Description

1. Objective(s): The key goal of this project is to develop methods for objectively monitoring and, ultimately, predicting outbursts of aberrant behaviors commonly seen among patients with a variety of neuropsychiatric conditions: dementia, PTSD, TBI, and schizophrenia. This initial study will be on patients with dementia. The analytic focus is on the measurement of electrodermal activity (EDA), a widely-studied physiological recording that indicates sympathetic tone; the central hypothesis in this approach is that sympathetic tone will increase prior to an outburst and, therefore, may allow therapeutic interventions to prevent it. Alterations of sympathetic activity have been implicated in the literature for each of these four conditions. Here, EDA recording holds the advantages of requiring neither effort nor communication on the part of the subject, and of being a noninvasive procedure. These factors make EDA potentially useful for the clinical assessment of arousal among patients with dementia, which will be the first of the specific groups studied under this protocol.
2. Research Design: The general design of all of these studies is the monitoring of EDA in subjects with a small device that can be worn on the wrist, ankle or arm; patterns of spontaneous EDA will then be assessed for features that may predict the occurrence of an outburst. In the initial study of dementia patients, the investigators will first survey EDA responses in commonly used paradigms (e.g., visual stimulus, EDA response). Currently, little is known about EDA in this population, and the investigators redress this by (1) establishing behavioral and physiological baselines for each subject in the study, (2) determining how these two classes of dependent measures cohere, and (3) evaluating whether patterns of EDA differ as a function of aberrant behaviors that are often seen in dementia: wandering, combativeness, and "sundowning" (agitation that typically develops late in the day). These behaviors are often grouped in the literature under the term "disorders of arousal", and are clinically well known to present as signs of disorientation and in some cases, distress. (4) Moreover, quantitative assessment of EDA change conceivably may reveal patterns that may signal the onset of problem behaviors.

Each subject will serve as his/her own control, providing within-subject measures of EDA signal over time and its correlation with aberrant behaviors. It is worth noting that the key EDA measures are not subject to bias based on experimenter ratings. Further, the aberrant behaviors will also be rated over time, using quantitative rating scales for each of them. In a second class of analyses, the investigators will perform group contrasts of subjects with and without these aberrant behaviors, as operationally defined by rating scales, to determine if patients with these problem behaviors are distinctive as a group with respect to EDA patterns. All statistical analysis will be performed on anonymized data, blind to group membership.

3. Methodology: EDA will be measured by standard techniques in all subjects: electrodes may be placed on the hands, feet, ankles, wrists, or arm according to preference and configured to measure conductivity or potential. In one portion of the study, a wearable device to measure EDA will be used to determine whether EDA predicts the occurrence of an outburst. In the study with dementia patients, assessments will be performed at an inpatient dementia care facility at the Bedford VAMC (GRECC). Over a two-year period, the investigators anticipate enrolling 60 subjects. Recruitment criteria include toleration of the EDA recording device worn on the wrist (similar to a watch) or the ankle. Skin potential, skin conductance, and membrane electrical power will be monitored and data recorded electronically. Data will be de-identified by assigning the serial subject number to each patient; a table linking the number to the subject's identity will be kept on a secure VA server, allowing re-identification after data analysis.

4. Findings: If successful, EDA may predict an outburst of aberrant behavior with enough lead time to permit a preventive intervention.

5. Clinical Relationships: The investigators hypothesize that: (a) stable physiologic baselines can be obtained for EDA measures, (b) EDA signals are altered as a function of aberrant behaviors ("disorders of arousal") on a within-subject basis, and (c) group differences will emerge between samples of patients with and without these aberrant behaviors.

6. Impact/Significance: If the EDA were borne out as a sensitive measure of disorders of arousal, this measure may find application in the assessment and treatment of dementia.