All Publications


  • Detection of Wandering Behaviors Using a Body-Worn Inertial Sensor in Patients With Cognitive Impairment: A Feasibility Study. Frontiers in neurology Kamil, R. J., Bakar, D., Ehrenburg, M., Wei, E. X., Pletnikova, A., Xiao, G., Oh, E. S., Mancini, M., Agrawal, Y. 2021; 12: 529661

    Abstract

    Patients with Alzheimer's disease (AD) and AD related dementias (ADRD) often experience spatial disorientation that can lead to wandering behavior, characterized by aimless or purposeless movement. Wandering behavior has been associated with falls, caregiver burden, and nursing home placement. Despite the substantial clinical consequences of wandering, there is currently no standardized approach to objectively quantify wandering behavior. In this pilot feasibility study, we used a lightweight inertial sensor to examine mobility characteristics of a small group of 12 older adults with ADRD and mild cognitive impairment in their homes. Specifically, we evaluated their compliance with wearing a sensor for a minimum of 4 days. We also examined the ability of the sensor to measure turning frequency and direction changes, given that frequent turns and direction changes during walking have been observed in patients who wander. We found that all patients were able to wear the sensor yielding quantitative turn data including number of turns over time, mean turn duration, mean peak turn speed, and mean turn angle. We found that wanderers make more frequent, quicker turns compared to non-wanderers, which is consistent with pacing or lapping behavior. This study provides preliminary evidence that continuous monitoring in patients with dementia is feasible using a wearable sensor. More studies are needed to explore if objective measures of turning behaviors collected using inertial sensors can be used to identify wandering behavior.

    View details for DOI 10.3389/fneur.2021.529661

    View details for PubMedID 33776875

    View details for PubMedCentralID PMC7991404

  • Vestibular function and cortical and sub-cortical alterations in an aging population HELIYON Jacob, A., Tward, D. J., Resnick, S., Smith, P. F., Lopez, C., Rebello, E., Wei, E. X., Ratnanather, J., Agrawal, Y. 2020; 6 (8): e04728

    Abstract

    While it is well known that the vestibular system is responsible for maintaining balance, posture and coordination, there is increasing evidence that it also plays an important role in cognition. Moreover, a growing number of epidemiological studies are demonstrating a link between vestibular dysfunction and cognitive deficits in older adults; however, the exact pathways through which vestibular loss may affect cognition are unknown. In this cross-sectional study, we sought to identify relationships between vestibular function and variation in morphometry in brain structures from structural neuroimaging. We used a subset of 80 participants from the Baltimore Longitudinal Study of Aging, who had both brain MRI and vestibular physiological data acquired during the same visit. Vestibular function was evaluated through the cervical vestibular-evoked myogenic potential (cVEMP). The brain structures of interest that we analyzed were the hippocampus, amygdala, thalamus, caudate nucleus, putamen, insula, entorhinal cortex (ERC), trans-entorhinal cortex (TEC) and perirhinal cortex, as these structures comprise or are connected with the putative "vestibular cortex." We modeled the volume and shape of these structures as a function of the presence/absence of cVEMP and the cVEMP amplitude, adjusting for age and sex. We observed reduced overall volumes of the hippocampus and the ERC associated with poorer vestibular function. In addition, we also found significant relationships between the shape of the hippocampus (p = 0.0008), amygdala (p = 0.01), thalamus (p = 0.008), caudate nucleus (p = 0.002), putamen (p = 0.02), and ERC-TEC complex (p = 0.008) and vestibular function. These findings provide novel insight into the multiple pathways through which vestibular loss may impact brain structures that are critically involved in spatial memory, navigation and orientation.

    View details for DOI 10.1016/j.heliyon.2020.e04728

    View details for Web of Science ID 000568517600027

    View details for PubMedID 32904672

    View details for PubMedCentralID PMC7457317

  • Psychometric Tests and Spatial Navigation: Data From the Baltimore Longitudinal Study of Aging FRONTIERS IN NEUROLOGY Wei, E. X., Anson, E. R., Resnick, S. M., Agrawal, Y. 2020; 11: 484

