Biomedical subjects

Elisabeth Pauli

Publications and source records attributed to Elisabeth Pauli.

11 recordsLinked to original sources

PubMed2007

A new clinico-pathological classification system for mesial temporal sclerosis.

We propose a histopathological classification system for hippocampal cell loss in patients suffering from mesial temporal lobe epilepsies (MTLE). One hundred and seventy-eight surgically resected specimens were microscopically examined with respect to neuronal cell loss in hippocampal subfields CA1-CA4 and dentate gyrus. Five distinct patterns were recognized within a consecutive cohort of anatomically well-preserved surgical specimens. The first group comprised hippocampi with neuronal cell densities not significantly different from age matched autopsy controls [no mesial temporal sclerosis (no MTS); n = 34, 19%]. A classical pattern with severe cell loss in CA1 and moderate neuronal loss in all other subfields excluding CA2 was observed in 33 cases (19%), whereas the vast majority of cases showed extensive neuronal cell loss in all hippocampal subfields (n = 94, 53%). Due to considerable similarities of neuronal cell loss patterns and clinical histories, we designated these two groups as MTS type 1a and 1b, respectively. We further distinguished two atypical variants characterized either by severe neuronal loss restricted to sector CA1 (MTS type 2; n = 10, 6%) or to the hilar region (MTS type 3, n = 7, 4%). Correlation with clinical data pointed to an early age of initial precipitating injury (IPI < 3 years) as important predictor of hippocampal pathology, i.e. MTS type 1a and 1b. In MTS type 2, IPIs were documented at a later age (mean 6 years), whereas in MTS type 3 and normal appearing hippocampus (no MTS) the first event appeared beyond the age of 13 and 16 years, respectively. In addition, postsurgical outcome was significantly worse in atypical MTS, especially MTS type 3 with only 28% of patients having seizure relief after 1-year follow-up period, compared to successful seizure control in MTS types 1a and 1b (72 and 73%). Our classification system appears suitable for stratifying the clinically heterogeneous group of MTLE patients also with respect to postsurgical outcome studies.

Adult↗

PubMed2006

Investigations in subjects with cough following upper respiratory tract infection.

The study aimed to investigate subjects with cough following acute upper respiratory tract infection (URTI), and to compare those subjects unable to suppress cough ("non-suppressors") with those who were able to suppress cough ("suppressors"). Forty-three URTI subjects participated, 31 with cough associated with acute URTI and 12 healthy controls; 21 of the coughing subjects were "suppressors", 10 were "non-suppressors". We obtained responses to chemical and mechanical stimulation of the nasal cavity or the pharynx using both psychophysical measures and event-related potentials. The study provided the following results: (1) "non-suppressors" did not exhibit significantly different intensity ratings or event-related potentials in comparison to "suppressors" in terms of responses to intranasal irritant, mechanical, or olfactory stimuli; (2) when pharyngeal mechanical stimuli were investigated "suppressors" rated the stimuli as more intense than "non-suppressors" and controls; (3) latencies of event-related potentials to pharyngeal stimuli were longest in "non-suppressors". Keeping in mind the relatively small sample size, it appears possible to differentiate certain types of cough during uncomplicated URTI. This may help to explain interindividual differences in responsiveness to cough medication.

Adolescent↗

PubMed2006

Combining fMRI and MEG increases the reliability of presurgical language localization: a clinical study on the difference between and congruence of both modalities.

To avoid neurological impairment during surgery near language-related eloquent brain areas, we performed presurgical functional brain mapping with functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in 172 patients using language tasks. For MEG localizations, we used either a moving equivalent-current dipole fit or a current-density reconstruction using a minimum variance beamformer with a spatial filter algorithm. We localized the Wernicke and Broca language areas for every patient. We integrated the results into a frameless stereotaxy system. To visualize the results in the navigation microscope during surgery, we superimposed the fMRI and MEG findings on the brain surface. MEG and fMRI results differed in 4% of cases, and in 19%, one modality showed activation but not the other. In the vicinity of large gliomas, the BOLD (blood oxygenation level-dependent) effect was suppressed in 53% of our patients. Of the 124 patients who had surgery, only 7 patients (5.6%) experienced a transient language deterioration, which resolved in all cases. We used MEG and fMRI to show different aspects of brain activity and to establish validation between MEG and fMRI. We conclude that measurement by both MEG and fMRI increases the degree of reliability of language area localization and that the combination of fMRI and MEG is useful for presurgical localization of language-related eloquent cortex.

