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P Halasz

Publications and source records attributed to P Halasz.

At least 19 recordsLinked to original sources
PubMed2005

EFNS guideline on the diagnosis and management of alcohol-related seizures: report of an EFNS task force.

Despite being a considerable problem in neurological practice and responsible for one-third of seizure-related admissions, there is little consensus as to the optimal investigation and management of alcohol-related seizures. The final literature search was undertaken in September 2004. Consensus recommendations are given graded according to the EFNS guidance regulations. To support the history taking, use of a structured questionnaire is recommended. When the drinking history is inconclusive, elevated values of carbohydrate-deficient transferrin and/or gammaglutamyl transferase can support a clinical suspicion. A first epileptic seizure should prompt neuroimaging (CT or MRI). Before starting any carbohydrate containing fluids or food, patients presenting with suspected alcohol overuse should be given prophylactic thiamine parenterally. After an alcohol withdrawal seizure (AWS), the patient should be observed in hospital for at least 24 h and the severity of withdrawal symptoms needs to be followed. For patients with no history of withdrawal seizures and mild to moderate withdrawal symptoms, routine seizure preventive treatment is not necessary. Generally, benzodiazepines are efficacious and safe for primary and secondary seizure prevention; diazepam or, if available, lorazepam, is recommended. The efficacy of other drugs is insufficiently documented. Concerning long-term recommendations for non-alcohol dependent patients with partial epilepsy and controlled seizures, small amounts of alcohol may be safe. Alcohol-related seizures require particular attention both in the diagnostic work-up and treatment. Benzodiazepines should be chosen for the treatment and prevention of recurrent AWS.

Alcohol Withdrawal Seizures↗
PubMed2004

Intentional seizure interruption may decrease the seizure frequency in drug-resistant temporal lobe epilepsy.

We investigated the nature of preictal subjective phenomena and whether they had any effect on the seizure frequency in 95 adult patients with medial temporal lobe epilepsy. Seventy-three (77%) patients indicated that they experienced seizure-provoking factors. Ten patients (11%) had prodromas independent of auras, while auras occurred in 89%. Forty-four patients (46%) reported that that they had tried to stop their seizures in the presence of prodroma or aura and this action had resulted in success at least once. Twenty-one patients (22%) regularly tried to stop their seizures because this effort was often successful according to their interpretation. Patients who reported that they could frequently inhibit their seizures had 1.8 +/- 1.6 seizures/month, a significantly lower mean seizure frequency than those 74 patients who did not do it regularly (4.6 +/- 4.8 seizures/month, P<0.001). Patients who reported regular experience in inhibiting intentionally their seizures more often had affective (P=0.05) and vertiginous auras (P<0.01) as well as isolated auras (P<0.05). Patients who experienced provoking factors showed the same seizure frequency as those who did not. Our results suggest that intentional seizure inhibition had an impact on the severity of drug-resistant epilepsy.

Adolescent↗
PubMed2003

Automatisms with preserved responsiveness and ictal aphasia: contradictory lateralising signs during a dominant temporal lobe seizure.

The 25-year-old right-handed woman suffering from temporal lobe epilepsy (TLE) was referred to our centre for presurgical evaluation. MRI showed a right-sided hippocampal sclerosis. During video-EEG-recorded seizures, abdominal aura was followed by oral automatisms, during which she was completely reactive to external stimuli, although she was unable to speak. Ictal EEG showed right temporal seizure pattern, without contralateral propagation. She had abnormal speech postictally. Speech-activated functional transcranial Doppler sonography revealed right-sided speech dominance. She has become seizure free after a right-sided amygdalo-hippocampectomy. In our patient, contradictory clinical ictal lateralising signs (automatisms with preserved responsiveness vs. ictal and postictal dysphasia) occurred during right-, speech-dominant-sided seizures. This is the first report when automatisms with preserved consciousness occurred during a seizure originating and involving the speech-dominant hemisphere.

Adult↗
PubMed2001

8-OH-DPAT and MK-801 affect epileptic activity independently of vigilance.

