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H P Meles

Publications and source records attributed to H P Meles.

4 recordsLinked to original sources
PubMed1980

Clinical and chronotopographic psychomotor seizure patterns (SEEG study with reference to postoperative results).

In 29 selected patients who underwent stereo-electroencephalographic exploration because of uncontrolled psychomotor epilepsy, 213 seizures were recorded. These seizures were analyzed in 10-second-intervals with respect to the sequence of clinical signs and the electrical chronotopographic patterns. By the aid of a computerized cluster analysis four comparatively distinct localization-patterns were found: a) opercular, b) frontobasal-cingular, c) temporobasal-limbic and d) posterior temporal neocortical. The lowest trend for propagation to the opposite hemisphere is found in a) followed by d). Fairly strong tendency for contralateral propagation is seen in c). Strategically important structures for contralateral propagation are: 1. amygdala and hippocampus, and to a lesser degree 2. the frontal cortex. Seizures propagating to the parietal cortex very often involve the frontal area of the same side before affecting the opposite hemisphere. For each of these "epileptic clusters" the characteristic clinical signs are pointed out. Special emphasis was put on the primictal symptom-sequence. By this and a similar study with Bancaud et al. we show that significantly better postoperative results are found, when strategy for surgery was based on the evidence of several SEEG recorded spontaneous seizures. In some patients belonging to the "temporobasal-limbic" cluster stereotactic procedures proved successful.

Amygdala↗
PubMed1977

Average multichannel EEG potential fields evoked from upper and lower hemi-retina: latency differences.

Checkerboard reversals shown to the upper hemiretina evoke EEG potentials which in anterior-posterior derivations are approximately inverted in polarity compared with potentials evoked by lower hemiretinal stimulation. Using a 48-channel system, EEG scalp field distributions of such responses were mapped. Examination of the map sequences shows that occipital positive maximal field values start to develop at about the same time in the two stimulus conditions, but peak much earlier and somewhat more anteriorly for upper than for lower hemiretinal stimulation. Thus, there is a difference of response latency in the two conditions, which accounts for the approximate inversion of polarity. Possible correlations with reports of higher receptor cell density, higher visual acuity, and shorter motor reaction time of the upper hemiretinal system are noted.

Adult↗