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Biomedical subjects

B Rilliet

Publications and source records attributed to B Rilliet.

At least 37 records · Page 2Linked to original sources
PubMed1992

Pathogenesis of diastematomyelia: can a surgical model in the chick embryo give some clues about the human malformation?

To reproduce diastematomyelia, a sagittal incision was carried out at the level of the rhomboidal sinus of 36- to 40-h-old chick embryos. A small piece of membrane shell, a small agar screen, or a piece of quail isochronous isotopic notochord was inserted into the gap. The embryos were killed and fixed after 9 days' incubation. Diastematomyelia was obtained in several embryos treated with interposition of a membrane screen or a piece of quail notochord. Microscopic examination revealed two hemicords, each containing its own central canal; in some cases one of the cords showed hydromyelia. Absence of the rump was seen in association with experimental diastematomyelia. The interposition of a resorbable agar screen did not succeed in reproducing diastematomyelia. The results of these surgical manipulations suggest that diastematomyelia cannot be explained by a primary disorder of neurulation. It supports the theory of noninvolution of a firm midline structure (probably the neurenteric canal, rapidly surrounded by mesodermal cells originating from the notochord), which prevents the fusion of the separated parts.

Animals↗
PubMed1992

Herald facial numbness.

Three unusual patients who developed subacute facial numbness as the heralding symptom of an expanding tumor that involved the trigeminal nerve fibers are reported. The first patient had clinical and electrophysiological evidence of an isolated mental neuropathy as a result of metastatic lesions with bone destruction from a renal cell carcinoma. The second patient had a sensorimotor trigeminal neuropathy caused by a direct compression of the semilunar ganglion by a cavernous hemangioma of Meckel's cave. The last patient experienced facial numbness as the unusual presenting manifestation of a primary brainstem lymphoma. Patients 1 and 3 died a few weeks after the admission, whereas patient 2 poorly recovered. Despite the availability of new techniques for early diagnosis, this report demonstrates how difficult it can initially be to differentiate a 'benign' trigeminal neuropathy from serious conditions and underscores the poor prognosis of fifth nerve fibers involvement by an expanding mass. Early referral with clinical and electrophysiological evaluation appears to be of crucial importance.

Adult↗
PubMed1992

[Cervical meningocele and meningomyelocystocele. Apropos of 4 cases].

Published cases of cervical dysraphic lesions are rare. Their estimated proportion is about 5% of the entire group of spinal dysraphism. Four cases are reported, representing 2 types of lesion: 2 meningoceles with a simple fibrous band fixing the posterior aspect of the cord to the skin and 2 meningomyelocystoceles with other associated anomalies (hydromyelia, hydrocephalus, Chiari II, Peter's ocular anomaly). The clinical presentation is that of a soft posterior cervical mass without marked neurological impairement. The surgical treatment is simple, consisting in the resection of the lesion, intradural exploration to untighten the cord if fixed by a fibrous band, and drainage of the hydrocephalus. Neurological outcome is generally good immediately but may need sometimes secondary surgical exploration.

Abnormalities, Multiple↗
PubMed1990

[Tumors of aqueduct of Sylvius. Presentation of 5 cases and review of the literature].

The authors reports their experience of 5 cases of intra- and peri-aqueductal tumors. With the exception of 1 case, a subependymoma of the aqueduct discovered at autopsy in a 77 year old woman, the 4 other patients (2 females and 2 males) are relatively young (respectively 14, 23, 14 and 26) at the time when they presented with signs of chronically raised intracranial pressure due to a triventricular hydrocephalus. One patient presented with a partial Parinaud's sign, but the focal and long tract signs were conspicuously absent in the other patients. The diagnosis of a space occupying lesion in the tectum mesencephali or in the aqueduct could only be ascertained with the recent use of M.R.I. The radiological work-up of the cases suggest that theses lesions, presumably of glial origin, are very slowly growing tumors. Four patients have been treated for their symptomatic hydrocephalus, but no treatment of the tumor has been proposed, as the clinical state and the images remain remarkably stable. (Mean duration of follow up from the time of shunting = 3.7 years, extremes = 1.5-8 years). A review of the literature shows that not more than 48 cases of tumors of the aqueduct have been reported. Because of the small number of such observations, there are, until now, no precise informations on the management of such cases to decide if the patient will benefit of an open or stereotactic biopsy associated with radiotherapy or if one can rely on serial clinical and radiological examinations. Further information on the long term follow up is needed.

Adolescent↗
PubMed1990

Cryptogenic hemifacial spasm. A neurophysiological study.

