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No strict relationship has been observed between seizure outcome after surgery and the psychosocial status of patients with refractory epilepsy. The main reason is that seizures are not the sole criteria in evaluating social outcome. The presurgical status in terms of education, the mainly neuropsychological associated handicap, socio-occupational life, and the expectations of the patient must be taken into account. Psychosocial adjustment after surgery needs to be prepared long before surgery, in full cooperation with the patient and his or her family. Standardized tools must be developed to allow for a multidisciplinary approach and an objective evaluation of the psychosocial status of epileptic patients after surgery.

Even in 1998 at the time of brain imaging, EEG recording is undoubtedly useful in clinical psychiatry when a true cerebral disease takes the form of an acute psychiatric disorder. Though the real place of EEG recording cannot be yet accurately quantified, it may help guide the diagnosis, as it is of either positive (ie, confirming the diagnosis via additional information) or negative (ie, rejecting various etiologies) value. Most of the time, only the former is considered in published studies. The clinical value of EEG recording in psychiatry emergency unit is therefore still not clearly established. The study of patients admitted during two years in the emergency unit at Sainte-Anne hospital (Paris, France) does not bring new conclusions, mainly because of bias in the modalities of admission and follow-up. As well, the role of EEG recording for the diagnosis of non-psychiatric diseases in psychiatry emergency units cannot be defined today. The authors review clinical situations where EEG recording is still highly advisable.

Resume Soixante dix-neuf sujets d'âge moyen 70,2 ans (31 hommes et 48 femmes) atteints de demence de type Alzheimer probable au stade de debut de la maladie et 17 sujets temoins d'âge moyen 72,2 ans (cinq hommes et 12 femmes) ont ete etudies en EEG quantifie avec analyse topographique et en EEG standard (lecture visuelle du trace analogique). Les resultats montrent que des parametres EEG simples tels que la frequence moyenne dominante (FM) dans la bande 3,5–13 Hz et le rapport alpha/theta permettent de discriminer des sujets normaux de patients DTA avec une sensibilite superieure a l'EEG classique. Les valeurs de 8,6 pour la FM et de 1,3 pour le rapport alpha/theta sont proposees comme frontieres entre normal et pathologique. L'analyse de la repartition topographique des anomalies n'apporte, par contre, aucun argument utile supplementaire a la discrimination des deux groupes.

Resume Les latences, les amplitudes et la localisation des maxima des pics des reponses evoquees auditives tardives ont ete etudiees dans trois groupes de sujets âges: normaux, deprimes et dements de type Alzheimer (DTA) probable. Les reponses evoquees par un paradigme oddball simple ont ete recueillies avec 16 electrodes disposees d'apres le SI 10–20 au cours de deux situations experimentales: comptage des stimulations rares et reponse motrice avec mesure du temps de reaction (TR). Aucune difference n'est observee entre les trois groupes en ce qui concerne les amplitudes. Une difference significative est observee pour les latences de P3 en comptage mental entre les groupes DTA et deprimes mais pas entre DTA et temoins ou temoins et deprimes. Cette difference n'atteint pas le seuil de significativite pour la reponse motrice. Le maximum d'amplitude du pic P3 se situe sur les regions anterieures chez la plupart des sujets dements alors qu'il a un maximum posterieur chez les sujets deprimes et chez les temoins. Ainsi, l'etude de la repartition topographique de la reponse P3 pourrait permettre de caracteriser, au stade precoce, certaines DTA alors que les amplitudes et les latences sont encore dans les limites de la normale.

