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Biomedical subjects

G E Valvassori

Publications and source records attributed to G E Valvassori.

7 recordsLinked to original sources

Evaluation of brain circulation by rapid rotational computed tomography.

Continuous rapid rotational CT brain scanning now permits the study of brain circulation. The parameters studied are related to the transit time of circulation and to blood flow differences within small portions of the brain. For ease of description, this study is called regional brain circulation (rBC). This preliminary report is based on our experience with 75 consecutive cases studied since August 1, 1978. Displays of normal brain, cerebral ischemia, and arteriovenous malformations are analyzed in this paper. The normal graphic display of rBC includes peak concentration, transit time, washin and washout phases. Clinical application to medical-surgical treatment is illustrated.

Aged

The large vestibular aqueduct syndrome.

The radiographic observation of 50 patients, each having an enlarged (greater than 1.5 mm. diameter) vestibular aqueduct, are analyzed. In addition to the aqueduct other associated inner ear anomalies have been identified in 60% of this population including: enlarged vestibule (14); enlarged vestibule and lateral semicircular canal (7); enlarged vestibule and hypoplastic cochlea (4); and hypoplastic cochlea (4). The large equeduct then presumably represents an arrested phase of inner ear development common to all 50 cases. Only 8 of these cases may fall into the Mondini or Mondini-Alexander classification wherein cochlear abnormalities have been identified. The size of the aqueduct ranged from 1.5 to 8 mm. in the anteroposterior diameter; the clinical incidence is 50 in 3700 consecutive cases referred for inner ear tomography. Bilateral involvement is twice as common as unilateral with a female to male predominance of 3:2. Most cases are associated with congenital hearing losses.

Adult

Bicaudate index in computerized tomography of Huntington disease and cerebral atrophy.

Ventricular sizes on computerized tomographic (CT) scans were compared in seven patients with Huntington disease, 20 patients with cerebral atrophy, and 20 normal controls. The bicaudate index--the ratio of the width of both lateral ventricles at the level of the heads of the caudate nuclei to the distance between the outer tables of the skull at the same level--significantly discriminated among the three groups. The bicaudate indices were: Huntington disease 0.209 +/- 0.007, cerebral atrophy 0.121 +/- 0.006, and controls 0.092 +/- 0.003.

Adult

Recurrent meningitis and labyrinthine gusher, related to congenital defects of the labyrinthine capsule and stapes footplate.

A congenital defect in the bony footplate of the stapes is now known to be a point of lowered resistance to extension of bacterial middle ear suppuration to the vestibule and thence to the meninges. Tomographic demonstration of the congenital pathologic condition of the ear permits the surgeon preoperatively to chart his surgical course. Despite antibiotic and chemotherapy, recurrent meningitis remains a serious disease as manifested by the death of two of the patients reported. The capacity for surgical correction of the congenital defect is manifested by one of our patients who has been free of meningitis for more than two years after surgery. If a congenital defect is considered in each case of recurrent meningitis, it is believed the mortality of this serious disease can be reversed.

Adult

The otologic manifestations of mandibulofacial dysostosis.

Sixteen patients (32 ears) with diagnoses of mandibulofacial dysostosis were reviewed. The characteristic otologic manifestations of the syndrome were delineated, found to be bilateral, and consist of the following: 1. Mild symmetric deformity of the auricle (grade 1 microtia). 2. Agenesis or hypoplastic development of the mastoid and mastoid antrum. 3. Absence of the external auditory canal. 4. Marked narrowing or agenesis of the middle ear cleft. 5. Agenesis or severe malformation of the malleus and incus. When present, the malleus and incus are most often rudimentary, fused to form a conglomerate mass, and ankylosed to either the atretic plate, epitympanum, or both. 6. Stapedial malformations which usually consist of a deformed suprastructure. 7. Frequently the tegmen assumes a more inferior (low lying) position than normal. 8. Occasionally, the facial nerve pursues an abnormal course and is located more anteriorly than would be expected. 9. A normal inner ear. 10. Normal bone conduction with a marked (greater than 50 dB) conductive hearing loss. 11. Marked disparity between the degree of auricular deformity (mild; grade 1 microtia) and the degree of deformity of the remaining first and second branchial arch derivatives that constitute the external and middle ears (severe).

Adolescent