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Biomedical subjects

A Brusa

Publications and source records attributed to A Brusa.

At least 19 recordsLinked to original sources
PubMed1995

Clinical evaluation of VEPs to interleaved checkerboard reversal stimulation of central, hemi- and peripheral fields.

The VEPs of 195 patients referred for supportive evidence of multiple sclerosis or optic neuritis were studied by a new method of interleaved checkerboard reversal stimulation of different areas of the visual field. In the first group of 95 patients checks of 40' subtense reversed in the whole field (28 degrees x 20 degrees), alternatively in the left and right hemifields and alternately in the central (5 degrees radius) and peripheral fields. In the second group of 100 patients checks reversed in the whole field and in interleaved mode in 3 visual field areas, comprising the central (4 degrees radius) and left and right hemisurround fields. In the first group abnormal responses were recorded from 52 eyes and there was partial disagreement among the stimulus conditions in 10 of the 52. Abnormalities were seen uniquely to central field stimulation in 3 eyes but never to whole field stimulation alone. In the second group abnormal responses were recorded in 58 eyes, again never uniquely to whole field stimulation, while abnormalities confined to one or two areas of the visual field were seen in 24, providing evidence of peripheral field involvement alone in 8 eyes. In the first group, waveforms created from the sum of the left and right hemifield and central and peripheral field responses showed quite close conformity to the whole field VEP, although amplitudes were significantly lower and latencies significantly shorter. In 7 eyes responses would have been differently classified (normal or abnormal) using the sum as compared with the whole fields.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Stereotactic radiotherapy with linear accelerators. Dosage considerations on collimators and photon beam energy].

The small X-ray beam profiles produced by linear accelerators and used in stereotactic radiosurgery were studied. Circular focusing and not-focusing beams outlined by additional collimators (diameter ranging 10 to 30 mm) and square field outlined by the jaws (field size 10 to 30 mm) were measured. 6 and 18-MV X-ray beams from a dual energy accelerator and 6 and 15-MV X-ray beams produced by 2 single-energy accelerators were used. Measurements were carried out with Kodak X Omat V films in a perspex phantom in the same conditions for all the fields. To study the profile characteristics we introduced the V80/V20 = (R80/R20)3 ratio where R80 and R20 are respectively the mean distance of the 80% and 20% isodose lines from the beams axis. Measurement results show that 6-MV X-ray beams have a higher V80/V20 ratio than the ones obtained with the other energies. There is no significant difference between the beams produced with focused collimators and those produced with not-focused collimators. Square fields outlined by the jaws have a V80/V20 ratio greatly dependent on the accelerator used. This ratio is generally worse than the ones obtained with beams outlined by additional collimators.

Photons↗
PubMed1994

[Digital fluorography in gastroenterological radiology].

The clinical value of two digital fluoroscopy systems not connected to a PACS was investigated and compared with that of conventional radiology. Some critical variables were considered: image intensifier diameter, image definition, examination time, acquisition speed, patient exposure and finally film consumption. The main problems in the use of the digital techniques consisted in the limited size of the examination fields, which was not big enough to demonstrate the whole colon during double contrast enema, and in the difficult representation of the actual size on the image printed on the laser films. Definition was considered as sufficient for GI examinations. The main advantages consisted in acquisition speed, allowing detailed examinations of cervical esophagus, cardias and fistulous tracts, reduced patient dose and finally the real time visualization of the acquired image on the TV monitor.

Digestive System↗
PubMed1987

Some little-known aspects of spinal cord softening.

311 cases of spinal cord softening, were selected for review. The following points emerged from this study: 1) spinal cord softening is a rare occurrence; 2) while formerly syphilis was the most frequent cause, recently reports of cases secondary to aortic disease or to embolism with diffuse signs of arteriosclerosis and circulatory failure pointing to a different pathogenesis have become more frequent; 3) the site of softening rarely corresponds to the vascular spinal territories as defined by the anatomists, from which it may be argued that often several arterial territories may be involved simultaneously or, alternatively, that the arterial territories are not so rigidly defined as anatomical research has led us to suppose; 4) the few cases of multiple vascular lesions show that, as happens in the brain, the cord may be damaged contemporaneously or successively in several areas.

Adolescent↗
PubMed1984

Roving lateral eye movements in coma. A clinical-pathological study.

Five patients in deep coma due to extensive supratentorial lesions presented roving lateral eye movements (ping-pong gaze), distinguished by the fact that the eyes, after moving to one extreme of gaze, returned to the midline instead of to the opposite extreme. The phenomenon was reported recently by Reynard et al.

Aged↗
PubMed1984

Progressive supranuclear palsy and In111-DTPA cisternography.

Three cases of progressive supranuclear palsy are reported in which In111-DTPA cisternography showed slow diffusion, ventricular reflux and failure of isotope clearance. The clinical diagnosis of progressive supranuclear palsy was confirmed histologically in two of these patients. The possible causes of the cisternographic changes and their relationship to the changes of CSF dynamics in progressive supranuclear palsy are discussed.

Aged↗
PubMed1984

Typical and reverse bobbing: a case with localizing value.

Report of a case of typical bobbing occasionally interpolated by reverse bobbing. The causative lesion, which lay in the most dorsal median portion of the pontine tegmentum, was a small primary hemorrhage, diagnosed in life by CT scanning and confirmed at necropsy. The pathological and clinical correlations of the phenomenon are discussed.

Aged↗
PubMed1984

[Palpebral nystagmus].

A case of palpebral nystagmus is reported. Two infarcts were present in the rostral pons, caudal midbrain and in the periaqueductal gray matter between the red nuclei, ventrally to the posterior commissure. The relationships between the palpebral nystagmus and the retraction of the upper lid together with the clinico-pathological significance of the two signs is discussed.

Brain Stem↗
PubMed1983

[Clinical use of a minicomputer in the evaluation of chemico-clinical parameters in the diagnosis of hepato-biliary-pancreatic diseases of surgical significance. 3 methods compared].

Bayes theorem; multivariance analysis, and the discriminating function of Mahalanobis applied to sixteen laboratory examinations employed in the diagnosis of diseases of the extrahepatic bile ducts and pancreas gave the following results: 1) the weight of each test was first measured in general terms, and then with regard to different levels of differentiation, with a classification in decreasing order in each case; 2) little redundancy was noted, and few examinations were of relatively negligible importance; furthermore, combinations of several tests did not lead to positive results; 3) reclassification according to the formula of Bayes and by means of the discriminating function proved sound supports for clinical decision, since they provided 70% and 80% of exact classification respectively; 4) the importance of the minicomputer in the construction of experimental diagnostic models was substantiated.

Biliary Tract Diseases↗
PubMed1979

The fine structure of subcortical neurofibrillary tangles in progressive supranuclear palsy.

The fine structure of subcortical neurofibrillary tangles was investigated in pallidum, substantia nigra, periaqueductal gray, pontine reticular gray, and dentate nucleus of 5 autopsy cases of Progressive Supranuclear Palsy. Only tangles due to straight 150 A wide filaments have been detected. These findings, obtained from a large series of cases and areas examined, confirm previous observations on the fine structure of neurofibrillary tangles in Progressive Supranuclear Palsy and suggest that the association between tangles due to straight filaments and tangles due to twisted tubules, so far described in one case, is probably exceptional.

Aged↗