A case of acute heart failure associated with Guillain-Barré syndrome

Abstract Guillain-Barré syndrome (GBS) is a disease of the peripheral nervous system, which is caused by aberrant immune responses directed against some components of peripheral nerves. GBS is rarely accompanied by cardiovascular involvement. We describe a case of acute neuropathy complicated by sudden heart failure and left ventricular dysfunction which had a presumably neurogenic origin. Pathogenesis of acute heart failure is probably due to transitorial stunned myocardium and neurogenic cardiac injury. We show a rare case of transitorial and acute cardiac dysfunction by echocardiography and laboratory markers of heart failure.     

Acute subcortical stroke and early serotonergic modification: a IDAP study

The intensity dependence of the auditory-evoked potentials (IDAP) is inversely related to serotonergic tone. Depression is frequently observed after stroke, associated with cognitive impairment and increased mortality. Aim of this study was to investigate the serotonergic tone in acute stroke patients by IDAP. Consecutive patients with an acute stroke admitted in our stroke unit were evaluated using clinical and instrumental examinations and compared with healthy controls. The IDAP was calculated as the linear amplitude/stimulus intensity function (ASF) slope, by measuring the peak-to-peak amplitude of Nl-P2 on four blocks of different stimulus intensities. Twenty patients were enrolled; 11 had a right brain infarction; nine had depressive symptoms (DS). The ASF slope of the auditory-evoked potentials was markedly increased in stroke patients compared with controls ( P  = 0.021). Stroke patients with DS had a significant steeper ASF slope than controls ( P  = 0.017). There was no statistical difference in ASF slope between stroke patients without DS and controls. Post-stroke depression pathophysiology is still debated. Our study suggests that in acute stroke patients with DS, there is a direct involvement of the serotonergic system, regardless the degree of disability and the site of the lesion.     

Spontaneous regression of optic pathways gliomas in three patients with neurofibromatosis type I and critical review of the literature

Case reports The authors report their experience about three children (two girls, one boy; average age 1.6 years) with a spontaneous regression of optic gliomas. All of them had a previous diagnosis of neurofibromatosis type 1 (NF 1). None of them underwent surgery or biopsy nor received chemotherapy or radiotherapy. The complete regression was documented by MRI scans performed during a mean follow-up of 6.3 years.Literature review Moreover, the authors analyze the features of the 16 cases previously reported in English literature of spontaneously regressed optic gliomas with an overview of the different therapeutic strategies. The knowledge that this kind of tumor, particularly in young patients, may regress is important in the decision of the best therapeutic approach.     

Automated assessment of cervical dystonia.

We developed an automated and objective method to measure posture and voluntary movements in patients with cervical dystonia using Fastrack, an electromagnetic system consisting of a stationary transmitter station and four sensors. The junction lines between the sensors attached to the head produced geometrical figures on which the corresponding aspects of the head were superimposed. The head position in the space was reconstructed and observed from axial, sagittal, and coronal planes. Four patients with cervical dystonia and 6 healthy subjects were studied. Each patient was representative of one of the typical patterns of cervical dystonia. The study allowed the authors to collect quantitative data on posture and range of motion of the head. This pilot study demonstrates the efficacy of the Fastrack system to objectively measure the head position in cervical dystonia patients.     

Cancer mortality among workers in the Tuscan tanning industry

The mortality of 2926 male workers at the tanneries in the "leather area" of Tuscany was examined from 1950 to 1983 comparing it with the national mortality. Cancer mortality was of particular concern because of the many chemicals known to be definite or suspected carcinogens used in the tanning cycle, in particular chromate pigments, benzidine based dyes, formaldehyde, and organic solvents. There was no excess of deaths for cancers of all sites but slight increases in deaths from cancer of the lung (SMR = 131, CI 95% = 88-182), bladder (SMR = 150, CI 95% = 48-349), kidney (SMR = 323, CI 95% = 86-827), pancreas (SMR = 146, CI 95% = 39-373), and leukaemias (SMR = 164, CI 95% = 53-382) occurred. Two cases of soft tissue sarcomas were observed versus 0.09 expected (SMR = 2178, CI 95% = 250-8023).     

