Clinical Neuroscience

[Apoptosis in focal brain ischaemia]

ZÁDOR Zsolt, LACZA Zsombor, BENYÓ Zoltán, HARKÁNY Tibor, HORTOBÁGYI Tibor

AUGUST 20, 2003

Clinical Neuroscience - 2003;56(07-08)

[Ischaemic stroke is one of the major causes of death and disability in the developed world. It is caused by focal impairment of cerebral blood flow. The subsequent ischaemic cell death is predominantly necrotic in nature. However, a therapeutically important characteristic is the delayed apoptotic cell demise in the border zone of the primary lesion core. Apoptosis is one of the most intensively studied field of current medical and biological research. The better understanding of its mechanism may provide novel and more effective ways of therapy in a wide range of diseases including ischemic stroke. The salient neurological features of focal brain ischaemia and the morphological signs of apoptotic and necrotic cell death are summarized. The mechanism of apoptosis is discussed. It is divided into an early genetic phase of decisionmaking followed by a cellular execution phase. The characteristics of the early shift in the finely tuned balance of proand antiapoptotic genes and their protein products, which is preceded by an inbalance in intracellular ionized calcium homeostasis, energy depletion and mitochondrial dysfunction is discussed. The crucial role of caspases in apoptosis is emphasized. The three possible pathways during the execution phase is described: the intrinsic- and extrinsic caspase activation cascade and the caspase-independent intracellular signal transduction route. The molecular mechanism of neural cell membrane damage in the execution phase is discussed and some examples of altered protein synthesis also known as message-selection are given. The important role of late reperfusion in the execution phase is emphasized. The possible targets of antiapoptotic therapeutic approaches and the results of experimental studies are presented as well as the perspectives of their use in human clinical care.]

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Clinical Neuroscience

[6th National Congress of the Hungarian Stroke Society]

[6th National Congress of the Hungarian Stroke Society 2003;56(07-08)]

Clinical Neuroscience

[Positron emission tomography in presurgical localization of epileptic foci]

JUHÁSZ Csaba

[The success of cortical resection for intractable epilepsy of neocortical origin is highly dependent on the accurate presurgical delineation of the regions responsible for generating seizures. In addition to EEG and structural imaging studies, functional neuroimaging such as positron emission tomography (PET) can assist lateralization and localization of epileptogenic cortical areas. In the presented studies, objectively delineated focal PET abnormalities have been analyzed in patients (mostly children) with intractable epilepsy, using two different tracers: 2-deoxy-2-[18F]fluoro-D-glucose (FDG), that measures regional brain glucose metabolism, and [11C]flumazenil (FMZ), that binds to GABAA receptors. The PET abnormalities were correlated with scalp and intracranial EEG findings, structural brain abnormalities, as well as surgical outcome data. In patients with extratemporal foci and no lesion on MRI, FMZ PET was more sensitive than FDG PET for identification of the seizure onset zone defined by intracranial EEG monitoring. In contrast, seizures commonly originated from the border of hypometabolic cortex detected by FDG PET suggesting that such areas are most likely epileptogenic, and should be addressed if subdural EEG is applied to delineate epileptic cortex. In patients with cortical lesions, perilesional cortex with decreased FMZ binding was significantly smaller than corresponding areas of glucose hypometabolism, and correlated well with spiking cortex. Extent of perilesional hypometabolism, on the other hand, showed a correlation with the life-time number of seizures suggesting a seizurerelated progression of brain dysfunction. FMZ PET proved to be also very sensitive for detection of dual pathology (coexistence of an epileptogenic cortical lesion and hippocampal sclerosis). This has a major clinical importance since resection of both the cortical lesion and the atrophic hippocampus is required to achieve optimal surgical results. Finally, the author demonstrated that in patients with neocortical epilepsy, FDG PET abnormalities correctly regionalize the epileptogenic area, but their size is not related to the extent of epileptogenic tissue to be removed. In contrast, complete resection of cortex with decreased FMZ binding predicts good surgical outcome suggesting that application of FMZ PET can improve surgical results in selected patients with intractable epilepsy of neocortical origin.]

Clinical Neuroscience

[Report on a research project from abroad (EFNS)]

ERTSEY Csaba

Clinical Neuroscience

[Imaging of dopamine transporter with 99mTc-TRODAT-SPECT in movement disorders]

KANYÓ Balázs, ÁRGYELÁN Miklós, DIBÓ György, SZAKONYI Zsolt, VÉCSEI László, FÜLÖP Ferenc, LÁNCZ Adrienn, FORGÁCS Péter, PÁVICS László

