INFECTION - AN AMENDMENT TO THE STROKE MODEL GUIDELINES

[Advances in the pathophysiology and management of infections in the acute phase of stroke]

Infection in the acute phase of stroke has been identified as an independent predictor of poor outcome, both in the short and intermediate term. Various factors raising the risk of developing an infection (exposure to multiple pathogens, disruption of the protective function of the mucous membranes and a state of relative immunosuppression) coexist during the acute phase of stroke. Several risk factors have been identified for their development (especially increasing age and stroke severity). It has been proposed that infection contributes to a worse prognosis through different mechanisms, notably the development of an inflammatory response to brain tissue (with a potential to add secondary damage to that caused by the ischemic insult). Clinical trials evaluating the prophylactic and early administration of antibiotics to reduce the incidence of infection in the acute phase of stroke have yielded inconsistent results. Immunomodulating strategies, which may provide therapeutic alternatives in the future, are currently being evaluated.

Experimental approaches to study functional recovery following cerebral ischemia

Valid experimental models and behavioral tests are indispensable for the development of therapies for stroke. The translational failure with neuroprotective drugs has forced us to look for alternative approaches. Restorative therapies aiming to facilitate the recovery process by pharmacotherapy or cell-based therapy have emerged as promising options. Here we describe the most common stroke models used in cell-based therapy studies with particular emphasis on their inherent complications, which may affect behavioral outcome. Loss of body weight, stress, hyperthermia, immunodepression, and infections particularly after severe transient middle cerebral artery occlusion (filament model) are recognized as possible confounders to impair performance in certain behavioral tasks and bias the treatment effects. Inherent limitations of stroke models should be carefully considered when planning experiments to ensure translation of behavioral data to the clinic.