Effect of a High-Intensity Tandem Bicycle Exercise Program on Clinical Severity, Functional Magnetic Resonance Imaging, and Plasma Biomarkers in Parkinson's Disease.

Rationale: The optimal modality, intensity, duration, frequency, and dose-response of exercise as a therapy for Parkinson's Disease (PD) are insufficiently understood. Objective: To assess the impact of a high-intensity tandem bicycle program on clinical severity, biomarkers, and functional MRI (fMRI) in PD. Methods: A single-center, parallel-group clinical trial was conducted. Thirteen PD patients aged 65 or younger were divided in two groups: a control group and an intervention group that incorporated a cycling program at 80% of each individual's maximum heart rate (HR) (≥80 rpm), three times a week, for 16 weeks. Both groups continued their conventional medications for PD. At baseline and at the end of follow-up, we determined in all participants the Unified Parkinson's Disease Rating Scale, anthropometry, VO2max, PD biomarkers, and fMRI. Results: VO2max improved in the intervention group (IG) (+5.7 ml/kg/min), while it slightly deteriorated in the control group (CG) (-1.6 ml/kg/min) (p = 0.041). Mean Unified Parkinson's Disease Rating Scale (UPDRS) went down by 5.7 points in the IG and showed a small 0.9-point increase in the CG (p = 0.11). fMRI showed activation of the right fusiform gyrus during the motor task and functional connectivity between the cingulum and areas of the frontal cortex, and between the cerebellar vermis and the thalamus and posterior temporal gyrus. Plasma brain-derived neurotrophic factor (BDNF) levels increased more than 10-fold in the IG and decreased in the CG (p = 0.028). Larger increases in plasma BDNF correlated with greater decreases in UPDRS (r = -0.58, p = 0.04). Conclusions: Our findings suggest that high-intensity tandem bicycle improves motor function and biochemical and functional neuroimaging variables in PD patients. Trial registration number: ISRCTN 13047118, Registered on February 8, 2018.

Developing a Social Cognition Task for fMRI in Patients with Mild Traumatic Brain Injury / Desarrollo de una tarea de Cognición Social para IRMf en pacientes con trauma craneoencefálico leve

Social cognition impairments are frequently found in patients with mild traumatic brain injury (TBI) when structural lesions may not reveal the severity of the injury. Though instruments used to assess social behavior are thought to be sensitive, the absence of structural damage in TBI patients may lead to underscore such problems. The aim of this study was to develop a complementary diagnostic tool such as a paradigm for functional Magnetic resonance Imaging (fMRI) involving a simple task that could tell how patients understand certain complex social behavior by identifying different movements with or without social intentions where language and complex cognitive process were not required. Eleven patients with mild TBI and social cognition difficulties and twelve control subjects were matched by demographic variables. A paradigm of social fMRI was developed by using dots in movement representing human motion, human motion with social intention such as dancing or sharing, and dots moving without meaning. Patients had less activation in parietotemporal junction and bilateral middle frontal gyrus in the social perception task movement compared with control group subjects. The fMRI paradigm developed can be an additional diagnostic tool for identifying social cognition impairments in mild TBI patients. Regardless the absence of structural injury, changes in activation areas suggest a prospective use of this tool since clinical, cognitive and functional outcomes support such finding.

Los cambios en la cognición social son encontrados frecuentemente en pacientes con trauma craneoencefálico leve (TCE) aunque no exista evidencia de lesiones estructurales. Aunque los instrumentos utilizados para evaluar la cognición social son sensibles al cambio, la ausencia de daño estructural en los pacientes con TCE puede llevar pasar por inadvertidos estos problemas. El objetivo de este estudio fue desarrollar una herramienta diagnóstica complementaria como un paradigma para resonancia magnética funcional (RMf), la cual involucra una tarea simple que pudiera explicar cómo los pacientes entienden ciertos comportamientos sociales complejos por medio de movimientos con o sin intención social sin intermediación del lenguaje. Participaron once pacientes con TCE leve y con reporte de alteraciones en cognición social, estos fueron emparejados con doce sujetos control por variables demográficas. Un paradigma de RMf fue desarrollado por medio de la animación puntos blancos sobre una pantalla negra que representan el movimiento humano, el movimiento humano con la intención social como el baile o el compartir, y puntos que se mueven sin significado. Los pacientes tuvieron menos activación en la unión parietotemporal y giro frontal medio bilateral frente al movimiento social en comparación con los sujetos del grupo de control. El paradigma de fMRI desarrollado puede ser una herramienta de diagnóstico adicional para identificar las alteraciones cognitivas sociales en pacientes con TCE leve. Independientemente de la ausencia de lesión estructural, los cambios en las áreas de activación sugieren la posibilidad de usar esta herramienta como pronóstico dado que los resultados clínicos, cognitivos y funcionales soportan este hallazgo.