Thalamic Functional Connectivity in Mild Traumatic Brain Injury

Research Posters improved 9% more in FGA than SWG. There were no significant changes in balance measured by tandem stance. Conclusions: Wearing strategically weighted BW for 4-hours a day over 5 days results in improvements in mobility and gait as compared to a shamweighted orthotic in mobility-limited community-dwelling older adults. Key Words: Gait, Psychomotor performance, Rehabilitation, Aged Disclosure(s): Jennifer Vincenzo received complimentary training and an assessment orthotic on BBTW from Motion Therapeutics, Inc. Country Meadows Retirement Communities, Inc. purchased orthotics for participants. The authors received no funds, assistance, or incentives otherwise. Research Poster 3650 HRV Biofeedback, Brain Injury, and Problem Solving: The Moderating Effect of Positive Affect Sonya Kim (New York University School of Medicine, Department of Rehabilitation Medicine), Joseph F. Rath, Vance Zemon, Marie M. Cavallo, Rollin McCraty, Ana Sostre, Frederick W. Foley Objective(s): To determine if relationship between heart rate variability/ HRV and problem-solving is moderated by positive affect. Design: Quasi-experimental. Setting: Community-based structured day program. Participants: Thirteen individuals, aged 23-63 years with severe, chronic brain injury (13-40 years post-onset). Interventions: HRV biofeedback. Main Outcome Measure(s): PANAS positive affect/PANAS-PA; category test/CT; HRV- index (coherence ratio/CR). Results: Bivariate regression using HRV-CR to predict CT revealed moderately-large effect size, with trend towards significance, pZ.085, ES(r) Z.50. Similar overall interaction effect was observed when PANAS-PA was added as moderator, pZ.07, ES (R2) Z.23. Johnson Neyman technique revealed that when PANAS-PA was low, coherence did not have significant relationship with improvements in CT. However, when PANAS-PA was 5.79 above the mean (36.64), the effect of coherence was in the expected negative direction (lower scores in CT reflect better performance) and significant, with large effect size, p<.05, ES(r) .60. Conclusions: Published studies demonstrate significant association between problem-solving and HRV (Thayer, 2006; Porges, 2001). This sample demonstrated moderate-to-large main effect for HRV, which did not reach statistical significance. Taking into account levels of positive affect clarified the relationship and revealed that the effect of HRV on problem-solving was largedand statistically significantdwhen positive affect was high. The significant role of PANAS-PA in moderating problemsolving performance is consistent with literature which found positive affect increases mental flexibility, creativity, and coping behaviors (Ashby, 1999; Damasio & Carvalho, 2013). Results are conceptually congruent with contemporary problem-solving cognitive rehabilitation models (e.g., Rath et al., 2011) and consistent with Shewchuk et al.’s (2000) study of healthy adults where negative problem-orientationdbeliefs and attitudes about one’s own problem-solving abilitydimpeded objective performance on CT. These findings have important implications for addressing affect and problem-orientation in cognitive rehabilitation; dispositions to harbor pessimism about self might impede motivation for/attainment of meaningful, goal-directed behavior. Key Words: HRV biofeedback, Problem solving, Positive affect Disclosure(s): Dr. McCraty is Director of Research at the Institute of HeartMath. Dr. Cavallo was formerly the Associate Director, Adult Day Services at AHRC NYC. Ms. Sostre is the Program Director-Community Supports for AHRC-NYC. Dr. Foley has served on advisory boards for Bayer Healthcare and Biogen Idec, received an investigator research grant from Bayer and has received honoraria as a speaker from Bayer, Biogen and Teva Neuroscience. The other authors have no conflicts of interest to disclose.

