HCN channels at the cell soma ensure the rapid electrical reactivity of fast-spiking interneurons in human neocortex.

Accumulating evidence indicates that there are substantial species differences in the properties of mammalian neurons, yet theories on circuit activity and information processing in the human brain are based heavily on results obtained from rodents and other experimental animals. This knowledge gap may be particularly important for understanding the neocortex, the brain area responsible for the most complex neuronal operations and showing the greatest evolutionary divergence. Here, we examined differences in the electrophysiological properties of human and mouse fast-spiking GABAergic basket cells, among the most abundant inhibitory interneurons in cortex. Analyses of membrane potential responses to current input, pharmacologically isolated somatic leak currents, isolated soma outside-out patch recordings, and immunohistochemical staining revealed that human neocortical basket cells abundantly express hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channel isoforms HCN1 and HCN2 at the cell soma membrane, whereas these channels are sparse at the rodent basket cell soma membrane. Antagonist experiments showed that HCN channels in human neurons contribute to the resting membrane potential and cell excitability at the cell soma, accelerate somatic membrane potential kinetics, and shorten the lag between excitatory postsynaptic potentials and action potential generation. These effects are important because the soma of human fast-spiking neurons without HCN channels exhibit low persistent ion leak and slow membrane potential kinetics, compared with mouse fast-spiking neurons. HCN channels speed up human cell membrane potential kinetics and help attain an input-output rate close to that of rodent cells. Computational modeling demonstrated that HCN channel activity at the human fast-spiking cell soma membrane is sufficient to accelerate the input-output function as observed in cell recordings. Thus, human and mouse fast-spiking neurons exhibit functionally significant differences in ion channel composition at the cell soma membrane to set the speed and fidelity of their input-output function. These HCN channels ensure fast electrical reactivity of fast-spiking cells in human neocortex.

Percutaneous Superficial Temporal Artery Access Facilitating Carotid Artery Stenting Performed From Distal Radial Artery.

PURPOSE: The purpose of the study is to describe carotid artery stenting (CAS) via distal transradial access (dTRA) facilitated by additional superficial temporal artery (STA) access, in a patient with complex aortic arch vessel anatomy. TECHNIQUE: A 72-year-old woman with a prior history of complex cervical surgery and radiotherapy due to laryngeal malignancy, presented with a symptomatic 90% stenosis of the left internal carotid artery (ICA). Due to high cervical lesion, the patient was rejected from carotid endarterectomy. Angiography demonstrated 90% stenosis of the left ICA and a type III aortic arch. After failure of left common carotid artery (CCA) cannulation with appropriate catheter support via dTRA and transfemoral approaches, CAS was attempted a second time. After percutaneous ultrasound guided access to right dTRA and left STA, a 0.035 inch guidewire introduced to the left CCA from the contralateral dTRA was snared and externalized via left STA to improve wire support for guiding advancement. Thereafter, the left ICA lesion was successfully stented with a 7×30 mm self-expanding stent via right dTRA. All vessels involved were patent at 6-month follow-up. CONCLUSION: The STA may be a promising adjunctive access site to increase transradial catheter support for CAS or neurointerventional procedures in the anterior circulation. CLINICAL IMPACT: Transradial cerebrovascular interventions have been gaining popularity, however, unstable catheter access to distal cerebrovascular structures limits its widespread use. Guidewire externalization technique via additional STA access may improve transradial catheter stabilty and increase procedural success with possibly low access stie complication rate.

Minimal invasive transnasal endoscopic removal of intracranial foreign body after airbag deployment.