Vigilance and parallel occurrence of epileptic activity after administration of the 5-HT(1A) agonist 8-OH-DPAT and the NMDA receptor antagonist MK-801 were studied in the genetic absence epilepsy model WAG/Rij rats. Spike-wave discharges (SWD) were present predominantly in passive awake and light slow wave sleep (SWS1) either in control animals or after treatments. Injection of 8-OH-DPAT (20.0 microg/rat i.c.v.) caused marked increase and MK-801 (10.0 microg/rat i.c.v.) decrease in SWD densities, thus the ratios of SWD in passive awake and in SWS1. SWD densities of MK-801 plus 8-OH-DPAT in combination were similar to those of CSF+CSF treated control rats. Both 8-OH-DPAT and MK-801 transiently increased the duration of active awake, increased latency and decreased duration of rapid eye movement (REM) sleep. 8-OH-DPAT increased the amount of SWD despite the decrease in the duration of SWS1. MK-801 decreased the amount of SWD despite the lack of significant change in duration of passive awake or SWS1. Pre-treatment with MK-801 reversed 8-OH-DPAT- induced increase in duration of SWD without any effect on 8-OH-DPAT-induced changes in sleep parameters. Our studies provide evidence that 8-OH-DPAT-induced epileptic activity is independent of its effect on sleep, and that interaction of serotonergic and glutamatergic systems plays a role in the generation of SWD, but not in the regulation of vigilance and sleep.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2001

Immunohistochemical and ultrastructural evidence that dendritic cells infiltrate stenotic aortocoronary saphenous vein bypass grafts.

We earlier speculated that antigen-presenting dendritic cells may be involved in the immune reactions leading to saphenous vein bypass graft failure. The purpose of this study was to confirm whether dendritic cells are present in stenotic human saphenous vein bypass grafts. Segments of stenotic saphenous vein grafts were explanted from 14 patients at re-do bypass operation and ten normal saphenous veins were harvested during femoro-popliteal grafting. Sections of specimens were analysed using cell type specific antibodies to identify dendritic cells (CD1a, S-100), T-lymphocytes (CD3), macrophages (CD68), smooth muscle cells (alpha-SMA) and endothelial cells (FVIII). Dual immunostaining, confocal immunofluorescent laser scanning microscopy and electron microscopy were used. Stenotic grafts showed structural alterations of intimal hyperplasia and varying degrees of atherosclerotic degeneration. No cells expressing CD1a and S-100 were observed in the intima and media of normal saphenous veins. Cells expressing these antigens were present around areas of medial neovascularization and within intimal atherosclerotic lesions in saphenous vein bypass grafts. Electron microscopy demonstrated the presence of cells containing a well-developed tubulovesicular system which is unique to cells from the dendritic cell family. Double immunohistochemistry and confocal immunofluorescent microscopy revealed the co-localization of T-lymphocytes with dendritic cells. Dendritic cells are present in stenotic saphenous vein bypass grafts. Dendritic cells may be responsible for antigen presentation and modulation of immune reactions in accelerated graft atherosclerosis through their interaction with T-lymphocytes.

Adult↗
PubMed2000

Hypersomnia in Wilson's disease: an unusual symptom in an unusual case.

Wilson's disease (WD) shows a wide heterogeneity in symptoms. In this case report we present hypersomnia as a symptom of WD. The male patient's complaints as fatigue, decreased level of concentration, and highly increased demand of sleeping started at his age of 21 years. No abnormality was found at physical examination. A moderate elevation in liver function tests was found, but all the other laboratory findings were within the normal range. The marked hypersomnia was verified by 24-h cassette EEG polisomnographic monitoring. No abnormality was found at physical examination. EEG, brain CT and MRI were normal. Neither toxic nor infectious disease was detectable. The diagnosis of WD was based on decreased coeruloplasmin level, increased baseline and forced urinary excretion of copper, and decreased level of serum copper. Kayser-Fleischer ring was not detectable. D-penicillamine (DPA) was introduced. At 8-10 months after the initiation of the therapy the patient's complaints gradually resolved. The control sleep record 14 months after the initiation of the DPA therapy was normal. Five years later the patient is currently on penicillamine treatment and he is free of any symptom.

Adult↗
PubMed1999

Serotonergic neurons in the brainstem of the wallaby, Macropus eugenii.

