Efficacy of a cognitive intervention program in patients with mild cognitive impairment.

BACKGROUND: Mild cognitive impairment (MCI) is a transitional state between normal aging and dementia. Identifying this condition would allow early interventions that may reduce the rate of progression to Alzheimer's disease (AD). We examined the efficacy of a six-month cognitive intervention program (CIP) in patients with MCI and to assess patients' condition at one-year follow-up. METHODS: Forty-six MCI participants assessed with neuropsychological, neurological, neuropsychiatry, and functional procedures were included in this study and followed up during a year. The sample was randomized into two subgroups: 24 participants (the "trained group") underwent the CIP during six months while 22 (control group) received no treatment. Sixteen participants dropped out of the study. The intervention focused on teaching cognitive strategies, cognitive training, and use of external aids, in sessions of two hours, twice per week for six months. Cognitive and functional measures were used as primary outcome and all were followed up at one year. RESULTS: The intervention effect (mean change from baseline) was significant (p < 0.05) on the Mini-Mental State Examination (1.74), the Clinical Dementia Rating Scale (0.14), the Boston Naming Test (2.92), block design (-13.66), matrix reasoning (-3.07), and semantic fluency (-3.071) tasks. Four patients (one trained and three controls) progressed to dementia after one year of follow-up. CONCLUSIONS: These results suggest that persons with MCI can improve their performance on cognitive and functional measures when provided with early cognitive training and it could persist in a long-term follow-up.

Neural Networks for Beat Perception in Musical Rhythm.

Entrainment of cortical rhythms to acoustic rhythms has been hypothesized to be the neural correlate of pulse and meter perception in music. Dynamic attending theory first proposed synchronization of endogenous perceptual rhythms nearly 40 years ago, but only recently has the pivotal role of neural synchrony been demonstrated. Significant progress has since been made in understanding the role of neural oscillations and the neural structures that support synchronized responses to musical rhythm. Synchronized neural activity has been observed in auditory and motor networks, and has been linked with attentional allocation and movement coordination. Here we describe a neurodynamic model that shows how self-organization of oscillations in interacting sensory and motor networks could be responsible for the formation of the pulse percept in complex rhythms. In a pulse synchronization study, we test the model's key prediction that pulse can be perceived at a frequency for which no spectral energy is present in the amplitude envelope of the acoustic rhythm. The result shows that participants perceive the pulse at the theoretically predicted frequency. This model is one of the few consistent with neurophysiological evidence on the role of neural oscillation, and it explains a phenomenon that other computational models fail to explain. Because it is based on a canonical model, the predictions hold for an entire family of dynamical systems, not only a specific one. Thus, this model provides a theoretical link between oscillatory neurodynamics and the induction of pulse and meter in musical rhythm.

Carcinoma colorrectal y colecistectomía / Colorectal carcinoma and cholecystectomy

En un estudio epidemiológico en pacientes mayores de 60 años con carcinoma colorrectal (301 casos) la incidencia de colecistectomía previa fue de 11%. En el grupo control de 1.000 personas mayores de 60 años hubo un 9,8%. La diferencia entre ambos grupos no es estadísticamente significativa. Tampoco hubo diferencia en cuanto a la distribuición por sexos y la localización de los tumores cuando se los relacionó a una colecistectomía previa