Search

People with epilepsy often report seizures precipitated by stress. This is believed to be due to effects of stress hormones, such as cortisol, on neuronal excitability. Cortisol, regardless of stress, is released in hourly pulses, whose effect on epileptic activity is unknown. We tested the relation between cortisol levels and the incidence of epileptiform abnormalities in the electroencephalogram of people with focal epilepsy. Morning cortisol levels were measured in saliva samples obtained every 15 min. Interictal epileptiform discharges were determined in the same time periods. We investigated the relationship between cortisol levels and the epileptiform discharges distinguishing persons with from those without stress-precipitated seizures (linear mixed model), and analysed the contribution of individual, epilepsy and recording characteristics with multivariable analysis. Twenty-nine recordings were performed in 21 individuals. Cortisol was positively related to incidence of epileptiform discharges (β = 0.26, P = 0.002) in people reporting stress-sensitive seizures, but not those who did not report stress sensitivity (β = -0.07, P = 0.64). The relationship between cortisol and epileptiform discharges was positively associated only with stress sensitivity of seizures (β = 0.31, P = 0.005). The relationship between cortisol levels and incidence of interictal epileptiform discharges in people with stress-sensitive seizures suggests that stress hormones influence disease activity in epilepsy, also under basal conditions. [ABSTRACT FROM AUTHOR]

Introduction: Fasciculations, the spontaneous activity of single motor units (MUs) are characteristic, but nonspecific for motor neuron disease (MND). We aimed to identify MU discharge properties to optimally differentiate MND patients from healthy controls.Methods: High-density surface electromyography recordings were performed in the thenar muscles during 10 min of rest. MU discharges were classified as "isolated" when the interspike intervals (ISIs) before and after were > 250 ms, "continual" when both ISIs were ≤ 250 ms, or as "other".Results: In patients (n = 30) compared with controls (n = 14), more MUs were active (9 vs. 3, P < 0.001) and generated relatively more isolated discharges (35% vs. 10%, P = 0.01). Two or more MUs with isolated discharges occurred more frequently in patients compared with controls (24% vs. <1% of 10-s windows, P < 0.001).Conclusions: More frequent occurrence of multiple MUs showing isolated discharges may improve identification of patients with MND. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to determine whether electrically evoked multiplet discharges (MDs) are related to severity of clinical deterioration in motor neuron disease (MND).Methods: Stimulated high-density surface electromyographic (HDsEMG) recordings were performed in thenar muscles. Data were collected from 31 MND patients. MDs from the HDsEMG recordings were determined at baseline. ALSFRS-R scores were obtained at baseline and at a maximum of 16 weeks follow-up.Results: The presence of MDs was associated with progressive deterioration of ALSFRS-R score (P = 0.02) and fine motor function (FMF) (P < 0.001). Patients who had a higher number of motor units that generated MDs (r = 0.61, P < 0.001) and patients who had a higher number of MDs (as percentage of applied stimuli) (r = 0.59, P = 0.001) had a more severe decline in FMF.Conclusions: Electrically evoked MDs are associated with more marked clinical deterioration in patients with MND. [ABSTRACT FROM AUTHOR]

Objective: To determine and compare the diagnostic accuracy of electrically elicited multiplet discharges (MDs) and fasciculation potentials (FPs) in motor neuron disease (MND).Methods: Patients were eligible when they had MND in their differential diagnosis and were referred for electromyogram (EMG). Stimulated high-density surface EMG of the thenar muscles was performed on the same day as standard EMG examination. High-density recordings were analysed for presence of MDs and needle EMG of any muscle investigated in the cervical region for presence of FPs.Results: Of the 61 patients enrolled in this diagnostic study, 24 patients were clinically diagnosed with amyotrophic lateral sclerosis (ALS) and 11 patients with progressive muscular atrophy (PMA). Another diagnosis was made in 26 patients. Sixteen patients in whom MDs were detected were diagnosed with either ALS (n = 11) or PMA (n = 5; sensitivity = 47.1%, PPV = 94.1%). MDs were detected in only one patient initially diagnosed with PMA, but in whom later on, multifocal motor neuropathy could not be excluded (specificity = 96.2%). Electrically elicited MDs had a higher specificity than FPs (96.2% vs 53.9%, p < 0.001, n = 26) and lower sensitivity (47.1% vs 85.3%, p = 0.002, n = 34). When considering presence of MDs in MND as neurogenic EMG abnormality, lower motor neuron involvement of ≥ 1 EMG region increased from 50% to 73.5% (p = 0.008, n = 34).Conclusions: Electrically evoked MDs are highly specific for ALS and PMA and are an early sign of lower motor neuron dysfunction. [ABSTRACT FROM AUTHOR]

