[Intracranial pressure increase and changes in cerebrovascular circulation, associated with brain death, studied by transcranial Doppler sonography]. / Koponyaüri nyomásfokozódást és agyhalált kísérö agyi véráramlás változások vizsgálata transcranialis Doppler szonográfiával.

Blood flow velocity of 24 patients in state of the brain death were examined by transcranial Doppler sonography. Authors expound the characteristic velocity-pulse graphs recorded in progressively increasing intracranial pressure and their chronology as well. The different forms of the oscillating flow and their successive development are described. The oscillating flow, the systolic spikes and the so called "zero Flow" are the transcranial Doppler signs of the ceased cerebral blood flow, and these signs can be used as one of the evidence of the brain death.

[Transcranial Doppler sonography, a new non-invasive method for the study of cerebrovascular circulation]. / Transcranialis Doppler-szonográfia, új, nem invazív modszer az agy vérkeringésének vizsgálatára.

Transcranial Doppler Sonography. Authors publish the experiences gained by 2300 examinations with Transcranial Doppler Sonography (TDS) which is a new, noninvasive ultrasound method to examine cerebral blood flow velocity in the basal arteries. The theoretical ground and the technique of the investigation is detailed. Mean values of blood flow velocity in the middle cerebral artery of 88 healthy volunteers in different age groups are reported. Authors stress on the numerous advantages of the utilization of this technique. Different pathological alterations of blood flow velocity and characteristic types of velocity-pulse figure are accounted. At last illustrative case reports proving the importance of TDS in different pathological states are presented.

Vasospasm after head injury studied by transcranial Doppler sonography.

During the past 2 years cerebral blood flow velocity was measured serially first of all in the middle cerebral arteries and in the bifurcation of the carotid arteries, less frequently in the other basal arteries by transcranial Doppler sonography in 36 head injured patients selected from 87 cerebral contusions and intracranial haematomas. Raised flow velocity referring to cerebral vasospasm was observed in 14 (40%) of 36 cases. Vasospasm developed between the 2nd and 8th days in the basal arteries, never on the first day. It was classified as slight (over 120 cm/sec) and sever (over 160 cm/sec) in the case of vasospasm lasting for several days. Development of vasospasm could be justified in 6 from 14 control angiographies. Authors' observations are compared with some literary data of traumatic vasospasm. The theoretical significance and practical usefulness of transcranial Doppler sonography in the study and follow up of the blood flow of the injured brain, especially in traumatic vasospasm, are emphasized.

Intra- and suprasellar tumours: surgical results.

Experience gained with the operation of 108 intra- and suprasellar tumours and the results of the surgical intervention are presented. The transcranial -- subfrontal approach of hypophyseal tumours offers today a circumspect and, in a considerable part of the cases, radical solution. Intratracheal anaesthesia eliminates the surgical risk and radiotherapy prevents relapse. The situation is not quite as unambiguous in the case of craniopharyngeomas and optic tumours. Of the rare varieties, ependymoma and angioblastoma, of the frequent varieties tuberculum sellae meningioma and dermoids, have a promising prospect. Depending upon the mode of appearance, the prognosis of cysticercus and of ectopic pinealoma can be favourable or unfavourable. Since in every case the main task is to save the vision, the result will therefore depend upon early diagnosis.

Planum sphenoidale meningioma. Attachment and blood supply.

By reviewing clinical and radiological data and surgical findings of 35 so-called "olfactory groove meningioma" cases, the authors conclude that this is not a homogenous group. According to the attachment and blood supply they differentiate two varieties, the planum sphenoidale meningioma (PM) and the olfactory meningioma (OM). It seems possible to distinguish both groups clinically and with regard to the localization of hyperostosis and pneumencephalographic and angiographic findings.

Effects of stereotactic lesions in intractable epilepsy.

The eras of surgical treatment of epilepsy are described and experience with the epilepsy operations, especially those obtained in the course of temporal epilepsy operations, and stereotactic attempts based on multielectrode EEG investigations, and ES. Classical, exposure and resection still seems adequate whilst stereotaxy develops in the selective elimination of the structure activating the coded seizure-pattern.

Stereotactic diagnosis of epilepsy by electrical stimulation.

The effects and role of electrostimulation have been studied in 44 acute stereo-EEG explorations. Analysis of the stimulus threshold and of the clinical and electrical responses allows to separate the epileptogenic, the irritative, the "physiologically" reacting and the actually "silent" areas of the epileptic brain. Electrical stimulation is a valuable diagnostic method to reveal the focality, the multiplicity and the degree of the seizure disposition in epilepsy.

Surgical and stereotactic attempts in intractable epilepsy.

The eras of surgical treatment of epilepsy, and experience with operations for epilepsy, especially those for temporal epilepsy, and stereotactic attempts based on depth multilead electrodes investigations and electro stimulation are described. Classical exposure and focus resection seems adequate whilst stereotaxy ought to be improved for the selective elimination of target structure activating the coded seizure pattern.

The value of electrostimulation in epileptic focus localization.

The ES is a non-physiological stimulus of the brain. However it represents an important and indispensable part of stero-EEG investigation since it is an easily adjustable method, capable of inducing typical electro-clinical seizures. From the clinical and electrical responses elicited by ES and from the data of the stimulation tresh-old, we are in agreement with other authors, we feel we can also distinguish several different reacting zones in the epileptic brain: 1. The epileptogenic zone from which the complete or almost complete electro-clinical seizure is reproducible immediately by ES or with short latency. These pathological responses show the severe dysfunction of the given structures. 2. The irritative zones from which seizure elements can be evoked, but the complete electro-clinical seizure does not. "Physiological" clinical responses can also be elicited, but by a very low threshold stimulus pointing to the pathological excitability of this zone. 3. The area reacting to "normal" stimulus threshold with a physiological response. 4. The silent area without any electro-clinical response in the functional state of the nervous system. One of the practical values of ES is that makes possible to separate these zones from each other in a given patient within certain limits, and it may help to reveal the localization, the multiplicity and the degree of the "seizure disposition" in epilepsy.

Experiences with radically operated acoustic tumours.

A series of one hundred acoustic tumours submitted to radical operation is reviewed. The authors emphasize the possibilities of early correct diagnosis without contrast studies, draw attention to variations in nature and site of the tumour, and evaluate preservation of the facial nerve.