Search

There is an emerging belief that electrically elicited blink reflexes (BR) may distinguish Alzheimer's disease (AD) from other disorders characterized by memory dysfunction. To qualitatively and quantitatively distinguish the effects that electrical stimulation has over the blink reflex (eBR) recorded from patients with AD and healthy controls (HCs), we did a systematic review of the literature, and conducted a meta-analysis. Following our selected criteria, 94 AD patients and 97 HCs were identified from articles published in English between 1950 and 2017. Although the 3 responses (R1, R2 and R3) of the eBR were studied in a number of patients, only the R2 response was quantified in all studies. Thresholds and stimulation intensities parameters were found to be used in a miscellaneous form, and the majority of times, such parameters deviated from validated guidelines. The stimulation frequencies used to elicit the BR responses ranged between 0.14 and 0.2 Hz. These frequencies favored HCs compared with AD patients (odds ratio = 1.08; 95% CI = 0.30-1.85), I 2 = 0% [ P = .99]; Q = 271.89 [ df = 7, P < .000]). Egger's regression test suggested publication bias (intercept = 32.38; 95% CI = -8.98 to -3.2; P = .001). Our results unveiled key shortcomings in the data reported; such shortcomings need to be corrected in future AD research looking for obtaining more reliable and reproducible eBR studies; otherwise, interventions may be misleading.

The content of the rectified motor evoked potential (MEP) induced by transcranial magnetic stimulation (TMS) has ambiguously been assessed without the precision that energy calculation deserves. This fact has misled data interpretation and misguided biomedical interventions. To definitively fill the gap that exits in the neurophysics processing of these signals, we computed, in Walls ( W ^ ), the bioenergy within the rectified MEP recorded from the human first digitorum index (FDI) muscle at rest and under isometric contraction. We also gauged the biowork exerted by this muscle. Here we show that bioenergy and biowork can accurately and successfully be assessed, validated, and determined in W ^ from MEP signals induced by TMS, regardless of knowing the mathematical expression of the function of the signal. Our novel neurophysics approach represents a dramatic paradigm shift in analysis and interpretation of the content of the MEP and will give a true meaning to the content of rectified signals. Importantly, this innovative approach allowed unveiling that women exerted more bioenergy than men at the magnetic stimulations used in this study. Revisitation of conclusions drawn from studies published elsewhere assessing rectified EMG signals that have used ambiguous units is strongly recommended., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this article.

Foramen magnum meningiomas represent a challenge for neurosurgeons. These tumors require careful surgical manipulation as they are often located in proximity to critical neurovascular structures and the cranial nerves. The far lateral approach is considered the safest neurosurgical approach for excising foramen magnum lesions. It facilitates the access to the anterior foramen magnum and reduces the retraction of vital structures. We describe key historical, epidemiological, genetic, epigenetic, clinical, and neurosurgical aspects of foramen magnum meningiomas. We emphasize the far lateral approach for lesions arising in the foramen magnum, as well as the most appropriate patient positioning for such approach. Caring for these aspects will be rewarded with the best perioperative neurosurgical outcomes., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: The jiggle of the motor evoked potential (MEP) induced by transcranial magnetic stimulation (TMS) depends on a number of factors including the assessment of this stochastic signal by the method known as area under curve (AUC). We aim to ascertain the MEP findings assessed by the AUC method obtained from individuals affected by lesions at different levels of the neuroaxis., Methods: We systematically search and critically appraise the scientific reports publishing on the MEP obtained from individuals with hypo- or hyperkinetic disorders of the neural system, and dissect the neurophysical assessment of the obtained data. To accomplish this, we used the instruments named to as U-Pen Instrument for Neurometric Evaluation Uncommonly and Rarely Obtained from NeuroSignals 1.0 (UPINEURON 1.0), and the Quality of Assessment Statistics Index (QuASI)., Results: The MEP differences found by the classical peak-to-peak method decreased or disappeared when the AUC was used. The opposite was also true (Kappa=<0.00). The internal consistency of the UPINEURON was 0.88. The mean of the UPINEURON 1.0 indicator was 34.8 (range=16-50), and the mean of the QuASI scores was 56.5 (range 30-80). Spearman correlation between UPINEURON 1.0 and QuASI was 0.513., Conclusions: The MEP jiggle found in individuals with disordered neural function is not a "minor" factor; it is beyond the underlying neural condition, sample size, type of coils, and number of trials, among other variables. The use of the novel indicators introduced in this investigation will help to improve the analysis of the AUC of neural signals. They may also lead to the reconsideration of current practices., (Copyright © 2015 Elsevier Inc. All rights reserved.)