Faculty Bibliography

OBJECTIVE: The aim of this study was to evaluate the effects of a novel divided attention task, walking under auditory constraints, on gait performance in older adults, and to determine whether the effect was moderated by cognitive status. DESIGN: Validation Cohort SETTING: General Community PARTICIPANTS: 104 older non-demented and ambulatory older adults INTERVENTIONS: Not applicable MAIN OUTCOME MEASURE(S): In this pilot study, we evaluated walking under auditory constraints (WUAC) in 104 older adults who completed three pairs of walking trials on a gait mat under one of three randomly assigned conditions: one pair without auditory stimulation, and two pairs with emotionally charged auditory stimulation with happy or sad sounds. RESULTS: The mean age of subjects was 80.6+/-4.9 years and 63% were women. The mean velocity during normal walking was 97.9+/-20.6 cm/sec and the mean cadence was 105.1+/-9.9 steps/min. The effect of walking under auditory constraints on gait characteristics was analyzed using a two factorial ANOVA with a 1-between factor (cognitively intact and minimal cognitive impairment groups) and a 1-within factor (type of auditory stimuli). Under both happy and sad auditory stimulation trials, cognitively intact older adults (n=96) showed an average increase in gait velocity of 2.68 cm/s (F[1.86, 191.71](1, 2)=3.99, p=0.02) and an average increase in cadence of 2.41 steps/min (F[1.75, 180.42]=10.12, p<0.001) compared to trials without auditory stimulation. In contrast, older adults with minimal cognitive impairment (Blessed test score 5-10, n=8) showed average reduction in gait velocity of 5.45 cm/s (F[1.87, 190.83]= 5.62, p=0.005) and in cadence of 3.88 steps/min (F[1.79, 183.10]=8.21, p=0.001) under both auditory stimulation conditions. Neither baseline fall history nor performance on activities of daily living accounted for these differences. CONCLUSIONS: Our results provide preliminary evidence of the differentiating effect of emotionally charged auditory stimuli on gait performance in older individuals with minimal cognitive impairment compared to those without. A divided attention task using emotionally charged auditory stimuli might be able to elicit compensatory enhancement in gait performance in cognitively intact older individuals, but lead to decompensation in those with minimal cognitive impairment. Further investigation is needed to compare gait performance with this task to other dual-task paradigms, and separately examine the effects of physiological aging versus cognitive impairment on gait performance under auditory constraints.

The purpose of this study was to investigate the potential of a high-throughput, easily implemented, cost-effective, video analysis software-based mobility protocol to quantify spine kinematics. This prospective cohort study of clinical biomechanics implemented 2-dimensional (2D) image processing at a tertiary-care academic institution. Ten healthy, able-bodied volunteers were recruited for 2D videography of gait and functional motion. The reliability of a 2D video analysis software program for gait and range of motion metrics was evaluated over 2 independent experimental sessions, assessing for inter-trial, inter-session, and inter-rater reliability. Healthy volunteers were evaluated for simple forward and side bending, rotation, treadmill stride length, and more complex seated-to-standing tasks. Based on established intraclass correlation coefficients, results indicated that reliability was considered good to excellent for simple forward and side bending, rotation, stride length, and more complex sit-to-standing tasks. In conclusion, a cost-effective, 2D, video analysis software-based mobility protocol represents a feasible and clinically useful approach for objective spine kinematics and gait metrics. As the complication rate of operative management in the setting of spinal deformity is weighed against functional performance and quality of life measures, an objective analysis tool in combination with an appropriate protocol will aid in clinical assessments and lead to an increased evidence base for management options and decision algorithms.

Patients or Programs: An 82-year-old woman with supraventricular tachycardia managed with carotid sinus massage. Program Description: The patient is an 82-year-old woman with medical history of hypertension, coronary artery disease, abdominal aortic aneurysm, and carotid artery stenosis after right carotid artery endarterectomy and who developed supraventricular tachycardia and presented to her outpatient clinic. Carotid sinus massage was implemented with termination of the arrhythmia. The patient subsequently began to complain of weakness in her left upper and lower extremity. The patient was transferred to an emergency department where examination revealed dysarthria, left lower facial palsy, and left hemiparesis. Setting: Acute rehabilitation hospital. Results: Magnetic resonance imaging revealed multiple rightsided acute infarctions of embolic etiology and subtle atherosclerosis of the right common carotid artery. The patient was stabilized on the neurology service and subsequently was admitted to a rehabilitation program where her dysarthria resolved and she regained strength in her left upper extremity. The patient was discharged with a mild residual weakness of her left hand, and functionally she was ambulating 300 ft with modified independence. Discussion: There have been few case reports that note neurologic complications after carotid sinus massage. Two large prospective studies that review complications after carotid sinus massage report neurologic rates from 0.1%-0.17%. To our knowledge, this is the first reported case of an embolic stroke after carotid sinus massage on a surgically treated carotid artery. In a background that included prior carotid artery endarterectomy and lack of bruits on carotid auscultation, there remains sufficient risk to embolize atherosclerotic disease and the potential exists for iatrogenic cerebral infarction. Conclusions: Physicians should only use vagal maneuvers in patients whose comorbidities permit. In an elderly population, especially those who have undergone carotid artery endarterectomies or other surgical procedures that indicate the severity of their atherosclerosis, carotid sinus massage should be implemented sparingly to terminate supraventricular tachycardia