[99mTc-TRODAT-1 is a new, technetium based radiopharmaceutical that selectively binds to the dopamine transporters. The aim of the study was to evaluate the dopamine transporter status in movement disorders. Methods - In eight healthy volunteers (age range 22-58 years), 28 patients with Parkinson’s disease (age range 42-80 years), 10 patients with Parkinsonian syndrome (age range 51-79 years) and 13 patients with essential tremor (age range 43-71 years) were 99mTc-TRODAT-SPECT tests performed. The results were evaluated visually and semiquantitatively. Results - The visual assessments were concordant with those of the semiquantitative in each case. The 99mTc- TRODAT uptake of the striatum was referenced to the cerebellum, the frontal and occipital cortex. The best deviation was found in aspect of the occipital cortex. The striatum/occipital ratio was the following: healthy volunteers: 2.12±0.27; Parkinson’s disease: 1.52±0.27; Parkinsonian syndrome: 1.57±0.26; essential tremor: 2.06±0.69. The striatal dopamine transporter availability was significantly lower in subjects with Parkinson's disease or Parkinsonian syndrome compared to the control subjects. There was no difference between healthy volunteers and patients with essential tremor. Using discriminant analysis, the discriminant function had significantly different values in the group of Parkinson’s disease than in Parkinsonian syndrome: f= -3.675×caud/occipit+6.293×put/occipit -2.548. Conclusion - 99mTc-TRODAT-SPECT is able to visualise the presynaptic dopaminergic degeneration. This method itself can be useful in differential diagnosis in some type of movement disorders.]

Clinical Neuroscience

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[Introduction - There are no previously published cases about intravenously applied recombinant tissue plasminogen activator in acute ischemic stroke during puerperium. Case presentation - We report a 40-year-old woman with postpartum acute ischemic stroke caused by multiple cervical artery dissections treated by systemic thrombolysis and endovascular intervention. Discussion - There are only limited data regarding thrombolytic treatment in acute stroke during pregnancy and puerperium. Current acute stroke treatment guidelines - while considering pregnancy as a relative exclusion criterion - do not deal with the postpartum state. Conclusion - As the condition is rare, randomized controlled trials are not feasible, therefore further reports on similar cases could eventually help us suggest guidelines or at least propose recommendations for the acute thrombolytic treatment of strokes occurring in pregnancy and puerperium.]

Clinical Neuroscience

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[The new coronavirus, SARS-CoV-2, which causes the COVID-19 disease can lead to severe acute respiratory distress syndrome (ARDS). It poses a serious challenge to the health care system, especially intensive care. Neurological patients, usually of advanced age and with a myriad of comorbidities, are at particular risk through the impact of the new coronavirus on their condition and nutritional capacity. Stroke is a leader in morbidity and mortality data, with a focus on dysphagia and its complications due to COVID-19 disease and acute cerebrovascular accident. In the acute phase of stroke, 30-50% of patients suffer from dysphagia, which still shows a prevalence of 10% six months later. Dysphagia results in decreased or insufficient fluid and nutrient uptake, supp­lemented by inactivity, leading to malnutrition and sarcopenia, which worsens overall condition, outcome, and rehabilitation efficiency. Screening and early detection of swallowing disorders is a fundamental issue in order to develop a personalized and timely-initiated nutritional therapy strategy. Nutritional therapy plays a key role in frequent intensive care due to COVID-19 disease, where it increases the chances of recovery and reduces the length of stay in the intensive care unit and mortality. This is especially true in critically ill patients requiring prolonged ventilation. In COVID-19 diagnosed patients, screening for dysphagia, bedside assessment, and instrumental examination, followed by swallowing rehabilitation, are of paramount importance. Stroke can also be a complication of the COVID-19 infection. Care for cerebrovascular patients has also adapted to the pandemic, “triazination” has become systemic, and dysphagia screening for stroke patients and nutritional therapy adapted to it have also shed new light. ]

Clinical Neuroscience

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[The reason of the unfavourable life expectancy of patients with chronic kidney disease (CKD) is not only the development of end-stage renal failure but the frequent appearance of cardiovascular diseases (CVD). Chronic kidney damage itself is a cardiovascular risk state and the occurrence of CVD/associated diseases is significantly higher in chronic kidney failure. Beside risk stratification and valid treatment of CVD (hypertension, diabetes mellitus, ischemic heart disease e.g.) we and the international nephrological community have left the cerebrovascular diseases of CKD patients out of consideration. However, up to 50% of patients suffering a stroke will die immediately, only 10% of stroke survivors can continue his/her profession, but the others will be permanently disabled. High blood pressure is a strong predictor of stroke and of other CVD in most of the patients. In stroke risk reduction it is particularly important to reach the target blood pressure values. The main object of the “Live under 140/90 mmHg” programme of the Hungarian Society of Hypertension is to familiarize with target blood pressure itself and how to reach target blood pressure. In 2010, prevention, early diagnosis and management of stroke are the most important challenges of this programme (The Brain Control Programme). We think it is advisable to prepare and publish a clinical practice guideline in collaboration with stroke societies which is similar to the guidelines of international societies and of the Hungarian Society of Stroke but specific for CKD patients. This guideline would help to give a uniform, up-to-date treatment for the cerebrovascular diseases of CKD patients.]