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Biomedical subjects

H Stefan

Publications and source records attributed to H Stefan.

At least 163 records · Page 9Linked to original sources
PubMed1990

Multichannel biomagnetic system for study of electrical activity in the brain and heart.

The authors designed a multichannel system for noninvasive measurement of the extremely weak magnetic fields generated by the brain and the heart. It uses a flat array of 37 superconducting magnetic field-sensing coils connected to sophisticated superconducting quantum interference devices. To prevent interference from external electromagnetic fields, the system is operated inside a shielded room. Complete sets of coherent data, even from spontaneous events, can be recorded. System performance was evaluated with phantom measurements and evoked-response studies. A spatial resolution of a few millimeters and a temporal resolution of a millisecond were obtained. First results in patients with partial epilepsy and investigations of the cardiac conductive pathway indicate that biomagnetism is now ready for a systematic clinical evaluation. Interpretation of measurements was facilitated by highlighting biomagnetically localized electrical activity in three-dimensional digital magnetic resonance images.

Brain↗
PubMed1990

[Chronic appendicitis in children].

Starting from 1976 to 1983, a total of 114 children was submitted to surgery for chronic appendicitis. The 5 to 13 years postappendectomy results were evaluated in 105 patients. From them, 68 (64.8%) were without complaints, 27 (25.7%) showed the substantial improvement. Of any favourable effect were 3 postappendectomy children, i.e. 2.8%. In one case, a serious postoperative complication occurred, this resulting in the small intestine strangulative ileus 2 mos. after the appendectomy. Different and even contradictory views are discussed in regard with the properly existence, signs, diagnosis and management of chronic appendicitis. The authors estimate chronic appendicitis to be the clinical and by no means the pathologico-anatomical diagnosis. According to them, the children are indicated to the elective appendectomy after preliminary investigation which is focused on the exclusion of other serious diseases similar in subjective complaints.

Adolescent↗
PubMed1990

[Surgical reconstruction of long esophageal stenoses in children].

Four cases related with the long stenosis of lower part of esophagus are referred to in children. These were stenoses of fibromuscular type, due to achalasia and resulting from etching with sulphuric acid as well as from tumor. The extramucous myotomy, esophagotomy and colonic replacement of long esophageal stenosis were elected. The condition is repairable by esophagomyotomy or esophagotomy when the function of stenotic portion of esophagus is preserved. To prevent postoperative complications such as fistula, diverticulum, gastroesophageal reflux and restenosis, the covering of incision with a patch from gastric fundus is recommended with subsequent fundoplication. Anatomical and functional lesion of esophageal wall in the presence of long stenosis requires its esophagoplasty as well as replacement with the intestinal interposition.

Adolescent↗
PubMed1990

[Abdominal actinomycosis in children].

A total of four children (1 female and 3 male subjects aged from 3.5 to 10 years) is reported as treated by surgery and antibiotics for the abdominal focus of actinomycosis. The infection was manifested as an infiltration around the inflamed appendix in one case, the second case was related with multiple infiltrations in the abdominal wall and pelvic region. Two patients showed cyst and eventually urachal sinus infiltrated with actinomycosis. The diagnosis was determined in all cases from histology. In three cases, the inflammatory tumor was exstirpated in toto. The treatment with penicillin combined with streptomycin or other antibiotic has lasted no longer than 6, 28, 29 and 80 days, respectively. The emphasis is made on the benefit of resectional surgery which reduces the amount of antibiotics needed and shortens the therapeutic course of actinomycosis.

Abdomen↗
PubMed1989

[Morton metatarsalgia].

Four cases of Morton's metatarsalgia are presented. In all cases history and clinical findings were typical. The duration of the disease until the assessment of the final diagnosis with an average of three years was very long. Conservative treatment in all cases was unsuccessful, operative excision of the neuroma resulted in complete relief of pain.

Adult↗
PubMed1989

CT, MRI and SPECT neuroimaging in status epilepticus with simple partial and complex partial seizures: case report.

A 35-year-old female patient suffering from epilepsy was examined during status epilepticus with simple partial and complex partial seizures by means of EEG, CT, MRI and ictal SPECT. All these examinations showed focal abnormalities with identical location due to oedema and hypervascularisation; these were, however, absent during examinations carried out before and after status epilepticus.

Adult↗
PubMed1989

[Neurophysiologic principles and clinical value of post-convulsive serum prolactin determination in epileptic seizure].