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e51 Research Poster 3651 The Effect of Cognitive Task Complexity on Postural Sway in Adults Following Concussion Mark A. Hirsch (Carolinas Medical Center), Lori Grafton, Michael S. Runyon, Mark Newman, Tami Pringnitz Guerrier, Janet P. Niemeier, Michael Gibbs, William Anderson, Harry James Norton Objective(s): To characterize short- and longer-term effects of concussion on equilibrium control in adults using divided attention paradigm. Hypothesis: Increased sway at 3 weeks post-concussion among adults with concussion relative to uninjured controls. Design: Controlled laboratory study using block randomization of dividedattention tasks. Setting: Departments of Physical Medicine and Rehabilitation, Emergency Medicine, and Carolinas Trauma Network Research Group. Participants: Eleven ambulatory adults with concussion (aged 37.612.1 years) without vestibular/orthopedic deficit and 10 age/gender matched uninjured controls (aged 38.911.9 years). Study approved by local ethics committee. Participants gave written informed consent. Standardized test of equilibrium, computerized dynamic posturography (EquiTest), with divided-attention tasks administered 1 and 3 weeks after concussion. Sway scores were compared to those of controls. One support surface condition, support sway-referenced (SSR), and three visual conditions, eyes open (EO), eyes closed (EC), or sway-referenced surround (SRS) were used. During SSR the floor and visual surround were controlled by a servomechanism to follow movements of the subjects’ center of gravity. Mixed model analyses of variance used to examine each measure. Interventions: N/A. Main Outcome Measure(s): Sensory Organization Test summary score (SOT) during Serial Addition, Serial Subtraction (SS), Letter-NumberSequencing task (LNS), and errors made during dual-tasking served as outcome measures. Results: We observed an improvement in SOT during SS (group by time interaction, FZ4.82, pZ0.028) and LNS (group by time interaction, FZ5.79, pZ0.0161) with less sway at 3 weeks post-concussion among the concussed group, but not control participants. Concussed participants made more errors during SOT dual-tasking at 3 weeks post-concussion (group by time interaction, FZ4.90, pZ0.026). Conclusions: Reduced sway 3 weeks after concussion could be due to reduction of attention demands and/or increased automaticity of balance. Increased errors were noted at follow-up which could indicate regression of recovery in balance control. Key Words: postural equilibrium, concussion, motor control Disclosure(s): None Disclosed. Research Poster 3653 Thalamic Functional Connectivity in Mild Traumatic Brain Injury Sarah Diane Banks (Vanderbilt University), Rogelio Adrian Coronado, Lori Rebecca Haislip, Christine M. Abraham, Benjamin N. Conrad, Victoria L. Morgan, Kristin R. Archer Objective(s): The purpose of this study was to examine the cross-sectional and longitudinal association between thalamic resting-state functional connectivity (FC) and psychological distress, clinical symptoms, and neuropsychological tests in patients with mild traumatic brain injury (mTBI). Design: Prospective case-control study. Setting: Level I trauma center. Participants: Thirteen patients with mTBI were consecutively sampled and 11 healthy control subjects were enrolled. Interventions: N/A. Main Outcome Measure(s): Resting-state FC (3T MRI scanner) was examined in the right and left thalamus, Default Mode Network (DMN),

e52 Dorsal Attention Network (DAN), and Frontoparietal Control Network (FPC) in patients with mTBI and age and sex-matched controls. Patientreported measurement of pain intensity (Brief Pain Inventory) and depressive (PHQ-9), post-traumatic stress disorder (PTSD Checklist) and post-concussive (Rivermead) symptoms were obtained. Neuropsychological tests included the Trails B and Tower test. Assessments occurred at 6 weeks and 4 months after hospitalization for the mTBI group. Results: Student’s t-tests found patients with mTBI had higher levels of pain and depressive, PTSD, and post-concussive symptoms and worse performance on Trails B compared to healthy controls (corrected p < 0.05). An increase in resting-state FC was found in the mTBI group compared to controls in the thalamus and between the thalamus and DMN and a decrease in FC was found between the thalamus and DAN and FPC in the mTBI group compared to controls. Spearman correlation coefficients indicated increases in resting-state FC between the thalamus and DAN were significantly associated with improvement in pain intensity and postconcussive symptoms (corrected p < 0.05). Conclusions: Data suggest that patients with mTBI have changes in thalamic resting-state FC. Findings also demonstrate that improvements in pain and post-concussive symptoms are correlated with normalization of thalamic connectivity over time. Key Words: Traumatic brain injury, Neuropsychological tests, Functional magnetic resonance imaging Disclosure(s): None Disclosed.

