-min period in our model, the concentration of HVA gradually increased over time and became stable after 90 min. After the i.p. application of distilled water the outflow CSF volume increased significantly, whereas the concentration of HVA significantly decreased over 30 min. CONCLUSIONS: The results observed suggest that alterations in serum osmolarity change the CSF volume and concentrations of neurotransmitter metabolites because of the osmotic arrival of water from CNS blood capillaries in all CSF compartments.

Decreased brain volume may be associated with the occurrence of peri-lead edema in Parkinson's disease patients with deep brain stimulation.

BACKGROUND: Peri-lead edema (PLE) is a poorly understood complication of deep brain stimulation (DBS), which has been described in patients presenting occasionally with profound and often delayed symptoms with an incidence ranging from 0.4% up to even 100%. Therefore, our study aims to investigate the association of brain and brain compartment volumes on magnetic resonance imaging (MRI) with the occurrence of PLE in Parkinson's disease (PD) patients after DBS implantation in subthalamic nuclei (STN). METHODS: This retrospective study included 125 consecutive PD patients who underwent STN DBS at the Department of Neurosurgery, Dubrava University Hospital from 2010 to 2022. Qualitative analysis was done on postoperative MRI T2-weighted sequence by two independent observers, marking PLE on midbrain, thalamus, and subcortical levels as mild, moderate, or severe. Quantitative volumetric analysis of brain and brain compartment volumes was conducted using an automated CIVET processing pipeline on preoperative MRI T1 MPRAGE sequences. In addition, observed PLE on individual hemispheres was delineated manually and measured using Analyze 14.0 software. RESULTS: In our cohort, PLE was observed in 32.17%, mostly bilaterally. Mild PLE was observed in the majority of patients, regardless of the level observed. Age, sex, diabetes, hypertension, vascular disease, and the use of anticoagulant/antiplatelet therapy showed no significant association with the occurrence of PLE. Total grey matter volume showed a significant association with the PLE occurrence (r = -0.22, p = 0.04), as well as cortex volume (r = -0.32, p = 0.0005). Cortical volumes of hemispheres, overall hemisphere volumes, as well as hemisphere/total intracranial volume ratio showed significant association with the PLE occurrence. Furthermore, the volume of the cortex and total grey volume represent moderate indicators, while hemisphere volumes, cortical volumes of hemispheres, and hemisphere/total intracranial volume ratio represent mild to moderate indicators of possible PLE occurrence. CONCLUSION: The results of our study suggest that the morphometric MRI measurements, as a useful tool, can provide relevant information about the structural status of the brain in patients with PD and represent moderate indicators of possible PLE occurrence. Identifying patients with greater brain atrophy, especially regarding grey matter before DBS implantation, will allow us to estimate the possible postoperative symptoms and intervene in a timely manner. Further studies are needed to confirm our findings and to investigate other potential predictors and risk factors of PLE occurrence.

Brain metastases of the mucoepidermoid lung carcinoma: a case report.

Mucoepidermoid carcinoma, a salivary gland tumor, rarely occurs in bronchial mucous glands. Brain metastases are rarely seen which makes for a challenging diagnosis and treatment approach. A 40-year-old woman presented with confusion, and ataxia, accompanied by a declining Glasgow Coma Score. Brain computerized tomography revealed two hyperdense, postcontrast-enhanced infra- and supratentorial lesions with perifocal edema. First causing obstructive hydrocephalus. The initial surgery involved external ventricular drainage system placement leading to the patient's clinical improvement. After radiological diagnostics, both lesions were resected without complications. Histopathological analysis revealed solid clusters of atypical, polygonal epithelial cells exhibiting mucin production, classified as a poorly differentiated mucoepidermoid carcinoma metastasis which originated from the upper lobe's apicoposterior segment and left lung. The correct treatment approach remains elusive due to the infrequent occurrence and challenging diagnosis. While new oncological and radiosurgery options promise improved overall survival rates, radical resection remains the preferred initial option.

Dysfunctional connectivity as a neurophysiologic mechanism of disorders of consciousness: a systematic review.

