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J Lehrner

Publications and source records attributed to J Lehrner.

8 recordsLinked to original sources
PubMed1998

Language-related hemispheric asymmetry in healthy subjects and patients with temporal lobe epilepsy as studied by event-related brain potentials and intracarotid amobarbital test.

There are current attempts to replace the WADA test for pre-surgical evaluation of hemispheric language capabilities by one of the methods of functional brain imaging. Recent PET and fMRI studies using verbal cognitive tasks like verb generation, semantic monitoring or semantic ('deep') encoding of words showed asymmetries of activation in the fronto-lateral cortex. In a previous ERP study subjects were required to indicate whether pronounceable non-words and abstract geometric figures were presented for the first time ('new item') or whether they had been shown before ('old item'). Group analyses of this study showed significant material-specific hemispheric asymmetries with ERPs being more negative-going in recordings of the posterior part of the left hemisphere with verbal material (CP5/6) but more negative-going in recordings of the right hemisphere with the spatial material (P7/8). The aim of the present study was to test statistically ERP lateralization effects in individual healthy subjects as well as WADA-tested patients suffering from seizures of the mesio-temporal lobe (MTL). In all subjects ERP lateralization with verbal material was tested in the electrode pair CP5/6, and ERP lateralization with figures in the electrode pair P7/8. Statistical analyses of single trials showed that in 20 out of 24 subjects ERPs with verbal material started to be more negative-going in CP5 as compared to CP6 in the period between 100 and 200 ms after stimulus onset or the subsequent time epoch (200-300 ms). In one subject not CP5/6 but the closely adjacent electrode pair P7/P8 showed this verbal material-related hemispheric effect. In patients language dominance as indicated by ERPs was not always consistent with the data of the WADA test. In one patient with left MTL seizures ERPs with verbal material and figures were found to be significantly lateralized to the right hemisphere although the WADA test assigned this patient to have a language-dominant left hemisphere.

Adult↗
PubMed1998

Clinical seizure lateralization in mesial temporal lobe epilepsy: differences between patients with unitemporal and bitemporal interictal spikes.

OBJECTIVE: To compare the reliability of clinical seizure lateralization in temporal lobe epilepsy patients with unitemporal and bitemporal independent interictal spikes and unilateral hippocampal atrophy or sclerosis (HA/HS) on MRI scan. PATIENTS AND METHODS: We studied 11 patients with unitemporal and 10 patients with bitemporal interictal spikes. We calculated a spike ratio by dividing the number of spikes ipsilateral to the side of HA/HS by those occurring contralaterally. RESULTS: Clinical seizure lateralization was correct, i.e., ipsilateral to the side of HA/HS, significantly more often in the unitemporal group. Spike ratios were significantly higher in seizures that were lateralized correctly as compared with both incorrectly and nonlateralized seizures. Within the individual patients, a significant positive correlation between spike ratios and the proportion of correctly lateralized seizures was found. We identified three categories of symptoms according to lateralization accuracy. Category 1 symptoms (version, postictal paresis, and early ictal vomiting/retching) lateralized to the side of HA/HS in 100% of patients in the uni- and bitemporal groups. Category 2 symptoms (dystonic posturing, mouth deviation, postictal dysnomia/dysphasia, and ictal speech) provided a 100% correct lateralization in the unitemporal but not in the bitemporal patients. Category 3 symptoms (nonversive early head turning and unilateral upper extremity automatisms) yielded erroneous lateralization in both patient groups. CONCLUSIONS: We conclude that reliable clinical seizure lateralization in mesial temporal lobe epilepsy can only be achieved in patients with unitemporal interictal spikes, whereas clinical lateralization in patients with bitemporal spikes must be viewed cautiously.

Adult↗
PubMed1997

Olfactory prodromal symptoms and unilateral olfactory dysfunction are associated in patients with right mesial temporal lobe epilepsy.

PURPOSE: We report a patient with mesial temporal lobe epilepsy (MTLE) with olfactory prodromal symptoms manifested as an unpleasant smell of onions, who was found to have an ipsilateral deficit of olfactory naming (olfactory agnosia). METHODS AND RESULTS: Preoperative olfactory testing revealed a selective right-sided olfactory deficit for naming of odors. Olfactory threshold was within the normal range. The patient has been seizure free after selective amygdalohippocampectomy for 4 months. No olfactory prodromal events have occurred since surgery. Olfactory testing 3 months after resection showed that right-sided odor naming was still impaired. CONCLUSIONS: We conclude that olfactory prodromal symptoms may be associated with unilateral olfactory dysfunction, and lateralization of seizure origin may be possible by unilateral olfactory testing.

Agnosia↗
PubMed1976

Lymphocyte-dependent antibodies in uveitis.

Lymphocyte-dependent antibodies were revealed in the serum of patients suffering from uveitis of various aetiologies. The serum was incubated with normal uveal tissue and the binding of non-immune human lymphocytes was investigated. In three cases of sympathetic ophthalmitis the lymphocytes accumulated around the melanine granules, while in another 17 patients with uveitis cases the lymphocytes accumulated around the capillaries. Uveal tissue incubated with control sera failed to bound lymphocytes. The lymphocytic infiltration in certain cases of chronic uveitis suggested the role of lymphocyte-mediating antibodies in the aetiology of these cases.

Autoantibodies↗