Optic nerve head drusen. High-resolution computed tomographic approach.

Optic nerve head drusen are rare, inherited concretions, which are almost always calcified; their appearance must be known because they represent one of the major causes of pseudopapilledema. The computed tomographic (CT) scan can show small and buried drusen, which are sometimes difficult to diagnose by the ophthalmoscopic examination. Four cases of drusen (two bilateral and two unilateral) were confirmed or diagnosed by high-resolution CT. The CT appearance of drusen is characteristic because the calcifications are well defined, punctate, and strictly located in the optic disc. The use of high-resolution CT scanners is very helpful.

[Acquired stenosis of the lumbar canal and vertebral hyperostosis]. / Sténose acquise des canaux lombaires et hyperostose vertébrale.

The authors present 12 cases of symptomatic acquired narrowing of the lumbar canal (with multiple nerve root involvement) in patients suffering from typical vertebral hyperostosis. In each case, the lesion was transverse stenosis due to hypertrophy of the articular apophyses of the last three lumbar vertebrae (posteromedial apophyses). Amongst the radiological abnormalities detected, especially with the aid of the C.T. scan in 6 cases, the authors stress the frequency of irregular bony proliferations on the non-articular surface of the articular apophyses and the ossification of the ligamenta flava, which has already been observed in the thoracic region in cases of vertebral hyperostosis.

Cortical atrophy in Parkinson disease: correlation between clinical and CT findings with special emphasis on prefrontal atrophy.

Thirty-seven patients with Parkinson disease were evaluated clinically and with computed tomography in order to determine the incidence of prefrontal atrophy. An age-matched healthy control group was also scanned. The computed tomographic criteria used were the width of cortical sulci and ventriculocerebral indices. Parkinsonian patients with frontal cortical atrophy represent only one patient out of three. They are much older than parkinsonian patients with normal computed tomographic scans, and the onset of their illness occurs later. No significant difference was found according to gender, parkinsonian clinical triad, psychomotor study, or mean duration of illness and/or dopatherapy to the time of computed tomography. This work seems to separate two Parkinson diseases: one beginning before 65 years and damaging the nigrostriate system, and another beginning after 65 years and damaging both the nigrostriate system and the cortex, particularly the frontal cortex.

[Odontoid bone. Apropos of a case]. / L'os odontoïde. A propos d'une observation.

Reporting a clinical observation, the authors emphasize upon the extreme scarceness of this variety of so called "congenital" pseudarthrosis of the odontoid process. The congenital origin, due to a lack of fusion, or the acquired one by avascular necrosis following a trauma is explained. The diagnosis may be clinical, consisting either on a vertebral syndrome occurring in childhood, or on a neurological syndrome in the adult age. It is mainly radiological : A scanner investigation is presented here. Owing to the potential neurological severity of the disease, the posterior fusion has to be recommanded.

Electrets for use as dosimeters in radiography.

A compact device for the manufacturing of electrets and for the measurement of the dose to the skin of the patient in radiography has been developed and described. The surface potential of a polarized polymer electret decreases when it is exposed to radiation. The measurement of the variation in surface potential appears to be a reliable method for the evaluation of the dose. The electret does not disturb the examination nor the radiographic image as it can be given tissue equivalent properties.

[Dorsal medullary compression in vertebral hyperostosis]. / Compression médullaire dorsale au cours de l'hyperostose vertébrale.

The authors present two observations of dorsal medullary compression by intraspinal benign osseous proliferations developing in subjects who present with anterior vertebral hyperostosis. In the second observation operative intervention confirmed the site and nature of the lesion. The authors have researched the same radiological findings in other cases of vertebral hyperostosis. They describe the lesions which are of considerable practical importance as they are able to injure the spinal cord and the nerve roots, resulting in a hyperostotic dorsal myelopathy. All unexplained paraplegias should be investigated for such lesions by meticulous tomographic studies.

Experimental embolization with inflatable and releasable balloons in dogs.

Experimental arterial occlusion was performed on eight dogs by means of inflatable and releasable balloons, in five of which a reliable and long lasting arterial occlusion was obtained. Three accidents occurred. One dog died when the liquid latex was emptied spontaneously from the balloon and the territory was embolized causing a severe general reaction. In two other dogs the emptying of the balloon, inflated with iodine, was followed by distal embolization of the empty latex balloon. The possibility of such accidents would be too great a risk for human application, but it now seems possible with the new glue, isobutyl-2-cyanoacrylate, to embolize vascular territories more accurately and more safely by means of inflatable and releasable balloons.

Congenital spondylolysis of cervical vertebrae with spondylolisthesis anf frontal narrowing of the spinal canal. Report of two cases.

Two cases of cervical spondylolisthesis, due to a congenital defect in the pars interarticularis of C6, associated with spina bifida and elongation of the contralateral pars interarticularis, are reported. Tomography showed an abnormal direction of the articular facets of C6 and demonstrated a narrow frontal diameter of the cervical spinal canal at the level of the malformation. Gas myelography showed a slight compression of the cord. Unlike previously reported cases the patients had neurological findings which, in one case at least, were certainly referable to the spinal cord.