Introduction: Disorders of consciousness (DOC) has been an object of numbers of research regarding the diagnosis, treatment and prognosis in last few decades. We believe that the DOC could be considered as a disconnection syndrome, although the exact mechanisms are not entirely understood. Moreover, different conceptual frameworks highly influence results interpretation. The aim of this systematic review is to assess the current knowledge regarding neurophysiological mechanisms of DOC and to establish possible influence on future clinical implications and usage. Methods: We have conducted a systematic review according to PRISMA guidelines through PubMed and Cochrane databases, with studies being selected for inclusion via a set inclusion and exclusion criteria. Results: Eighty-nine studies were included in this systematic review according to the selected criteria. This includes case studies, randomized controlled trials, controlled clinical trials, and observational studies with no control arms. The total number of DOC patients encompassed in the studies cited in this review is 1,533. Conclusion: Connectomics and network neuroscience offer quantitative frameworks for analysing dynamic brain connectivity. Functional MRI studies show evidence of abnormal connectivity patterns and whole-brain topological reorganization, primarily affecting sensory-related resting state networks (RSNs), confirmed by EEG studies. As previously described, DOC patients are identified by diminished global information processing, i.e., network integration and increased local information processing, i.e., network segregation. Further studies using effective connectivity measurement tools instead of functional connectivity as well as the standardization of the study process are needed.

Bilateral posterior fossa chronic subdural hematoma as a cause of hydrocephalus.

Background: Infratentorial chronic subdural hematoma (cSDH) is still a rather elusive neurosurgical entity, which, due to its proximity and likely compression of the cerebellum and brainstem, can lead to devastating consequences. To establish standardized treatment, more studies and reports regarding its therapy are needed. We report a case of a simultaneous unilateral supratentorial and bilateral infratentorial cSDH, with the latter causing hydrocephalus and successfully treated with a bilateral burr-hole trepanation of occipital bone and placement of subdural drains. Case Description: A 71-year-old man with gait disturbance, Glasgow Coma Scale 12, and a radiologically verified unilateral supratentorial and bilateral cSDH of the posterior fossa causing cerebellum, brainstem, and fourth ventricle compression with obstructive hydrocephalus, underwent surgical evacuation of infratentorial hematoma with a bilateral burr-hole trepanation. The postoperative course was uneventful, with a control head computed tomography scan showing the resolution of the hematoma and hydrocephalus. The patient was discharged with no newly acquired neurological deficits. Conclusion: Due to a limited number of reports and studies involving infratentorial cSDHs causing hydrocephalus, decision-making and optimal surgical treatment remain unclear. We recommend a timely surgical evacuation of the hematoma if the patient is symptomatic while avoiding placement of external ventricular drainage.

GPi DBS treatment outcome in children with monogenic dystonia: a case series and review of the literature.

Introduction: Dystonia is the third most common pediatric movement disorder and is often difficult to treat. Deep brain stimulation (DBS) of the internal pallidum (GPi) has been demonstrated as a safe and effective treatment for genetic dystonia in adolescents and adults. The results of DBS in children are limited to individual cases or case series, although it has been proven to be an effective procedure in carefully selected pediatric cohorts. The aim of our study was to present the treatment outcome for 7- to 9-year-old pediatric patients with disabling monogenic isolated generalized DYT-THAP1 and DYT-KMT2B dystonia after bilateral GPi-DBS. Patients and results: We present three boys aged <10 years; two siblings with disabling generalized DYT-THAP1 dystonia and a boy with monogenic-complex DYT-KMT2B. Dystonia onset occurred between the ages of 3 and 6. Significantly disabled children were mostly dependent on their parents. Pharmacotherapy was inefficient and patients underwent bilateral GPi-DBS. Clinical signs of dystonia improved significantly in the first month after the implantation and continued to maintain improved motor functions, which were found to have improved further at follow-up. These patients were ambulant without support and included in everyday activities. All patients had significantly lower Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) values, indicating >25% improvement over the first 15 months. However, there was a decline in speech and upper limb function, manifesting with bradylalia, bradykinesia, and dysphonia, which decreased after treatment with trihexyphenidyl. Conclusion: Although reports of patients with monogenic dystonia, particularly DYT-THAP1, treated with DBS are still scarce, DBS should be considered as an efficient treatment approach in children with pharmacoresistent dystonia, especially with generalized monogenic dystonia and to prevent severe and disabling symptoms that reduce the quality of life, including emotional and social aspects. Patients require an individual approach and parents should be properly informed about expectations and possible outcomes, including relapses and impairments, in addition to DBS responsiveness and related improvements. Furthermore, early genetic diagnosis and the provision of appropriate treatments, including DBS, are mandatory for preventing severe neurologic impairments.