    Abstract

    Spatial cognition is the process by which individuals interact with their spatial environment. Spatial cognition encompasses the specific skills of spatial memory, spatial orientation, and spatial navigation. Prior studies have shown an association between psychometric tests of spatial ability and self-reported or virtual measures of spatial navigation. In this study, we examined whether psychometric spatial cognitive tests predict performance on a dynamic spatial navigation task that involves movement through an environment. We recruited 151 community-dwelling adult participants [mean (SD) age 69.7 (13.6), range 24.6-93.2] from the Baltimore Longitudinal Study of Aging (BLSA). Spatial navigation ability was assessed using the triangle completion task (TCT), and two quantities, the angle and distance of deviation, were computed. Visuospatial cognitive ability was assessed primarily using the Card Rotations Test. Additional tests of executive function, memory, and attention were also administered. In multiple linear regression analyses adjusting for age, sex, race, and education, cognitive tests of visuospatial ability, executive function, and perceptual motor speed and integration were significantly associated with spatial navigation, as determined by performance on the TCT. These findings suggest that dynamic spatial navigation ability is related to spatial memory, executive function, and motor processing speed.

    View details for DOI 10.3389/fneur.2020.00484

    View details for Web of Science ID 000543906900001

    View details for PubMedID 32595588

    View details for PubMedCentralID PMC7300262

  • Ankyloglossia: Update on Trends in Diagnosis and Management in the United States, 2012-2016. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery Wei, E. X., Tunkel, D., Boss, E., Walsh, J. 2020; 163 (5): 1029-1031

    Abstract

    Ankyloglossia, or "tongue-tie," refers to limited tongue mobility caused by a restrictive lingual frenulum. Previous studies have demonstrated rapid increases in diagnosis and treatment of ankyloglossia in the United States up to 2012. We performed an updated retrospective review of data from the National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality (AHRQ) to evaluate trends in diagnosis of ankyloglossia and use of lingual frenotomy in the hospital setting. From 2012 to 2016, there was an 110.4% increase in reported diagnosis of ankyloglossia in the inpatient setting with similar increases in lingual frenotomy procedures. As seen previously, sex, type of insurance, median income ZIP code, and geographic region were associated with diagnosis of ankyloglossia. The observed trends from prior to 2012 have continued to increase, while unanswered questions about diagnostic criteria and about which infants should undergo frenotomy remain.

    View details for DOI 10.1177/0194599820925415

    View details for PubMedID 32427523

  • Association Between Saccule and Semicircular Canal Impairments and Cognitive Performance Among Vestibular Patients. Ear and hearing Pineault, K., Pearson, D., Wei, E., Kamil, R., Klatt, B., Agrawal, Y. 2019; 41 (3): 686-692

    Abstract

    Growing evidence suggests that vestibular function impacts higher-order cognitive ability such as visuospatial processing and executive functioning. Despite evidence demonstrating vestibular functional impairment impacting cognitive performance, it is unknown whether cognitive ability is differentially affected according to the type of vestibular impairment (semicircular canal [SCC] versus saccule) among patients with diagnosed vestibular disease.Fifty-four patients who presented to an academic neurotologic clinic were recruited into the study. All patients received a specific vestibular diagnosis. Forty-one patients had saccule function measured with the cervical vestibular-evoked myogenic potential, and 43 had SCC function measured using caloric irrigation. Cognitive tests were administered to assess cognitive performance among patients. One hundred twenty-five matched controls were recruited from the Baltimore Longitudinal Study of Aging to compare cognitive performance in patients relative to age-matched healthy controls.Using multivariate linear regression analyses, patients with bilaterally absent cervical vestibular-evoked myogenic potential responses (i.e., bilateral saccular impairments) were found to take longer in completing the Trail-Making test (β = 25.7 sec, 95% confidence interval = 0.3 to 51.6) and to make significantly more errors on the Benton Visual Retention test part-C (β = 4.5 errors, 95% confidence interval [CI] = 1.2 to 7.8). Patients with bilateral SCC impairment were found to make significantly more errors on the Benton Visual Retention test part-C (β = 9.8 errors, 95% CI = 0.2 to 19.4). From case-control analysis, for each SD difference in Trail-Making test part-B time, there was a corresponding 142% increase in odds of having vestibular impairment (odds ratio = 2.42, 95% CI = 1.44 to 4.07).These data suggest that bilateral saccule and SCC vestibular impairments may significantly affect various domains of cognitive performance. Notably, the cognitive performance in patients in this study was significantly poorer relative to age-matched healthy adults. Cognitive assessment may be considered in patients with saccule and SCC impairments, and cognitive deficits in vestibular patients may represent an important target for intervention.