Airbag induced injuries such as skull and cervical spine fractures, epidural and subdural hematomas, atlantooccipital dislocations or brainstem lacerations are already documented in published literature, however, no previous case have been published about a penetrating foreign body of the skull base following airbag deployment. Removal of an intracranial foreign body is very dangerous and difficult, or even if it possible and necessary, requires open surgery in most of the cases. In this article we present the minimal invasive, transnasal removal of a coin from the intracranial, frontobasal region using high-resolution endoscopy combined with image-guided navigation.
We report the case of a 59-year-old male who was brought to the emergency department after a car accident. He suffered a penetrating injury by a coin that was placed on the car’s airbag at the moment of the accident. Upon the airbag being deployed the foreign body entered the skin through the right lower eyelid, crossing the orbital cavity, ethmoid cells, sphenoid sinus and the anterior part of the planum sphenoidale at an equal distance of 2mm from the two internal carotid arteries, extending into the intracranial space, without injuring the pituitary stalk and the chiasm. We proceeded to remove the coin endoscopically using a transnasal transseptal transsphenoidal approach under general anesthesia. The dura was closed with a multilayer skull base reconstruction technique using two layers of abdominal free fat and nasal septal mucoperiosteal flap. There were no postoperative complications, nor CSF rhinorrhea. The patient was discharged 10 days after the operation.
To our knowledge, this is the first publi­shed case of a penetrating foreign body of the skull base, extending into the intracranial cavity following airbag deployment. In some dedicated cases, a minimal invasive endoscopic approach should be considered as an alternative to anterior craniotomy if access is possible when foreign bodies from the skull base area need to be removed. This procedure is efficient, safe and minimally invasive. 

Efficacy and safety of minimally invasive surgery with thrombolysis in intracerebral haemorrhage evacuation (MISTIE III): a randomised, controlled, open-label, blinded endpoint phase 3 trial.

BACKGROUND: Acute stroke due to supratentorial intracerebral haemorrhage is associated with high morbidity and mortality. Open craniotomy haematoma evacuation has not been found to have any benefit in large randomised trials. We assessed whether minimally invasive catheter evacuation followed by thrombolysis (MISTIE), with the aim of decreasing clot size to 15 mL or less, would improve functional outcome in patients with intracerebral haemorrhage. METHODS: MISTIE III was an open-label, blinded endpoint, phase 3 trial done at 78 hospitals in the USA, Canada, Europe, Australia, and Asia. We enrolled patients aged 18 years or older with spontaneous, non-traumatic, supratentorial intracerebral haemorrhage of 30 mL or more. We used a computer-generated number sequence with a block size of four or six to centrally randomise patients to image-guided MISTIE treatment (1·0 mg alteplase every 8 h for up to nine doses) or standard medical care. Primary outcome was good functional outcome, defined as the proportion of patients who achieved a modified Rankin Scale (mRS) score of 0-3 at 365 days, adjusted for group differences in prespecified baseline covariates (stability intracerebral haemorrhage size, age, Glasgow Coma Scale, stability intraventricular haemorrhage size, and clot location). Analysis of the primary efficacy outcome was done in the modified intention-to-treat (mITT) population, which included all eligible, randomly assigned patients who were exposed to treatment. All randomly assigned patients were included in the safety analysis. This study is registered with ClinicalTrials.gov, number NCT01827046. FINDINGS: Between Dec 30, 2013, and Aug 15, 2017, 506 patients were randomly allocated: 255 (50%) to the MISTIE group and 251 (50%) to standard medical care. 499 patients (n=250 in the MISTIE group; n=249 in the standard medical care group) received treatment and were included in the mITT analysis set. The mITT primary adjusted efficacy analysis estimated that 45% of patients in the MISTIE group and 41% patients in the standard medical care group had achieved an mRS score of 0-3 at 365 days (adjusted risk difference 4% [95% CI -4 to 12]; p=0·33). Sensitivity analyses of 365-day mRS using generalised ordered logistic regression models adjusted for baseline variables showed that the estimated odds ratios comparing MISTIE with standard medical care for mRS scores higher than 5 versus 5 or less, higher than 4 versus 4 or less, higher than 3 versus 3 or less, and higher than 2 versus 2 or less were 0·60 (p=0·03), 0·84 (p=0·42), 0·87 (p=0·49), and 0·82 (p=0·44), respectively. At 7 days, two (1%) of 255 patients in the MISTIE group and ten (4%) of 251 patients in the standard medical care group had died (p=0·02) and at 30 days, 24 (9%) patients in the MISTIE group and 37 (15%) patients in the standard medical care group had died (p=0·07). The number of patients with symptomatic bleeding and brain bacterial infections was similar between the MISTIE and standard medical care groups (six [2%] of 255 patients vs three [1%] of 251 patients; p=0·33 for symptomatic bleeding; two [1%] of 255 patients vs 0 [0%] of 251 patients; p=0·16 for brain bacterial infections). At 30 days, 76 (30%) of 255 patients in the MISTIE group and 84 (33%) of 251 patients in the standard medical care group had one or more serious adverse event, and the difference in number of serious adverse events between the groups was statistically significant (p=0·012). INTERPRETATION: For moderate to large intracerebral haemorrhage, MISTIE did not improve the proportion of patients who achieved a good response 365 days after intracerebral haemorrhage. The procedure was safely adopted by our sample of surgeons. FUNDING: National Institute of Neurological Disorders and Stroke and Genentech.

