[Imaging of neuro-ophthalmological emergencies]. / Imagerie des urgences en neuro-ophtalmologie.

MRI often is mandatory in the diagnostic work-up of visual loss, visual field alterations and oculomotor problems. It is performed emergently in patients with painful diplopia associated to mydriasis, to exclude aneurysm, or in patients with painful Horner syndrome to exclude dissection of the internal carotid artery. CT scan in emergency remains useful in case of acute lateral hemianopsia or acute post traumatic visual loss. Progressive neuro-ophthalmological symptoms may require imaging examination in a short delay to define the therapeutic strategy: monocular transient blindness (dissection or carotid stenosis), progressive visual loss (optic nerve compression), bitemporal hemianopsia (optic chiasm lesion), painful visual loss (optic neuritis). A very precise clinical indication is helpful for the choice of imaging protocol and to improve its diagnosis value.

A type-II beta-turn, proline-containing, cyclic pentapeptide as a building block for the construction of models of the cleavage site of pro-oxytocin.

Previous studies have indicated that proteolytic activation of pro-hormones and pro-proteins occurs most frequently at the level of basic amino acids arranged in doublets and that the dibasic sites are situated in or next to beta-turns. Investigations utilizing synthetic peptides reproducing the N-terminal processing domain of pro-oxytocin-neurophysin have suggested a close relationship between the secondary structure of the cleavage locus and enzyme recognition, the minimal recognized sequence being the -Pro-Leu-Gly-Gly-Lys-Arg-Ala-Val-Leu- segment of the native precursor. NMR investigations and energy minimization studies have demonstrated that this sequence is organized in two type-II beta-turns involving the -Pro-Leu-Gly-Gly- and -Lys-Arg-Ala-Val- sequences. To further strengthen the above reported hypothesis and to study the role of turn subtypes, a new proline containing cyclic substrate of the processing enzyme, in which the N-terminal side that comes before the Lys-Arg pair is constrained to adopt a type-lI beta-turn, has been synthesized. The presence of a type-II beta-turn structure in this cyclic peptide model has been demonstrated by a combined NMR, CD and FT-IR absorption investigation. A preliminary study shows that PC1 is able to recognize and process our constrained substrate.

[Amaurosis]. / Amauroses.

Amaurosis is an organic loss of visual acuity which can attain blindness and which occurs suddenly in the absence of other ophthalmological changes. It constitutes an ophthalmologic emergency requiring a careful aetiologic work-up in order to determine therapy. We will discuss various aetiologies of amaurosis and its treatment. Amaurosis can be of ophthalmologic origin, i.e., retinal vascular occlusion of neuro-ophthalmologic origin, or ischaemic and inflammatory neuropathy, or it can present as transient unilateral blindness in carotid pathology, during cardiac embolism and in some haematologic disorders. Such unilateral transient blindness can at any time become complicated by definitive ischaemia; it is thus urgent to detect the mechanisms in order to institute treatment. Since the causes of amaurosis are varied, the importance of history taking must be underlined in order to determine the circumstances of the loss of vision, its characteristics and the existence of accompanying signs.

[Should Tolosa-Hunt syndrome still be an exclusion diagnosis?]. / Le syndrome de Tolosa-Hunt doit-il encore être un diagnostic d'élimination?

Since Hunt et al's description (1961) Tolosa-Hunt syndrome has been a matter of controversies about its nosological identity and differential diagnosis. We report 7 cases diagnosed between 1979 and 1990. Four of them had a low-resolution CT and the diagnosis was made after a long follow-up, according to classical criteria of exclusion. The last 3 cases had a modern high-resolution CT or a MRI (2 cases) and the diagnosis was established in a few days. MRI has considerably simplified the differential diagnosis but it has not completely resolved it. Alterations of shape and signal of the cavernous sinus are similar to those of lymphoma, sarcoidosis and meningioma. When MRI is normal diabetic ophthalmoplegia, migrainous ophthalmoplegia and giant-cell arteritis must also be considered. We conclude that the diagnosis of the Tolosa-Hunt syndrome can generally be made in a few days, without a cavernous sinus biopsy. There is no reason to doubt that this syndrome is a specific nosological entity.

[Benign intracranial hypertension and minocycline]. / Hypertension intracrânienne bénigne et minocycline.

A 19 year-old woman complained of headache and nausea occurring while she was taking minocycline for acne. Examination showed bilateral papilloedema and a bilateral VIth nerve palsy. Symptoms and signs rapidly resolved after the drug was stopped. Benign intracranial hypertension due to tetracyclines is well known in infants. It is rare in adults. Its pathophysiology remains unknown. The role of vitamin A is inconsistent. Others biological factors or personal susceptibility could be involved.

[Results of bromocriptine treatment of giant or invasive prolactin adenomas. Apropos of 20 cases]. / Résultats du traitement par Bromocriptine des adénomes à prolactine géants ou expansifs. A propos de 20 observations.

The therapeutic results of twenty patients with giant expansive prolactinomas were studied under bromocriptine as treatment of first intent (Group I, n = 10) or of second intent after surgery with or without radiotherapy (Group II, n = 10). Patients in Group I (PRL: 350-17 000 ng/ml) were given bromocriptine alone (10 to 20 mg/day) for a period of 21 days to 22 months. The visual fields and acuity returned to normal in 8 days to 3 months in 4 out of 7 patients and significantly improved in 2 out of 7 patients. A reduction in tumour size was demonstrated on CT scanning in 7 out of 10 patients mainly in the suprasellar region (6/9) with appearances of a partially empty sella in 4 cases. Normalisation of the PRL (7 out of 10 cases) was accompanied by a correction of one or more other hypophyseal deficits in 3 patients. Bromocriptine was continued in 5 out of 10 cases with a good result after 12 to 22 months follow-up. Five patients were referred secondarily for surgery for spontaneous rhinorrhea in 1 patient or because Bromocriptine was only partially effective in 4 patients; a postoperative visual improvement with reduced serum prolactin levels was observed in these 4 cases. In Group II (PRL: 200-11 600 ng/ml after surgery), bromocriptine therapy (5 to 30 mg/day for 1.5 to 72 months) was associated with normalisation or a significant improvement in visual symptoms in 6 out of 9 cases and a reduction in tumour size in 8 out of 10 cases.(ABSTRACT TRUNCATED AT 250 WORDS)