Intraoperative monitoring of the motor pathway using transtracheal stimulation of the cervical spine in dogs.

Although SEP monitoring of the spinal cord has been a well established method recently, not an ultimate, perfectly developed technique for monitoring of the motor system is known so far, particularly, because of the disturbing effect of narcotic drugs and relaxants on the motor evoked potentials. In this study the upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed to the cervical spinous processes. Single and serial stimuli were applied.

Multimodal electrophysiological examinations in patients suffering from various tumors of the pineal region.

Multimodal electrophysiological examinations: blink-, glabella- and masseter-reflexes, as well as brain stem acoustic, somatosensory and visual evoked potentials were examined in thirteen patients with clear consciousness suffering from extra-axial, chronic, expanding processes in the tectal region. According to the data, the authors came to the conclusion that several modalities were often required to make a correct diagnosis or to the localization of the space occupying processes. Functional disturbances of the whole of the lower brain stem, but especially of the mesencephalon and of the lower pons were found in cases of expanding processes surrounding the tectum.

Correlation between central somatosensory conduction time, blood flow velocity, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

In this retrospective study of 67 aneurysmal patients, the predictive role of central conduction time (CCT) on vasospasm occurrence evaluated by means of transcranial Doppler sonography (TCD) and the correlation of CCT to blood flow velocity measured simultaneously in postoperative course were studied. Data about the clinical state of patients at the time of admission (Hunt Hess scale), severity of subarachnoidal hemorrhage on initial CT scan (Fisher grade), timing of surgery (acute or delayed), outcome (Glasgow Outcome Scale), severity of vasospasm graded by highest mean blood flow velocity (BFV) during the entire clinical course and CCT values measured at admission (preoperatively), then postoperatively (one day after surgery) and simultaneously with later TCD investigations were collected from the files. Interhemispheric difference of CCT was also calculated.

Organization of the ambiguus nucleus in the frog (Rana esculenta).

The common root of the glossopharyngeal, vagal, and accessory nerves and the individual branches of the vagus complex were labeled with cobalt, and the organization of the ambiguus nucleus was studied. The cell column labeled through the common root extended from the upper part of the medulla to the rostral spinal cord over a distance of about 3,500 microns. The labeling of individual branches revealed four subdivisions.

Segmentation of 2-D and 3-D objects from MRI volume data using constrained elastic deformations of flexible Fourier contour and surface models.

This paper describes a new model-based segmentation technique combining desirable properties of physical models (snakes), shape representation by Fourier parametrization, and modelling of natural shape variability. Flexible parametric shape models are represented by a parameter vector describing the mean contour and by a set of eigenmodes of the parameters characterizing the shape variation. Usually the segmentation process is divided into an initial placement of the mean model and an elastic deformation restricted to the model variability.

Examinations of the motor conduction time between the motor cortex and the Erb point in patients suffering from tumors of the central nervous system.

The cortical latency and the motor conduction time between the motor cortex and the Erb point were investigated in 85 patients with intracranial and in 9 patients with space-occupying spinal tumors. Electrophysiological examinations revealed pathological changes in 19% of intracranial events, and in 100% of cases of spinal tumors. In these latter cases close correlation was registered between the motor evoked potentials and the clinical symptoms of the patients.

Investigation of the dendritic geometry of brain stem motoneurons with different functions using multivariant statistical techniques in the frog.

We give an account of an effort to make quantitative morphological distinctions between motoneurons innervating functionally different muscles in the trigeminal and facial motor nuclei of the frog. Six groups of neurons were considered in the two nuclei on the basis of their peripheral targets. One group consisted of neurons (n = 7) innervating the levator bulbi muscle, which separates the orbital cavity from the oral cavity.

[Albers-Schönberg disease].

The authors while describing their patients suffering from osteopetrosis disease, discuss its morphological aspects and possible patho-mechanism. The disease with osteosclerosis can be inherited recessively or dominantly. The recessively inherited type is less frequent and leads to early death due to secondary developing myelofibrosis.

Multimodality electroneurophysiological findings in intra-axial and extra-axial lesions of the brain stem.

In 330 patients with a space occupying lesion of the posterior cranial fossa, the blink (BR) and masseter (MR) reflexes and brain stem auditory (BAEP) and somatosensory evoked potentials (SEP) were registered. The aim of our study was to look for electrophysiological criteria of differentiating between lesions within or outside the brain stem. The ipsilateral loss of BAEP in cerebellopontine angle tumours and the altered SEP in tumours within the brain stem turned out as frequent, almost specific findings.

[Ultrasonographic examination of the circulation in the hepatic vein in diffuse liver diseases].

Unlabelled: 59 patients suffering from diffuse liver lesion and 28 healthy individuals had undergone duplex ultrasound examination of the hepatic vein circulation. Three time-velocity spectra had been noticed and later divided into three groups: 1. Normal (triphasic) spectrum.

