Cognitive impairment among World Trade Center responders: Long-term implications of re-experiencing the 9/11 terrorist attacks

The hypothesis that rapid eye movement (REM) sleep disturbances are the hallmark of posttraumatic stress disorder (PTSD), proposed by Ross and colleagues in 1989, has stimulated a wealth of clinical, preclinical, and animal studies on the role of sleep in the pathophysiology of PTSD. The present review revisits this influential hypothesis in light of clinical and experimental findings that have since accumulated. Polysomnographic studies conducted in adults with PTSD have yielded mixed findings regarding REM sleep disturbances, and they generally suggest modest and nonspecific sleep disruptions. Prospective and treatment studies have provided more robust evidence for the relationship between sleep disturbances and psychiatric outcomes and symptoms. Experimental animal and human studies that have probed the relationship between REM sleep and fear responses, as well as studies focused more broadly on sleep-dependent affective and memory processes, also provide strong support for the hypothesis that sleep plays an important role in PTSD-relevant processes. Overall, the literature suggests that disturbed REM or non-REM sleep can contribute to maladaptive stress and trauma responses and may constitute a modifiable risk factor for poor psychiatric outcomes. Clinicians need to consider that the chronic sleep disruption associated with nightmares may affect the efficacy of first-line PTSD treatments, but targeted sleep treatments may accelerate recovery from PTSD. The field is ripe for prospective and longitudinal studies in high-risk groups to clarify how changes in sleep physiology and neurobiology contribute to increased risk of poor psychiatric outcomes.

Cross validation study of the MoCA for the detection of Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) in a community-based cohort residing in the Southeastern United States. One hundred and eighteen English-speaking older adults, who underwent diagnostic evaluation as part of an on-going prospective study, were administered the MoCA and MMSE. Twenty were diagnosed with AD, 24 met criteria for amnestic MCI and 74 were considered cognitively normal. Sensitivities and specificities were calculated using the recommended cut-off scores and ROC curve analyses were performed to determine optimal sensitivity and specificity. The influence of age, education and gender on MoCA score was also examined. Using a cut-off score of 24 or below, the MMSE was insensitive to cognitive impairment. Using the recommended cut-off score of 26, the MoCA detected 97% of those with cognitive impairment but specificity was fair (35%). Using a lower cut-off score of 23, the MoCA exhibited excellent sensitivity (96%) and specificity (95%). The MoCA appears to have utility as a cognitive screen for early detection of AD and for MCI and warrants further investigation regarding its applicability in primary care settings, varying ethnic groups, and younger at-risk individuals. (c) 2008 John Wiley & Sons, Ltd.

Posttraumatic stress disorder (PTSD) is highly prevalent among US veterans because of combat and may impair cognition. To determine whether PTSD is associated with the risk of developing dementia among older US veterans receiving treatment in the Department of Veterans Affairs medical centers. A stratified, retrospective cohort study conducted using the Department of Veterans Affairs National Patient Care Database. Department of Veterans Affairs medical centers in the United States. A total of 181 093 veterans 55 years or older without dementia from fiscal years 1997 through 2000 (53 155 veterans with and 127 938 veterans without PTSD). During the follow-up period between October 1, 2000, and December 31, 2007, 31 107 (17.2%) veterans were ascertained to have newly diagnosed dementia according to International Classification of Diseases, Ninth Revision, Clinical Modification codes. The mean baseline age of the veterans was 68.8 years, and 174 806 (96.5%) were men. Veterans with PTSD had a 7-year cumulative incident dementia rate of 10.6%, whereas those without had a rate of 6.6% (P < .001). With age as the time scale, Cox proportional hazards models indicated that patients with PTSD were more than twice as likely to develop incident dementia compared with those without PTSD (hazard ratio, 2.31; 95% confidence interval, 2.24-2.39). After multivariable adjustment, patients with PTSD were still more likely to develop dementia (hazard ratio, 1.77; 95% confidence interval, 1.70-1.85). Results were similar when we excluded those with a history of head injury, substance abuse, or clinical depression. In a predominantly male veteran cohort, those diagnosed as having PTSD were at a nearly 2-fold-higher risk of developing dementia compared with those without PTSD. Mechanisms linking these important disorders need to be identified with the hope of finding ways to reduce the increased risk of dementia associated with PTSD.