Strokes restricted to the insular cortex

Résumé: L'objectif de l'étude est de caractériser la manifestation clinique d'une atteinte vasculaire cérébrale ischémique aiguë limitée au cortex insulaire, région intrigante et méconnue du cerveau humain. Dans la pratique clinique, une atteinte vasculaire aiguë limitée à l'insula, sans compromission d'autres régions cérébrales, est exceptionnelle et sa manifestation clinique neurologique est souvent non reconnue. L'étude est focalisée sur quatre patients, inscrits dans le Lausanne Stroke Registry, présentant une nouvelle atteinte vasculaire cérébrale avec une lésion unique purement limitée au cortex insulaire, objectivée à l'aide de la résonance magnétique (IRM). L'étude a mis en évidence cinq manifestations cliniques principales : 1) Troubles de la sensibilité corporelle sont révélé chez trois patients avec une atteinte insulaire postérieure (deux avec un syndrome pseudothalamique, un avec un déficit à distribution partielle). 2) Un patient avec une lésion insulaire postérieure gauche présent des troubles du goût. 3) Un syndrome pseudovestibulaire avec vertiges non rotatoires, instabilité à la marche sans nystagmus, est mis en évidence chez trois patients avec une atteinte ischémique insulaire postérieure. 4) Un patient avec atteinte de l'insula postérieure droite présente des épisodes d'hypertension artérielle d'origine cryptique. 5) Des troubles neuropsychologiques tels qu'aphasie et dysarthrie sont détectés chez les patients avec une atteinte insulaire postérieure gauche, un épisode de somatoparaphrénie est rapporté avec une atteinte insulaire postérieure droite. En conclusion, les atteintes vasculaires cérébrales ischémiques aiguës limitées au cortex insulaire postérieur peuvent se manifester principalement avec un tableau clinique caractérisé par un syndrome pseudothalamique associé à une symptomatologie pseudovertigineuse. Les lésions insulaires postérieures peuvent se manifester avec une dysarthrie et des troubles du goût, une aphasie (gauche), une somatoparaphrénie et une dysfonction hypertensive (droite). L'étude n'a pas mis en évidence de dysphagie, reportée dans les atteintes insulaires antérieures. Abstract: Objective: To characterize clinically acute insular strokes from four patients with, a first ever acute stroke restricted to the insula on MRI. Methods: The authors studied the clinical presentation of four patients with a first ever acute stroke restricted to the insula on MRI. Results: The authors found five main groups of clinical presentations: 1) somatosensory deficits in three patients with posterior insular stroke (two with a transient pseudothalamic sensory syndrome, one with partial distribution); 2) gustatory disorder in a patient with left posterior insular infarct; 3) vestibular-like syndrome, with dizziness, gait instability, and tendency to fall, but no nystagmus, in three patients with posterior insular strokes; 4) cardiovascular disturbances, consisting of hypertensive episodes in a patient with a right posterior insular infarct; and 5) neuropsychological disorders, including aphasia (left posterior insula), dysarthria, and transient somatoparaphrenia (right posterior insula). Conclusion: Strokes restricted to the posterior insula may present with pseudothalamic sensory and vestibular-like syndromes as prominent clinical manifestations, but also dysarthria and aphasia (in left lesions), somatoparaphrenia (right lesions) and gustatory dysfunction and blood pressure with hypertensive episodes in right lesions; we did not find acute dysphagia reported in anterior, insular strokes.

Trends in food availability in Switzerland, 1961-2007.

Trends in food availability in Switzerland were assessed using the Food and Agricultural Organization food balance sheets for the period 1961-2007. A relatively stable trend in the daily caloric supply was found: 3545 kcal/day in 1961 and 3465 kcal/day in 2007. Calories associated with carbohydrates decreased (slope±s.e.: -1.1±0.2 kcal/day/year), namely regarding cereals (-2.9±0.6 kcal/day/year) and fruit (-1.5±0.1 kcal/day/year), while the availability of sugars increased (1.2±0.5 kcal/day/year). In 1961, protein, fat, carbohydrates and alcohol represented 10.6, 33.5, 50.0 and 5.9% of total caloric supply, respectively; in 2007, the values were 10.8, 40.3, 43.7 and 5.2%. In 1961, palm, groundnut and sunflowerseed oil represented 3.4, 30.7 and 5.3% of total vegetable oils, respectively; in 2007, the values were 10.4, 3.7 and 31.6%. We conclude that between 1961 and 2007 total caloric availability remained relatively stable in Switzerland; the health effects of the increased and differing fat availability should be evaluated.

Natural malaria infection reduces starvation resistance of nutritionally stressed mosquitoes.

In disease ecology, there is growing evidence that environmental quality interacts with parasite and host to determine host susceptibility to an infection. Most studies of malaria parasites have focused on the infection costs incurred by the hosts, and few have investigated the costs on mosquito vectors. The interplay between the environment, the vector and the parasite has therefore mostly been ignored and often relied on unnatural or allopatric Plasmodium/vector associations. Here, we investigated the effects of natural avian malaria infection on both fecundity and survival of field-caught female Culex pipiens mosquitoes, individually maintained in laboratory conditions. We manipulated environmental quality by providing mosquitoes with different concentrations of glucose-feeding solution prior to submitting them to a starvation challenge. We used molecular-based methods to assess mosquitoes' infection status. We found that mosquitoes infected with Plasmodium had lower starvation resistance than uninfected ones only under low nutritional conditions. The effect of nutritional stress varied with time, with the difference of starvation resistance between optimally and suboptimally fed mosquitoes increasing from spring to summer, as shown by a significant interaction between diet treatment and months of capture. Infected and uninfected mosquitoes had similar clutch size, indicating no effect of infection on fecundity. Overall, this study suggests that avian malaria vectors may suffer Plasmodium infection costs in their natural habitat, under certain environmental conditions. This may have major implications for disease transmission in the wild.