Measurement of postictal serum-prolactin concentrations in epileptic seizures in order to distinguish them from psychogenic seizures is at present used only rarely and non-systematically. Studies of 209 Grand mal seizures, 232 complex-partial seizures, 102 simple-partial seizures and 15 generalized seizures published between 1980 and 1987 differ in their standards of seizure classification as well as in their criteria for evaluating increases in postictal serum-prolactin concentrations. A significant rise was seen in 88% of Grand mal seizures, 78% of complex-partial seizures, 22% of simple-partial seizures and 6% of generalized seizures. The discussion of both these general findings and our own investigations is based on the presentation of neuroanatomical and neurophysiological principles of prolactin secretion.

Adult↗
PubMed1989

Epileptic but not psychogenic seizures are accompanied by simultaneous elevation of serum pituitary hormones and cortisol levels.

The circadian rhythm of serum prolactin was determined in 12 patients with seizures, and 28 age- and sex-matched healthy subjects (14 men and 14 women). Blood was also collected every 15 min for 2 h immediately after a simultaneously video/EEG-documented epileptic (6 patients) and psychogenic seizure (5 patients) for the determination of prolactin, thyrotropin, growth hormone, cortisol, melatonin, catecholamines and serotonin. During the seizure-free interval, the circadian profile of serum prolactin was lower in female patients than in healthy women. Serum prolactin, thyrotropin, growth hormone, and cortisol were increased postictally, followed by a decrease, after a grand mal or complex partial seizure, but not after a psychogenic seizure in comparison to baseline serum hormone levels obtained during the same time on a seizure-free day. During the seizure and for 2 h afterwards, blood serotonin, serum melatonin, dopamine, and epinephrine did not alter and were within the reference limits of healthy subjects. Serum norepinephrine was lower in patients compared to healthy subjects (p less than 0.05). The simultaneous elevation of serum prolactin, thyrotropin, growth hormone, and cortisol points to a central stimulation of the hypothalamic-pituitary axis during an epileptic seizure, but not during seizures of psychogenic origin.

Catecholamines↗
PubMed1988

[Treatment of drug-resistant focal epilepsy using visual orientation activity].

A 24 year old female with drug-resistant epilepsy showed control over her complex-partial seizures. The patient suppressed paroxysmal activity up to 20 minutes. There was evidence of a relation between the occipital localization of the epileptic focus and the mode of control. Under controlled conditions increase of the visual activity was associated with decreasing paroxysmal activity. Especially varying visual orientation suppressed epileptic activity, while visual focusing or closed eyes enhanced it. Neither auditory nor somatosensory activity interfered with paroxysms. The comparison between 32 weeks before and 12 weeks after the study showed a significant reduction of the weekly seizure frequency. The possibility of a "sensory control" of epileptic activity is discussed.

Adult↗
PubMed1987

Functional and morphological abnormalities in temporal lobe epilepsy: a comparison of interictal and ictal EEG, CT, MRI, SPECT and PET.

Ten patients suffering from drug-resistant complex partial seizures, with EEG abnormalities in the temporal region, were studied by means of non-invasive electrophysiological techniques (video-monitored, 16-channel, prolonged surface and sphenoidal EEG) as well as by imaging techniques (CT, MRI, SPECT and PET). Analysis of interictal and ictal EEG indicated the localization of epileptic activity in one side in eight cases. CT demonstrated focal abnormalities in three, SPECT in five unequivocally (in another four questionably, with the same lateralization as indicated by PET), MRI in eight, and PET in all cases. While only EEG provided specific diagnostic information, the focus definition was consistently good on PET images, poor on CT scans, and generally good but less consistent on MRI.

Adult↗
PubMed1987

Day by day variations of the amount of spike-wave activity in 24 hour cassette recordings.

For interpretation of mobile long-term EEG monitoring in patients suffering from absence epilepsies with regular spike-wave (S-W) paroxysms, the fluctuating amount of this parameter has to be taken into account if, for example, therapeutic effects are to be judged. An 'S-W variogram' is derived resembling the statistical properties of the day by day variability as an orienting criterion in this respect.

Circadian Rhythm↗
PubMed1987

Initial experience with 99m Tc-hexamethyl-propylene amine oxime (HM-PAO) single photon emission computed tomography (SPECT) in patients with focal epilepsy.

Brain single photon emission computed tomography (SPECT) was performed in 16 patients with focal epilepsy, as well as EEG, using 99m Tc-HM-PAO SPECT and a rotating gamma camera system. Pathological Tc-HM-PAO SPECT findings were registered in 75%. CT was positive in 25%. MRI was positive in 76%. The results of Tc-HM-PAO SPECT findings were compared with those of CT and MRI. 61% of the MRI findings correlated with the pathological SPECT findings with respect to the side of the hemisphere, and in 75% of the patients the focal EEG abnormality and the pathological Tc-HM-PAO-SPECT findings were localized in the same hemisphere.

Adolescent↗