[Demonstration of cobalt in histological sections using ion microanalysis by high mass resolution : application to the study of experimental chronic epilepsy in the rat]

Cobalt is specifically detected in ion microanalysis by high mass resolution. This method allows detection of the remaining cobalt in histological sections of Rat's cortex, after treatment by topic application of cobalt powder and demonstrates a diffusion of the metal into the epileptic area.

Penetration of cefamandole, cephalothin, and desacetylcephalothin into fibrin clots

The conversion of cephalothin into a less active metabolite (desacetylcephalothin) might influence its distribution in tissues. An experimental rabbit model devised to determine concentrations of antibiotics in subcutaneous fibrin clots was used in this study. Groups of five to six animals received 100-mg/kg intravenous injections of either cefamandole or cephalothin. One hour after the injection, the concentration of cefamandole in serum was 20 times higher than that of cephalothin. Whereas cephalothin was undetectable at 4 h, cefamandole was still detectable at the end of the experiment. The half-lives of cephalothin and cefamandole in serum were 16 and 27 min, respectively. The concentration of cefamandole found in fibrin clots was severalfold higher than that of cephalothin. The half-life of cefamandole in clots (81 min) was superior to that of cephalothin (38 min). Although concentrations of both antibiotics were higher in serum than in clots at 1 h, the concentrations of these drugs in the clots persisted at higher levels throughout the next 5 h of the experiment. The extent of binding of cefamandole (87%) to rabbit serum was greater than that of cephalothin (50%). At least 55% of cephalothin was metabolized in vivo into its less active metabolite desacetylcephalothin. This metabolite was found in higher proportion in the serum (75%) than in the clots (55%). Whereas only 12% of the free (unbound) cephalothin reached the clots, 78% of the free cefamandole was found in the clots. This lower level of penetration of unbound cephalothin might be explained by the short half-life of this antibiotic, not permitting equilibrium to occur.

[Late syringomyelic syndromes in paraplegics]

The authors have reviewed 35 cases in the literature and reported on 12 cases seen personally of late onset syringomyelia in paraplegics. Initial pain was found to be present in only slightly more than half the cases and an insidious onset particularly with sensory disturbance led sometimes to delayed recognition. In the fully developed case, it can closely simulate idiopathic syringomyelia with arthropathy but impairment of touch and proprioception sometimes occurs in addition. Neurosurgical treatment to the fluid-filled cavity, does not seem to modify obviously the spontaneous evolution of the condition. In 5 cases, the paraplegia was not of traumatic origin. Possible mechanisms are discussed.

[Behavioral manifestations induced by electric stimulation of the anterior cingulate gyrus in man]

The electrical stimulation of a restricted part of area 24 in awake man elicits important behavioral changes. The present study is dealing with 83 epileptic patients whose brain activity was recorded in SEEG conditions, with a view to possible neurosurgery. In order to determine how seizures originate and propagate, 116 multileads electrodes (65 right, 51 left) were stereotaxically inserted in the anterior part of the cingular gyrus. 521 stimulations were performed. In 362 cases, this stimulation induced a particular behaviour which was characterized by an arousal, motor activities (involving fingers and hand, mouth, legs, eyes, associated movements of hand mouth, highly integrated movements), thymic modifications and hallucinatory manifestations. Topographical organization of the effective area in the cingular gyrus and the relation between the electrical responses and stimulation parameters are studied.

[Neurophysiopathological hypothesis on startle epilepsy in man]

Clinical observation and S.E.E.G. recordings performed with a surgical purpose in a typical case of startle-epilepsy has led to a reassessment of the relationship of this form of epilepsy and "Startle reaction". It is confirmed that the critical discharges take origin in the primary motor cortex. The authors discuss, in the light of experimental data already published, the physiopathological hypotheses likely to lead to a better understanding of startle epilepsy. On the one hand it is suggested that the startle reaction may be responsible through a feed-back mechanism for triggering the epileptogenic focus. On the other hand it is assumed that afferent pathways, central organization and efferent systems involved in startle reaction and actual fits are different.