Patients with peripheral nerve or spinal cord lesions frequently report perceptual distortions related to position, shape, texture or temperature of the affected areas. This study aimed to describe the phenomenology of such body image alterations during the course of upper limb, lower limb or spinal anaesthetic blocks in patients (n = 36) undergoing orthopaedic surgery. Multimodal sensory testing and assessment of motor function were performed at regular intervals, and the relationship between the reported body image distortions and the progression of sensory and motor impairment was analysed. We found that perceptual changes concerning the shape and size of the deafferented limb occurred in the great majority of patients. In all of them, illusions of swelling, elongation or shortening of the limb coincided with the impairment of warm, cold and/or pinprick sensations, suggesting that thin myelinated Adelta- and/or unmyelinated C-fibres may provide a source of tonic modulation to the limb's cortical representation. Such perceptual alterations of shape and size of body parts differed clearly from postural illusions in terms of frequency, time course and influence of vision. In addition to perceptual changes in the deafferented area, almost half of the patients felt their unanaesthetized lips and/or mouth swelling during the course of upper limb block, suggesting the unmasking of dynamic interactions between somatotopically adjacent cortical representations. Conflicting sensations could co-exist in the patient's body image, such as the illusion of swelling of a limb, which, at the same time, was felt to be missing. The sense of ownership of the deafferented limb was impaired in some cases. These observations show that the perception of body shape and the awareness of its postural variations are built from different plastic models. They also underline the contribution of peripheral afferent activity to the maintenance of a unified body image.

BIS can be used in severely comatose patients as an assessment of brain death onset, enabling appropriate scheduling of either EEG or cerebral angiography to confirm brain death.

We report that in vivo injection of endotoxin (EDTX, 6 mg. kg(-)(1)) induces cardiovascular alterations in rats that closely mimic the clinical situation, as assessed by in vivo hemodynamic measurements in anesthetized and conscious, chronically instrumented animals. The patch-clamp technique was used to characterize the L-type calcium current (I(Ca)) and its autonomic regulation in isolated cardiac myocytes. The density of I(Ca) progressively decreased at 12 and 36 h after EDTX injection. However, the dihydropyridine (+/-)Bay K 8644 (100 nM) enhanced I(Ca) to levels similar to those in control and EDTX-treated myocytes. In addition, the net stimulatory effect of a beta-adrenergic agonist (isoproterenol) on I(Ca) was increased 12 h after EDTX injection. This change in the beta-adrenergic effect declined 24 h later. The potentiation in the beta-adrenergic stimulation of I(Ca) was mimicked by L858051 (10 microM), a direct activator of adenylyl cyclase, but not by IBMX (200 microM), a phosphodiesterase inhibitor. Besides, the antiadrenergic effect of acetylcholine on I(Ca) was unchanged 12 h after EDTX injection, but increased 36 h after EDTX injection. These results support the hypothesis that time-dependent changes in the adenylyl cyclase pathway in cardiac myocytes may contribute, via the autonomic regulation of I(Ca), to the severity of myocardial dysfunction during sepsis.