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Biomedical subjects

L Bognár

Publications and source records attributed to L Bognár.

13 recordsLinked to original sources
PubMed2004

Bilateral epilepsy surgery in a 4-year-old child.

OBJECTIVE: Reports on bilateral epilepsy surgical interventions are anecdotal because of the possible neurological deficits caused by them. METHODS: We report on a four-year-old amaurotic child with catastrophic epilepsy due to bilateral occipital cortical dysplasia. After video-EEG monitoring and intraoperative electrocorticography he underwent a two-step bilateral occipital lobectomy. RESULTS: The first resection resulted in only temporary seizure cessation; however, he became seizure-free after the second operation (follow-up: 20 months). CONCLUSION: Patients with catastrophic epilepsy due to bilateral epileptogenic lesions but without a high risk of additional postsurgical deficit may be good candidates for epilepsy surgery.

Blindness↗
PubMed2001

[Surgically treatable epilepsy--a review].

20-25% of epileptic patients do not become seizure free on adequate drug therapy. In 25-50% of patients with intractable epilepsy, the brain area responsible for seizures is well localizable and does not involve eloquent regions. In these patients, the surgical excision of the epileptic focus may lead to relief from seizures. In Hungary, there may be 5-6000 patients who needs an epilepsy surgery, but till now only 200 patients with chronic epilepsy underwent a surgical procedure. In the surgically remediable epilepsies, the operation is not a "ultima ratio". Concerning these syndromes, if 2-3 adequate antiepileptic drugs do not lead to seizure freedom within 1-3 years after the epilepsy onset, then a presurgical evaluation is necessary. The most common surgically remediable epilepsy is the temporal lobe epilepsy in which 60-90% of drug-resistant patients could be surgically cured. In lesional neocortical epilepsies 50-80% of patients become postoperatively seizure free. In childhood hemispheric epilepsies, the surgery could lead to seizure freedom in 70-80% of patients. The basic tools of the presurgical evaluation are the detailed history, the high resolution-MRI, the video-EEG monitoring, and the neuropsychological assessment. These investigation methods are usually enough to evaluate the necessity of the surgery and the postoperative outcome as well as to plan the localization and the extension of the resection. In some cases, ictal SPECT, PET, or video-EEG monitoring with intracranial electrodes could also be necessary in order to localize the epileptic focus.

Algorithms↗
PubMed2001

Temporary cerebral histic hypoxia in simulated microgravity.

The authors determined in their previous examinations that the vertical component of diagonal optokinetic nystagmus (DOKN) decreases considerably more in the conditions of hypoxia and antiorthostatic posture than does the horizontal component. Relying on these findings, they reasoned that the tectal and pretectal gaze centers, which organize vertical eye movement, are more sensitive to both hypoxia and antiorthostatic posture than is the pontine gaze center, which directs horizontal eye movement. In their present examinations, the authors sought to discover how cranial shifting of body fluids alters the DOKN and cardiopulmonary dynamics. They established that, at-30-degree antiorthostatic posture during 3 hours' loading, the diminution of pulse rate and systolic blood pressure is accompanied by continuous enhancement of diastolic blood pressure, diminishment of the carbonometric value, and augmentation of respiratory rate. The disturbances of DOKN, which mimicked previous similar findings under conditions of hypoxia and antiorthostatic posture, may be caused by the hypocapnia that is induced by antiorthostatic posture and that produces histic hypoxia. However, hypocapnia does not exclude the possibility of cerebrovascular injury, which was detected during animal experiments in microgravity or in simulated microgravity. To resolve this issue ultimately, further investigations are necessary.

Adolescent↗
PubMed2000

[Chiari I. malformation, a new childhood disease?].

From July 1, 1994 to July 1, 1997 a total of 17 children with Chiari I malformation diagnosed by MRI was seen in our hospital. Six of them underwent craniocervical decompression and tonsilar resection. The major complaints of all these children were gait ataxia and persisting (longer than 6 month) headache, and one child had acutely presenting vertigo and problem of swallowing. The MRI showed that in all cases the tonsils were displaced below the level of CI. Hydrocephalus or syrinx was not seen. At surgery the tonsils were resected. All the patients can be considered cured and symptom free at an average follow up of 13 month.

Arnold-Chiari Malformation↗
PubMed2000

[Neuronavigation in pediatric neurosurgery].

The precise orientation in the intracranial space is essential for the minimal invasive neurosurgical interventions. The CT and MR based neuro-navigation permits small, targeted exposures on the skull, and intraoperatively gives exact graphic-interactive guidance to the targeted intracranial lesions. The use of neuro-navigation can shorten the time of surgery and diminish the surgical mortality and morbidity. The favourable experiences of the first 21 neuro-navigation aided operations in pediatric patients performed in the National Institute of Neurosurgery (Budapest, Hungary) with the Vector Vision Neuro-navigation System (BrainLAB Gmbh, Germany) are discussed.