[Early experiences in surgical treatment of thoracic disc herniation from posterior transdural approach at Neurosurgery Clinic Szeged University]. / A thoracalis porckorong-sérvesedés hátsó transduralis feltárása során nyert korai tapasztalatok a Szegedi Tudományegyetem, Idegsebészeti Klinikán.

Background - Because of the rare occurrence of thoracic disc herniation and surgery needed treatment the used approaches and their efficiency are still subjects of discussions. In Hungarian practice, the most frequent explorations are costotransversectomy and laminectomy, but there are many other important methods available like thoracoscopic and posterior transdural approaches. This case report will present the benefits and the surgical procedure of posterior transdural sequesterectomy, carry out for the first time in Hungary at the Neurosurgical Department on Szeged University. Case presentation - A 50-year-old female patient with achondroplasic nanism has been operated several times since 2011. She suffered from a progressive, multi-segment affected degenerative discopathy and myelopathy. Finally in the background of the recurrent paraparesis was confirmed thoracic disc herniations at the levels of T8 and T9. The use of intraoperative electrophysiology was not feasable, because the earlier described cervical myelopathy. For this reason we used the posterior transdural approach, as the best and safest, visual control warranted technique. Conclusions - The posterior transdural approach offers an alternative option for experienced surgeons, furthermore in contrast with traditional, technically difficult to implement or special instrumentation demanding approaches this technique seems to be more efficient.

Plasticity in Single Axon Glutamatergic Connection to GABAergic Interneurons Regulates Complex Events in the Human Neocortex.

In the human neocortex, single excitatory pyramidal cells can elicit very large glutamatergic EPSPs (VLEs) in inhibitory GABAergic interneurons capable of triggering their firing with short (3-5 ms) delay. Similar strong excitatory connections between two individual neurons have not been found in nonhuman cortices, suggesting that these synapses are specific to human interneurons. The VLEs are crucial for generating neocortical complex events, observed as single pyramidal cell spike-evoked discharge of cell assemblies in the frontal and temporal cortices. However, long-term plasticity of the VLE connections and how the plasticity modulates neocortical complex events has not been studied. Using triple and dual whole-cell recordings from synaptically connected human neocortical layers 2-3 neurons, we show that VLEs in fast-spiking GABAergic interneurons exhibit robust activity-induced long-term depression (LTD). The LTD by single pyramidal cell 40 Hz spike bursts is specific to connections with VLEs, requires group I metabotropic glutamate receptors, and has a presynaptic mechanism. The LTD of VLE connections alters suprathreshold activation of interneurons in the complex events suppressing the discharge of fast-spiking GABAergic cells. The VLEs triggering the complex events may contribute to cognitive processes in the human neocortex, and their long-term plasticity can alter the discharging cortical cell assemblies by learning.

[Early experience with minimal invasive treatment of thirty-one thoracolumbar injury cases]. / Korai tapasztalataink thoracolumbalis gerincsérülések minimálinvazív mutéti kezelésével.

The authors report on their experience with minimal invasive treatment of thirtyone thoracolumbar injury cases. The medical charts, radiological documentation (preop CT and MRI scans, postop CT scans at 3 and 6 months) were analysed retrospectively. All pedicle screws were inserted appropriately, there was no neurological deterioration or surgical site infection postoperatively. There were three cases of radiological loss of correction, however, these were clinically irrelevant. There were no screw loosening or implant failure observed. According to our experience, which coincedes with literature data, this minimally invasive percutaneous pedicle screw technique can be recommended for the treatment of thoracolumbar injury.

[Guidelines for the treatment of traumatic brain injury - 2017]. / Baleseti agysérültek ellátásának irányelvei - 2017.