Comparative anatomy of cranial nerve motor nuclei: with a comment on evolution of the craniofacial region.

Changes of cranial nerve nuclei are investigated at three crucial points of phylogenesis in frogs, lizards and rats. Profound changes can be observed in the trigeminal and facial motor nuclei parallel to transformation of the primary mandibular joint into the secondary mandibular joint. New muscles appear for mastication and facial expression and they are innervated by new types of neurons.

Mesencephalic projections of the cochlear nucleus in the frog, Rana esculenta.

The lectin Phaseolus vulgaris leucoagglutinin was injected into chochlear nucleus in order to study the trajectory and projections of the auditory pathway in the frog. A strong contralateral and a weak ipsilateral fiber bundle representing the lemniscus lateralis could be followed to the torus semicircularis. The following areas of termination could be discerned in the mesencephalon: (1) Each of the five subnuclei of the torus semicircularis received fibers from the cochlear nucleus, the largest number of fibers terminated in the principal nucleus.

The efferent system of cranial nerve nuclei: a comparative neuromorphological study.

A number of inconsistencies and controversies are inherent in the classification of cranial nerve nuclei based on the concepts of the various head-theories. The assumption of head segmentation, which is common to these theories, serves as the basis for designating the dorsomedial nuclei as the somatomotor column, although they innervate striated muscles of a viscus and a specific sense organ. The ventrolateral nuclei are called the specific visceromotor column; they innervate striated muscles in the branchiogenous area, but many of these muscles insert on skeletal elements.

Simulation of the Effect of Synapses: the Significance of the Dendritic Diameter in Impulse Propagation.

The effectiveness of synapses at various sites of the dendritic tree was studied using a segmental cable model with a program developed by Hines (Int. J. Biomed.

The Extent of the Dendritic Tree and the Number of Synapses in the Frog Motoneuron.

Frog motoneurons were intracellularly labelled with cobaltic lysine in the brachial and the lumbar segments of the spinal cord, and the material was processed for light microscopy in serial sections. With the aid of the neuron reconstruction system NEUTRACE, the dendritic tree of neurons was reconstructed and the length and surface area of dendrites measured. The surface of somata was determined with the prolate - oblate average ellipsoid calculation.

Synapses on motoneuron dendrites in the brachial section of the frog spinal cord: a computer-aided electron microscopic study of cobalt-filled cells.

Cobalt-labelled motoneuron dendrites of the frog spinal cord at the level of the second spinal nerve were photographed in the electron microscope from long series of ultrathin sections. Three-dimensional computer reconstructions of 120 dendrite segments were analysed. The samples were taken from two locations: proximal to cell body and distal, as defined in a transverse plane of the spinal cord.

Postmarketing surveillance-one of the key issues in drug development.

The terms "postmarketing surveillance" or "human phase IV studies" are applied to all those examinations which are performed with a drug following its registration. The principles, methods of these examinations are discussed on the basis of international experiences. The authors also give some examples from Hungarian practice referring to this subject.

Effect of intravenous cimetidine, ranitidine and pentagastrin and intragastric prostaglandin E1 treatments on gastric transmucosal potential difference in the rat.

Effects of intravenous cimetidine, ranitidine and intragastric prostaglandin E1 (alprostadil) treatments on the transmucosal potential difference (PD) of the stomach were compared. It was also investigated whether the above-mentioned drugs influenced the decrease of PD which followed both intragastric administration of 30% alcohol or Ca++ solution in 5 Mm final concentration and intravenous administration of pentagastrin. Both cimetidine and ranitidine treatments led to significant (p < 0.

Recurrent dorsal root potentials and motoneuron morphology in the frog spinal cord.

About one third of motoneurons stimulated intracellularly evoked dorsal root potentials (DRP) in the lumbar segments of the isolated and perfused frog spinal cord. Axon collaterals were found in one of the 22 motoneurons filled with HRP (horseradish peroxidase) through the stimulating electrode. In further experiments injecting individual motoneurons with cobalt, and filling the ventral roots with HRP or cobalt, the frequency of occurrence of axon collaterals was about 2% of the number of labelled motor cells.

[Duplex ultrasonography of the portal circulation before and after sclerotherapy of esophageal varices].

Authors examined 40 patients suffered from portal hypertension before and after sclerotherapy of esophageal varices with duplex ultrasonography. The patients were divided into four groups: the first and recurrently bleeding patients and those who were treated with propranolol. The average velocity of the main portal vein before the treatment was significantly lower in the patient group, than in the normal control group.

Spatial distribution of pre- and postsynaptic sites of axon terminals in the dorsal horn of the frog spinal cord.

Axon terminals which could be interpreted as dorsal root boutons, were photographed from a series of 98 ultrathin sections with a Jeol 100B electron microscope. A total of 13 boutons were recovered for computer reconstruction. Two of them were terminal boutons, eight en passant boutons and three boutons were only partially recovered.