Lipomas of the corpus callosum and epilepsy.

An analysis of four cases of lipomas of the corpus callosum with epilepsy, and a review of the literature, have led to the following conclusions: (1) Epilepsy as an almost constant feature is often severe, nearly always partial, and begins before the age of 15. (2) Pathophysiology of the seizures appears to be essentially an interhemispheric disconnection (rather than the classic theory that seizures depend upon an infiltration of the cingulate gyri by fibrous tissue growing out from the capsule of the lipoma). This disconnection is responsible for a facilitatory and disinhibitory action that favors the appearance of seizures caused by an epileptogenic lesion (the effects of which remain subthreshold in the presence of an intact corpus callosum playing its normal inhibitory role). This hypothesis is clearly applicable in explaining the epilepsies--in every way comparable--that are observed in agenesis of the corpus callosum and in Marchiafava-Bignami disease.

[Multimodal evoked potentials in partial epilepsy in children]. / Etude des potentiels évoqués multimodalitaires dans les épilepsies partielles de l'enfant.

A multimodal evoked potential study was realised in three groups of children or adolescents 5 to 15 years old. The first group included 25 normal non-epileptic subjects; the second group was composed of 27 subjects with partial idiopathic epilepsy (PIE) (benign childhood epilepsy with centro-temporal spike; childhood epilepsy with occipital paroxysms); the third group was formed of 20 subjects with partial symptomatic epilepsy (PSE) without patent anatomical lesion or with anatomical lesion. Recording for each subject included: flash visual evoked potentials, pattern visual evoked potentials, brainstem auditory evoked potentials and somatosensory evoked potentials. Each curve obtained was studied for the response morphology, the measure of the different wave latencies, the inter-peak latencies (conduction time) and the amplitudes. A statistical treatment of the data was performed to evaluate the significance of variation of the different parameter values obtained for the various groups. Among the significantly modified parameters, we found: an increase of the amplitudes in the PIE and a decrease in the PSE, specially when an anatomical lesion exists; an asymmetrical amplitude of the somatosensory responses in the PIE with centro-temporal spike; an increase of the central somatosensory conduction time in the PSE with anatomical lesion.

Sleep electroencephalogram at the early stage of Creutzfeldt-Jakob disease.

We describe sleep EEG studies in three patients at the early stage of Creutzfeldt-Jakob disease. Little work has been devoted to the study of the sleep EEG in the course of the CJ disease: disorganized sleep architecture was noted, associated with a decrease in stage 4 and an almost complete disappearance of the REM stage. Our patients were considered to have normal stage 2; yet spindles and K complexes were rare at this stage. No evolution towards stage 4 was noted. The percentage of rapid eye movement sleep was significantly low in two cases and normal in one case. Sleep disturbances in the other dementing disorders are reported.

[Multimodal evoked potentials in human immunodeficiency virus infection]. / Potentiels évoqués multimodaux dans l'infection par le virus de l'immunodéficience humaine.

We have studied 95 HIV seropositive patients (77 males and 18 females; mean age: 31 years): 67 had no neurological symptoms or signs, 28 had various neurological symptoms and signs. This study included a full multimodal evoked potentials (MEP) assessment: visual evoked potentials by flash and reversal checkerboard; brainstem auditory evoked potentials; somatosensory evoked potentials obtained by stimulation of the median nerve. Patient evaluation further included: electroencephalography, electromyography with measurement of conduction velocities and neuroimaging (brain CT scan and/or MRI). We found abnormal MEP for all modalities. The prevalence of abnormal results was high in neurological symptomatic patients; in non neurological ones, the changes tended to be more frequent with the progression of the HIV infection. Whatever the stage of the disease, the various modes were equally affected. MEP were abnormal in 54.7 p. 100 of the cases: in 41.8 p. 100 (28/67) of patient without neurological signs (in 4/12 of fully asymptomatic subjects, 11/34 ARC patients and 13/21 AIDS patients) vs 85.7 p. 100 of neurological symptomatic patients. In neurological asymptomatic patients, a similar proportion of abnormal MEP was found in asymptomatic and ARC patients, while the evolution into AIDS was associated with a higher prevalence of abnormal MEP. In the latter group, MEP changes were nearly as frequent as in neurological symptomatic patients. Comparison between MEP and other electrophysiological procedures (EEG, EMG) and with neuroimaging techniques (CT Scan, MRI) showed the high sensitivity of the MEP technique at all stages of the disease. EMG was a sensitive method and complementary to MEP. The EEG and neuroimaging techniques showed abnormalities principally at the neurological symptomatic stage. Previous studies could not be properly compared.(ABSTRACT TRUNCATED AT 250 WORDS)

[Tomodensitometric study of cerebral accidents causing acute hemiplegia in children]. / Etude tomodensitométrique des accidents cérébraux responsables des hémiplégies aigues de l'enfant.