Adolescent↗
PubMed2000

[Neuroendoscopic removal of a colloid cyst of the third ventricle].

The removal of the benign and only slightly symptomatic but by virtue of their localization potentially fatal lesions is a challenge for the neurosurgeons. Such cases demand a therapy without any postoperative morbidity. The neuroendoscopy meets these requirements and proves to be effective in more and more fields of the art. This article reports a case when colloid cyst was resected entirely by use of a neuroendoscope, firstly in Hungary.

Adolescent↗
PubMed2000

Effect of microgravitation on the human equilibrium.

The 38-year period of human space exploration has gained for us a lot of experience in the problem of space motion sickness. The authors collected some causes of space sickness from the literature and from their research results. We collaborated with the Soviet-Russian space researchers and elaborated those vestibular research methods that were carried out by human space missions in the Soviet-Russian space station, on Earth, and after flight: spontaneous eye movement, foveal and peripheral optokinetic nystagmus, and vestibular stimulation. Using an earthly model of the effect of microgravitation on the human body, we tried to provide explanations of the origin of space motion sickness.

Adult↗
PubMed1999

Antiorthostatic posture as an earth model of the effect of microgravity on the human body.

We examined the horizontal and vertical component of diagonal optokinetic nystagmus (DOKN) in sitting posture and in the last 15 minutes of antiorthostatic posture at -30 degrees lasting 3 hours. The antiorthostatic posture is suited to the earthy model of the fluid shifting observed in microgravity. We found that the frequency of the vertical component of DOKN is rarer in antiorthostatic posture than in sitting posture. Moreover, the amplitude of the vertical component of DOKN is lower in antiorthostatic posture than is the amplitude of the horizontal component. According to our examinations, we suppose that the frequency and amplitude of vertical OKN are directed by different cerebral structures. Furthermore, we found that the heart rate becomes slower and the diastolic pressure is augmented after antiorthostatic posture and visual stimulation.

Adult↗
PubMed1998

[A new technic in the management of hydrocephalus: neuro-endoscopy].

Conventional valve shunting for treatment of hydrocephalus has a high rate of long-term complication. After a brief historical review of neurosurgical endoscopy the authors present the different indications and methods of neuroendoscopy. Between 1995 and 1997 twenty-two pediatric patients underwent endoscopic surgery at National Institute of Neurosurgery. Twelve of them had third ventriculo-cistemostomy, and cystic wall fenestration was performed in ten children. All but one patient benefited from this minimally invasive endoscopic technic. Minor transient complications were seen in three cases, and only one patient had long-term pupillary dilatation due to the surgical procedure.

Child↗
PubMed1997

Brain tumors during the first year of life.

Of 1728 childhood brain tumors treated at the National Institute of Neurosurgery, Budapest during the years from 1954 until 1995, 83 of the affected children were younger than one year of age. Because of the advent of the CT and MRI scans in the last 11 years, 51 out of the 83 are presented, these being patients treated since these technological advances have been available. There was a male predominance, with 30 boys and 21 girls. Five of the 51 infants were diagnosed before two months of age. The ratio of supratentorial to infratentorial tumors was almost 1:1. Vomiting, alteration of psychomotor development, and macrocrania were the most common presenting features. Craniotomy and tumor debulking was performed in 85% of the children and 94% of the infants. The most frequent histological diagnosis was benign glioma, PNET, malignant glioma, and craniopharyngioma. The surgical mortality rate was 5% for the children and 13% for the infant group. All five neonates survived the surgical procedure. Radiation therapy was given in 29% of the children and in 7% of infants.

Adolescent↗
PubMed1993

Multiple intracranial melanoma metastases treated with surgery and radiosurgery with long term control. A case report.

A case of malignant melanoma with multiplex brain metastases is described, where both surgical and radiosurgical treatment was applied. Due to CNS manifestations the patient was operated on in two sessions. First the symptomatic large tumor was removed, and the other, small lesion which could not be reached from the same approach was operated later. The primary skin lesion was discovered and removed between the two operations. A CT scan three months after the second operation revealed recurrence at the site of the first operation, and the appearance of two new tumors. The intracranial neoplasms were treated in one session by stereotactic radiosurgery using a linear accelerator. Six months after this treatment a new skin lesion was removed and the patient received DTIC therapy. Successive CT scans after the irradiation showed a steady regression of the radiosurgically treated tumors, and more than one year after the irradiation no tumor could be detected on the CT scans.

Adult↗