Traumatic brain injury (TBI) is recognized to be the main cause of death and disability in the first four decades representing a major socio-economical problem worldwide. Recent communications revealed a particularly worrying image about the quality of care for TBI in Hungary. For any improvement a systematic approach characterized by utilization of scientific evidence based guidelines forming the basis for close monitoring of the actual care are considered a prerequisite. In Hungary the first evidence based guidelines in the field of TBI have been issued by the National Society for Anesthesiology and Intensive Care more than two decades ago followed by joint guidelines of the Hungarian Neurosurgical Society and the Hungarian College of Neurosurgeons. These publications were primarily based on the work of the European Brain Injury Consortium as well as guidelines issued by the Brain Trauma Foundation. Recent renewal of the latter and a need to refresh the outdated national guidelines was met by a call from regulatory authorities to issue the updated version of the Hungarian TBI-guidelines. The present review is aimed to briefly summarize the most fundamental elements of the national head injury guidelines that would hopefully be officially issued in a far more detailed format soon.

Molecular and Electrophysiological Characterization of GABAergic Interneurons Expressing the Transcription Factor COUP-TFII in the Adult Human Temporal Cortex.

Transcription factors contribute to the differentiation of cortical neurons, orchestrate specific interneuronal circuits, and define synaptic relationships. We have investigated neurons expressing chicken ovalbumin upstream promoter transcription factor II (COUP-TFII), which plays a role in the migration of GABAergic neurons. Whole-cell, patch-clamp recording in vitro combined with colocalization of molecular cell markers in the adult cortex differentiates distinct interneurons. The majority of strongly COUP-TFII-expressing neurons were in layers I-III. Most calretinin (CR) and/or cholecystokinin- (CCK) and/or reelin-positive interneurons were also COUP-TFII-positive. CR-, CCK-, or reelin-positive neurons formed 80%, 20%, or 17% of COUP-TFII-positive interneurons, respectively. About half of COUP-TFII-/CCK-positive interneurons were CR-positive, a quarter of them reelin-positive, but none expressed both. Interneurons positive for COUP-TFII fired irregular, accommodating and adapting trains of action potentials (APs) and innervated mostly small dendritic shafts and rarely spines or somata. Paired recording showed that a calretinin-/COUP-TFII-positive interneuron elicited inhibitory postsynaptic potentials (IPSPs) in a reciprocally connected pyramidal cell. Calbindin, somatostatin, or parvalbumin-immunoreactive interneurons and most pyramidal cells express no immunohistochemically detectable COUP-TFII. In layers V and VI, some pyramidal cells expressed a low level of COUP-TFII in the nucleus. In conclusion, COUP-TFII is expressed in a diverse subset of GABAergic interneurons predominantly innervating small dendritic shafts originating from both interneurons and pyramidal cells.

[ENDOSCOPIC REMOVAL OF TUBERCULUM SELLAE MENINGEOMA THROUGH ENDONASAL TRANSSPHENOIDAL APPROACH]. / TUBERCULUM SELLAE MENINGEOMA ENDOSZKÓPOS ELTÁVOLÍTÁSA ENDONASALIS TRANSSPHENOIDALIS FELTÁRÁSBÓL.

Experiences acquired in our department with endoscope assisted microsurgical transsphenoidal pituitary surgery encouraged us to expanded the endoscopic approach to skull base lesions. The endoscopic endonasal transsphenoidal approach proved to be less traumatic to the traditional microsurgical approaches, yet very effective. The endoscopic transsphenoidal technique was applied in a patient havin anterior skull base tumor. The patient was a 49-year-old woman with several months history of left visual defect. The magnetic resonance (MR) scans of the skull revealed a midline anterior fossa space-occupying lesion measuring 21 x 16 x 22 mm located on planum sphenoidale, tuberculum sellae and intrasellar. The tumor compressed both optic nerves and optic chiasm. Total resection of the tumor was achieved by use of endoscopic transnasal, transsphenoidal technique. This is the first reported case of an anterior fossa meningeoma being treated by an endoscopic transsphenoidal technique in Hungary.

Regulation of cortical microcircuits by unitary GABA-mediated volume transmission.