Computerized Axial Tomography (C.A.T.) easily distinguishes between the two types of cerebral accident responsible for the two major categories of acute hemiplegia in childhood. 1) In hemiplegias which develop in association with hemiclonic status epilepticus (H. H. and H. H. E. syndromes), in the majority of cases there is an appearance of cortico-sub-cortical atrophy involving the whole hemisphere contralateral to the hemiplegia. This atrophy develops following oedema of the hemisphere which accompanies the initial status epilepticus and which is clearly shown by a very early T.A.C. 2) In congenital or acquired hemiplegias not associated with status epilepticus there is, in most cases, an appearance of cerebral infarction or, very rarely, haemorrhage. It is thus possible, from a physiopathogenic standpoint, to draw a clear distinction between these two major forms of acute infantile hemiplegia. The first (H. H. and H. H. E. syndromes) usually result from hemispheric atrophy which develops in association with a unilateral or predominantly lateral episode of status epilepticus, whilst the second group are usually the result of cerebral infarction.

[Musical hallucinations]. / Les hallucinations musicales.

Musical hallucinations are rarely reported. Acquired deafness play an important role in their development. The anatomical and neurophysiological substrates for the musical hallucinations are unknown. Most authors related the perceptual disturbance to organic origin (central or peripheral).

[Diagnostic criteria of depressive pseudodementia]. / Critères pour le diagnostic de pseudodémence dépressive.

Ten patients fulfilling the DSM III (A, B, C, D) criteria for both dementia and major depression and presenting the diagnostic dilemma of depressive pseudodementia were included in a prospective study in search of indices for the differential diagnosis of depressive pseudodementia (DPSD) and organic dementia (OD). Patients were assessed with the Hamilton Depression Rating Scale (HDRS), the Blessed Dementia Rating Scale (BDRS), the Wells's criteria, the Mini Mental State (MMS), computerized tomography (CT scan) of the brain, the dexamethasone suppression test (DST), total plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) and sleep electroencephalograms (EEG). Patients suffering from DPSD were defined as showing an improvement higher than 50% in both the HDRS et BDRS scores following adequate antidepressant treatment. Wells's criteria, MMS scores, CT scan and DST do not contribute to the separation of DPSD (n = 6) and OD (n = 4). On the contrary, plasma MHPG levels higher than 35 ng/ml and EEG measures of sleep structure and REM sleep significantly differentiate the two groups.

[Value of computerized axial tomography in cranio-cerebral injuries]. / Intérêt de la tomographie axiale commandée par ordinateur (tacographie) dans les traumatismes crânio-cérébraux

Since May 1975 was have been working in the field of C.A.T. and its application to study head injuries. We are presenting differents groups of patients studied by C.A.T. I. -- DATA OF C.A.T. IN THE CASES OF EMERGENCY AND IMMEDIATE POST-OPERATIVE FOLLOW-UP OF HEAD INJURIES A) EMERGENCY STATE As soon as the clinical state of an head injured patient was supposed to need an operation, C.A.T. was realized; so differents abnormal scanners may be observed: 1. epidural hematoma, 2. subdural hematoma, 3. intra-cerebral hematoma, 4. acute subdural hematoma or contusion. We must do some comments: -- The Emi-scanner is pre-eminent in showing the exact topography of the lesion : so, the flap is easier to realise. -- In most cases the Emi-scanner is easier to interpret than angiogram for example contusion and hematoma. We know the goods results in hematomas and the poors results in surgery of contusions. -- But the senior advantage of C.A.T. is to provide all the informations in the totality of skull content. Emi-scanner shows bilateral lesions, ipsilateral lesion. C.A.T. is pre-eminent in showing the presence of this two lesions, more accurately than senior methods of investigations, so C.A.T. permits emergency neurosurgical treatment. B) C.A.T. AND FOLLOW-UP Repeated studies at post-intervals can be accomplished without risk to the patient, thus making follow-up simpler and more effective to the neurosurgical attitude. C) POST-OPERATIVE CONTROL AND C.A.T. Post-operative complications are always hard to diagnosis. C.A.T. is painless, quick and safe, and easier to interpret than an angiogram. II -- SEQUELLAE STADE AND C.A.T. In this field certains advantages of C.A.T. are immediatly apparents. In most cases the C.A.T. is the best screening method. Patients carried out are: -- psychiatric troubles, -- post-traumatic epilepsy. The results are not reliable. There is no anatomical-clinical relation in most cases. Differents pictures are observed: -- asymetrical ventricle enlargment, -- global ventricule enlargment, -- partial cerebral atrophy. III -- DISCUSSION 1. We are at the beginning of our study. 2. This not always possible to obtain a C.A.T. in emergency for a head injury, especialy at night. 3. Patients investigated following head trauma are among the most difficult to study with C.A.T. These invididuals send to be restless and uncooperative. Numerous artefacts produced by patient motion may lead to erroneous negative or positive diagnosis, so general anesthesia is often helpful. It is hoped that as a more rapid scanners become available this problem will be obviated. The C.A.T. alone is not capable, to provide all the necessary date concerning head injury. The C.A.T. is, however, re-adjusting our total investigation (E.E.G., angiograms) philosophy and practice rather than replacing the standard neuroradiological technique, except, may be, with epidural hematoma.