The organisation and cytoarchitecture of the serotonergic neurons in a diprotodont marsupial were examined by using serial sections of the brainstem processed for serotonin immunohistochemistry and routine histology. The topographic distribution of serotonergic neurons in the brainstem of the adult wallaby (Macropus eugenii) was similar to that of eutherian mammals. Serotonergic neurons were divided into rostral and caudal groups, separated by an oblique boundary through the pontomedullary junction. Approximately 52% of the serotonergic neurons in the wallaby brainstem were located in the rostral midline nuclei (caudal linear nucleus, dorsal, median, and pontine raphe nuclei and the interpeduncular nucleus), whereas 21% were found in the caudal midline region (nuclei raphe magnus, obscurus, and pallidus). The remaining serotonergic neurons (27%) were located in more lateral regions such as the pedunculopontine tegmental nuclei, the supralemniscal nuclei (B9 group), and the ventrolateral medulla. The largest serotonergic group, the dorsal raphe, contained one-third of the brainstem serotonergic neurons and showed five subdivisions, similar to that described in other species. In contrast, the median raphe did not show clear subdivisions. The internal complexity of the raphe nuclei and the degree of lateralisation of serotonergic neurons suggest that the wallaby serotonergic system is similar in organisation to that described for the cat and rabbit. This study supports the suggestion that the serotonergic system is evolutionally well conserved and provides baseline data for a quantitative study of serotonergic innervation of the developing cortex in the wallaby.

Animals↗
PubMed1998

The 5-HT1A agonist 8-OH-DPAT increases the number of spike-wave discharges in a genetic rat model of absence epilepsy.

The effects of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) on the epileptiform activity has been investigated in adult WAG/RIJ rats. Either intraperitoneal (0.1-0.5 mg/kg) or intracerebroventricular (2-20 microg/rat) administration of 8-OH-DPAT caused marked, dose-dependent increases in the number and mean cumulative duration of spike-wave discharges. These effects were attenuated by NAN-190, a 5-HT1A receptor antagonist. These data indicate that serotonergic system regulates the epileptiform activity in this genetic model of human absence epilepsy.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Substratum-induced morphological changes in a marine bacterium and their relevance to biofilm structure.

The effects of surfaces on the physiology of bacteria adhering to surfaces or immobilized within biofilms are receiving more interest. A study of the effects of hydrophobic and hydrophilic substrata on the colonization behavior of a marine bacterium, SW5, revealed major differences in the morphology of SW5 on these surfaces. Using epifluorescence, scanning confocal laser, and on-line visualization (time-lapse video) microscopy, the organisms at hydrophobic surfaces were characterized by the formation of tightly packed biofilms, consisting of single and paired cells, whereas those at hydrophilic surfaces exhibited sparse colonization and the formation of chains more than 100 microns long, anchored at the surface by the terminal (colonizing) cell. The results are discussed in terms of the possible factors inducing the observed morphological differences and the significance of these differences in terms of biofilm structure and plasmid transfer when SW5 is the recipient organism.

Bacteria↗
PubMed1993

Substance P- and tyrosine hydroxylase-containing neurons in the human dorsal motor nucleus of the vagus nerve.

The aim of this study was to provide a comprehensive account of the topography, morphology, and frequencies of the substance P- and tyrosine hydroxylase-containing neurons in the human dorsal motor nucleus of the vagus nerve. The morphology of immunoreactive neurons was studied and the variations of the cell distributions were presented by three-dimensional computer reconstructions. Three types of substance P-like immunoreactive neurons were identified. They were predominantly located in the dorsointermediate, centrointermediate, caudointermediate, and caudal division of the dorsal motor nucleus of the vagus nerve. The morphology of substance P-like immunoreactive neurons varied according to the subnuclei in which they were found. Three types of tyrosine hydroxylase-like immunoreactive neurons were identified, mainly in the periphery of the dorsal motor nucleus of the vagus nerve, including the medial fringe, ventrointermediate, and dorsointermediate subnuclei of the 10. Many cells throughout the ventrointermediate subnucleus of the dorsal motor nucleus of the vagus nerve are seen ventrally to intermingle with the tyrosine hydroxylase neurons of the intermediate reticular zone. Computer reconstructions provided a three-dimensional view of the positions of substance P- and tyrosine hydroxylase-like immunoreactive neurons within the subdivisions of the dorsal motor nucleus of the vagus nerve. The uneven distribution of substance P- and tyrosine hydroxylase-like immunoreactive neurons within the subdivisions suggests an involvement of these substances in some, but not all, autonomic functions of the dorsal motor nucleus of the vagus nerve.

Aged↗
PubMed1991

Cytoarchitecture of serotonin-synthesizing neurons in the pontine tegmentum of the human brain.

