Lukas Tamayo-Orrego

Actividad Muscular y Fuerza Muscular en la Deglución Atípica

Objective: To characterize muscle activity and muscle strength in patients with atypical swallowing (AS; n = 88) and competent lips (CL) or incompetent lips (IL) versus a control group (Ctrl; n = 90) Methods and materials: an analytical case-control study was conducted using surface electromyography (sEMG) of the orbicularis oris, mentalis and masseter muscles. Compression forces of the orbicularis oris, right and left masseters muscle (Cfrmm, Cflmm)) , tongue tensile strength (Tts) via myoscan analysis and resistance of the orbicularis oris (Roo) via dynamometry were determined. Comparisons were made with the Mann-Whitney U test under a 95% confidence interval. Results: The amplitude of the sEMG record of the orbicularis oris muscle, in maximal contraction, was lower (p<0.01) in the atypical swallowing group (596.40 ± 175.83) compared to controls (659.83 ± 203.79). The muscle strength studied in the experimental group was lower (p<0.01) than in controls (CFo: AS: 0.31 ± 0.13; Ctrl: 0.38 ± 0, 11; Cfrmm: AS: 0.40 ± 0.08; Ctrl: 0.50 ± 0.11; Cflmm: AS: 0.41 ± 0.08; Ctrl: 0.58 ± 0.59; Tts, AS: 0.52 ± 0.14, Ctrl: 0.65 ± 0.14, and Roo: AS: 2.47 ± 0.61; Ctrl: 2.73 ± 0.60). Patients with incompetent lips had a greater muscle activity of the orbicularis oris in swallowing (AS of IL: 197.01 ± 85.84; AS of CL: 160.54 ± 97.03; Ctrl: 147.18 ± 80.10). Conclusion: Patients with atypical swallowing showed differences in the strength of studied muscles and the muscle activity of the orbicular oris muscle compared to controls.

Artículo originalEfecto diferencial del subtipo clínico en los potenciales evocados cognitivos de pacientes con déficit de atención e hiperactividadDifferential effects of Attention deficit/hyperactivity disorder subtypes in event-related potentials

BACKGROUND To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. METHODS A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. RESULTS ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. CONCLUSIONS The results show differences in the event-related potentials between combined and inattentive ADHD subjects.

Efecto diferencial del subtipo clínico en los potenciales evocados cognitivos de pacientes con déficit de atención e hiperactividad

BACKGROUND To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. METHODS A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. RESULTS ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. CONCLUSIONS The results show differences in the event-related potentials between combined and inattentive ADHD subjects.

Protocol for the combination of neurohistological techniques on vibratome obtained sections

INTRODUCTION The histological study of the nervous system requires the use of special techniques. Currently, no methods are available to visualize simultaneously all the cellular constituents of nervous tissue. OBJECTIVES A protocol was adapted for staining nervous tissue by modification of a formerly difficult procedure. MATERIALS AND METHODS Slices of brain and spinal cord, 4 mm thick, were taken from adult mice, previously fixed by intracardiac perfusion with 4% paraformaldehyde. Vibratome sections were obtained with thickness of 15-25 µm. These were mounted on glass slides prepared with gelatin as an adhesive. The preparations were subjected to staining protocol Luxol Fast Blue-PAS-hematoxylin (LPH) combined with silver staining method (LPH-Holmes). RESULTS LPH technique yielded an excellent differentiation of gray and white matter in all regions of the nervous system. A panoramic view of the gray matter was colored pink in contrast to the myelinated nerve fibers and tracts which were light blue. The combination LPH-Holmes retained the staining characteristics but significantly improved the demarcation of axons and tracts. CONCLUSIONS A protocol was standardized for the LPH and LPH-Holmes nervous tissue stains applied in combination to tissue slices obtained with a vibratome. The method was shorter, less wasteful and less expensive than the original and also better preserved the integrity of nervous tissue.