Clinical Neuroscience

[Positron emission tomography in presurgical localization of epileptic foci]

JUHÁSZ Csaba

AUGUST 20, 2003

Clinical Neuroscience - 2003;56(07-08)

[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.]

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Clinical Neuroscience

[Two cases of frontotemporal dementia]

SZABÓ Erzsébet, SZABÓ Mihály

[Frontotemporal dementias represent the third most common cause of primer degenerative dementias next to Alzheimer’s disease and Lewy body disease. Frontotemporal dementia constitutes 10-20% of all praesenilis dementias. The authors present the results of the 10 years' clinical, neuropsychological, neuropathological examinations and brain imaging with the examples of two cases. At the early stage of frontotemporal dementia changes of personality and social conduct are prominent, whereas cognitive functions are relativelly well preserved. The usual dementia tests are not sufficiently sensitive to disclose noncognitive symptoms. Clinical diagnosis as well as differentiation from functional psychiatric disorders can be difficult. Brain imaging present the frontal and the anterior temporal lobe atrophy and selective hypometabolism in these areas. The typical onset is between at the age 50 and 65 years. It is very rare under the age of 30. The symptoms of two patients started at the age of 42-44. The first diagnosis was post traumatic stress disorder. Later stereotyped behaviour, mental rigidity, hyperorality, irritability, progressive reduction of speech and vegetative dysfunctions appeared. Besides the affecting of the irresistibly worsening symptoms and the medical care requiring strength and inventiveness, the authentic informing of the relatives is also a challenge. The caregivers have special relationship with the patients and their relatives.]

Clinical Neuroscience

[Apoptosis in focal brain ischaemia]

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

[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.]

Clinical Neuroscience

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

ERTSEY Csaba

Clinical Neuroscience

[CONGRESS CALENDAR]

Clinical Neuroscience

[Hungarian Branch of the International League Against Epilepsy]

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[Zonisamide: one of the first-line antiepileptic drugs in focal epilepsy ]

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Clinical Neuroscience

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Clinical Neuroscience

[Decisional collisions between evidence and experience based medicine in care of people with epilepsy]

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Clinical Neuroscience

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Clinical Neuroscience

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DÖMÖTÖR Johanna, CLEMENS Béla, EMRI Miklós, PUSKÁS Szilvia, FEKETE István

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