Transient perioperative visual loss after an elective neurosurgical procedure.

OBJECTIVE: To describe a case of reversible visual loss after a neurosurgical intervention and to discuss the role of the prone position as a potential risk factor. OBSERVATION: A 63-year-old woman without significant medical previous history underwent elective resection of a left parieto-occipital meningioma. Preoperatively, the patient presented a right homonymous lower quadranopsia. The surgical procedure was not complicated. The patient was positioned in prone with a mild inclination of the table in reverse Trendelenburg position. The head was maintained in a Mayfield skull clamp, and ocular compression was excluded. There was no significant hypotension, hemodilution or vasopressors infusion during the procedure. Immediately after recovery from anesthesia, the patient experienced total blindness and flash visual evoked potentials confirmed the absence of retinal, primary or late occipital activities. A progressive, but finally complete recovery started after 24 hours. CONCLUSION: This case illustrates the individual risk for visual injury after the prone position during some neurosurgical interventions.

Intracranial brain parenchymal spread of mucormycosis through olfactory tract: a diffusion-weighted imaging-based concept.

Mucormycosis is an opportunistic fungal infection involving among others the paranasal sinuses, nasal fossa and brain parenchyma. Mucor can invade the brain parenchyma by either contiguous spread from the paranasal sinuses or through vascular invasion. We report a case of fatal rhino-cerebral mucormycosis in whom cytotoxic edema at magnetic resonance diffusion-weighted imaging was symmetrically restricted to both neocortical and paleocortical primary areas of olfactory projection at earliest phase of the disease process. Shortly later tissue damage extended into the whole brain. This undescribed observation raised the hypothesis of preferential way of brain invasion by Mucor through the olfactory tract.

Drug-drug interactions in the intensive care unit: Do they really matter?

PURPOSE: To describe prevalence and patterns of potential drug-drug interactions (pDDIs) in the intensive care unit (ICU), occurrence of adverse drug events (ADEs), and agreement between different compendia and intensivists' perceptions. METHODS: A cross-sectional study. Drug profiles of all adult patients from 2 academic ICUs were screened on day 3 upon admission. We identified pDDIs using 3 compendia (Stockley's, Micromedex, and Epocrates) and documented their mechanism of action, clinical consequences, severity, level of evidence, and management. Medical records were searched to identify ADEs potentially related to major pDDIs. Agreement between information sources (compendia, intensivists) was evaluated. RESULTS: We identified 1120 pDDIs among 275 patients. Median number of pDDIs per patient was 3.0 (interquartile range, 1-6), with 79% of patients presenting with at least 1 pDDI. Major pDDIs were detected in 18% of patients, with potentially related to ADEs in 4% of patients. Only 13% of all pDDIs were documented simultaneously in all 3 compendia. Different information sources (compendia, clinicians) showed "no" to "fair" agreement. CONCLUSIONS: Potential drug-drug interactions occurred in most ICU patients, contrasting with low rates of potentially related ADEs, which may have been underestimated. Sources of information are inconsistent, challenging the identification of pDDIs.

[Acute methanol intoxication: physiopathology, prognosis and treatment]. / Intoxication aiguë par le méthanol : physiopathologie, pronostic et traitement.

Acute methanol poisoning is mainly the consequence of voluntary or accidental ingestion. The mortality and morbidity rates remain very high despite intensive care therapy. Methanol by itself is poorly toxic. Methanol is transformed in the liver into formaldehyde and thereafter formic acid. Metabolic acidosis is the main biological feature of poisoning. Acidosis is related to formic acid accumulation, and also to a less extent to lactate production. In contrast to rodents, primates are relatively deficient in tetrahydrofolate reductase and therefore formic acid is usually the final metabolite. Formic acid is able to inhibit cytochrome oxidase activity in the mitochondria, leading to histotoxic hypoxia. The most sensitive organs to the effects of formic acid are the brain and the visual pathway, while other organs may also be seriously damaged according to the severity of metabolic acidosis. Hemodialysis remains indicated for the removal of both methanol and formic acid. Fomepizole is a recently approved antidote. It appears safe and effective. Analysis of its cost-effectiveness ratio is still ongoing in methanol poisoning.

A Belgian traveler who acquired yellow fever in the Gambia.

A 47-year-old Belgian woman acquired yellow fever during a 1-week vacation in The Gambia; she had never been vaccinated against yellow fever. She died of massive gastrointestinal bleeding 7 days after the onset of the first symptoms. This dramatic case demonstrates that it is important for persons to be vaccinated against yellow fever before they travel to countries where yellow fever is endemic, even if the country, like The Gambia, does not require travelers to be vaccinated.

Carcinogenicity, mutagenicity and teratogenicity of manganese compounds.

Manganese, an essential trace element, is one of the most used metals in the industry. Recently, several new manganese compounds have been introduced as fungicide, as antiknock agent in petrol and as contrasting agent in nuclear magnetic resonance tomography. Manganese displays a somewhat unique behaviour with regard to its toxicity. It is relatively non-toxic to the adult organism except to the brain where it causes Parkinson-like symptoms when inhaled even at moderate amounts over longer periods of time. Relatively high doses of manganese affect DNA replication and repair in bacteria and causes mutations in microorganism and mammalian cells although the Ames test does not appear to be particularly responsive to manganese. In mammalian cells, manganese causes DNA damage and chromosome aberrations. Information on organic manganese derivatives is still insufficient. Large amounts of manganese affect fertility in mammals and are toxic to the embryo and foetus. The fungicide MANEB and the contrasting agent MnDPDP also can be embryotoxic, but the latter only at doses much higher than those clinically employed. Information on the anti-knock agent MMT is inadequate. On the other hand, manganese deficiency can also affect fertility and be teratogenic. Information on cancer due to manganese is scanty but the results available do not indicate that inorganic manganese is carcinogenic. More information is desirable with regard to the organic manganese derivatives. It may surprise that an agent that causes mutations is not also carcinogenic. The experience with manganese shows that conclusions with regard to carcinogenicity of an agent based on the observation of mutations are subject to uncertainties. Altogether, it appears that, because of the very high doses at which positive effects have been found, manganese would not represent a significant carcinogenic risk to the population and workers. Care must, however, be exercised with respect to central-nervous symptoms after chronic exposure and with respect to effects on the embryo. Pregnant women should not be exposed to manganese at the work place.

[Efficacy and safety of acetaminophen-codeine in the treatment of pain]. / Efficacité et sécurité de l'association paracétamol-codéine dans le traitement de la douleur.

The treatment of acute or chronic pain of variable intensity and origin, is efficiently achieved by the association of paracetamol and codeine. At a dose of 1000 mg paracetamol and 60 mg of codeine, this association is considered one of the most efficient as compared to other analgesics of level II in the OMS classification, like tramadol.