0861 Age, Race, And Continuous Positive Airway Pressure (CPAP) Confidence Score At 1-week Predict 3-month CPAP Adherence In Older Adults With Amnestic Mild Cognitive Impairment And Moderate To Severe Obstructive Sleep Apnea

Introduction

Adherence to continuous positive airway pressure (CPAP) may delay cognitive decline in older adults with obstructive sleep apnea (OSA) and amnestic mild cognitive impairment (MCI), defined as deficits in memory that do not significantly impact daily functioning. The aim of this analysis was to identify predictors of CPAP adherence in this population.

Methods

Data are from Memories 2, an ongoing multisite clinical trial on the effect of treatment of moderate to severe OSA on cognitive decline in older adults 65-85 years of age who have amnestic MCI. Unadjusted and adjusted linear models were used to examine predictors of mean hours of CPAP use at 3 months. Predictors were age, sex (male/female), race (White/Non-White), education (more than high school, less than high school), Apnea-hypopnea index (AHI), Epworth Sleepiness Scale (ESS), and CPAP Comfort and Confidence scores at 7 days. Collinearity in the adjusted model for CPAP use at 3 months was examined using the variance inflation factor.

Results

Of 57 participants, most were male (54%), White (72%), with a mean age of 66.3 years (SD: 6.1). Mean AHI in this sample was 35.1 (SD: 19.9), with mean daily hours of CPAP use at 3 months 5.3 hours (SD: 2.3). Adjusted linear model results demonstrated that younger age (β=-0.13, SE=0.04, p=0.0032), White race (β=2.56, SE=0.58, p<0.0001), and higher 7-day CPAP Confidence score (β=0.48, SE=0.17, p=0.0086) were significantly associated with CPAP use at 3 months. Sex, education, AHI, ESS, and CPAP comfort were not statistically significant predictors of adherence.

Conclusion

Tailored interventions to increase self-efficacy during the first 7 days of CPAP treatment, especially in Non-Whites and those older than 74 years, may improve long-term CPAP adherence in older adults with amnestic MCI.

Support

R01AG054435

Effect of retrieval effort and switching demand on fMRI activation during semantic word generation in schizophrenia

Verbal fluency deficits in schizophrenia are difficult to interpret because the tasks are multi-factorial and groups differ in total words generated. We manipulated retrieval and switching demands by requiring alternation between over-learned sequences in which retrieval is relatively automatic (OS) and semantic categories requiring increased retrieval effort (SC). Controlled processing was also manipulated by including switching and non-switching conditions, and formal thought disorder (FTD) was assessed with the communication disorders index (CDI). The OS/SC semantic fluency paradigm was administered during fMRI to 13 patients with schizophrenia and 14 matched controls. Images were acquired on a 3 Tesla Siemens scanner using compressed image acquisition to allow for cued overt word production. Subjects alternated between OS, SC, OS-switch, SC-switch, and baseline blocks. Images were pre-processed in SPM-2, and a two-stage random effects analysis tested within and between group contrasts. There were no group performance differences. fMRI analysis did not reveal any group differences during the OS non-switching condition. Both groups produced expected activation in bilateral prefrontal and inferior parietal regions. However, during the SC condition patients had greater activation than controls in left prefrontal, right anterior cingulate, right superior temporal, bilateral thalamus, and left parietal regions. There was also evidence of patient over-activation in prefrontal, superior temporal, superior parietal, and visual association areas when a switching component was added. FTD was negatively correlated with BOLD response in the right anterior cingulate, cuneus and superior frontal gyrus during increased retrieval demand, and positively correlated with fMRI activation in the left lingual gyrus, right fusiform gyrus and left superior parietal lobule during increased switching demand. These results indicate that patients are able to successfully perform effortful semantic fluency tasks during non-speeded conditions. When retrieval is relatively automatic there does not appear to be an effect of schizophrenia on fMRI response. However, when retrieval and controlled processing demands increase, patients have greater activation than controls despite unimpaired task performance. This inefficient BOLD response may explain why patients are slower and less accurate on standard self-paced fluency tasks.

Controlled and automatic processing during animal word list generation in schizophrenia

Controlled and automatic aspects of semantic-associative functioning in schizophrenia were investigated by evaluating performance on animal word list generation (WLG). Responses from control (n = 47) and patient (n = 38) participants were subjected to multidimensional scaling (MDS), cluster analysis (CA), and indices on the basis of number of shared attributes (SA) between consecutive responses. Patient MDS results accounted for less variance and contained more error than control data. CA results yielded fewer and less clear animal-response subgroups among patients yet demonstrated intact associations among strongly related exemplars. The SA indices revealed better clustering and more effective switching among response clusters in controls than patients. Results suggest that animal WLG in schizophrenia is compromised both by aberrant automatic semantic-associative network activation and by controlled processes such as search, access, and selection. This pattern is consistent with prominent frontotemporal pathology evident in the disorder.

Seatbelts contribute to location of lesion in moderate to severe closed head trauma

The relationship between seatbelt use and injury severity, brain lesion location, and functional outcome was investigated in 163 individuals who sustained traumatic brain injuries in motor vehicle collisions. Of this group, 31 were using a seatbelt at the time of the accident and 132 were not. Restrained motor vehicle occupants were significantly more likely to sustain damage to subcortical brain structures than unrestrained occupants. Conversely, unrestrained occupants sustained a greater frequency of posterior brain lesions. In addition, demographic and behavioral variables were significantly related to increased likelihood of seatbelt use. Analyses revealed no significant differences between groups for injury severity variables and functional outcome measures. Seatbelts alter the body's response to forces applied in motor vehicle collisions, creating disparities in lesion sites between restrained and unrestrained motor vehicle occupants. The relationship between seatbelt use and injury severity and functional outcome is discussed.