[NOVEL CELL-BIOLOGICAL IDEAS DEDUCIBLE FROM MORPHOLOGICAL OBSERVATIONS ON “DARK” NEURONS REVISITED]
GALLYAS Ferenc
MAY 20, 2007
Clinical Neuroscience - 2007;60(05-06)
GALLYAS Ferenc
MAY 20, 2007
Clinical Neuroscience - 2007;60(05-06)
[The origin, nature and fate of ”dark“ (dramatically shrunken and hyperbasophilic) neurons are century-old problems in both human and experimental neuropathology. Until a few years ago, hardly any cell-biological conclusion had been drawn from their histological investigation. On the basis of light and electron microscopic findings in animal experiments performed during the past few years, my research team has put forward novel ideas concerning 1. the nature of ”dark“ neurons (malfunction of an energystoring gel-structure that is ubiquitously present in all intracellular spaces between the ultrastructural elements), 2. the mechanism of their formation (non-programmed initiation of a whole-cell phase-transition in this gel-structure), 3. their capability of recovery (programmed for some physiological purpose), 4. their death mode (neither necrotic nor apoptotic), and 5. their relationship with the apoptotic cell death (the gel structure in question is programmed for the morphological execution of ontogenetic apoptosis). Based on morphological observations, this paper revisits these ideas in order to bring them to the attention of researchers who are in a position to investigate their validity by means of experimental paradigms other than those used here.]
Clinical Neuroscience
[Objective - Examination of the effect of local botulinus toxin treatment on spastic upper limb, on patients with different brain injury. Patients and method - Prospective study in Traumatic Brain Injury Rehabilitation Unit of the National Institute for Medical Rehabilitation in the year 2003 and 2004. Thirteen patients (eight with stroke and five with traumatic brain injury) were treated locally on the spastic upper limb with 100 units botulinus A toxin. Results - Spasticity decreased one or two level on Modified Ashworth Scale, and in nine cases the good result were observed still at the end of 3rd month. No local or other complication was detected. Conclusions - Local treatment with botulinus toxin is an effective and safe method to decrease spasticity on upper limb in patients with different brain injury.]
Clinical Neuroscience
Clinical Neuroscience
[Objectives - To present evidence of changes in seizure semiology suggesting late contralateral epileptogenesis after incomplete surgery in a patient with temporal lobe epilepsy. Methods - The presently 36 year old female patient was followed across 18 years by clinical observation and EEG, and video-EEG monitored before and 18 years after surgery. Results - The patient had complex partial seizures defined by video-EEG which started from the right temporal lobe with an ictal spread to the contralateral (left) temporal lobe. After right amygdalo-hippocampectomy she did not become seizure free. Years after surgery a new type of seizure emerged. Video-EEG monitoring 18 yrs after surgery revealed two seizure types. One started in the right temporal region clinically resembling to the earlier seizures. The new seizure type showed left sided electroclinical pattern. The postoperative MRI detected bilateral hippocampal sclerosis. Side specific memory tasks revealed bilateral hippocampal dysfunctions with subdominant (right) side predominance. Conclusions - The well documented evolution from unilateral to bilateral seizures suggests late contralateral epileptogenesis in which the persisting seizure spread from the primary epileptogenic side and/or the earlier silent contralateral hippocampal sclerosis (HS) may play role. This case show that progressive changes with bilateral involvement may occur during the course of chronic temporal lobe epilepsy.]
Clinical Neuroscience
Clinical Oncology
[Cell proliferation and cell death (mainly apoptosis) have programs forming a network to maintain the functional integrity of the organism. Apoptosis has an external and internal units with ligands, signalling pathways and targets. Besides, some other participants (e.g. p53) are involved in the regulation of cell death. Although, apoptosis is a multitargeted process, there is no useful therapy, if it is needed, to correct accumulation of unwanted cells.]
