VA Palo Alto Healthcare System

About: VA Palo Alto Healthcare System is a healthcare organization based out in Palo Alto, California, United States. It is known for research contribution in the topics: Population & Health care. The organization has 2548 authors who have published 4605 publications receiving 209938 citations.

Response of the human circadian system to millisecond flashes of light.

Abstract: Ocular light sensitivity is the primary mechanism by which the central circadian clock, located in the suprachiasmatic nucleus (SCN), remains synchronized with the external geophysical day. This process is dependent on both the intensity and timing of the light exposure. Little is known about the impact of the duration of light exposure on the synchronization process in humans. In vitro and behavioral data, however, indicate the circadian clock in rodents can respond to sequences of millisecond light flashes. In a cross-over design, we tested the capacity of humans (n = 7) to respond to a sequence of 60 2-msec pulses of moderately bright light (473 lux) given over an hour during the night. Compared to a control dark exposure, after which there was a 3.5±7.3 min circadian phase delay, the millisecond light flashes delayed the circadian clock by 45±13 min (p<0.01). These light flashes also concomitantly increased subjective and objective alertness while suppressing delta and sigma activity (p<0.05) in the electroencephalogram (EEG). Our data indicate that phase shifting of the human circadian clock and immediate alerting effects can be observed in response to brief flashes of light. These data are consistent with the hypothesis that the circadian system can temporally integrate extraordinarily brief light exposures.

Diabetes self-management support using mHealth and enhanced informal caregiving

Abstract: Objective To characterize diabetes patient engagement and clinician notifications for an mHealth interactive voice response (IVR) service. Design Observational study. Methods For three to six months, VA patients with diabetes received weekly IVR calls assessing health status and self-care along with tailored education. Patients could enroll with an informal caregiver who received suggestions on self-management support. Notifications were issued to clinicians when patients reported significant problems. Results Patients (n = 303) participated for a total of 5684 patient-weeks, during which 84% of calls were completed. The odds of call completion decreased over time (AOR = 0.96, p Conclusions By providing information that is reliable, valid, and actionable, IVR-based mHealth services may increase access to between-visit monitoring and diabetes self-management support. The system detects abnormal glycemia and blood pressure levels that might otherwise go unreported, although thresholds for clinician notifications might require adjustment to avoid overloading clinicians. Patient engagement might be enhanced by addressing health literacy and psychological distress.

The contributions of self-reported injury characteristics and psychiatric symptoms to cognitive functioning in OEF/OIF veterans with mild traumatic brain injury.

Abstract: Mild traumatic brain injury (mTBI) affects a significant number of combat veterans returning from Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF). Although resolution of mTBI symptoms is expected over time, some individuals continue to report lingering cognitive difficulties. This study examined the contributions of self-reported mTBI injury characteristics (e.g., loss of consciousness, post-traumatic amnesia) and psychiatric symptoms to both subjective and objective cognitive functioning in a sample of 167 OEF/OIF veterans seen in a TBI clinic. Injury characteristics were not associated with performance on neuropsychological tests but were variably related to subjective ratings of cognitive functioning. Psychiatric symptoms were highly prevalent and fully mediated most of the relationships between injury characteristics and cognitive ratings. This indicates that mTBI characteristics such as longer time since injury and loss of consciousness or post-traumatic amnesia can lead to increased perceived cognitive deficits despite having no objective effects on cognitive performance. Psychiatric symptoms were associated with both cognitive ratings and neuropsychological performance, illustrating the important role that psychiatric treatment can potentially play in optimizing functioning. Finally, subjective cognitive ratings were not predictive of neuropsychological performance once psychiatric functioning was statistically controlled, suggesting that neuropsychological assessment provides valuable information that cannot be gleaned from self-report alone. (JINS, 2012, 18, 576–584)