Biomedical subjects

E J Colon

Publications and source records attributed to E J Colon.

At least 55 records · Page 3Linked to original sources

PubMed1979

A qualitative comparison of two contrast media for cerebral angiography. A clinical method.

A qualitative comparison of two contrast media for cerebral angiography with regard to contrast should, preferably, be based on a comparison made in two different hemispheres of one patient. Two problems then arise which made evaluation difficult. Vasodilation occurs after the first contrast injection as a result of which the second contrast medium to be compared flows into a dilated vascular tree. In addition, in the case of a comparison in two different hemispheres, variations of image geometry occur, resulting in differences of sharpness and contrast. The method of solving these problems is discussed and is illustrated by a comparison of two contrast media which might be expected to produce differences in contrast because of their physical properties. The results of this clinical comparison show that the expected differences can be partly demonstrated.

Adolescent↗

PubMed1979

The discriminating role of EEG power spectra in dyslexic children.

The aim of this investigation is to compare EEG power-density spectra between dyslexic and normal children. The children have been selected on the basis of specific reading and writing tasks; those with severe organic diseases and mental disorders were excluded. Groups aged 8, 9 and 10 years have been compared. In the 8-year-old group the power in the alpha band is higher in normals, in the 9-year-old group there was a higher power of the mu rhythm in normals and in the 10-year-old group the power in the temporal theta band is lower in normals. A possible relation between these findings and psychomotor development is discussed.

Age Factors↗

PubMed1979

EEG spectra in children aged 8, 9 and 10 years. Reference values.

In a group of normal children aged 8, 9 and 10 years power density spectra of a 100-second EEG period were made over four different brain regions. All children had to undergo medical and psychological examinations prior to this EEG and the criteria for normality were based on these examinations. Reference values of the power density distribution for children between 8 and 10.5 years are given.

Age Factors↗

PubMed1979

Off-response: its clinical incidence in very young children.

Off-responses to repetitive photic stimulation may be of various shapes. In particular, very young children with respiratory distress showed a typical off-response. This reaction is rather peculiar; it consists of a triphasic, very sharp wave followed by a depolarization of longer duration. The latency is about 200 msec. This off-response seems to be the reaction of an immature brain.

Adolescent↗

PubMed1979

Reliability of Doppler sonography in extracranial cerebro-vascular stenosis.

Of our patients who underwent quantitative Doppler sonography (Haemato-Tacho-Graphy), 382 underwent carotid angiography and 61 vertebral artery angiography. The reliability of the method proved to be between 90 and 95 percent for carotid as well as for vertebral arteries. The HTG proved to be a useful addition to angiography in patients with extracranial cerebro-vascular stenosis.

Carotid Artery Diseases↗

PubMed1979

[The effects of ordinary provocation on the power density spectrum. A clinical electroencephalographic study (author's transl)].

In the search for methods which might increase the discrimination of the EEG, the power density spectra of a random sample of patients during different conditions were analysed. Power density spectra were made during eyes closed, eyes open, after hyperventilation, during photic stimulation, and during auditory stimulation. It proved that the spectra may change under different provocation tests, sometimes in a rather peculiar way. The conclusion was, that these analyses improve explicit the EEG diagnosis, a problem however is the time required for spectra interpretation.

Acoustic Stimulation↗

PubMed1977

Cortical and cervical somatosensory evoked responses in demyelinating diseases.

In six patients suffering from a multifocal neurological disease of the demyelinating type, a somatosensory evoked response was analyzed in the cortical and cervical are after stimulating the right index finger and the right nervus suralis. The results of the investigation with this method indicate that localization of the central nervous system pathology seems to lie within the realms of possibility, in which case this method will be a useful addition to the tools used to evaluate quantitatively the results of different treatments in this type of disease.

Adult↗

PubMed1975

A long-term study of the effects of electro-convulsions on the structure of the cerebral cortex.

In this study is described the quantitative structure of one circumscribed area of the cerebral cortex 2 months after a series of electro-consulsions. The results indicate a persistent change in the nuclear volume of the cerebral neurons in this area. There was no loss of neurons in the cortex. The changes described are diffuse in the cerebral cortex and not restricted to particular architectonic layers.

Animals↗

PubMed1973