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Biomedical subjects

A Bes

Publications and source records attributed to A Bes.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Influence of age on several parameters of the Doppler signal at the carotid level (author's transl)].

Doppler recordings are an interesting method of exploration of the circulatory system and more information can be obtained than is generally accepted. This study demonstrates the influence of age on the Doppler signal treated in 3 different ways. This is done in order to obtain supplementary criteria if possible, which can be used to assess arterial aging and its possible pathological character. The results show the dispersion of the resistance index R after 50 years of age, many subjects having an increased index. The influence of various factors such as hypertension, smoking..., are analyzed. Particular attention is drawn to the morphological changes in the curve. Hard echos that are usually filtered are specifically analyzed. These represent the reflexion of ultrasounds on the arterial wall and it could be possible to obtain information on flow rate and vessel wall elasticity. Preliminary results show important variations of the signal with age. Doppler recordings from the carotid vessels can be used to follow, in an approximate manner, the rapid variations of cerebral blood perfusion. The during of circulatory disturbance was studied when the cerebral circulation was exposed to a particular situation requiring rapid adaptation: in this case the squatting-standing test. Large differences were observed according to age.

Adult↗
PubMedDate not supplied

The prognostic value of noninvasive CBF measurement in subarachnoid hemorrhage.

Seventy-four measurements of cerebral blood flow (CBF) were performed using the Xenon 133 inhalation method in 50 cases of spontaneous subarachnoid hemorrhage. This method is non-traumatic, reproducible and dependable. A correlation was found between clinical condition and CBF values, but in a number of cases which cannot be dismissed, very low mean CBF values or ischemic foci were revealed where clinical state gave no indication of same. A poor correlation appeared between vasospasm seen by angiography and ischemic foci detected by isotopic technique. Patients' age influenced CBF values but not clinical evolution. CBF values, measured in the first two weeks of illness, were significantly higher in those patients having favorable outcome, whatever their clinical state at the time of CBF measurement (comas excluded). The figure of 60 ml/100g/min. for mean cortical flow seemed to be a critical level below which risk of complications was greater. Conversely, in every case where mean cortical flow measured above 70 ml, outcome was favorable. Thus, CBF measurement promises to be a valuable prognostic tool, playing an important role in the therapeutic strategy for this type of patient.

Adult↗
PubMedDate not supplied

[Cerebral blood flow in 20 depressed adolescents].

Regional cerebral blood flow was compared in twenty depressed adolescents and ten normal controls using the Xenon 133 inhalation method. There were no differences in mean hemispheric blood flow. The main difference was the loss of the "hyperfrontal distribution" in the depressed adolescents: the prefrontal values were only 5.4% greater than the blood flow in the rest of the hemisphere, compared with 13.5% in the controls.

Adolescent↗