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Biomedical subjects

C Munari

Publications and source records attributed to C Munari.

At least 73 records · Page 4Linked to original sources
PubMed1987

Stereotactic aspiration of colloid cysts of the third ventricle. Preliminary report.

From January, 1979, to July, 1986, 10 patients (6 females, 4 males; 12-59 years, mean 37) with colloid cysts of the third ventricle were treated by stereotactic aspiration (Talairach's method). Five cysts have been completely aspirated. The mean residual volume of the other 5 was 19% of the initial volume. Clinical symptoms completely cleared in all but one patient. The advantages of the procedure are discussed.

Adolescent↗
PubMed1987

[Value of bifocal stereotaxic destruction in case of dyskinesia in patients with a motor deficit of cerebral origin].

Authors report a study concerning 12 dyskinetic patients with cerebral palsy. The clinical pre-operative examination shows that many signs and symptoms are associated: volitional and postural dyskinesia, athetosis and dystonia, pyramidal deficit and spasticity. Talairach's stereotactic methodology has been used for bifocal (VPL thalamic nucleus and internal pallidum) Yttrium 90 implantation. After stereotactic bifocal lesions, involuntary movements have been reduced in 45.5% of cases and have disappeared in 27% of cases. Impairment of previous motor deficit has been observed in 3% of cases; volitional and postural dyskinesia seems to be the most curable symptomatology. Clinical results in athetoid involuntary movements and dystonia are less rewarding. Because of important anatomical modifications often observed cerebral palsy patients, the authors stress the interest of individual acute neurophysiological study and discuss about the stereotactic targets and the modalities of destruction. They insist upon the necessity of rigorous selection of indications based on acute clinical examination in the perspective of improvement of global functional capacities.

Adolescent↗
PubMed1986

Alterations of GABA-mediated synaptic transmission in human epilepsy.

Although animal models consistently indicate that gamma-amino-butyric acid (GABA) synaptic function (GABA levels, synthesis, uptake and/or receptors) is decreased in seizure states, there is little evidence to date in support of such a hypothesis for human epilepsy. This chapter presents the results of an in-depth study of the activity of the GABA-synthesizing enzyme L-glutamic acid decarboxylase (GAD) in brain tissue removed during neurosurgical resection for intractable epilepsy. The tissue studied is unique in that identified (by stereo EEG) foci were excised (rather than large blocks of tissue containing mixtures of foci and nonepileptic material) and compared with nonepileptic (stereo EEG and morphological definitions) tissue from the same patients. In patients in which there was no indication of a tumor, GAD activity in the foci was low in more than 50% of the patients examined. Furthermore, when the population distribution of GAD was compared in epileptic versus nonepileptic tissue fragments from all patients, the peak distribution of epileptic tissue fragments occurred at much lower GAD activities than for the nonepileptic fragments (0-20 versus 41-80 nmol CO2/mg protein X hr, respectively). A small subgroup of epileptic fragments occurred with a normal GAD distribution, indicating that the presence of an epileptic focus was not invariably associated with low GAD activity. When the low levels of GABA "A" binding sites in these epileptic tissue fragments are taken into consideration in combination with the low GAD levels, then it can be estimated that 60 to 70% of the present patient population had deficient GABAergic transmission in epileptic foci as compared to nonepileptic brain tissue from the same patients. It follows that the GABA hypothesis of human epilepsy is not an exclusive or unitary hypothesis, and some patients appear to have normally functioning GABA synapses (as assessed biochemically) in epileptogenic areas. Thus, other neurotransmitter and neurohumoral systems certainly play a role in the epileptic process.

Animals↗
PubMed1985

[Electro-clinical semiology of subintrant temporal lobe seizures].

The authors recorded 10 to 67 TLS (mean 29) in 10 patients (5 M, 5 F; 9 to 41 years, mean 23) during 'acute' (4-6 hours) stereo-EEG exploration. At the onset of seizures, we observed: subjective manifestations (often epigastric), autonomic symptoms, and oro-alimentary 'automatisms'. Affective, unpleasant, manifestations occurred in only 2 patients. The discharges may only affect the Ammon's horn, but they never involve only the amygdala. There is a strong relationship between the duration of the discharge, the number of cerebral structures (temporal and, later, extratemporal) involved in the discharge, and the clinical symptomatology. Somatomotor lateralized manifestations, and gestural 'automatisms' only occur when the discharges spread to extratemporal cerebral structures. The secondary generalizations are very rare and are also linked to a large extratemporal spread of the discharge.

Adolescent↗
PubMed1985

Cryptic vascular malformations diagnosed by stereotactic biopsies--a preliminary study.