Deep brain stimulation in disorders of consciousness: 10 years of a single center experience.

Disorders of consciousness (DoC), namely unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), represent severe conditions with significant consequences for patients and their families. Several studies have reported the regaining of consciousness in such patients using deep brain stimulation (DBS) of subcortical structures or brainstem nuclei. Our study aims to present the 10 years' experience of a single center using DBS as a therapy on a cohort of patients with DoC. Eighty Three consecutive patients were evaluated between 2011 and 2022; entry criteria consisted of neurophysiological and neurological evaluations and neuroimaging examinations. Out of 83, 36 patients were considered candidates for DBS implantation, and 32 patients were implanted: 27 patients had UWS, and five had MCS. The stimulation target was the centromedian-parafascicular complex in the left hemisphere in hypoxic brain lesion or the one better preserved in patients with traumatic brain injury. The level of consciousness was improved in seven patients. Three out of five MCS patients emerged to full awareness, with the ability to interact and communicate. Two of them can live largely independently. Four out of 27 UWS patients showed consciousness improvement with two patients emerging to full awareness, and the other two reaching MCS. In patients with DoC lasting longer than 12 months following traumatic brain injury or 6 months following anoxic-ischemic brain lesion, spontaneous recovery is rare. Thus, DBS of certain thalamic nuclei could be recommended as a treatment option for patients who meet neurological, neurophysiological and neuroimaging criteria, especially in earlier phases, before occurrence of irreversible musculoskeletal changes. Furthermore, we emphasize the importance of cooperation between centers worldwide in studies on the potentials of DBS in treating patients with DoC.

Applicability of clinical genetic testing for deep brain stimulation treatment in monogenic Parkinson's disease and monogenic dystonia: a multidisciplinary team perspective.

In this perspective article, we highlight the possible applicability of genetic testing in Parkinson's disease and dystonia patients treated with deep brain stimulation (DBS). DBS, a neuromodulatory technique employing electrical stimulation, has historically targeted motor symptoms in advanced PD and dystonia, yet its precise mechanisms remain elusive. Genetic insights have emerged as potential determinants of DBS efficacy. Known PD genes such as GBA, SNCA, LRRK2, and PRKN are most studied, even though further studies are required to make firm conclusions. Variable outcomes depending on genotype is present in genetic dystonia, as DYT-TOR1A, NBIA/DYTPANK2, DYT-SCGE and X-linked dystonia-parkinsonism have demonstrated promising outcomes following GPi-DBS, while varying outcomes have been documented in DYT-THAP1. We present two clinical vignettes that illustrate the applicability of genetics in clinical practice, with one PD patient with compound GBA mutations and one GNAL dystonia patient. Integrating genetic testing into clinical practice is pivotal, particularly with advancements in next-generation sequencing. However, there is a clear need for further research, especially in rarer monogenic forms. Our perspective is that applying genetics in PD and dystonia is possible today, and despite challenges, it has the potential to refine patient selection and enhance treatment outcomes.

Dependence of cerebrospinal fluid pressure and volume on the changes in serum osmolarity in cats.

OBJECTIVES: To study the effect of blood osmolarity on cerebrospinal fluid (CSF) volume and CSF pressure in cats. METHODS: Three types of methods were used on anesthetized cats. The first, ventriculo-cisternal perfusion (12.96 µL/min) before and after i.v. application of 20% mannitol; the second, measuring the outflow of CSF by cisternal free drainage; and the third, measuring CSF pressure in the ventricles of an intact CSF system, with the second and third method being performed before and after the i.p. application of a hypo-osmolar substance (distilled water). RESULTS: In the first group, the application of 20% mannitol led to a significantly reduced (p < 0.005) outflow volume (from 12.60 ± 0.29 to 0.94 ± 0.09 µL/min). In the second group, the outflow CSF volume significantly increased (p < 0.001) after the application of distilled water (from 18.8 ± 0.3 to 28.2 ± 0.7 µL/min). In the third group, after the application of distilled water, the CSF pressure also significantly increased (p < 0.05; from 8.3 ± 0.8 to 16.1 ± 0.14 cm H(2)O). CONCLUSION: We conclude that changes in serum osmolarity change the CSF volume because of the osmotic gradient between the blood and all of the CSF compartments, and also that the change in CSF pressure is closely associated with changes in CSF volume.

