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Biomedical subjects

A Palma

Publications and source records attributed to A Palma.

At least 91 records · Page 5Linked to original sources
PubMed1978

New aspects of cerebrospinal fluid dynamics in humans investigated by sequential gamma camera cisternography, with data evaluation by the digital multichannel analyzer. Part 4: A unifying criterion of the development of hydrocephalic syndrome. Its dynamic basis.

In the final part of this series we present all of the clinical material, and the patients are classified by different cisternographic syndromes on the dynamic basis offered for our method: dynamic disconnection between ventricular system and basal cisterns, brain atrophy, initial dynamic decompensation or prehydrocephalus, communicating hydrocephalus with and without epicortical fluid circulation. A nomogram method for clinical estimation of CSF production based on the mathematical properties of our analysis of the ventricular reflux is proposed. The different normal and pathological characteristics of fluid movements in the spinal canal are given, and their importance as signs of turbulence in the posterior fossa are emphasized. Different aspects of the dynamics of CSF production are shown and discussed, and an evolving conception of hydrocephalus development is presented.

Adolescent↗
PubMed1978

New aspects of cerebrospinal fluid dynamics in humans investigated by sequential gammacamera cisternography, with data evaluation by the digital multichannel analyzer. Part 3: Physiopathology of the ventricular reflux.

Although well described and intensively used for diagnostic purposes, the ventricular reflux as a gammacisternographic phenomen has not yet been satisfactorily explained, and its physiopathology is a subject of controversy. Based on our method of quantitative gammacisternography and gammaventriculography we study the evolution of the tracer concentrations in two main chambers:--the basal cisterns together with the upper cervical canal, considered as a functional unity (the distribution area) and--the ventricular system. We propose the mathematical analysis of a theoretical model which represents the normal and pathological situations of these two chambers, as a method for measuring ventricular volume and ventricular tracer clearance. From the correlation in results with patients and models, we suggest turbulence as the main factor in generating backmixing or total mixing, the appearance of which is called ventricular reflux. We deny the existence of a real inversion of CSF flow. The spinal canal velocity of isotope flow is proposed as additional evidence of turbulence. The normal general dynamics of CSF are delineated, and we propose the following factors that lead to ventricular reflux:--partial obstruction to epicortical CSF flow;--total obstruction to epicortical CSF flow. Their principal characteristics are given, and the importance of using their quantitative parameters in descriptions of patients is stressed. Different aspects in the evolution of hydrocephalus, transependymal resorption, and factors involved in hydrodynamic changes etc. are discussed.

Cerebral Ventriculography↗
PubMed1977

New aspects of cerebrospinal fluid dynamics in humans investigated by sequential gamma camera cisternography, with data evaluation by the digital multichannel analyzer. 2nd part: pathology of cerebrospinal fluid flow in the subarachnoid space of the brain convexity.

The use of the sequential gamma camera technique with evaluation of the stored information in the digital analyzing system to investigate CSF dynamics quantitatively has given interesting new information about the circulation in the epicortical SA space. The streaming of I131HSA-labelled CSF in a protracted bolus or bulk was submitted to quantitative and temporal analysis by defining the activity maxima and their amounts as well as their times of appearance. Different modalities of activity evolution in various regions make it possible to define three main types of circulatory disturbance, which are: 1. Global epicortical inhibition, 2. circumscribed epicortical inhibition by a) restriction of the SA space, b) dilatation of the SA space, and 3. gamma cisternographic asymmetry, apparently due to restriction, with a fully functioning but dilated SA space and no real inhibition. The pathological conditions in the SA space leading to these different flow disturbance modalities are presented, and the necessity to perform quantitative and temporal analysis for definition of the functional flow conditions is emphasized.

Cerebrospinal Fluid↗
PubMed1977

The empty sella syndrome analysis of 10 cases.

Ten cases of the empty sella syndrome are presented. In four a pituitary adenoma had been treated by surgery with or without radiotherapy. In three women there was a close relation pregnancy, and two boys had congenital malformations. Five cases presented with appearances of pseudotomour, and the remainder had cerebrospinal fluid (CSF) fistula. Four fistulas were spontaneous, one was post-traumatic aggravated by the intrasellar implantation of YT-90. Two were occult CSF fistulas causing recurrent meningitis. Gamma cisternography and iodocisternography proved to be good diagnostic tests, both for the empty sella and for CSF fistulas. Nine cases were operated on. In four na intrasellar cyst was present. In the other five an empty sella with deficient or absent diaphragm was found. Treatment of most cases consisted of covering the floor of the sella with lyophilized dura, which was fixed in place with biological glue.

Adenoma↗
PubMed1977

[New aspects of cerebrospinal fluid dynamics in man revealed by sequential camera scintigraphy and analysis with the digital computer. Part 1: method and physiologic patterns].

1. The use of rapid sequential gamma camera scintigraphy in conjunction with computer aided storage and evaluation of data has been shown to be a promising method for the analysis of CSF dynamics in man. 2. Using this method rapid flow of CSF in the basal cisterns can be studied. The further course of tracer activity in different CSF compartments can be followed, and slow currents may be demonstrated. 3. Using this technique the patterns of varying regional CSF dynamics and reabsorption states can be examined. Intracranial activity after 24 hours is 40 to 45% anar behaviour of CSF circulation patterns in the basal cisterns, cisterna magna, and upper cervical area leads us to suggest that this complex of spaces forms a functional unity which may be called "The distribution center of CSF". Further movements of tracer substance seem to start from this complex. 5. In the well recognised CSF pathways over the cerebral convexities some characteristic patterns of fluid flow are demonstrated. The flow times at different situations over the convexities are given. 6. Analysis of spinal CSF flow shows that there are considerable variations in spinal CSF dynamics. 7. Finally, the different uses of this method in various situations are indicated.

Blood-Brain Barrier↗
PubMed1977

Gamma-encephalography in the diagnosis of subdural effusions in infancy and childhood.

The results of the use of gamma-encephalography (GEG) as a diagnostic tool in a group of 28 patients with subdural effusions and 46 membranes confirmed at surgery are presented. 27 patients were submitted to bilateral surgical expolorations and 1 was unilaterally explored. Positive GEG: membranes were present in 34, in 8 the test was nonconclusive and there were 4 false-negatives. Negative GEG: membranes were absent in 6, 1 case was nonconclusive and 2 were false-positive tests. Therefore, from 28 patients with 46 membranes the GEG was correct in two thirds of the cases, it was nonconclusive in 9 cases and the image did not confirm the surgical findings in 6 cases (false-positive or false-negative). The results suggest that the presence of a medium or thick membrane almost always results in a positive image, whereas the presence of a thin membrane leads to a nonconclusive result or in some cases a false-negative one. The general data from the literature correlates well with the present series.

Child, Preschool↗