Research Poster 3657 Self-Selected Walking Speed is Predictive of Community Walking Behavior in Older Adults Addie Middleton (University of South Carolina), George D. Fulk, Michael W. Beets, Troy Michael Herter, Stacy L. Fritz Objective(s): To determine the relative capabilities of self-selected walking speed (SSWS), maximal walking speed (MWS), and walking speed reserve (WSR) to provide insight into community walking behavior in community-dwelling older adults. Design: Criterion-related validity study. Setting: Community. Participants: Convenience sample of 67 community-dwelling older adults (age 80.39(6.73) years) without a current musculoskeletal condition affecting ambulation and/or history of a neurologic condition. Interventions: N/A. Main Outcome Measure(s): SSWS and MWS were assessed using a 10 meter walk test. WSR was calculated as a difference (MWS e SSWS) and ratio (MWS/SSWS). Community walking behavior, quantified as steps/ day, was measured by seven days of activity monitoring. Linear and logistic (<8,000 steps/day) regression was used to examine the relative capabilities of SSWS, MWS, and WSR to predict community walking behavior. Receiver operating characteristic curves were constructed and optimal cutpoints, along with the associated sensitivity, specificity, and likelihood ratios (+LR, -LR), were identified. Results: The sample averaged 7261.16 (2903.95) steps per day with a SSWS of 1.07 (0.23) m/s, MWS 1.41 (0.31) m/s, WSR difference 0.34 (0.16) m/s, and WSR ratio 1.33 (0.17). SSWS (R2 Z 0.51), MWS (R2 Z 0.35), and WSR calculated as a ratio (R2 Z 0.06) were significant predictors of community walking behavior in unadjusted linear regression. Cutpoints for identifying participants achieving <8,000 steps/day were SSWS 0.97 m/s (44.2% sensitivity, 95.7% specificity, 10.28 +LR, 0.58 -LR) and MWS 1.39 m/s (60.5% sensitivity, 78.3% specificity, 2.79 +LR, 0.50 -LR). Conclusions: SSWS may be a feasible proxy for assessing and monitoring community walking behavior in active older adults. Further research is needed in less active older adults. Key Words: Geriatric assessment, Walking, Physical activity Disclosure(s): None Disclosed.

Research Posters Research Poster 3660 Effect of Eccentric Activity on Contralateral Limb Force Production in Incomplete Spinal Cord Injury Lise Worthen-Chaudhari (The Ohio State University), Michael McNally, James Schmiedeler, D. Michele Basso Objective(s): Evaluate effect of repetitive, isokinetic eccentric activity on contralateral force production [1] in an individual with incomplete spinal cord injury (iSCI). Design: Case-control. Setting: Outpatient neurorehabilitation. Participants: One female individual with iSCI (56 years; AIS C; paraplegia, 2 yrs. post SCI) and one female individual without neurologic involvement (44 years; control). Interventions: Repetitive, eccentric maximal voluntary contractions (MVCs) of the left quadriceps. Activity was repeated until fatigue occurred (>7% reduction in peak torque). Isokinetic speed was 30 degrees/sec; initial and terminal knee angles were 20 and 90 degrees, respectively. Participants were verbally encouraged to produce best effort for each MVC attempt. Main Outcome Measure(s): Change in right knee eccentric extension torque following intervention. Mean of three trials of isokinetic, eccentric MVC, with 30 seconds rest between each trial, were recorded for MVC pre and post intervention. Results: After the intervention, the control demonstrated an increase of 25% peak eccentric MVC on the contralateral side while the participant with iSCI showed no change (1% increase). The individual with iSCI required a higher dose of activity to meet fatigue criteria: the control performed 3x12 repetitions while the individual with iSCI performed 5x25 repetitions. Conclusions: Contralateral force potentiation following ipsilateral eccentric activity is demonstrated by individuals without neural impairment but was not apparent in an individual with iSCI. Future research will elucidate the effect of iSCI on contralateral neural and force potentiation, as well as on muscle fatigue, after targeted eccentric training. Key Words: Neurosciences, Gait disorders, Neurologic, Spinal cord injuries Disclosure(s): None Disclosed. Research Poster 3663 An Interdisciplinary Approach to Atypical Guillian-Barre Syndrome with History of Methimazole Use: A Case Report Jennifer Eftychiou (NYU Langone Medical Center/HJD-Rusk Institute of Rehabilitation Medicine), Jennifer M. DelCorro-Cao, Jacob R. Peacock Objective(s): To illustrate a patient’s clinical and functional improvements after discontinuation of methimazole treatment coinciding with Atypical GBS. Design: Case Report. Setting: Adult Inpatient Rehabilitation Unit. Participants: 77 year old functionally independent male with two consecutive admissions for Guillain-Barre Syndrome. Interventions: 3 hours of PT/OT, 5 days/week focusing on: trunk/lower extremity motor control, ataxia management, B/IADL retraining emphasizing return to home, work, and community setting. Main Outcome Measure(s): This case describes a 77 year old male with Graves’ disease treated with methimazole, hospitalized twice with diagnosis of Atypical GBS versus Paraneoplastic Syndrome. Unsuccessful bouts of IVIG and negative lung biopsy results led to trial off methimazole with careful cardiac monitoring. This led to rapid improvement of motor control and resolution of ataxia. The following outcome measures were utilized: 1. Functional Independence Measure (FIM) 2. Berg Balance Scale (BBS) 3. Videotaped sessions for gait analysis, patient education and home accessibility. Results: Initial FIM scores were maximum assistance for standing BADLs and total assistance for ambulation and stairs. Within a week from stopping

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