Publications by authors named "Koutsarnakis C"

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  • The study explores how the volume of cerebrospinal fluid (CSF) removed during the Lumbar Tap Test (LTT) affects gait improvement in patients with idiopathic normal pressure hydrocephalus (iNPH).
  • Seventy-six iNPH patients were analyzed, with results showing that larger volumes of CSF removed (greater than 40 ml) correlate with significantly better improvements in walking ability.
  • Additionally, patients with more severe initial gait issues showed greater improvement regardless of the CSF volume removed, emphasizing the impact of initial condition on recovery.
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  • * This study utilized advanced techniques on samples from 1065 humans and 41 rhesus macaques to explore these connections, revealing a link between the posterior precuneus (POS2) and the temporal pole areas through the cingulum.
  • * Findings enhance our understanding of brain connectivity and could help integrate anatomical knowledge with functional roles in both healthy and diseased brains.
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  • Deep Brain Stimulation (DBS) effectively improves symptoms of Parkinson's disease, including tremor, bradykinesia, rigidity, and axial symptoms, by stimulating specific white matter tracts.
  • A study involving 237 patients identified distinct brain tracts linked to improvements in each symptom, with tremor associated with the primary motor cortex and cerebellum, and axial symptoms linked to the supplementary motor cortex and brainstem.
  • An introduced algorithm utilizes these symptom-tract connections to tailor DBS settings for individual patients, aiming to enhance treatment effectiveness based on the most impactful symptoms for each person.
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Comprehensive understanding of the neural circuits involving the ventral tegmental area is essential for elucidating the anatomofunctional mechanisms governing human behaviour, in addition to the therapeutic and adverse effects of deep brain stimulation for neuropsychiatric diseases. Although the ventral tegmental area has been targeted successfully with deep brain stimulation for different neuropsychiatric diseases, the axonal connectivity of the region is not fully understood. Here, using fibre microdissections in human cadaveric hemispheres, population-based high-definition fibre tractography and previously reported deep brain stimulation hotspots, we find that the ventral tegmental area participates in an intricate network involving the serotonergic pontine nuclei, basal ganglia, limbic system, basal forebrain and prefrontal cortex, which is implicated in the treatment of obsessive-compulsive disorder, major depressive disorder, Alzheimer's disease, cluster headaches and aggressive behaviours.

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Objective: The lateral retrocanthal transorbital endoscopic approach (LRCTEA) facilitates trajectory to the middle fossa, preserving the lateral canthal tendon and thus avoiding postoperative complications such as eyelid malposition. Here, the authors sought to define the surgical anatomy and technique of LRCTEA using a stepwise approach in cadaveric heads and offer an in-depth examination of existing quantitative data from cadaveric studies.

Methods: The authors performed LRCTEA to the middle cranial fossa under neuronavigation in 7 cadaveric head specimens that underwent high-resolution (1-mm) CT scans preceding the dissections.

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Introduction: The connectivity of the temporoparietal (TP) region has been the subject of multiple anatomical and functional studies. Its role in high cognitive functions has been primarily correlated with long association fiber connections. As a major sensory integration hub, coactivation of areas within the TP requires a stream of short association fibers running between its subregions.

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High grade gliomas are the most common primary aggressive brain tumours with a very poor prognosis and a median survival of less than 2 years. The standard management protocol of newly diagnosed glioblastoma patients involves surgery followed by radiotherapy, chemotherapy in the form of temozolomide and further adjuvant temozolomide. The recent advances in molecular profiling of high-grade gliomas have further enhanced our understanding of the disease.

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Background: Aim of the present study is to investigate whether preoperative neurocognitive status is prognostically associated with overall survival (OS) in newly diagnosed glioblastoma (GBM) patients.

Methods: Ninety patients with dominant-hemisphere IDH-wild-type GBM were assessed by Mini Mental Status Exam (MMSE), Trail Making Test (TMT) A and B parts, and Control Word Association Test (COWAT) phonemic and semantic subtests. Demographics, Karnofsky Performance Scale, tumor parameters, type of surgery, and adjuvant therapy data were available for patients.

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Background And Objectives: Anterior temporal lobectomy and amygdalohippocampectomy is a challenging procedure because of the deep surgical trajectory and complex regional neurovascular anatomy. A thorough knowledge of the involved anatomic structures is crucial for a safe and effective procedure. Our objective is to explore the white matter pathways in or around the operative corridor and to illuminate the 3-dimensional relationships of the pertinent operative parenchymal and skull base anatomy, aiming to inform and simplify surgical practice.