Brain↗

PubMed2006

When do patients forget their seizures? An electroclinical study.

Accurate knowledge of the frequency of epileptic seizures is a precondition for evaluating the efficacy of pharmacotherapy. It is a well-known fact that the information provided by epilepsy patients about the number of seizures they experience is often unreliable. In the present study, we aimed to identify predictors of a higher risk of unrecognized events. Thirty patients who underwent presurgical evaluation in a video/EEG monitoring unit were recruited. As soon as the patient became aware of a seizure, he or she completed a standardized questionnaire on the subjective perception of the seizure, which was then compared with the video/EEG findings. Of the 138 seizures recorded, 49.3% were reliably detected by the patient, whereas 44.2% went unnoticed; the remainder were incompletely or uncertainly perceived. Subjects in whom events occurred during sleep or originated in (or propagated to) the left temporal lobe had a significantly higher percentage of unrecognized events.

Adult↗

PubMed2005

Model based prognosis of postoperative object naming in left temporal lobe epilepsy.

Epilepsy surgery in the left temporal lobe is associated with a high risk of naming decline. In the present study, in 45 patients with left temporal lobe epilepsy (TLE) and confirmed left hemisphere language dominance, 13 (29%) patients demonstrated postoperative decrement >or=5 naming failures in the Boston Naming Test (BNT). Multivariate discriminant analysis with age at onset of epilepsy, age at first risk, age at operation and preoperative naming performance as predictors indicated that 12 (92%) patients with later naming decline could be identified preoperatively. Univariate group comparisons revealed that specifically patients with seizure onset later than 14 years without preceding risk factors (e.g., febrile seizures) are in danger of postoperative dysnomia. It is hypothesized, that there is a strong connection between stable naming performance and deviant intrahemispheric speech representation as a result of early brain damage and/or chronic seizures.

Adult↗

PubMed2004

Ictal pleasant sensations: cerebral localization and lateralization.

Ictal pleasant feelings are a rare sign of focal epilepsies. The most popular description was performed by Dostojevskij, who reported an aura by Myshken in one of his books. No convincing evidence has been published concerning the cerebral localization of ictal happiness. In this study, the findings of 11 patients with ictal pleasant feelings are described. In eight patients, the origin of the focal epileptic activity was found in the temporal lobe (most often temporal inferior basal); in three patients, frontal or parietal lobe in addition to temporal lobe involvement was found. According to our findings ictal happiness is a localizing sign pointing to the ictal involvement of temporal mesiobasal areas. Lateralization to the right temporal lobe was found in seven and to the left temporal lobe in four patients.

Adolescent↗

PubMed2003

Outcome of epilepsy surgery correlates with sympathetic modulation and neuroimaging of the heart.

