Thyroid storm induced by strangulation

Thyroid storm most often occurs in patients with known thyrotoxicosis. This report discusses a severe case of thyroid storm developing as a direct result of strangulation in a patient without a preexisting history of thyroid disease. Classification and treatment of this entity are discussed.     

Spontaneous firing rate of lateral septal neurons decreases after forced swimming test in Wistar rat

The systemic or local administration of diverse antidepressants increases the neuronal firing rate of the lateral septal nucleus (LSN), whereas some stressful situations decrease its firing rate; however, any long-lasting effect exerted by the forced swimming (FS) test (15-min pretest and 5-min test 24 h later) on the firing rate of the LSN is unknown. Therefore, single-unit extracellular recordings were obtained from the LSN neurons of control rats (Ctrl, n=6) and FS rats (n=10) 2 h after the last swimming session. In other rats, spontaneous firing rate of cortical neurons was recorded under the same experimental conditions. The firing rate of the LSN neurons of the animals in the FS group was significantly lower (9.2+/-1.7 spikes/10 s; P<.004, n=35) in comparison with the Ctrl group (21.1+/-3.4 spikes/10 s, n=22). The reduced firing rate in the LSN after swimming tests was both evident and generalized given that approximately 83% of the total recorded neurons from the FS group fired below the mean+/-1 S.D. rate obtained from the Ctrl group. Accordingly, the mean first-order interval of neuronal firing rate in the FS group (621.3+/-22.6 ms) was significantly greater (P<.05) than that observed in the Ctrl group (391.5+/-29.2 ms), but no significant differences were found in the variation coefficient of these two experimental groups, illustrating regularity of firing. Nonsignificant differences or even an opposite trend were observed in the firing rate of cortical neurons in the FS group (26.3+/-8.4 spikes/10 s) as compared with Ctrl group (15.4+/-1.1 spikes/10 s). Accordingly, no differences were found in the variation coefficient (FS 55.3+/-7.2%, Ctrl 55.8+/-3.6%) or average first-order interval (FS 417.8+/-71.8 ms, Ctrl 494.1+/-64.5 ms). We conclude that the FS test constitutes a situation whose capacity for inducing long-lasting despair is reflected in a reduction in the firing rate of LSN neurons as it occurs in situations of anxiety and fear, contrary to the actions of antidepressant drugs.     

The histamine H3 receptor as a novel therapeutic target for cognitive and sleep disorders

Histamine H3 receptor pharmacology, functions and biochemistry are far from being fully understood; however, progress is being made. Activation of this Gi/GO-protein-coupled receptor affects cognition, the sleep-wake cycle, obesity and epilepsy, which are physiological and pathological conditions that are the main focus of research into the therapeutic potential of selective H3 receptor ligands. This heterogeneity of targets can be reconciled partially by the fact that the histamine system constitutes one of the most important brain-activating systems and that H3 receptors regulate the activity of histamine and other neurotransmitter systems. Furthermore, the H3 receptor shows functional constitutive activity, polymorphisms in humans and rodents with a differential distribution of splice variants in the CNS, and potential coupling to different intracellular signal transduction mechanisms. In light of the genetic, pharmacological and functional complexity of the H3 receptor, the importance of the histamine system as a therapeutic target to control the sleep-wake cycle and cognitive disorders will be discussed.     

Posterior ischemic optic neuropathy related to profound shock after penetrating thoracoabdominal trauma

Ischemic optic neuropathy is a rare cause of blindness reported most commonly in association with collagen-vascular diseases, infectious processes, and systemic hypotension related to massive exsanguinating hemorrhage. We report what we believe to be the first case of posterior ischemic optic neuropathy due to perioperative hypotension in a patient who had a penetrating thoracoabdominal injury with massive hemorrhage, severe hypotension, massive microcapillary circulatory leak, multiple system organ failure, and acute respiratory distress syndrome. Although the incidence of postoperative visual loss is low (-0.002%), awareness of this entity must be raised within the trauma surgical community.     

Early cerebral hemodynamic changes during passive movements and motor recovery after stroke

Recovery from hemiplegia is a complex phenomenon that depends on various adaptive processes involving both the affected and the unaffected hemisphere. Our aim in this study was to investigate changes in cerebral perfusion in hemiplegic stroke patients during passive movements and their correlation with the subsequent motor recovery. The study included 30 patients with single, subcortical ischemic cerebral lesions. Within 14 days (range 8 to 14 days) from stroke onset, all patients were examined for the effects of passive elbow movements on cerebral blood flow in the middle cerebral arteries (MCAs) by means of bilateral transcranial Doppler (TCD) ultrasonography. On the same day as TCD assessment, they were also evaluated clinically with the Canadian Neurological Scale (CNS) and with Medical Research Council (MRC) scale for motor deficit of the affected arm. A clinical evaluation using the same scales was repeated after two months of motor rehabilitation therapy. We investigated the relationship between changes of Mean Flow Velocity (MFV) during passive movements and degree of recovery after stroke. The logistic regression procedure indicated that out of all factors considered as possibly related to a good clinical motor deficit recovery of the affected arm, evaluated by means of MRC, only the MFV percentage increase played a predictive role. In particular, for each additional point of contralateral MFV percentage increase during passive movement of the affected arm, the relative probability of good clinical recovery increased 5.68 times (95% CI=1.76-18.40; p=0.004). Similar results were found when the clinical recovery was measured by means of the CNS (slope=0.40, p<0.001). Passive movements in hemiplegic stroke patients before clinical recovery elicit activation patterns that may be critical for the restoration of motor function.I n particular, early and consistent activation of the affected hemisphere, as detected with TCD, seems to predict the positive evolution of a motor deficit.