    View details for DOI 10.1097/AUD.0000000000000795

    View details for PubMedID 31567562

    View details for PubMedCentralID PMC7080562

  • Saccular function is associated with both angular and distance errors on the triangle completion test. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology Anson, E. R., Ehrenburg, M. R., Wei, E. X., Bakar, D., Simonsick, E., Agrawal, Y. 2019; 130 (11): 2137-2143

    Abstract

    The present study was designed to determine whether healthy older adults with age-related vestibular loss have deficits in spatial navigation.154 adults participating in the Baltimore Longitudinal Study of Aging were tested for semicircular canal, saccular, and utricular function and spatial navigation ability using the blindfolded Triangle Completion Test (TCT). Multiple linear regression was used to investigate the relationships between each measure of vestibular function and performance on the TCT (angular error, end point error, and distance walked) while controlling for age and sex.Individuals with abnormal saccular function made larger angular errors (β = 4.2°, p < 0.05) and larger end point errors (β = 13.6 cm, p < 0.05). Independent of vestibular function, older age was associated with larger angular (β's = 2.2-2.8°, p's < 0.005) and end point errors (β's = 7.5-9.0 cm, p's < 0.005) for each decade increment in age.Saccular function appears to play a prominent role in accurate spatial navigation during a blindfolded navigation task.We hypothesize that gravitational cues detected by the saccule may be integrated into estimation of place as well as heading direction.

    View details for DOI 10.1016/j.clinph.2019.08.027

    View details for PubMedID 31569041

    View details for PubMedCentralID PMC6874399

  • Increased Prevalence of Vestibular Loss in Mild Cognitive Impairment and Alzheimer's Disease. Current Alzheimer research Wei, E. X., Oh, E. S., Harun, A., Ehrenburg, M., Xue, Q. L., Simonsick, E., Agrawal, Y. 2019; 16 (12): 1143-1150

    Abstract

    Recent evidence has shown that Alzheimer's Disease (AD) patients have reduced vestibular function relative to healthy controls. In this study, we evaluated whether patients with Mild Cognitive Impairment (MCI) also have reduced vestibular function relative to controls, and compared the level of vestibular impairment between MCI and AD patients.Vestibular physiologic function was assessed in 77 patients (26 MCI, 51 AD) and 295 matched controls using 3 clinical vestibular tests. The association between vestibular loss and cognitive impairment was evaluated using conditional logistic regression models.Individuals with vestibular impairment had a 3 to 4-fold increased odds of being in the MCI vs. control group (p-values < 0.05). MCI patients had a level of vestibular impairment that was intermediate between controls and AD.These findings suggest a dose-response relationship between vestibular loss and cognitive status, and support the hypothesis that vestibular loss contributes to cognitive decline.

    View details for DOI 10.2174/1567205016666190816114838

    View details for PubMedID 31418661

  • Association Between Vestibular Vertigo and Motor Vehicle Accidents: Data From the 2016 National Health Interview Survey EAR AND HEARING Wei, E. X., Agrawal, Y. 2018; 39 (6): 1232-1235

    Abstract

    Recent evidence has shown that individuals with vestibular impairment have higher rates of self-reported driving difficulty compared with individuals without vestibular impairment. However, it is unknown whether individuals with vestibular impairment are more likely to be involved in motor vehicle accidents. We used data from the 2016 National Health Interview Survey of U.S. adults to evaluate whether individuals with vestibular vertigo are more likely to experience motor vehicle accidents relative to individuals without vestibular vertigo. In multivariate analysis, vestibular vertigo was associated with an over threefold increased odds of motor vehicle accidents (odds ratio, 3.5; 95% confidence interval, 1.7-7.3). This study supports an association between vestibular dysfunction and driving impairment, and provides a relative risk of motor vehicle accidents associated with vestibular vertigo that clinicians may utilize in counseling patients on the potential safety hazards of driving.

    View details for DOI 10.1097/AUD.0000000000000602

    View details for Web of Science ID 000457578500017

    View details for PubMedID 29782443

  • "Text It" program to track falls in patients with Alzheimer's disease and dementia. Alzheimer's & dementia (New York, N. Y.) Kamil, R. J., Bakar, D., Ehrenburg, M., Frankenthaler, S., Wei, E. X., Anson, E., Oh, E., Agrawal, Y. 2018; 4: 137-140

    Abstract

    Falls are a significant problem among older adults with Alzheimer's disease, leading to high rates of fracture, hospitalization, and death. Tracking falls in older adults, particularly those with cognitive impairment, is a clinical and research challenge.This prospective pilot study evaluated the feasibility of a text message program to track falls among patients with dementia. We also compared this technique with the calendar method of fall data collection.There was a 96% completion rate of text messaging and 100% of calendars; however, the text-gathered data were more accurate.A text-messaging platform to track falls shows promise in cognitively impaired individuals.

