[Visual evoked potentials in disorders of the cerebral circulation].

Visual evoked potentials were analysed in 15 patients before and after operations performed in the acute and cold periods of rupture of cerebral aneurysms. The analysis made it possible to identify the regions of the disturbed latency and shape of the potentials. The location of the aneurysm determines the site of the region of impairment of the visual evoked potentials, whose area correlates with the severity of the patients' condition in the acute period.

[Prophylaxis of brain edema in neurosurgical operations].

Rational surgical approaches providing for preservation of the arteries and veins of the brain and minimal mechanical damage to it during the removal of tumors, the use of adequate anesthesia which prevents the development of vegetative reactions of central origin, and postoperative correction of the patients' condition under clinical and physiological control allow the development of cerebral edema to be prevented. Experience in the management of 1,447 patients with intracranial, mainly extracerebral, tumors showed that postoperative lethality can be reduced from 27.0 to 4.

[Approach to tumors of the chiasm-sellar region with preservation of the olfactory tracts].

Mobilization of the olfactory tract in mono- and bifrontal approach to the chiasmal-sellar region with preservation of its own vascular network down to the olfactory trigone on the side of the approach and for a distance of 20 mm from the other side creates adequate conditions for the operation. According to the EEG values, the degree of the operative trauma does not increase essentially and the prognosis of vision restoration is no worse. The olfactory function is restored immediately after surgery in most cases.

[Role of the EEG in predicting the outcome of craniocerebral injuries].

The severity of the patient's clinical condition and the outcome of craniocerebral trauma are determined by the state of the brain stem structures which are irritated as the result of the injury; this is reflected in the development of the corresponding clinical syndromes and EEG changes. On comparison of the results of clinico-neurological and electroencephalographic evaluation of the function of the stem structures, 3 prognostically unfavourable criteria of the outcome of a severe craniocerebral trauma are described. The obtained data can be used for earlier detection of coarse affections of the brain stem and the application of opportune pathogenetic treatment.

[Dynamics of the bioelectrical activity of the brain in patients with intrasellar pituitary adenomas irradiated with a proton beam].

Sixty patients with pituitary endosellar adenomas irradiated with the proton beam were examined using EEG prior to and following irradiation in the period ranging from 14 days to 3 years. Fourteen days to three months after the proton irradiation, intensified irritation of the diencephalic structures was recorded. Later on, gradual normalization of bioelectrical activity was observed.

[Electroencephalographic signs of a pathologic process in the area of the cerebellopontine angle].

Electroencephalographic examination of patients with giant neurinomas of the auditory nerve treated with diazepam and sombrevin in the preoperative period was effective in specifying definite signs, making it possible, on the basis of the EEG findings, to localize the pathological process at the level of the posterior cranial fossa and to establish its predominant impact on the structures of the posterior cranial fossa. The electroencephalographic data obtained from these patients under electrophysiological control during surgery correlated with the changes in the EEG pattern found in the preoperative period. As a result of the examination carried out, a totality of indices were specified, enabling the localization of the pathological process at the level of the posterior cranial fossa.

[Clinico-physiologic evaluation of the viability of the brain as an organ in segmental lesions of the brain stem].

Segmental lesions of the brain stem with the dissociation syndrome may prevail in the clinical picture of the disease in neurosurgical patients with total cerebral hypoxia as well as with primary or secondary local lesions of the stem. Coarse segmental lesions of the stem, which are often not associated with total affection of the brain, lead to death of the brain as an organ in functionally preserved structures above and below the level of dissociation.

[Bioelectrical activity of the brain in patients with craniocerebral injuries and irritation of brain stem structures].

Affection of the stem structures in craniocerebral injury causes their irritation at different levels and of different degree, which determines the severity of the patient's clinical condition with the corresponding EEG changes. Irritation of a high degree induces functional block of the stem structures which hinders the clinical and EEG manifestations of the local symptoms. The therapeutic measures should be aimed at removing the causes of brain stem affection and at reducing the degree of irritation of the median structures.

[Neurologic and electroencephalographic evaluations after a single irradiation of pituitary adenomas with protons having 1000 MeV of energy].

The brain was examined (on the basis of neurological and electroencephalographic findings) in 43 patients with hypophysis adenomas both before and at various intervals after a single exposure of the tumour to protons with an energy of 1,000 MeV. The irradiation was performed by the stereotaxic convergent method. The radiation dose absorbed by the tumour was 100 Gy.

[Clinico-electroencephalographic characteristics of the condition of brain stem systems following surgical and non-surgical brain injury].

The paper is concerned with a study of the stem structures in 186 patients during and following a removal of brain tumors and in 42 patients with acute brain traumas. A correlation of the EEG, the clinical picture and action of the central adreno- and cholinolytics and adrenomimetics demonstrated that in acute influences on the stem it is always in an irritative state. A significant degree of stem structures irritation during its direct affection is accompanied by an appearance in the EEG of synchronized low forms of fluctuations and clinical symptoms of vegetative hyperergia.