A series of 14 cryptic vascular malformations (CVM) deeply situated or localized in functional cortical areas were diagnosed by serial stereotactic biopsies. No history was suggestive of hemorrhage, despite a substantial hematoma being evacuated during biopsy procedures in 4 patients. Retrospectively, CVM without hematoma were found to have certain characteristics that should raise the suspicion as to the correct diagnosis. At the time of discharge from the hospital, only 1 patient had mild aggravation of a preexisting motor deficit, which further improved. Serial stereotactic biopsies provided the required histological diagnosis with relatively low risk.

Adolescent↗
PubMed1985

Correlation between stereo-EEG, CT-scan and stereotactic biopsy data in epileptic patients with low-grade gliomas.

Stereo-EEG activity, which was recorded precisely from the same location as stereotactic biopsies, was studied on 11 patients with low-grade glioma and severe partial epilepsy. The volume of the lesions varied from 6 to 72 cm3 (mean 23 cm3). A very depressed activity was recorded in all the 25 specimens of solid tumor and in more than half of infiltrated white matter. The background activity was still conserved in all 'normal' fragments, while it is never found in solid tumor; sometimes it could be found in the infiltrating tumors of white or gray matter. High voltage theta and delta activity was recorded in neither 'normal' nor solid tumors. We emphasize the importance of considering the stage of evolution when we evaluate the significance of the stereo-EEG activity.

Adolescent↗
PubMed1985

[Stereotaxic treatment of expanding cysts in craniopharyngiomas by endocavitary beta-irradiation (Re-186; Au-198; Y-90)].

The authors report the results of 17 intracystic injection of colloidal 186 rhenium, 2 colloidal 198 gold, and 1 colloidal 90 yttrium for endocavitary treatment of 18 cystic craniopharyngiomas (16 pts during a period ranging from January 1975 till July 1982. Follow-up studies ranging from 12 to 72 months (m: 36 m) revealed that all craniopharyngiomas cysts were effectively treated with cessation of fluid formation, progressive shrinkage of the formerly expansive cysts, and finally cyst obliteration in 75% of the cases. No early or late side-effects were observed during the entire observation period. Late reexpansion of one craniopharyngioma cyst, observed at 11 months, was successfully treated by a second injection. Leakage of colloid isotope into the CSF spaces during the "test" or "therapeutic" injections occurred in 18% of the global number of injections, however no clinical complications were observed. On the basis of a clinical dosimetric study a 30 000 rads wall-dose, not exceeding 40 000 rads is actually considered as the safer dose for endocavitary treatment of craniopharyngioma.

Adolescent↗
PubMed1984

Somatomotor manifestations in temporal lobe seizures.

Some authors include somatomotor manifestations (SMM) among the clinical features of temporal lobe seizures in man; however, data are limited and conflicting. This study describes 101 seizures recorded during stereo-EEG explorations in 50 patients, selected on the basis of the demonstration of onset in temporal lobe structures (stereo-EEG) and the presence of lateralized SMM and/or secondary generalization (SG). SMM and SG were present in about 20% of our population of patients with temporal seizures explored with stereo-EEG, and were only rarely observed during the first 10 s (early SMM) of the seizures (less than 10%). Seizures characterized by early SMM were generally induced by electrical stimulation or chemical activation and only exceptionally spontaneous. In all cases the ictal electrical discharge also involved at an early stage extratemporal structures such as the rolandic operculum, the parietal lobe, or contralateral temporal structures. In most cases (greater than 90%) SMM represented a late (greater than 10 s) event in the ictal symptomatology. The face and the upper limb were by far the most frequently involved segments. Thirty-eight percent of seizures ended up in SG. The associated ictal symptomatology was rather poor and differed from our previous findings in temporal lobe seizures: oroalimentary automatisms were relatively rare, whereas an impairment of consciousness was observed in more than 50% of seizures. The critical electrical discharge had a long duration and always involved extratemporal structures in one or both hemispheres. The involvement of the central region could be demonstrated in all patients with deep electrodes in that region. In conclusion, SMM are not characteristic of temporal lobe seizures, and their presence indicates spreading of the critical discharge beyond the temporal lobe.

Adolescent↗
PubMed1983

Brain regional pharmacokinetics of 11C-labeled diphenylhydantoin: positron emission tomography in humans.

We used positron emission tomography to study the regional cerebral pharmacokinetics of 11C-labeled diphenylhydantoin (11C-DPH), which was given intravenously to 10 patients (8 intractable partial epileptics and 2 nonepileptics). In the nonaffected hemisphere, 11C-DPH concentration in gray matter reached equilibrium with blood within 20 minutes but was still rising at 60 minutes in white matter, where equilibrium was too slow to be detected owing to the fast physical decay of 11C. Brain-blood concentration ratios at 50 minutes were 1.37 and 1.06 in gray and white matter, respectively, similar but less variable than steady-state DPH ratios reported in human brain surgical samples. There was no indication that normal brain regions of medically resistant epileptics bind DPH less effectively than in nonepileptic patients. Brain and blood 11C-DPH concentrations were well correlated, confirming that the latter gives a reliable estimate of the former in unaffected brain regions.

