Examinando por Autor "Leon-Ariza, Daniel S."

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    Auditory and Lower Limb Tactile Prepulse Inhibition in Primary Restless Legs Syndrome : Clues to Its Pathophysiology
    (2015-08) Leon-Sarmiento, Fidias E.; Peckham, Elizabeth; Leon-Ariza, Daniel S.; Bara Jimenez, William; Hallett, Mark
    The resting sensory discomfort transiently relieved upon movement of the affected area in restless legs syndrome suggests that sensorimotor integration mechanisms, specifically gating, may be altered in the disease. The authors sought to determine the effects of prepulse auditory and tactile stimulation applied to lower limbs on the blink reflex of patients with restless legs syndrome and healthy subjects. Seventeen patients with restless legs syndrome and 17 age- and sex-matched healthy controls were investigated. Auditory stimuli and tactile lower limb stimulation were applied as prepulses. The R2 response of the blink reflex induced by electrical stimulation applied to the right supraorbital nerve was selected as the test stimulus. Time intervals between prepulses and response-eliciting stimuli were 40, 70, 90, 110, and 200 milliseconds. There were no differences in either the auditory or tactile prepulse conditions between patients and controls and no differences between these measures within subject groups. We concluded that the tactile lower limb and the auditory prepulse effects on the brainstem interneurons mediating the blink reflex share common neural pathways. Because forebrain interneurons mediate these prepulse effects, they are likely not involved in the disordered sensorimotor interaction of restless legs syndrome.
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    Chemosensory disturbances-associated nanocholinergic dysfunction : The case of, not only, myasthenia gravis
    (2015-09-01) Leon Sarmiento, Fidias E.; Leon-Ariza, Juan S.; Prada, Diddier G.; Leon-Ariza, Daniel S.
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    Corrigendum to "A new neurometric dissection of the area-under-curve-associated jiggle of the motor evoked potential induced by transcranial magnetic stimulation"
    (2015-12-01) Leon-Sarmiento, Fidias E.; Rizzo Sierra, Carlos V.; Leon-Ariza, Juan S.; Leon-Ariza, Daniel S.; Sobota, Rosanna; Prada, Diddier G.
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    Key Aspects in Foramen Magnum Meningiomas: From Old Neuroanatomical Conceptions to Current Far Lateral Neurosurgical Intervention
    (2017-10) Leon-Ariza, Daniel S.; Campero, Alvaro; Romero Chaparro, Rubby J.; Prada, Diddier G.; Vargas Grau, Gabriel; Rhoton Jr., Albert L.
    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.
  • Publicación
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    A new neurometric dissection of the area-under-curve-associated jiggle of the motor evoked potential induced by transcranial magnetic stimulation
    (2015-02-14) Leon-Sarmiento, Fidias E.; Rizzo Sierra, Carlos V.; Leon-Ariza, Juan S.; Leon-Ariza, Daniel S.; Sobota, Rosanna; Prada, Diddier G.
    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.
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    Remote dysfunctions in spinal cord injury : Closer than ever
    (2015-04-04) Leon-Ariza, Daniel S.; Leon-Ariza, Juan S.; Bayona, Edgardo A.; Bayona Prieto, Jaime; Leon-Sarmiento, Fidias E.
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    Sensory aspects in myasthenia gravis : A translational approach
    (2016-09-15) Leon-Sarmiento, Fidias E.; Leon-Ariza, Juan S.; Prada, Diddier G.; Leon-Ariza, Daniel S.; Rizzo Sierra, Carlos V.
    Myasthenia gravis is a paradigmatic muscle disorder characterized by abnormal fatigue and muscle weakness that worsens with activities and improves with rest. Clinical and research studies done on nicotinic acetylcholine receptors have advanced our knowledge of the muscle involvement in myasthenia. Current views still state that sensory deficits are not “features of myasthenia gravis”. This article discusses the gap that exists on sensory neural transmission in myasthenia that has remained after > 300 years of research in this neurological disorder. We outline the neurobiological characteristics of sensory and motor synapses, reinterpret the nanocholinergic commonalities that exist in both sensory and motor pathways, discuss the clinical findings on altered sensory pathways in myasthenia, and propose a novel way to score anomalies resulting from multineuronal inability associated sensory troubles due to eugenic nanocholinergic instability and autoimmunity. This medicine-based evidence could serve as a template to further identify novel targets for studying new medications that may offer a better therapeutic benefit in both sensory and motor dysfunction for patients. Importantly, this review may help to re-orient current practices in myasthenia.
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    The Vagus Nerve Somatosensory-evoked Potential in Neural Disorders: Systematic Review and Illustrative Vignettes
    (2021-03-12) Leon-Ariza, Juan S.; Mosquera, Mario A.; Siomin, Vitaly; Fonseca, Angelo; Leon-Ariza, Daniel S.; Gualdron, Mayra A.; Leon-Sarmiento, Fidias E.; Salud Comuniudes
    Objective. To review the scientific publications reporting vagal nerve somatosensory-evoked potential (VSEP) findings from individuals with brain disorders, and present novel physiological explanations on the VSEP origin. Methods. We did a systematic review on the papers reporting VSEP findings from individuals with brain disorders and their controls. We evaluated papers published from 2003 to date indexed in PubMed, Web of Science, and Scielo databases. We extracted the following information: number of patients and controls, type of neural disorder, age, gender, stimulating/recording and grounding electrodes as well as stimulus side, intensity, duration, frequency, and polarity. Information about physiological parameters, neurobiological variables, and correlation studies was also reviewed. Representative vignettes were included to add support to our conclusions. Results. The VSEP was studied in 297 patients with neural disorders such as Parkinson’s disease (PD), Alzheimer’s disease, vascular dementia, mild cognitive impairment, subjective memory impairment, major depression, and multiple sclerosis. Scalp responses marked as the VSEP showed high variability, low validity, and poor reproducibility. VSEP latencies and amplitudes did not correlate with disease duration, unified PD rating scale score, or heart function in PD patients nor with cerebrospinal fluid β amyloid, phosphor-τ, and cognitive tests from patients with mental disorders. Vignettes demonstrated that the VSEP was volume conduction propagating from muscles surrounding the scalp recording electrodes. Conclusion. The VSEP is not a brain-evoked potential of neural origin but muscle activity induced by electrical stimulation of the tragus region of the ear. This review and illustrative vignettes argue against assessing the parasympathetic system using the so-called VSEP.