PubMed Health⌕ Search

Biomedical subjects

A Sólyom

Publications and source records attributed to A Sólyom.

10 recordsLinked to original sources
PubMed1989

Some basic features of the pathological and normal motor system studied by chronic deep electrodes.

Our stereotactic experiences in agreement with the literature showed, that different target points could influence the same motor disturbance. To choose the best target point or target point combinations we generally implant the electrodes into VL, Vim, CM, P, dentate nucleus and motor cortex. To ensure the correct sequence of therapeutic lesions we developed an investigation system, taking into consideration the resting and the working state of the motor system. We elicited events centrally (stimulation of the different target points) and peripherally (reflexes) and recorded the evoked potentials at the non-stimulated sites along with the motor and motor modulation effects in the appropriate muscles. The elicited events depend on the site of stimulation and registration and on the state of muscle activity. The centrally and peripherally elicited events influence each other. With our technique the elicited events and their functional dependency is most explicit within the motor system. The results help to explain some basic motor functions and help to answer some of our therapeutic questions.

Athetosis↗
PubMed1987

[Rett's syndrome].

Explore the source record for details and available documents.

Autistic Disorder↗
PubMed1987

Investigation of trigeminal SEP with scalp and deep electrodes.

A special technique for stimulating and recording trigeminal somatosensory evoked potential (SEP) is described. Eleven healthy subjects and seven patients with chronically implanted deep electrodes have been investigated. Characteristic polyphasic waves were repeatedly observed. The recording of somatosensory evoked potential following trigeminal stimulation is a more difficult technique. This paper describes data in control subjects with scalp electrodes and data on patients with electrodes in the nucleus ventralis posteromedialis and cortical white matter. Depth recording may provide useful information about the origin, nature, and properties of trigeminal SEP.

Electrodes, Implanted↗
PubMed1985

The spread of somatosensory-evoked potentials within the nervous system.

Four thalamic and cortical recordings were carried out in 5 patients. The thalamic-evoked potentials were typical and revealed a triphasic complex, but their latencies showed a relatively high standard deviation. They could be divided into two groups according to their latencies, both of which had low SD. These data suggested that there could be two types of latency of thalamic SEP, because the 4 patients' body sizes were very similar. More detailed surface, cortical and depth recordings are needed to resolve these questions.

Afferent Pathways↗
PubMed1980

Evoked responses by physiological sensory inputs in human central motor structures.

In human with chronic implanted electrodes physiological evoked responses could be detected from those structures they were thought to be parts mainly of central motor system. Investigating the functional changes of evoked responses to motor states and attention the results have suggested the responses do not sign the centres to treat as directly the sensory inputs i.e. auditory, visual, somatosensory stimuli as motor stimuli.

Attention↗
PubMed1980

The function of the human cerebellum studied by evoked potentials and motor reactions.

The authors investigated the cerebellar function of patients with chronic implanted electrodes. The investigations were carried out using elicited compulsion events--evoked potentials and motor reactions--in different functional motor states, i.e., rest and contraction. The compulsion events are the result of motor control processes which eliminate the transient effect of stimuli. In connection with the cerebellum, these motor control processes in some ways mirror the function of the cerebellum. The evoked potentials recorded in the cerebellum have specific features and specific functional dependence as well. On stimulation of the cerebellum, the first effect on motor activity is always inhibitory. Altering the cerebellar function by high frequency stimulation appears to cause cerebellar symptoms such as hypotonia and ataxia.

Cerebellum↗
PubMed1979

Frequency resonance investigation of the H reflex.

Results of a previous study demostrated transformation of the sustained activity of a muscle into rhythmic, tremor-like activity by stimulation of different motor centres. The optimum for this transformation was in the 4-7 Hz frequency band (resonance band). Sustained rhythmic stimulation with stimuli at 0.1-20 per second caused a normal frequency curve of the H reflex in subjects with intact motor systems. The resonance phenomenon of the frequency curve of the H reflex was in agreement with that found in previous studies stimulating the different motor centres. As this requires connections between spinal and higher motor centres, it is suggested that this investigation is appropriate for a detailed functional study of spinal cord lesions.

Electric Stimulation↗