A new approach to testing of long-term resistance of the spine to mechanical stress.

This paper studies the movement of the cervical spine from a side-bending to a return to the neutral position. The importance of muscular and ligamentous elements of the spine are emphasized. Directions for future research are noted.

[Reaction of the cerebral vertebrae in imagined changes in the shape of the cervical spine]. / Reakce krcních obratlu na predstavované zmeny tvaru krcní pátere.

Postural reaction of the cervical vertebrae on imagined, but actually not performed changes in the shape of the cervical spine in the sagittal plane are described. The percentage of reacting vertebrae is relatively high. The findings seem to indicate, that 1.) the described phenomena belong to the constant features of the spinal dynamics, 2.) that there, probably, exist residual traces of preceding activities and 3. that these changes are due to the activation of the polymetameric system of the intrasegmental muscles.

Radiological diagnosis of developmental disorders of the nervous system and adjacent structures.

On the basis of the author's own experiences and drawing on data available in the literature, present possibilities of neuroradiological diagnosis of developmental disorders of the spine and skull, developmental anomalies of meninges of the brain and the spinal cord and of the central nervous system, the brain and the spinal cord are discussed. The rapid development of investigative methods in the past decades has brought about an immense amount of new information gained in the diagnosis of these anomalies and has facilitated their early detection and a more accurate evaluation. The morphological aspect is not, however, the only factor in the estimation of the clinical relevance of these disorders. For this reason not only the morphological, but also the functional relationship of developmental disorders of the nervous system to the adjacent structures is emphasized and, on the other hand, the influence of these anomalies on the nervous system is discussed. Many years' experiences in clinical neurology and problems of manual medicine indicate that these relations may be the cause of the various clinical symptoms. In this respect the presented findings mean a contribution to the treatment of the clinical complaints that are pathogenetically related to developmental disorders.

CT response of brain parenchyma to intravenous contrast injections.

Pre- and postcontrast scans of the same normal brain tissue layer were compared in 20 patients in order to evaluate postcontrast density response. The original purpose of this investigation was to explain a paradoxical phenomenon of density decrease, which has been regularly observed in our patients. Control phantom measurements revealed that the decrease of density values is a function of the time interval between the analysed and the previous scan. Prolonged interscan interval--due to contrast injection--enables a change in the sensitivity of CT detectors to be registered. It is probable that any study of cerebral blood volume could be unfavourably influenced by this phenomenon. Comparison between the postcontrast brain scan density decrease and density decrease of a phantom showed substantially no difference, so that we estimate the contrast response of the brain parenchyma in toto as insignificant. Further, a comparative analysis between contrast response of the white and gray matter has been made. The gray-white matter difference increased from precontrast 4.56 H to postcontrast 7.82 H. The relatively high difference of 3.26 H between the white and gray matter enhancement compared with negligible enhancement of the brain slice as a whole leads us to the hypothesis, that an absolute decrease of white matter density, as a biological reaction to the injected contrast solution, has to be presumed.