We have employed immunohistochemical and morphometric procedures to study serotonin-synthesizing (PH8-immunoreactive) neurons in the pontine reticular formation of the adult human. PH8-immunoreactive neurons were found in three cytoarchitectural regions: the median raphe nucleus (MnR), oral pontine reticular nucleus (PnO), and supralemniscal region (group B9). On the basis of cell size, morphology, and position, it was possible to distinguish distinct subgroups within the MnR (dorsal, midline, and paramedian cell clusters) and within the PnO (dorsal and central cell clusters), whereas within the B9 there were no distinct cell clusters. We have estimated that there are approximately 125,000 PH8-immunoreactive neurons in the human pontine tegmentum; 64,400 in the MnR, 30,700 in PnO and 29,000 in B9. The large numbers of serotonin-synthesizing neurons in the human pontine tegmentum contrasts with their relative paucity in nonprimate species such as rats and cats. Nonhuman primates also have large numbers of pontine serotonergic neurons but the morphology of these neurons and their spatial arrangement is significantly different in humans. These results are discussed with respect to the possible projections and functions of these neurons in humans.

Aged↗
PubMed1990

Development of retinal vasculature in the cat: processes and mechanisms.

Two principal processes can be distinguished in the development of the retinal circulation in the cat. One process, which forms most of the inner layer of vasculature, involves three stages. First, beginning prior to E (embryonic day) 26, spindle cells of mesenchymal origin spread over the inner surface of the retina. Second, beginning at approximately E48, a network of coarse capillaries forms, apparently derived from spindle cells. Third, major vessels differentiate from the capillary plexus, and the capillaries become thinner and more widely spaced. All three stages begin at the optic disc and spread towards the margin of the retina. The other process involves budding of capillary sized vessels from existing vasculature. This process forms the inner layer of vasculature at the area centralis, the outer layer of vasculature, and the radial peripapillary capillaries. It begins between P (postnatal day) 7 and P10 at the area centralis and spreads to the margins of the retina. The radial peripapillary capillaries form at a later stage (P20). The different topographies of the two processes suggest that they are controlled by distinct mechanisms. In the first process, the formation of vessels follows a pattern set by the early migration of spindle cells. In the second process, the vessels form in a pattern determined by the metabolic needs of the developing retina.

Animals↗
PubMed1989

The human locus coeruleus complex: an immunohistochemical and three dimensional reconstruction study.

The CA (catecholamine/catecholaminergic) cell populations of the locus coeruleus (LC) and subcoeruleus (SubC) were studied using serial sections of the human brainstem immunostained with an antibody against tyrosine hydroxylase. The tyrosine hydroxylase-immunoreactive (TH-IR) neurons were plotted in a computer reconstruction system and their number and soma size determined. Serial section computer analysis was then used to create a three dimensional reconstruction of the LC complex. The number of cells containing neuromelanin pigment was also determined and compared with the number of TH-IR cells. In our sample there were 53,900 TH-IR cells in the LC and a further 6260 cells in the SubC. These numbers were very similar to our estimates of the number of cells containing neuromelanin pigment and we concluded that virtually all of these cells were also tyrosine hydroxylase positive. The average soma size of the TH-IR cells of the LC was 37 microns and in the SubC 34 microns. In addition to these quantitative observations the morphology of the TH-IR and the Nissl stained cells is described in some detail. We also compared the groups of immunoreactive cells in the human pons with the noradrenergic groups A5-A7 described in the rat. Although in the human these groups are contiguous, A5 is not part of the LC complex. However we did find that the A7 group is equivalent to the rostroventral part of SubC while the remainder of SubC is formed by ventral A6.

Humans↗
PubMed1989

Topography of the retina in the elephant Loxodonta africana.

The distribution of neurones in the ganglion cell layer of the retina of an African elephant is described. The eye was obtained post-mortem from an infant animal, which died of an unknown disease. It is assumed that most of the neurones observed in the ganglion cell layer are ganglion cells. Ganglion cells concentrate along a horizontal axis extending across the retina inferior to the optic disc, as in the visual streak described in the retina of many mammals. They also concentrate in the upper temporal retina, in a pattern distinctive to elephants. We suggest that this latter concentration has evolved to monitor the animal's trunk. Features of the eye, including its size, orientation and fundal pigmentation, are also described.

Animals↗