GABA (gamma-aminobutyric acid) is predominantly released by local interneurons in the cerebral cortex to particular subcellular domains of the target cells. This suggests that compartmentalized, synapse-specific action of GABA is required in cortical networks for phasic inhibition. However, GABA released at the synaptic cleft diffuses to receptors outside the postsynaptic density and thus tonically activates extrasynaptic GABA(A) and GABA(B) receptors, which include subtypes of both receptor families especially sensitive to low concentrations of GABA. The synaptic and extrasynaptic action of GABA corroborates the idea that neurons of the brain use synaptic (or wiring) transmission and non-synaptic (or volume) transmission for communication. However, re-uptake mechanisms restrict the spatial extent of extrasynaptic GABA-mediated effects, and it has been proposed that the concerted action of several presynaptic interneurons, the sustained firing of individual cells or an increase in release-site density is required to reach ambient GABA levels sufficient to activate extrasynaptic receptors. Here we show that individual neurogliaform cells release enough GABA for volume transmission within the axonal cloud and, thus, that neurogliaform cells do not require synapses to produce inhibitory responses in the overwhelming majority of nearby neurons. Neurogliaform cells suppress connections between other neurons acting on presynaptic terminals that do not receive synapses at all in the cerebral cortex. They also reach extrasynaptic, delta-subunit-containing GABA(A) (GABA(Adelta)) receptors responsible for tonic inhibition. We show that GABA(Adelta) receptors are localized to neurogliaform cells preferentially among cortical interneurons. Neurosteroids, which are modulators of GABA(Adelta) receptors, alter unitary GABA-mediated effects between neurogliaform cells. In contrast to the specifically placed synapses formed by other interneurons, the output of neurosteroid-sensitive neurogliaform cells represents the ultimate form of the lack of spatial specificity in GABA-mediated systems, leading to long-lasting network hyperpolarization combined with widespread suppression of communication in the local circuit.

Electrophysiology and Morphology of Human Cortical Supragranular Pyramidal Cells in a Wide Age Range.

The basic excitatory neurons of the cerebral cortex, the pyramidal cells, are the most important signal integrators for the local circuit. They have quite characteristic morphological and electrophysiological properties that are known to be largely constant with age in the young and adult cortex. However, the brain undergoes several dynamic changes throughout life, such as in the phases of early development and cognitive decline in the aging brain. We set out to search for intrinsic cellular changes in supragranular pyramidal cells across a broad age range: from birth to 85 years of age and we found differences in several biophysical properties between defined age groups. During the first year of life, subthreshold and suprathreshold electrophysiological properties changed in a way that shows that pyramidal cells become less excitable with maturation, but also become temporarily more precise. According to our findings, the morphological features of the three-dimensional reconstructions from different life stages showed consistent morphological properties and systematic dendritic spine analysis of an infantile and an old pyramidal cell showed clear significant differences in the distribution of spine shapes. Overall, the changes that occur during development and aging may have lasting effects on the properties of pyramidal cells in the cerebral cortex. Understanding these changes is important to unravel the complex mechanisms underlying brain development, cognition and age-related neurodegenerative diseases.

Aging-associated weakening of the action potential in fast-spiking interneurons in the human neocortex.

Aging is associated with the slowdown of neuronal processing and cognitive performance in the brain; however, the exact cellular mechanisms behind this deterioration in humans are poorly elucidated. Recordings in human acute brain slices prepared from tissue resected during brain surgery enable the investigation of neuronal changes with age. Although neocortical fast-spiking cells are widely implicated in neuronal network activities underlying cognitive processes, they are vulnerable to neurodegeneration. Herein, we analyzed the electrical properties of 147 fast-spiking interneurons in neocortex samples resected in brain surgery from 106 patients aged 11-84 years. By studying the electrophysiological features of action potentials and passive membrane properties, we report that action potential overshoot significantly decreases and spike half-width increases with age. Moreover, the action potential maximum-rise speed (but not the repolarization speed or the afterhyperpolarization amplitude) significantly changed with age, suggesting a particular weakening of the sodium channel current generated in the soma. Cell passive membrane properties measured as the input resistance, membrane time constant, and cell capacitance remained unaffected by senescence. Thus, we conclude that the action potential in fast-spiking interneurons shows a significant weakening in the human neocortex with age. This may contribute to the deterioration of cortical functions by aging.

Fluoxetine (prozac) and serotonin act on excitatory synaptic transmission to suppress single layer 2/3 pyramidal neuron-triggered cell assemblies in the human prefrontal cortex.

