Publications by authors named "Jan Klener"

Background And Objectives: Endovascular treatment of cerebral aneurysms has tremendously advanced over the past decades. Nevertheless, aneurysm residual and recurrence remain challenges after embolization. The objective of this study was to elucidate the portion of embolized aneurysms requiring open surgery and evaluate whether newer endovascular treatments have changed the need for open surgery after failed embolization.

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Introduction: The prognosis of glioblastoma remains unfavorable. TTFields utilize low intensity electric fields (frequency 150-300 kHz) that disrupt cellular processes critical for cancer cell viability and tumor progression. TTFields are delivered via transducer arrays placed on the patients' scalp.

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Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th-April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH).

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Calcifying pseudoneoplasm of neuroaxis (CAPNON) is a rare lesion of the central nervous system with uncertain histogenesis. We further explored phenotypic spectrum of the entity with respect to possible histogenesis. We collected 5 cases of CAPNONs, performed a detailed morphological assessment, and performed an extensive immunohistochemical analysis (EMA, progesterone receptors, MUC4, SSTR2A, cytokeratin AE1/3, cytokeratin 18, GFAP, neurofilaments, desmin, nestin, synaptophysin, S100 protein, SOX10, CD56, Podoplanin, SATB2, ERG, CD45, and CD163) to elucidate the histogenesis.

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The misdiagnosis of a ruptured aneurysm directly endangers patient's life and health due to the high risk of rebleeding and its sequelae. In this paper, we present two uncommon cases of anterior communicating artery aneurysm rupture with a relatively small intracerebral bleeding, seemingly without a diffuse subarachnoid hemorrhage (SAH), and a relatively mild clinical presentation. In these cases, the initial diagnosis failed, leading to missed aneurysmal ruptures.

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The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care.

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Intradural spinal arteriovenous fistulas (sAVF) are spinal vascular lesions that usually manifest due to myelopathy or local symptoms caused by venous congestion and ischemia. In addition, perimedullary arteriovenous fistulas (PMAVF) in particular may rupture and cause subarachnoid or intramedullary hemorrhage along with relevant symptoms. Subarachnoid hemorrhage (SAH) can propagate into cranial space with clinically dominant symptoms and signs of typical aneurysmal intracranial SAH.

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Article Synopsis
  • Glioblastoma multiforme (GBM) is a serious brain tumor that usually only gives patients about 10 to 14 months to live, and most patients don't survive longer than three years.
  • A new treatment called Tumor-treating fields (TTField) uses special electric fields to help kill the cancer cells and has been approved for treating a tough version of GBM called recurrent GBM (RGBM).
  • In a small study, some patients who received TTField therapy are now healthy and have been cancer-free for over seven years, which is really promising!
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Brain tumors and neurovascular diseases represent the most frequent and serious areas of intracranial neurosurgery. The recent advances in microneurosurgery aim at the complete treatment of the lesions (i.e.

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Background: For a number of years, FDG-PET was considered as a gold standard for the differential diagnosis of recurrent glioma and radionecrosis. Recently published papers have introduced a wealth of scepticism into this area. The aim of this work is to specify the added value of FDG PET, as compared to MRI, in terms of diagnostics of recurrent gliomas in the clinical setting of the PET Centre Prague.

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