Resume Vingt patients atteints de demence de type Alzheimer probable ont ete examine sur le plan neuropsychologique et EEG a deux temps differents separes par un intervalle moyen de 14,5 mois. Au terme de cette periode, les sujets qui se sont aggraves sur le plan neuropsychologique (n = 8) ont ete separes des sujets qui sont restes stables (n = 12). Lorsque l'on regarde les caracteristiques EEG au ler examen (T1), mais aussi apres le suivi evolutif au 2e examen (T2) ou lorsque l'on regarde la difference T1–T2 aucune difference significative n'apparait entre les deux groupes, tant a la periode initiale qu'au terme de la periode de suivi. On ne peut cependant conclure que l'EEG n'a pas d'interet dans l'appreciation de l'evolutivite des demences car les sujets qui restent stables sur le plan cognitif et sur le plan EEG ont, en general dans notre etude, une frequence moyenne qui reste stable. La stabilite de la frequence moyenne pourrait donc constituer un parametre interessant pour l'appreciation du potentiel evolutif des demences mais cela doit etre teste sur une population plus importante de sujets et comportant notamment, parmi les aggraves, plus de sujets passant du stade modere au stade severe.

Resume Quarante et un sujets atteints de demence de type Alzheimer (DTA) probable ont ete etudies en EEG quantifie (Q-EEG) et en emission monophotonique a l'isopropyl-iodoamphetamine (SPECT-IMP). Quatre groupes sont distingues selon la topographie de l'hypoperfusion SPECT : frontal, temporo-parietal, fronto-parietal et fronto-temporo-parietal. L'analyse Q-EEG montre que les deux derniers groupes ont des alterations EEG nettement plus marquees que les deux premiers. Des parametres Q-EEG dans les limites de la normale pourraient etre en faveur du diagnostic de DTA avec atteinte frontale ou temporoparietale dominante. Mais des biais lies a la duree d'evolution ou au degre d'evolutivite ne peuvent etre exclus. Quoi qu'il en soit les modifications de l'EEG sont diffuses et ne refletent pas la topographie de l'hyperfusion SPECT. Cela remet en question l'interet de l'analyse de la topographie des anomalies de l'EEG dans les DTA et souleve le probleme de la signification des alterations regionales de perfusion observees en SPECT.

Background Impaired inhibition has been reported in patients with schizophrenia in a variety of cognitive and motor tasks. Recent transcranial magnetic stimulation studies performed during rest show reduced cortical inhibition in primary motor cortex (M1) at rest in schizophrenia patients, supporting the hypothesis of impaired GABA-ergic inhibition as an underlying mechanism. However, cortical excitability and intracortical inhibition in M1 are highly task-dependent, for example, inhibiting a planned motor response leads to reduced excitability and enhanced intracortical inhibition. Studies on task-dependent cortical excitability and inhibition are lacking in schizophrenia. The aim of this study was therefore to investigate cortical excitability and intracortical inhibition during voluntary motor inhibition in patients with schizophrenia. Methods 25 stabilized patients with schizophrenia (DSMIV) and a group of 23 age-comparable healthy volunteers were included. We used a modified version of the Go–Stop task to study voluntary motor inhibition. This task consisted of moving the index finger in response to Go and Stop signals. In 30% of trials the subject received a visual cue to inhibit the prepared finger lift. Paired-pulse transcranial magnetic stimulation (TMS) was used to measure M1 excitability and short-latency intracortical inhibition (SICI%) during three phases of the task: (i) early without movement preparation (Early); (ii) late with preparation of finger lift (Late prep ); and (iii) late with inhibition of finger lift (Late inhib ). Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle. Results Patients and control subjects performed equally on the voluntary inhibition task, with similar stop signal reaction times (mean SSRT controls 189 ± 21 ms and patients 186 ± 31 ms, P = 0.6). TMS at rest revealed similar resting and active motor thresholds in patients and controls (P > 0.9). The cortical silent period was shorter in the patients but did not differ significantly (mean controls 162 ± 30 ms and patients 147 ± 61 ms, P = 0.36). During the Go–Stop task, cortical excitability was similar in patients and controls with a task-dependent modulation of MEPs (mean RMS MEPs: Early = 477 μV, Late prep = 854 μV, and Late inhib = 531 μV; effect of Phase, P F = 4.5, P = 0.02) with posthoc comparisons revealing a significant reduction in the Late inhib phase in patients compared to controls ( P = 0.02). In patients the SICI% during Late inhib correlated negatively with SSRT ( R = − 0.72, P inhib had longer SSRT. Conclusions To our knowledge this is the first study on task-dependent modulation of cortical excitability and intracortical inhibition in patients with schizophrenia. We show that patients with schizophrenia have reduced SICI during voluntary inhibition of a prepared finger lift. Surprisingly, there were no differences found in task performance or in MEP amplitudes during the task. These findings show that schizophrenia patients are capable of inhibiting motor tasks despite having reduced intracortical inhibition. This suggests the use of compensatory mechanisms in voluntary motor inhibition in stabilized schizophrenia patients.