Selective serotonin reuptake inhibitors are the most widely prescribed drugs targeting the CNS with acute and chronic effects in cognitive, emotional and behavioral processes. This suggests that microcircuits of the human cerebral cortex are powerfully modulated by selective serotonin reuptake inhibitors, however, direct measurements of serotonergic regulation on human synaptic interactions are missing. Using multiple whole-cell patch-clamp recordings from neurons in acute cortical slices derived from nonpathological human samples of the prefrontal cortex, we show that neuronal assemblies triggered by single action potentials of individual neurons in the human cortex are suppressed by therapeutic doses of fluoxetine (Prozac). This effect is boosted and can be mimicked by physiological concentrations of serotonin through 5HT-2A and 5HT-1A receptors. Monosynaptic excitatory connections from pyramidal cells to interneurons were suppressed by application of serotonin leaving the monosynaptic output of GABAergic cells unaffected. Changes in failure rate, in paired-pulse ratio, and in the coefficient of variation of the amplitude of EPSPs suggest a presynaptic action of serotonin. In conclusion, activation of neuronal assemblies, which were suggested as building blocks of high order cognitive processes, are effectively downregulated by the acute action of selective serotonin reuptake inhibitors or serotonin at the site of pyramidal output in human microcircuits.

Observations of changes of blood pressure before and after neurosurgical decompression in hypertensive patients with different types of neurovascular compression of brain stem.

AIMS: The neurovascular pulsatile compression of the rostral ventrolateral medulla can be divided into different subtypes. The posterior inferior cerebellar artery and/or vertebral artery can compress either the rostral ventrolateral medulla or the cranial nerves IX and X or both and on left, right or both sides. METHODS: It was retrospectively investigated whether the types of neurovascular compression can influence blood pressure values. Data from 13 resistant hypertensive patients after decompression were investigated. RESULTS: Six patients had 2 compressions, two had only medulla compression, four had only nerve compression on the left side and one had 2 compressions on both sides. There was no correlation between the types of compression and the levels of blood pressure, either before or after the decompression. Both, systolic and diastolic blood pressures and pulse pressure also decreased in all cases after the decompression but the change was significant only in the group with 2 compressions on the left side. CONCLUSION: According to our data, in a severe hypertension not responding to conventional antihypertensive therapy, the surgical decompression of the brain stem independently of the types of neurovascular compression could guarantee a decrease of blood pressure and improved sensitivity to antihypertensive medication.

Post-operative management of primary glioblastoma multiforme in patients over 60 years of age.

BACKGROUND AND PURPOSE: Optimal treatment for elderly patients with glioblastoma multiforme is not well defined. We evaluated the efficacy of post-operative radiotherapy with or without concomitant and/or adjuvant temozolomide in patient, aged > or = 60 years to assess survival and identify prognostic factors of survival. METHODS: A retrospective analysis of overall survival and progression-free survival in patients with newly diagnosed glioblastoma multiforme aged > or = 60 years treated with post-operative radiotherapy with or without temozolomide chemotherapy was conducted at our institutions. Prognostic factors were determined by univariate and multivariate analyses. RESULTS: Of 75 study participants (54.7% male; median age at first diagnosis, 65.1 years), 29 (38.7%) underwent gross total resection, whereas others underwent partial resection or biopsy only. All but 1 patient received radiotherapy. Twenty patients received concomitant temozolomic e only. Adjuvant temozolomide (1-50 cycles) was administered in 42 patients; 16 received > or = 6 cycles. Median overall survival was 10.3 months. One- and 2-year overall survival rates were 42.6% and 6.7%, respectively. Median progression-free survival was 4.1 months. Radiochemotherapy was generally well tolerated. Median overall survival was 15.3 and 29.6 months for patients who received 6-12 cycles and >12 cycles of adjuvant temozolomide, respectively. There were no significant differences in overall survival between age groups (60-64, 65-69, and > or = 70 years). Adjuvant temozolomide, Karnofsky performance status > or = 70, and additional surgery after progression were significant prognostic factors of longer overall survival (p<0.05). CONCLUSIONS: Radiochemotherapy, including > or = 6 cycles of adjuvant temozolomide, was safe and prolonged survival of glioblastoma patients aged > or = 60 years. Aggressive therapy should not be withheld from patients aged > or = 60 years with good performance status because of age.

