Biomedical subjects

R A De Korte

Publications and source records attributed to R A De Korte.

3 recordsLinked to original sources

PubMed1981

Interhemispheric differences in photosensitive epilepsy. II. Intermittent photic stimulation.

Of a consecutive series of 138 photosensitive epileptic patients 57 showed a unilateral preponderance of asymmetrical discharges on IPS, significant in each individual at the 5% level. There was no association between asymmetry of IPS-induced discharges and clinical evidence of cerebral pathology (partial or secondary generalized epilepsy, neurological deficit, left handedness, etc.). It is concluded that these results, together with our previous findings of asymmetrical pattern sensitivity suggest that the cortical hyperexcitability postulated in primary cortico-reticular epilepsy is not uniformly distributed.

Adult↗

PubMed1980

EEG sensitivity to television: effects of ambient lighting.

The effect of ambient lighting on EEG sensitivity to television has been tested in 16 photosensitive epileptic patients. Those who were not sensitive to 50 Hz IPS responded to TV at a viewing distance of 1 m or less and showed a consistent increase of EEG activation by television when the room was brightly lit. Most of those who were sensitive to 50 Hz IPS were also TV-sensitive at viewing distances greater than 1 m and the effect was most marked with lights off. The results are discussed in the context of previous work showing that some patients with TV epilepsy respond to the raster pattern of the screen and some, at greater distance, to 50 Hz flicker.

Adolescent↗

PubMed1980

Self-induction of epileptic seizures by eyeclosure: incidence and recognition.

Self-induction of epileptic seizures is generally regarded as a rarity, chiefly observed in patients of subnormal intelligence. During EEG recordings with open eyes in a consecutive series of 48 photosensitive patients, however, 13 subjects induced paroxysmal activity of seizures by eyeclosure with forced upward deviation of the eyes. Eyeclosure on command produced a different type of oculographic artefact and induced paroxysmal activity in only one subject. Two patients were of subnormal intelligence but all displayed psychiatric or psychosocial problems. The incidence of induced paroxysmal activity was reduced by reduction of ambient lighting. Eight patients admitted self-induction of seizures. We conclude that this phenomenon occurs more often than was previously supposed and can be recongnized by the recording in photosensitive patients of prolonged EEGs with eyes open and in a brightly lit environment.

Adolescent↗