Biomedical subjects
Publications and source records attributed to M Sramka.
This paper discusses the transformation of computed tomography (CT) and magnetic resonance (MR) images, which maps the stereotactic volumetric cube of one examination to another. There are some mathematical problems connected with the present method. This approach provides a better visual detection and localization of the target point for the neurosurgeon or radiologist.
In Huntington's chorea, embryonal brain tissue (striatum) was implanted in the caudate nucleus bilaterally, using stereotaxy assisted by CT. A special cannula allowed the placement into the brain of 3 or 4 grafts of embryonal tissue along the determined trajectory by one introduction of the cannula. The pathophysiological mechanism of neurotransplantation in Huntington's chorea is to compensate for the degenerated striatal tissue by embryonal striatum, so it is necessary to supply a quantity of embryonal striatal tissue which enables the whole functional integrity. Therefore, we use material from several embryos.
Long-term results (5-20 years) recorded in 304 patients operated on stereotactically for psychopathologic disorders are presented. The largest group of 260 surgically treated subjects represented aggressive patients. This group consisted of 150 patients with mental retardation, 70 with epilepsy, 20 with schizophrenia, and 20 patients with sexual deviations. Amygdalectomy for patients with normal intellect and posterior hypothalamotomy for those with reduced intellect proved to be the most effective procedure. Symmetrical operations were also effective. In some cases a combination of two target was necessary. In epileptics with aggressivity the combination of amygdalectomy and hippocampectomy yielded the best results. In aggressivity with sexual deviations anterior hypothalamotomy was the most effective operation. Favorable results in aggressivity therapy were recorded in 60% of patients. In patients with criminal sexual deviations, in drug addicts, and in alcoholics, anterior hypothalamotomy was found to be most effective, with favorable results in 50% of patients. In patients with depression, thalamotomy or stimulation of the limbic regions of the thalamus decreased the depression, with favorable results recorded in 66% of patients. The results of the surgically treated patients show that target-oriented stereotactic operations remove psychopathologic symptoms, improve the effectiveness of psychoactive drugs and the social adaptability of patients. (Ref. 15.)
Therapeutic brain stimulation was applied in 74 patients with resistant forms of epilepsy. It was shown that low frequency stimulation of certain zones of the head of the caudate nucleus and higher frequency stimulation of the dentate nucleus of the cerebellum lead to a marked suppression of interparoxysmal epileptic activity and to a disruption of both focal and generalized epileptic discharges. It is necessary to determine, by means of stereo-electroencephalography, the variability for localizing the inhibitory zones of the structures to implant the neurostimulators exactly.
The paper describes pathophysiological mechanisms and analyzes the results of surgical treatment of severe forms of drug-resistant generalized epilepsy in 150 patients who underwent surgery at the departments of stereotactic and functional neurosurgery in Tbilisi and Bratislava. The epileptic system of all patients was localized stereoelectroencephalographically (SEEG) by recording spontaneous activity or evoked aparoxysms. SEEG examination indicate that pacemakers of epileptic activity are most frequently localized in the mediobasal structures of the temporal lobes. The long-term results of stereotactic treatment of generalized forms of epilepsy show recovery in 50% of patients and marked improvement in 30%. An individually determined strategy of surgical procedures is the main principle of surgical treatment of severe drug-resistant forms of epilepsy. Depending on indications it can include resection of the cortex or lobes of the brain, single or repeated stereotactic destructions of the pacemaker structures of the epileptic system and the pathways of spread of the spasm discharge, as well as therapeutic electrostimulation of the brain inhibitory systems.
Herpes simplex virus (HSV) DNA was found by spot blot hybridization in the right nc. amygdalae of 3 out 10 patients who underwent curative stereotactic surgery for severe mental retardation with aggressive behavior and/or paranoic schizophrenia. Of these, 6 were also tested for the presence of CMV DNA sequences with negative results. Biopsy specimens from nc. amygdalae of another 7 psychotic patients were cultured in vitro but no virus was isolated.
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Therapeutic electrical stimulation of nucleus caudatus was performed in 26 patients suffering from epilepsy. Sixteen of them had previously undergone destructive stereotactic surgery in different deep brain structures and the stimulation was indicated as an additional procedure. The results reported are related to 10 patients stimulated without any other surgical treatment. In 3 subjects stimulation of temporal lobe structures was performed as well. Good therapeutic effects were obtained in 2 cases following caudate stimulation. Mild improvement or no effect were obtained in the other cases, including the two submitted to hippocampal stimulation. Interesting speculation on the relationships between caudate and hippocampal electrical activity have been generated.
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For frequently associated spasticity with involuntary movements in cerebral palsy operations on cerebellar nuclei or on the pulvinar of the thalamus are recommended. We combined both approaches in 45 patients. The combination was possible after experiences with transtentorial dentatotomy, in which the electrodes are introduced into the deep structures of the cerebellum from a burr-hole on the lambdoid suture. The same lambdoid approach may equally well be applied for introducing electrodes into the pulvinar of the thalamus. The lesion in the pulvinar may moreover be combined with the target in the centrum medianum or in the nuclei VIM-VCP or VOP. Lesions are always asymmetric and multilocular. Their influence on the clinical picture is quite favourable.
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