Journal of neurology
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Journal of neurology · Mar 2012
Meta AnalysisA meta-analytic approach to estimating nocebo effects in neuropathic pain trials.
The development of non-specific adverse effects following the administration of an active or inert substance is referred to as nocebo phenomenon. We aimed to estimate the frequency and severity of nocebo responses in clinical trials of pharmacological treatments for neuropathic pain. A systematic Medline search for all randomized, placebo-controlled neuropathic pain trials published between 2000 and 2010 was carried out. ⋯ Furthermore, nocebo severity displayed a significant association with the study population (p = 0.0386). Our data indicates a powerful nocebo effect in neuropathic pain trials that may be influenced by gender- and population-related factors. A strong nocebo effect may be adversely affecting adherence and efficacy of current treatments for neuropathic pain in clinical practice.
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Journal of neurology · Mar 2012
Multicenter StudyPredictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma.
Bilateral absence of cortical N20 responses of median nerve somatosensory evoked potentials (SEP) predicts poor neurological outcome in postanoxic coma after cardiopulmonary resuscitation (CPR). Although SEP is easy to perform and available in most hospitals, it is worthwhile to know how neurological signs are associated with SEP results. The aim of this study was to investigate whether specific clinical neurological signs are associated with either an absent or a present median nerve SEP in patients after CPR. ⋯ The highest positive predictive values (0.71-0.83) for a present SEP were found for motor scores of withdrawal to painful stimuli or better. Multivariate analyses showed a fair diagnostic accuracy (0.78) for neurological examination in predicting an absent or present SEP at 48 or 72 h after CPR. This study shows that neurological examination cannot reliably predict absent or present cortical N20 responses in median nerve SEPs in patients after CPR.
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Journal of neurology · Mar 2012
Anti-LRP4 autoantibodies in AChR- and MuSK-antibody-negative myasthenia gravis.
Myasthenia gravis (MG) is an autoimmune disorder characterized by a defect in synaptic transmission at the neuromuscular junction causing fluctuating muscle weakness with a decremental response to repetitive nerve stimulation or altered jitter in single-fiber electromyography (EMG). Approximately 80% of all myasthenia gravis patients have autoantibodies against the nicotinic acetylcholine receptor in their serum. Autoantibodies against the tyrosine kinase muscle-specific kinase (MuSK) are responsible for 5-10% of all myasthenia gravis cases. ⋯ The results showed that 12 out of 13 antisera from double-seronegative MG patients bound to proteins concentrated at the neuromuscular junction of adult mouse skeletal muscle and that approximately 50% of the tested sera specifically bound to HEK293 cells transfected with human LRP4. Moreover, 4 out of these 13 sera inhibited agrin-induced aggregation of AChRs in cultured myotubes by more than 50%, suggesting a pathogenic role regarding the dysfunction of the neuromuscular endplate. These results indicate that LRP4 is a novel target for autoantibodies and is a diagnostic marker in seronegative MG patients.