Influence of geomedical factors on Guillain-Barré syndrome incidence in the region of western Slovakia.

During 5-years of follow-up we identified 58 cases of the Guillain-Barré syndrome in the Western Slovakia (approximately 1,300,000 inhabitants). The incidence of this disease fluctuated between 0.4-1.

[The relation of speech to the right and left cerebral hemispheres].

Verbal speech functions are localized in right-handed subjects nearly exclusively and in left-handed ones mostly in the left hemisphere. Much information on these functions has been obtained by studying patients affected with spontaneous damages, as well as after hemispherectomy, after severing the corpus callosum, and during electric stimulation of the brain in neurosurgical procedures. In the presylvian region of the hemisphere dominant for speech, a region for the production and identification of speech was found, surrounded by an area for shortterm verbal memory.

[Interaction of the cerebral hemispheres in relation to their functional asymmetry].

Neurophysiological and neuropsychological methods are used to investigate the influence of one hemisphere on the activity of the other one. The findings concern contralateral motor irradiation, mirror movements and contralateral transmission of evoked potentials. At transcallosal transmission of information both quality and quantity of the information as well as the functional specification of the hemispheres is called into play.

[Left-handedness and its clinical significance].

The occurrence rate of lefthanded persons is estimated to range between 4-8% in the human population, according to the criteria used. On assessing pathological lefthandedness, the role of all factors affecting the development of a lefthanded subject has to be considered. There are morphological differences between left- and righthanded subjects.

[Relation of functional hemisphere asymmetry to motor performance].

Motor prevalence of one upper extremity can be quantitatively expressed by the ratio of the number of performances carried out by one and the other extremity. One-sided prevalence is most markedly manifested at differentiated performances of the distal part of the extremity which require graded rapid changes of position. The competence of the left hemisphere for sequential analysis is presumably the basis of motor prevalence in right-handed persons.