A group of 10 subjects, normal volunteers (6 men, 4 women), mean age 27.2 years, right-handers, has been selected for a double-blind study of caffeine effects (400 mg per os) versus placebo. One week delay separated the two EEG sessions quantified by spectral analysis. During each session (16 EEG channels, common reference), each subject was recorded four times: 2.5 min, in eyes-closed condition, under diffuse attention, followed by 2.5 min, during a visuo-spatial task ("eyes open" condition: presentation of a picture). These two EEG recordings were obtained before the oral administration and repeated 1 hr after the administration of caffeine or placebo. Individual and group results presented globally: 1) an increase in mean frequencies of alpha activity in "eyes closed" condition, and of delta activity in "eyes open" condition; 2) a decrease of alpha activity amplitudes (both RMS and % values) in both conditions; 3) a decrease of total RMS amplitudes in "eyes closed" condition; 4) an increase of relative % amplitudes for beta 2% fast activity in the "eyes open condition". These results characterize the psycho-stimulant effects of caffeine, especially over the left temporal area which was confirming an initial statistical hypothesis of specific cerebral local activation. The non-parametric permutation tests of Fisher, were not always reaching statistical significance for the same EEG channel quantified by one of the 17 analyzed spectral parameters, except on the left temporal area. During the visuo-spatial task, the decrease in alpha amplitudes (RMS and %) was also statistically significant, but over larger areas: over left and right temporal, central and parietal regions. In both conditions, eyes closed and eyes open, the alpha RMS amplitude was also decreased over the right anterior frontal area.

Activity of 29 histologically identified units in the SFO was recorded in parallel to blood pressure monitoring. The responsiveness of these units to angiotensin II (AII) applied either iontophoretically or via the carotid artery (IC) was investigated together with the capacity of the vasodilator substance NO2- to block the AII response. Fifty-five% of the SFO units responded to iontophoretic application of AII (vs. 27% in the surrounding areas). SFO units were also activated by blood pressure depressions, either as a mirror image (type B) or only restricted to the initial descendent phase of the hypotensive wave (type A). But 8 of the 29 units responded in a mixed A and B fashion, i.e., dramatic firing in the very beginning of the hypotension followed by a sustained moderate response until recovery. Hypertensive spontaneous fluctuations rarely and inconsistently elicited an inhibitory response. An unexpected phenomenon of a hypotensive response following IC injections of low doses of AII was observed and used in this investigation. These observations together with the finding that vasoplegics inhibited unit firing suggest that the SFO is equipped with units able to sense a reduction in local vessels' calibre and fire in relation to it. When activated chemically, electrically or mechanically these units may then trigger hypertensive, antidiuretic and drinking responses.

Here we present some preliminary results in subjects suffering from dementia of the Alzheimer type (DAT). We studied 28 patients, diagnosed as having «probable DAT», according to the NINCDS-ADRDA Work Group criteria, with mean age of 73.5 (SD=6.3) years, mean duration of illness of 2.8 (SD=1.7) years, and mean age at onset of 70.7 (SD=6.8) years