Temporal lobe epilepsy (TLE) is frequently associated with sympathetic over-activity. Single photon emission computed tomography (SPECT) with 123iodine-meta-iodobenzylguanidine (MIBG), a norepinephrine analogue, showed reduced tracer uptake in cardiac sympathetic nerve endings, indicating myocardial catecholamine disturbance. We investigated whether outcome of epilepsy surgery correlates with cardiac autonomic function in TLE patients. We studied 16 TLE patients before and after epilepsy surgery. We recorded heart rate (HR) and determined sympathetic and parasympathetic cardiac modulation as powers of low (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.5 Hz) heart rate oscillations. The LF/HF-ratio was calculated as index of sympathovagal balance. Cardiac MIBG uptake was assessed with MIBG-SPECT and compared to control data. After surgery, eight patients were seizure-free and eight had persistent seizures. Sympathetic LF-power and LF/HF-ratio were higher in patients who had persistent seizures than in patients who became seizure-free. After surgery, both parameters decreased in seizure-free patients but increased in patients with persistent seizures. MIBG uptake was lower in patients than controls and even lower in the patient subgroup who had persistent seizures. In this subgroup, MIBG uptake further decreased after surgery (P<0.05). Sympathetic cardiac modulation decreased in TLE patients after successful surgery, but further increased if seizures persisted. Reduction of cardiac MIBG uptake progressed after surgery in patients with persistent seizures. Interference of epileptogenic discharges with autonomic neuronal transmission might account for sympathetic cardiac over-stimulation and reduced MIBG uptake. Both findings are possible risk factors for sudden unexplained death and might be relevant for risk stratification in epilepsy patients.

3-Iodobenzylguanidine↗

PubMed2003

[Fractionated stereotactically guided radiotherapy for pharmacoresistant epilepsy].

AIM: This prospective study evaluated the efficiency of fractionated stereotactically guided radiotherapy as a treatment of pharmacoresistant temporal lobe epilepsy. PATIENTS AND METHODS: Inclusion criteria were patients aged between 17 and 65 years with one-sided temporally located focus, without sufficient epilepsy control by antiepileptic drugs or neurosurgery. Between 1997 and 1999, two groups of six patients each were treated with 21 Gy (7 times 3 Gy) and 30 Gy (15 times 2 Gy). Study end points were seizure frequency, intensity, seizure length and neuropsychological parameters. RESULTS: All patients experienced a marked reduction in seizure frequency. The mean reduction of seizures was 37% (range 9-77%, i. e. seizures reduced from a monthly mean number of 11.75 to 7.52) at 18 months following radiation treatment and 46% (23-94%, i. e. 0.2-23 seizures per month) during the whole follow-up time. Seizure length was reduced in five out of eleven patients and intensity of seizures in seven out of eleven patients. CONCLUSION: Radiotherapy was identified as safe and effective for pharmacoresistant epilepsy since a very good reduction of seizure frequency was observed. It is no substitute for regular use of antiepileptic drugs, but means an appropriate alternative for patients with contraindication against neurosurgery or insufficient seizure reduction after neurosurgery.

Adolescent↗

PubMed2002

Somatotopic organization of the ventral and dorsal finger surface representations in human primary sensory cortex evaluated by magnetoencephalography.

Cortical reorganization of the subtly differentiated hand map after peripheral nerve injury might be better understood if there was a topographic conception of the homuncular representation of the dorsal finger surfaces in humans, in addition to the well-established sequential rostrocaudal array of the ventral finger aspects in cortical area 3b. In the present magnetoencephalographic study, tactile pneumatic stimulation was delivered to the fingertip and to the ventral and dorsal proximal phalanx of each digit of the dominant hand in 20 right-handed volunteers. Source localization of equivalent current dipoles underlying the recorded somatosensory evoked magnetic field was performed using a Cartesian coordinate system established by the anatomical landmarks nasion and preauricular points. Of the first major peak of each somatosensory evoked field, the region with the maximum field power (root-mean-square across channels) was selected for source reconstruction. Analysis of variance for repeated measures yielded significant results with respect to the arrangement of digits along the vertical coordinate axis, demonstrating a sequential array from the most inferiorly located D1 to the most superiorly located D5 for all different stimulus positions. This is the first study providing evidence for a sequential topographical arrangement of not only the ventral but also the dorsal surface representations of the individual digits in the human somatosensory cortex. The study contributes to a better understanding of the somatosensory hand representation in human primary cortex and provides useful information with regard to cortical plasticity studies in patients with peripheral nerve injuries at the upper extremity.

Adult↗

PubMed2002

Clinical effects of topiramate against secondarily generalized tonic--clonic seizures.