Cognitive Impact of Deep Brain Stimulation in Parkinson's Disease Patients: A Systematic Review.

Introduction: Parkinson's disease (PD) patients have a significantly higher risk of developing dementia in later disease stages, leading to severe impairments in quality of life and self-functioning. Questions remain on how deep brain stimulation (DBS) affects cognition, and whether we can individualize therapy and reduce the risk for adverse cognitive effects. Our aim in this systematic review is to assess the current knowledge in the field and determine if the findings could influence clinical practice. Methods: We have conducted a systematic review according to PRISMA guidelines through MEDLINE and Embase databases, with studies being selected for inclusion via a set inclusion and exclusion criteria. Results: Sixty-seven studies were included in this systematic review according to the selected criteria. This includes 6 meta-analyses, 18 randomized controlled trials, 17 controlled clinical trials, and 26 observational studies with no control arms. The total number of PD patients encompassed in the studies cited in this review is 3677, not including the meta-analyses. Conclusion: Cognitive function in PD patients can deteriorate, in most cases mildly, but still impactful to the quality of life. The strongest evidence is present for deterioration in verbal fluency, while inconclusive evidence is still present for executive function, memory, attention and processing speed. Global cognition does not appear to be significantly impacted by DBS, especially if cognitive screening is performed prior to the procedure, as lower baseline cognitive function is connected to poor outcomes. Further randomized controlled studies are required to increase the level of evidence, especially in the case of globus pallidus internus DBS, pedunculopontine nucleus DBS, and the ventral intermediate nucleus of thalamus DBS, and more long-term studies are required for all respective targets.

Spontaneous spinal subdural hematoma in COVID-19 patient: Croatian national COVID hospital experience.

Background: Spontaneous spinal subdural hematoma (SSDH) is a rare condition and causes of acute spinal cord compression, with symptoms varying from mild to severe neurological deficit. SSDH could occur as a consequence of posttraumatic, iatrogenic, or spontaneous causes, including underlying arteriovenous malformations, tumors, or coagulation disorder. Due to its rarity, it is difficult to establish standardized treatment. We present a rare case of SSDH in COVID-19 patient and course of treatment in COVID hospital. Case Description: A 71-year-old female patient was admitted due to instability, weakness of the left leg, and intensive pain in the upper part of thoracic spine as well as mild respiratory symptoms of COVID-19. She was not on pronounced anticoagulant therapy and her coagulogram at admission was within normal range. MRI revealed acute subdural hematoma at the level C VII to Th III compressing the spinal cord. The patient underwent a decompressive Th I and Th II laminectomy and hematoma evacuation. Post-operative MRI revealed a satisfactory decompression and re-expansion of the spinal cord. COVID-19 symptoms remained mild. Conclusion: SSDH represents a neurological emergency, possibly leading to significant deficit and requires urgent recognition and treatment. One of the main difficulties when diagnosing is to consider such condition when there is no history of anticoagulant treatment or previous trauma. Since high incidence of coagulation abnormalities and thromboembolic events was described COVID-19 patients, when considering the pathology of the central nervous system, the bleeding within it due to COVID-19 should be taken into account, in both brain and spine.

Frameless stereotactic brain biopsy and external ventricular drainage placement using the RONNA G4 system.

Robot-assisted stereotactic procedures are among the latest technological improvements in neurosurgery. Herein, to the best of our knowledge, we report a first external ventricular drainage (EVD) placement using the RONNA G4 robotic system preformed together with brain biopsy, all in one procedure. A patient was presented with progressive drowsiness, cognitive slowing, poor mobility and incontinent. Magnetic resonance imaging brain scans revealed multicentric process located in the basal ganglia right with extensive vasogenic edema and dilatated ventricular system. Using the RONNAplan software two trajectories were planned: one for brain biopsy on the left side and one for EVD implantation on the right side; the procedures went without complications. The RONNA G4 robotic system is an accurate neurosurgical tool for performing frameless brain biopsies and EVD placement. Further studies are needed in order to enroll a larger patient sample and to calculate the possible placement deviation, and to perform the comparison with other robotic systems.