Inhibition of endogenous human dentin MMPs by Gluma.

OBJECTIVE: The objective of this study was to determine if Gluma dentin desensitizer (5.0% glutaraldehyde and 35% HEMA in water) can inhibit the endogenous MMPs of dentin matrices in 60 s and to evaluate its effect on dentin matrix stiffness and dry mass weight. METHODS: Dentin beams of 2 mm×1 mm×6 mm were obtained from extracted human third molars coronal dentin. To measure the influence of Gluma treatment time on total MMP activity of dentin, beams were dipped in 37% phosphoric acid (PA) for 15 s and rinsed in water. The acid-etched beams were then dipped in Gluma for 5, 15, 30 or 60 s, rinsed in water and incubated into SensoLyte generic MMP substrate (AnaSpec, Inc.) for 60 min. Controls were dipped in water for 60 s. Additional beams of 1 mm×1 mm×6 mm were completely demineralized in 37% PA for 18 h, rinsed and used to evaluate changes on the dry weight and modulus of elasticity (E) after 60 s of Gluma treatment followed by incubation in simulated body fluid buffer for 0, 1 or 4 weeks. E was measured by 3-pt flexure. RESULTS: Gluma treatment inhibited total MMP activity of acid-etched dentin by 44, 50, 84, 86% after 5, 15, 30 or 60 s of exposure, respectively. All completely demineralized dentin beams lost stiffness after 1 and 4 weeks, with no significant differences between the control and Gluma-treated dentin. Gluma treatment for 60 s yielded significantly less dry mass loss than the control after 4 weeks. SIGNIFICANCE: The use of Gluma may contribute to the preservation of adhesive interfaces by its cross-linking and inhibitory properties of endogenous dentin MMPs.

Stabilization of dentin matrix after cross-linking treatments, in vitro.

OBJECTIVES: To evaluate the effect of EDC on elastic modulus (E), MMPs activity, hydroxyproline (HYP) release and thermal denaturation temperature of demineralized dentin collagen. METHODS: Dentin beams were obtained from human molars and completely demineralized in 10 wt% H3PO4 for 18 h. The initial E and MMP activity were determined with three-point bending and microcolorimetric assay, respectively. Extra demineralized beams were dehydrated and the initial dry mass (DM) was determined. All the beams were distributed into groups (n=10) and treated for 30 s or 60 s with: water, 0.5 M, 1 M or 2 M EDC or 10% glutaraldehyde (GA). After treatment, the new E and MMP activity were redetermined. The beams submitted to DM measurements were storage for 1 week in artificial saliva, after that the mass loss and HYP release were evaluated. The collagen thermal denaturation temperature (TDT) was determined by DSC analysis. Data for E, MMP activity and HYP release were submitted to Wilcoxon and Kruskal-Wallis or Mann-Whitney tests. Mass loss and TDT data were submitted to ANOVA and Tukey tests at the 5% of significance. RESULTS: EDC was able to significantly increase collagen stiffness in 60s. 10% GA groups obtained the highest E values after both 30 and 60s. All cross-linking agents decreased MMP activity and HYP release and increased TDT temperature. Significant differences were identified among EDC groups after 30 or 60 s of cross-linking, 1M or 2M EDC showed the lowest MMP activity. SIGNIFICANCE: Cross-linking agents are capable of preventing dentin collagen degradation. EDC treatment may be clinically useful to increase resin-dentin stability.