Clinical Neuroscience
Interest in the hippocampal formation and its role in navigation and memory arose in the second part of the 20th century, at least in part due to the curious case of Henry G. Molaison, who underwent brain surgery for intractable epilepsy. The temporal association observed between the removal of his entorhinal cortex along with a significant part of hippocampus and the developing severe memory deficit inspired scientists to focus on these regions. The subsequent discovery of the so-called place cells in the hippocampus launched the description of many other functional cell types and neuronal networks throughout the Papez-circuit that has a key role in memory processes and spatial information coding (speed, head direction, border, grid, object-vector etc). Each of these cell types has its own unique characteristics, and together they form the so-called “Brain GPS”. The aim of this short survey is to highlight for practicing neurologists the types of cells and neuronal networks that represent the anatomical substrates and physiological correlates of pathological entities affecting the limbic system, especially in the temporal lobe. For that purpose, we survey early discoveries along with the most relevant neuroscience observations from the recent literature. By this brief survey, we highlight main cell types in the hippocampal formation, and describe their roles in spatial navigation and memory processes. In recent decades, an array of new and functionally unique neuron types has been recognized in the hippocampal formation, but likely more remain to be discovered. For a better understanding of the heterogeneous presentations of neurological disorders affecting this anatomical region, insights into the constantly evolving neuroscience behind may be helpful. The public health consequences of diseases that affect memory and spatial navigation are high, and grow as the population ages, prompting scientist to focus on further exploring this brain region.
Lege Artis Medicinae
[Hungarian professional periodicals started quite late in European context. Their publishing, editing and editorial philosophy were equally influenced by specific historical and political situations. Certain breaking points of history resulted in termination of professional journals (War of Independence 1848-1849, First and Second World Wars), however there were periods, which instigated the progress of sciences and founding of new scientific journals. Both trends were apparent in years after the fall of former Hungarian regime in 1990. The structure of book and journal publishing has changed substantially, some publishers fell “victim” others started successfully as well. The latters include the then-established publishing house Literatura Medica and its own scientific journal, Lege Artis Medicinae (according to its subtitle: New Hungarian Medical Herald) issued first in 1990. Its appearance enhanced significantly the medical press market. Its scientific publications compete with articles of the well-established domestic medical journals however its philosophy set brand-new trends on the market. Concerning the medical community, it takes on its problems and provides a forum for them. These problems are emerging questions in health care, economy and prevention, in close interrelation with system of public health institutions, infrastructure and situation of those providing individual health services. In all of them, Lege Artis Medicinae follows consequently the ideas of traditional social medicine.]
Clinical Neuroscience
Background and aims – Description of two cases of rare intravascular large B-cell lymphoma and secondary T-cell lymphoma diagnosed postmortem, that manifested clinically as longitudinally extensive transverse myelitis (LETM). We discuss causes of diagnostic difficulties, deceptive radiological and histological investigations, and outline diagnostic procedures based on our and previously reported cases. Case reports – Our first case, a 48-year-old female was admitted to the neurological department due to paraparesis. MRI suggested LETM, but the treatments were ineffective. She died after four weeks because of pneumonia and untreatable polyserositis. Pathological examination revealed intravascular large B-cell lymphoma (IVL). Our second case, a 61-year-old man presented with headache and paraparesis. MRI showed small bitemporal lesions and lesions suggesting LETM. Diagnostic investigations were unsuccessful, including tests for possible lymphoma (CSF flow cytometry and muscle biopsy for suspected IVL). Chest CT showed focal inflammation in a small area of the lung, and adrenal adenoma. Brain biopsy sample from the affected temporal area suggested T-cell mediated lymphocytic (paraneoplastic or viral) meningoencephalitis and excluded diffuse large B-cell lymphoma. The symptoms worsened, and the patient died in the sixth week of disease. The pathological examination of the presumed adenoma in the adrenal gland, the pancreatic tail and the lung lesions revealed peripheral T-cell lymphoma, as did the brain and spinal cord lesions. Even at histological examination, the T-cell lymphoma had the misleading appearance of inflammatory condition as did the MRI. Conclusion – Lymphoma can manifest as LETM. In cases of etiologically unclear atypical LETM in patients older than 40 years, a random skin biopsy (with subcutaneous adipose tissue) from the thigh and from the abdomen is strongly recommended as soon as possible. This may detect IVL and provide the possibility of prompt chemotherapy. In case of suspicion of lymphoma, parallel examination of the CSF by flow cytometry is also recommended. If skin biopsy is negative but lymphoma suspicion remains high, biopsy from other sites (bone marrow, lymph nodes or adrenal gland lesion) or from a simultaneously existing cerebral lesion is suggested, to exclude or prove diffuse large B-cell lymphoma, IVL, or a rare T-cell lymphoma.
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