OBJECTIVE: Intensive and quantitative evaluation of the duration, intensity and frequency of tonic and clonic signs of secondarily generalized tonic-clonic seizures (GTCS) in patients with pharmacoresistant partial seizures during topiramate (TPM) treatment. METHODS: Thirty patients suffering from refractory partial seizures with secondarily GTCS undergoing presurgical evaluation were randomized into a low dosage (100 mg daily) and a parallel medium dosage (200 mg daily) group of TPM add-on medication (15 patients for each group). Study phases included a 3 days baseline video-EEG phase, a 10 days TPM titration phase without video-EEG and a 3 days TPM dose maintenance phase with video-EEG. During the baseline and the dose maintenance phase seizures were recorded using video-EEG monitoring and the following parameters were measured for each recorded secondarily generalized tonic and clonic signs: duration (lasting seconds), intensity (on a 0-3 scale), frequency (numbers per 24 h). RESULTS: A total of 46 complex partial seizures with secondarily generalized tonic-clonic signs during the baseline phase and 20 during the dose maintenance phase were intensively analyzed. More patients in the medium dosage group than in the low dosage groups were free from secondarily GTCS during the dose maintenance phase (nine vs. two, P<0.05). Intergroup comparison suggested that the duration of all tonic signs decreased more in the medium dosage group computing the reduction from baseline to the dose maintenance phase (P<0.05). There were statistically more significant reductions in the duration and intensity of clonic signs in the medium dosage group (P<0.05). CONCLUSION: TPM has an early dose-dependant effect on secondarily GTCS in patients with pharmacoresistant partial seizures. SHORT COMMUNICATION: The present study intensively analyzed the duration, intensity, and frequency of secondarily generalized tonic and clonic signs in patients with pharmacoresistant partial seizures. The quantitative data suggested that TPM had a robust early inhibitory effect on secondarily generalized tonic-clonic signs; effects were more prominent in the medium dosage group (200 mg daily) than in the low dosage group (100 mg daily).

Adolescent↗

PubMed2002

Influence on ictal seizure semiology of rapid withdrawal of carbamazepine and valproate in monotherapy.

PURPOSE: To quantify changes in ictal seizure semiology during rapid withdrawal of carbamazepine (CBZ) and valproate (VPA) from a monoregimen in presurgical evaluation. METHODS: Therapeutic intensive seizure analysis (TISA) with video-EEG monitoring was used in 33 patients with pharmacoresistant partial epilepsy undergoing complete withdrawal of CBZ (20 patients) or VPA (13 patients) from a monoregimen. Monitoring phases included a 3-day baseline phase, a 3-day rapid antiepileptic drug (AED) withdrawal phase, and another 3-day AED-free phase with AEDs in subtherapeutic levels. Seizure variables as complete processes and their various elements (ictal signs) were analyzed, including duration (seconds), intensity (on a scale of 0 to 3), frequency (number per 3 days), and total duration of seizures and ictal signs in 3 days (seconds). The localization of seizure patterns on ictal EEG recording (EEG seizure onset) and the first appearing clinical ictal phenomena (initial ictal signs) were recorded. RESULTS: A total of 188 seizures in the CBZ group and 57 seizures in the VPA group were investigated. Compared with the baseline phase, the CBZ group showed increases in duration, frequency of seizures, various ictal signs, and secondarily generalized tonic and clonic signs during the following two phases. Significantly increased values of the VPA group were observed in seizure duration and frequency of hypermotoric phenomena during the AED-free phase. More patients in the CBZ group had secondarily generalized clonic signs during the AED-free phase. EEG seizure onset and initial ictal signs showed no obvious changes between study phases. CONCLUSIONS: Withdrawal of CBZ is followed more quickly by an increase of seizure frequency and severity than is the case for VPA withdrawal. Both CBZ and VPA withdrawal influences seizure propagation rather than the seizure-onset characteristics, which speaks in favor of its use in presurgical evaluation.

Adult↗