Adolescent↗
PubMed1983

Indications for the use of gamma-aminobutyric acid (GABA)-agonists in convulsant disorders.

From studies using pharmacological models of convulsive disorders and also from the neurochemical analysis of epileptogenic tissue removed during neurosurgical resection (cortectomy), there is strong evidence that at least a subgroup of epileptic disorders may be linked (among other things) to a deficit in GABAergic neurotransmissions. This deficit may be found at the level of GABA synthesis or at the GABA-recognition site; whether these GABA neurons are lost or are dysfunctional is not yet answered. This suggests that GABA-agonists will be of potential use in epilepsy. GABA-agonists (progabide, SL 75102, muscimol, THIP) for the classical GABA-recognition sites as well as other compounds active at sites in the GABA-receptor macromolecular complex (eg, diazepam and phenobarbital) exhibit a wide range of anticonvulsant effects in different animal models and species. However, for some of these compounds (eg, muscimol) secondary central effects occur at the same dose level as the anticonvulsant actions, and for others (eg, THIP) such secondary effects may limit the use to certain types of seizures. This problem may be related to the high affinity of such compounds for the GABA recognition site as compounds with a more moderate affinity (eg, progabide, SL 75102) have a wider margin between anticonvulsant and secondary central effects in rodents. Clinical results using progabide suggests that the GABA hypothesis of convulsive disorders has indeed a rational foundation as a significant percent of refractory or unresponsive epileptic patients with different types of seizures (eg, complex partial or primary generalized) have a significant clinical improvement with this GABA-agonist.

Animals↗
PubMed1982

[Cerebral concentrations of anticonvulsants in patients with epilepsy of tumoral origin (author's transl)].

(1) The concentrations of various anticonvulsants (PB, PHT, CBZ, VPA) were measured in brain specimens from 7 patients who had undergone neurosurgery for a therapy resistant epilepsy of tumoral origin (astrocytoma) in 6 cases, glioblastoma in 1 case). (2) Great interindividual variability of the mean brain/plasma concentration ratios was observed for PB in 5 patients (range: 0.4-1.0). A mean brain/plasma ratio of 1.0 was recorded for PHT and CBZ (one patient each). (3) In the different tissue specimens (7-14) from the same patient AED concentrations varied greatly, even in neighboring areas. (4) Intraindividual variations were more marked in the present group of patients than in previously studied non-tumoral epileptics. (5) No correlation was found between the localization of the lesions and the variations in AED concentrations. (6) Brain AED concentration appeared to be higher in the few samples of non-tumoral tissue and lower in the 'epileptogenic' areas as defined by stereo-EEG seconding. (7) On the basis of these data, the hypothesis can be formulated that the therapy resistance of these patients may be at least partly explained by the presence of low AED concentration (even in presence of 'therapeutic' AED plasma levels) in the epileptogenic areas.

Adolescent↗
PubMed1982

[Motor and postural manifestations of temporal lobe epilepsy seizure].

This study reports on 73 epileptic seizures (in 36 patients) originating in the temporal lobe (stereo-EEG) presenting motor or postural signs. Motor symptoms occur rarely in the early phase of seizures (less than 10% of our series) and they are exceptional during spontaneous seizures. The critical electrical discharge always affects extra-temporal structures such as the rolandic operculum, the cingulate gyrus, etc. The occurrence of motor symptoms during the late phase of seizures is associated with a long duration of the critical discharge and, again, with the involvement of extra-temporal structures. The characteristics of the associated clinical signs (e.g., frequent loss of contact with the environment, relatively rare oroalimentary automatic activities), together with the high frequency of secondary 'generalizations' are consistent with the stereo-EEG findings and indicate that these seizures also affect extra-temporal regions.

Adolescent↗
PubMed1980

[Althesin in the treatment of status epilepticus].

In view of its anticonvulsant effects in the experimental animal, its low toxicity, and its manageability, Althesin was used at doses of 80-600 mg in the treatment of barbiturate and benzodiazepine resistant epilepsy in 11 patients aged 15 months to 62 yr. Lasting suspension of the disease was obtained in 8 subjects. Burst suppression was achieved in 7 of these cases with 80-120 drops/min of a 10% solution of Althesin in 10% laevulose. No side-effects were observed.

Adolescent↗