Whether hemifacial spasm (HFS) is due to axono-axonal ephaptic transmission or to facial nucleus abnormal hyperexcitability remains controversial. The neurophysiological hallmark of HFS is the delayed response (DR). This response has an indirect pathway and thus a long latency. It is evoked A) as a distant response in muscles innervated by a facial branch other than the one stimulated, and B) in muscles innervated by the branch stimulated. In this work, 99 single all-or-none DRs of 24 cases of cryptogenic HFS were studied by threshold stimulation of a branch, or of the trunk, of the facial nerve. A) Eighty-eight distant DRs were studied. Fifty-four of them were frequently evoked as double discharges (DDs), or sometimes as multiple discharges, with a 3 to 7 ms interval. A collision technique, using paired stimuli, showed that the second discharge of 12 out of 20 DDs was accompanied by a back-wave due to a proximal ectopic re-excitation on the axon, or to the back-firing of an alpha cell (F-response), or to both. F-waves in HFS were more frequent than in normals or in other facial pathologies. B) Eleven DRs were recorded in muscles innervated by the facial branch stimulated. Some of them persisted when, using a stronger stimulus, the same all-or-none potential was also evoked as a direct response. In other cases both the direct response and the DR were evoked with identical stimulation threshold. The direct-indirect response interval of these 11 DRs was shorter than the normal M-F interval. These findings suggest that, in the case of HFS, axons are interconnected by uni- and bidirectional ephapses. Self-sustained repetitive firing in such a group of axons apparently results from re-excitations occurring both at the ephapse site and at the cellular level (F-responses). Spasm develops when several groups fire together. The changing excitability of the alpha cells modulates the importance of the phenomenon.

Adult↗
PubMed1986

[Late complications of closed injuries of the extracranial carotid artery. Apropos of 2 cases].

Closed injury with lesions of the great vessels of the neck are rare and usually due to high energy mechanisms with severe secondary deficit. 2 cases are reported, concerning young patients with relatively mild injury, neurological deficit not developing before 6 months after the traumatism in the first case and 8 months in the second. At this stage, the neurological signs were immediately severe, with cerebral infarction, leading to death in the first case. Pathological lesion of lesion of pseudo-anevrismal type, localised at the right carotid and subclavian artery bifurcation, was evidenced in the first case. In the second case, a bilateral intimal lesion of the carotid arteries at C1 level is illustrated on angiography. The mechanism of these lesions as well as the delayed manifestation of neurological deficits are discussed.

Adult↗
PubMed1986

[Myelopathies in a context of generalized infection: myelitis or compression?].

Four patients with rapidly progressive tetraparesis in relation with skin or joint infection and septicemia are reviewed. Clinical signs of medullary compression was present in all cases, confirmed by neuroradiological examinations. However, all surgical approaches failed to demonstrate clear evidence of compression. Within three weeks, the neurological picture of severe tetraparesis had an excellent clinical evolution in all cases. One of the patients died after developing pulmonary complications: necropsy did not show any signs of compression. The difficulty of differential diagnosis between an infectious compressive surgical pathology and an inflammatory disease (acute transverse myelitis type) is emphasized, with review of literature.

Aged↗
PubMed1986

[Study of the deterioration factors in adult patients with cranio-cerebral injuries who "talk and die"].

Between 1978 and 1984, the University Hospital of Geneva (Hôpital Cantonal Universitaire) received 46 head injured patients who "talked and died" after their brain insult. Only 14 of them had associated systemic lesions whilst two thirds of the series had an isolated head injury. Detailed review of the case records shows that death was preventable in a quarter of the cases. For 28 patients (60%), the factors contributing to death are avoidable or, at least, their management should be greatly improved. The diagnosis was confirmed by autopsy in 31 patients (67%).

Brain Injuries↗
PubMed1981

Calcifications in pituitary adenomas.

In a surgical series of 755 pituitary adenomas, 51 cases (6.75%) showed intratumoral calcifications on microscopic examination and 13 of these were visible on roentgenographic examination (1.72%). Thirty-eight of these 51 cases were prolactinomas, the highest incidence being in male patients. There was no correlation between age, sex, levels of hormone, size of the tumor, and the presence of calcifications. Four patterns of radiological calcifications were encountered. Histologically, the calcifications were most frequently found within the tumor masses. Their rare occurrence within fibrous or degenerative areas speaks against their dystrophic nature. Previously reported calcified bodies in fetal and newborn pituitaries and the recently described physiological hyperprolactinemia in early infancy suggest a possible hormonal influence in the genesis of calcifications in prolactinomas.

Adenoma↗
PubMed1981

Benign ependymal cyst of the pons.

Clinical presentation, radiological aspects, surgical treatment and histology of a case of an ependyma-lined cyst of the pons are depicted. Slight psychomotor retardation and long-standing neurological signs associated with a marked dolichocephalic skull and right aortic arch suggest a congenital anomaly. Differential diagnosis of cystic lesions in the posterior fossa is discussed.

Aorta, Thoracic↗
PubMed1979

[Dysplastic gangliocytoma of the cerebellum].

A case of dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease) is reported, discovered on a routine autopsy. Clinical and anatomopathological data of the case are compared with previously reported cases. Review of the various proposed pathogenic hypotheses.

Adult↗
PubMed1978

[Internuclear ophthalmoplegia in infectious encephalitis: observation on a case of listeriosis].

An internuclear ophthalmoplegia was diagnosed and recorded electro-oculographically in a patient with pontomedullary listeriosis. The etiological differential diagnosis in case of internuclear ophthalmoplegia is discussed. It is emphasized that listeria monocytogenes encephalitis should be considered because this pathology may be electively located in the pontomedullary area and because of the encreasing frequency of human listeriosis.

Adult↗