[Techniques and indications of neurosurgical treatment of oligometastatic renal cell carcinomas in case of spinal metastases]. / Oligometasztatikus vesesejtes karcinóma idegsebészi ellátásának technikái és indikációi gerincáttétek esetén.

The treatment of spinal metastases is a huge challenge, but both oncological and surgical treatment have improved significantly. Spine surgeons use the experience of spine surgeries performed for an increased number of degenerative causes during spine surgeries performed for an increased number of tumors. Establishing an indication for surgery is at least as much of a challenge as the surgery itself, for which there are many objective point systems available. Renal cell carcinoma metastases are less sensitive to radiation, which is why careful surgery is even more important. In our short summary, we review the symptoms, the examination, the grading systems used and the surgical options.

[Neurosurgical management for metastatic brain tumors in renal cell carcinoma]. / Oligometasztatikus vesesejtes karcinóma idegsebészi ellátásának technikái és indikációi agyi áttétek esetén.

The therapeutic approach to brain metastases has changed significantly in the last 30 years. The development of surgical technique, the use of new MRI techniques, preoperative surgical planning and the administration of intraoperative navigation reduced the risks of surgery and improved the results. In the case of aggressive renal cell carcinomas, we detect brain metastases relatively often, which are difficult to treat, but the improved surgical and radiosurgery techniques can also be used with success. In our report, we present the neurosurgical management of metastatic spreading of renal cell carcinoma to the brain. Modern surgical planning and more precise, tailored approach with modern radiosurgery techniques are able to improve the outcome and prolong survival even in aggressive types of renal cell carcinomas that give rise to brain metastases. In more severe cases and even in the case of multiple brain metastases, cranial surgery can be recommended.

[The benefits of a hybrid operation room in neurosurgery.] / A hibrid muto elonyei idegsebészeti mutétek során.

INTRODUCTION: The hybrid operation room - with a robotic arm equipped angiographic device - started its operation in November 2019 at the Department of Neurosurgery, Szeged, Hungary. OBJECTIVE: We report the benefits of the hybrid operation room in the neurosurgery practice based on our results and experiences of the last 1.5 years. METHOD: 576 operations took place between 15. 11. 2019 and 01. 03. 2021, which include 332 neurointerventions amd 244 skull-brain and spine surgeries. By using Siemens ARTIS pheno®, we performed purely catheter only interventions or surgical only interventions, but combined treatments were also performed in several cases (catheter and surgical intervention). Thanks to ARTIS pheno® versatility, it is used as a modern imaging system in preoperative examination or as navigation system in spine surgery and control imaging for intra- and postoperative examinations. DISCUSSION: We created three categories based on the results of the last months according to the need of using the hybrid operation room for the given operation: (1) strongly recommended, (2) recommended, (3) advantageous. Strongly recommended: if the two teams (surgical and interventional team) have to work together during the operation. Recommended: if the two teams are not participating together in the operation, but the other team is on standby and may join the operation if necessary. Advantageous: this category means the possibility of performing control imaging before the wound closure. CONCLUSION: Based on our experience, the hybrid operation room provides significant help in neurosurgery. It has become part of our daily care, and we think it is indispensable in the work of a neurosurgery center. Orv Hetil. 2023; 164(43): 1701-1711.

Temporal disparity of action potentials triggered in axon initial segments and distal axons in the neocortex.

Neural population activity determines the timing of synaptic inputs, which arrive to dendrites, cell bodies, and axon initial segments (AISs) of cortical neurons. Action potential initiation in the AIS (AIS-APs) is driven by input integration, and the phase preference of AIS-APs during network oscillations is characteristic to cell classes. Distal regions of cortical axons do not receive synaptic inputs, yet experimental induction protocols can trigger retroaxonal action potentials (RA-APs) in axons distal from the soma. We report spontaneously occurring RA-APs in human and rodent cortical interneurons that appear uncorrelated to inputs and population activity. Network-linked triggering of AIS-APs versus input-independent timing of RA-APs of the same interneurons results in disparate temporal contribution of a single cell to in vivo network operation through perisomatic and distal axonal firing.