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Background: Cerebral hyperperfusion syndrome (CHS) following bypass surgery is a major cause of neurological morbidity and mortality. However, data regarding its prevention have not been assorted until date.

Objective: The objective of this study was to review the literature and evaluate whether any conclusion can be drawn regarding the effectiveness of any measure on preventing bypass-related CHS.

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Article Synopsis
  • High-grade glioma (HGG) patients with IDH1 wild-type tumors experience more severe neurocognitive function (NCF) deficits compared to those with IDH1 mutant tumors, as demonstrated by various cognitive tests.
  • The study involved 147 HGG patients and assessed their NCF using tests like the Mini Mental Status Exam and Trail Making Test, revealing significant performance differences based on their IDH1 status.
  • The results suggest that tumor growth characteristics have a more substantial impact on cognitive function than age, tumor volume, or grade in these patients, particularly highlighting deficits in executive functions for the IDH1 wild-type group.
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•Both patients and surgeons seem to show significant satisfaction with virtual spinal clinics.•Virtual spinal clinics may be an important adjunct to traditional face-to-face clinics.•Limitations in physical examination constitute main concern.

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Autotaxin (ATX) is the ectoenzyme producing the bulk of lysophosphatidic acid (LPA) in circulation. ATX and LPA-mediated signaling (the ATX-LPA axis) play critical roles in the vascular and nervous system development. In adults, this axis contributes to diverse processes, including coagulation, inflammation, fibroproliferation and angiogenesis under physiological and/or pathophysiological conditions.

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Objective: The anterior petrosectomy, also known as the Kawase approach, and the retrosigmoid intradural suprameatal approach (RISA) have both been used to reduce the petrous apex and access the petroclival region. Our goal was to compare the volumes and 3-dimensional shapes of bony resection obtained through each approach while trying to resemble realistic surgical settings.

Methods: Five cadaveric specimens totaling 10 sides were dissected and analyzed.

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  • Three-dimensional relationships in limbic and paralimbic areas are complex, making surgical approaches challenging due to their intricate anatomy and connectivity.
  • The study aims to fill a gap in literature by providing a detailed, systematic manual for dissecting and illustrating major limbic structures.
  • Fourteen clear, reproducible steps are outlined to help both novice and experienced anatomists and neurosurgeons understand the anatomy and facilitate dissections.
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The diversity in technical configuration between clinically available radiosurgery systems, results in accordingly diverse treatment times for the same physical dose prescription, spanning from several min to more than 1 h. This, combined with evidence supporting the impact of dose delivery temporal pattern on the bio-effectiveness of low-LET radiation treatments, challenges the 'acute exposure' assumption adopted clinically to estimate the biological outcome of a given treatment scheme under the concept of biologically effective dose (BED).: In this work, the treatment plans of 30 patients underwent CyberKnife radiosurgery for vestibular schwannoma (VS), prescribing a marginal dose of 13 Gy to the tumor, were retrospectively reviewed and the corresponding dose distributions were resolved in the temporal domain.

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Purpose: The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure.

Methods: Seven cadaver heads were imaged with computed tomography scan.

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Visuospatial neglect possesses significant heterogeneity in clinical features and neuroanatomical substrates. Behavioral dissociations on different neglect tasks have been reported in the past, and the investigation of their respective anatomical correlates at cortical and, to a lesser degree, subcortical levels has been attempted in stroke studies. We report a patient with a neoplasm occupying the right ventral post-central gyrus and anterior supramarginal gyrus.

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Spondylodiscitis is a common referral to spinal on call services. Identification of the causative organism is vital in order to dictate the appropriate antibiotic treatment. In this context, the surgical and interventional radiology team is often asked to perform a diagnostic biopsy.

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Objective: There is a lack of definite anatomical landmarks for the inferior extension of the standard retrosigmoid approach. In this study, we evaluated whether the posterior condylar emissary vein (PCEV) can be used as an intraoperative landmark for optimizing the surgical corridor.

Methods: We performed the standard retrosigmoid approach on 5 formalin-fixed and latex-injected cadaveric specimens and measured the distance between the PCEV near its bony canal and the vertebral artery (VA).

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Background: Recent studies advocate a connectivity pattern wider than previously believed of the uncinate fasciculus that extends to the ventrolateral and dorsolateral prefrontal cortices. These new percepts on the connectivity of the tract suggest a more expansive role for the uncinate fasciculus. Our aim was to shed light on this controversy through fiber dissections.

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Grade II gliomas are slow growing tumours that usually affect younger patients. The mainstream treatment modality at present is surgical. The role of radiation therapy in the management of grade II gliomas has been the subject of considerable debate.

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