Spike patterning by Ca2+-dependent regulation of a muscarinic cation current in entorhinal cortex layer II neurons

In entorhinal cortex layer II neurons, muscarinic receptor activation promotes depolarization via activation of a nonspecific cation current (I(NCM)). Under muscarinic influence, these neurons also develop changes in excitability that result in activity-dependent induction of delayed firing and bursting activity. To identify the membrane processes underlying these phenomena, we examined whether I(NCM) may undergo activity-dependent regulation. Our voltage-clamp experiments revealed that appropriate depolarizing protocols increased the basal level of inward current activated during muscarinic stimulation and suggested that this effect was due to I(NCM) upregulation. In the presence of low buffering for intracellular Ca(2+), this upregulation was transient, and its decay could be followed by a phase of I(NCM) downregulation. Both up- and downregulation were elicited by depolarizing stimuli able to activate voltage-gated Ca(2+) channels (VGCC); both were sensitive to increasing concentrations of intracellular Ca(2+)-chelating agents with downregulation being abolished at lower Ca(2+)-buffering capacities; both were reduced or suppressed by VGCC block or in the absence of extracellular Ca(2+). These data indicate that relatively small increases in [Ca(2+)](i) driven by firing activity can induce upregulation of a basal muscarinic depolarizing-current level, whereas more pronounced [Ca(2+)](i) elevations can result in I(NCM) downregulation. We propose that the interaction of activity-dependent positive and negative feedback mechanisms on I(NCM) allows entorhinal cortex layer II neurons to exhibit emergent properties, such as delayed firing and enhanced or suppressed responses to repeated stimuli, that may be of importance in the memory functions of the temporal lobe and in the pathophysiology of epilepsy.     

Physiological unloading of cardiopulmonary mechanoreceptors by posture changes does not influence the pressor response to isometric exercise in healthy humans

Summary In recent studies in humans the role of cardiopulmonary baroreflexes in modulating the cardiovascular responses to isometric exercise (somatic pressor reflex) has been investigated by performing static hand-grip exercise during deactivation of cardiopulmonary receptors produced by low levels of lower body negative pressure; however, findings from these studies have not been consistent. The purpose of this study was to investigate whether a more physiological unloading stimulus of cardiopulmonary baroreceptors, obtained by sequentially changing posture, could influence the pressor response to somatic afferent stimulation induced by isometric, exercise. To accomplish this, ten healthy subjects performed a 2-min isometric handgrip (IHG) at 30% maximal voluntary contraction after 10 min of supine rest and, in rapid sequence, after 10 min of sitting and 10 min of standing, at the time when, owing to their transitory nature, the cardiovascular effects, due to arterial baroreceptor intervention should have been minimal. During IHG arterial pressure (BP_a) was continuously and noninvasively measured to quantify accurately the blood pressure response to IHG both in magnitude and time course. Results showed that the pressor response to IHG was not significantly influenced by change in posture, either in magnitude or in time course. The mean arterial pressure increased by 17.4 (SEM 2.5), 18.6 (SEM 1.2) and 17.0 (SEM 1.3) mmHg in supine, sitting and standing [2.3 (SEM 0.3), 2.5 (SEM 0.2) and 2.3 (SEM 0.2) kPa] positions, respectively. Also the heart rate response to IHG was unaffected by change in posture. Most important, the sum of the separate BP_a responses induced by supine IHG and by posture change from supine to sitting (summation of reflexes) was not significantly different from the pressor response observed during sitting IHG (interaction of reflexes). Likewise, the sum of the separate BP_a. responses induced by sitting IHG and by changing postures from sitting to standing was not significantly different from the pressor response to standing IHG. These data indicate that, under physiological conditions, cardiopulmonary baroreflexes do not exert a significant role in modulating the reflex pressor drive from muscles during isometric exercise in healthy humans.     

Hepatitis C viraemia in adults with type 2 autoimmune hepatitis.

Sera from 14 patients with type 2 autoimmune hepatitis (anti-LKM1 positive) were investigated for evidence of hepatitis C virus (HCV) infection. Antibodies to HCV were detected in 13 patients by both commercial and "in-house" ELISAs and also by a second generation recombinant immunoblot assay. Nine of the 13 (69%) anti-HCV positive patients were shown to be viraemic by a polymerase chain reaction-based assay for serum HCV RNA. Neither anti-HCV nor serum HCV RNA were detected in any of 6 controls with primary biliary cirrhosis or in 39 healthy blood donors. These findings strongly suggest a role for HCV in the pathogenesis of type 2 autoimmune hepatitis.