Objective To determine whether there is a relation between electrically evoked multiplet discharges (MDs) and motor axonal excitability properties. We hypothesized that electrically evoked MDs share their underlying pathophysiological mechanism with fasciculations. Methods High-density surface EMG and motor nerve excitability recordings of the thenar muscles were performed in 22 patients with motor neuron disease (MND) in their differential diagnosis and who were referred for EMG examination. Results Supernormality (hyperexcitable phase following the refractory period) was significantly increased in patients with MDs ( n = 10) compared to patients without MDs ( n = 12) (25.5% vs 17.0%; p = 0.02). Depolarizing threshold electrotonus differed significantly between both groups as well (TEdpeak, 76.6% vs 66.6%, p < 0.01; TEd90-100 ms, 51.7% vs 44.3%, p < 0.01) Conclusions Our findings imply that the same pathophysiological excitability changes are involved in generating MDs and fasciculations. Yet, MDs may be quantified more easily, and may be more specific for abnormal distal excitability than fasciculations, because fasciculations may originate along the motor axon as well as in the neuron cell body. Significance MDs are potentially useful as objective measure of increased distal axonal excitability at individual motor unit level and might complement clinical studies in MND. [ABSTRACT FROM AUTHOR]

Abstract: Objective: (a) To relate MRI patterns of brain injury to somatosensory evoked potentials (SEPs), and (b) to determine the prognostic value of SEPs in addition to continuous EEG monitoring (cEEG) and cerebral imaging, in term asphyxiated newborns. Methods: Fifty one consecutive neonates were studied. Survivors were followed for at least 2years. cEEG, started within 24h, was done for ⩾24h and scored. SEPs and MRIs were performed in the first week. Brain injury patterns were classified. Results: Bilaterally abnormal SEPs had a sensitivity of 90% (28/31) and specificity of 85% (17/20) in predicting a poor outcome, defined as death or severe handicap. SEPs were of particular value in predicting outcome in isolated symmetrical white matter injury and predicting the development of hemiparesis in isolated asymmetrical watershed injury. Binary logistic regression analysis revealed a significant relation to outcome separately for cEEG, deep grey matter injury on MRI and SEPs. SEPs provided additional value when added to cEEG and MRI in the model (p =0.034). Conclusions: SEPs are of additional prognostic value after term birth asphyxia. Significance: In certain patterns of postasphyxial neonatal brain injury like asymmetrical watershed lesions and symmetrical white matter injury, EPs are complementary to information obtained from cEEG and MRI for prognostication. [Copyright &y& Elsevier]

“Evidence” in the form of data collected and analysis thereof is fundamental to medicine, health and science. In this paper, we discuss the “evidence-based” aspect of evidence-based medicine in terms of statistical inference, acknowledging that this latter field of statistical inference often also goes by various near-synonymous names—such as inductive inference (amongst philosophers), econometrics (amongst economists), machine learning (amongst computer scientists) and, in more recent times, data mining (in some circles). Three central issues to this discussion of “evidence-based” are (i) whether or not the statistical analysis can and/or should be objective and/or whether or not (subjective) prior knowledge can and/or should be incorporated, (ii) whether or not the analysis should be invariant to the framing of the problem (e.g. does it matter whether we analyse the ratio of proportions of morbidity to non-morbidity rather than simply the proportion of morbidity?), and (iii) whether or not, as we get more and more data, our analysis should be able to converge arbitrarily closely to the process which is generating our observed data. For many problems of data analysis, it would appear that desiderata (ii) and (iii) above require us to invoke at least some form of subjective (Bayesian) prior knowledge. This sits uncomfortably with the understandable but perhaps impossible desire of many medical publications that at least all the statistical hypothesis testing has to be classical non-Bayesian—i.e. it is not permitted to use any (subjective) prior knowledge. [ABSTRACT FROM AUTHOR]

A list of the journal's reviewers for 2010 is presented including Ganesh Acharya, Anuprily Agarwal and Mark Alanis.