    View details for DOI 10.1016/j.trci.2018.03.001

    View details for PubMedID 29955657

    View details for PubMedCentralID PMC6021553

  • Vestibular Loss Predicts Poorer Spatial Cognition in Patients with Alzheimer's Disease. Journal of Alzheimer's disease : JAD Wei, E. X., Oh, E. S., Harun, A., Ehrenburg, M., Agrawal, Y. 2018; 61 (3): 995-1003

    Abstract

    The vestibular system is an important contributor to balance control, spatial orientation, and falls risk. Recent evidence has shown that Alzheimer's disease (AD) patients have a higher prevalence of vestibular impairment relative to healthy controls. We sought to evaluate whether vestibular loss is specifically associated with poor spatial cognitive skills among patients with mild cognitive impairment (MCI) and AD. We enrolled 50 patients (22 MCI and 28 AD) from an interdisciplinary Memory Clinic and measured vestibular physiologic function in all patients. Spatial cognitive function was assessed using the Money Road Map Test (MRMT) and the Trail Making Test Part B (TMT-B). General cognitive function was assessed with the Mini-Mental Status Examination (MMSE). In multivariable linear regression analyses adjusted for age, gender, education level, and MMSE, MCI and AD patients with vestibular loss made significantly more errors on the MRMT relative to patients with normal vestibular function (β= 7.3, 95% CI 2.4, 12.1 for unilateral vestibular loss and β= 6.4, 95% CI 1.9, 10.9 for bilateral vestibular loss). We further stratified AD patients into "spatially normal" and "spatially impaired" groups based on MRMT performance, and found that the prevalence of vestibular loss was significantly higher in the spatially impaired AD group relative to the spatially normal AD group. These findings support the hypothesis that vestibular loss contributes specifically to a decline in spatial cognitive ability in MCI and AD patients, independently of general cognitive decline, and may predict a "spatially impaired" subtype of AD.

    View details for DOI 10.3233/JAD-170751

    View details for PubMedID 29254098

  • Saccular Impairment in Alzheimer's Disease Is Associated with Driving Difficulty. Dementia and geriatric cognitive disorders Wei, E. X., Oh, E. S., Harun, A., Ehrenburg, M., Agrawal, Y. 2017; 44 (5-6): 294-302

    Abstract

    Patients with Alzheimer's disease (AD) experience increased rates of vestibular loss. Recent studies suggest that saccular impairment in mild cognitive impairment (MCI) and AD patients is associated with impaired spatial cognitive function. However, the impact of saccular impairment on everyday behaviors that rely on spatial cognitive function is unknown.We recruited 60 patients (21 MCI and 39 AD) from an interdisciplinary Memory Clinic. Saccular function was measured, and a visuospatial questionnaire was administered to assess whether participants experienced impairments in terms of driving difficulty, losing objects, falls, and fear of falling.In multiple logistic regression analyses, MCI and AD patients with bilateral saccular impairment had a significant, greater than 12-fold odds of driving difficulty (OR 12.1, 95% CI 1.2, 117.7) compared to MCI and AD patients with normal saccular function, and the association appears to be mediated by spatial cognition as measured by the Money Road Map Test.This study suggests a novel link between saccular impairment and driving difficulty in MCI and AD patients and demonstrates that driving difficulty may be a real-world manifestation of impaired spatial cognition associated with saccular impairment.

    View details for DOI 10.1159/000485123

    View details for PubMedID 29393172

    View details for PubMedCentralID PMC5906193

  • Vestibular Dysfunction and Difficulty with Driving: Data from the 2001-2004 National Health and Nutrition Examination Surveys. Frontiers in neurology Wei, E. X., Agrawal, Y. 2017; 8: 557

    Abstract

    There is growing understanding of the role of vestibular function in spatial navigation and orientation. Individuals with vestibular dysfunction demonstrate impaired performance on static and dynamic tests of spatial cognition, but there is sparse literature characterizing how these impairments might affect individuals in the real-world. Given the important role of visuospatial ability in driving a motor vehicle, we sought to evaluate whether individuals with vestibular dysfunction might have increased driving difficulty.We used data from the 2001-2004 National Health and Nutrition Examination Surveys to evaluate the influence of vestibular dysfunction in driving difficulty in a nationally representative sample of U.S. adults aged ≥50 years (n = 3,071). Vestibular function was measured with the modified Romberg test. Furthermore, since vestibular dysfunction is a known contributor to falls risk, we assessed whether individuals with vestibular dysfunction and concomitant driving difficulty were at an increased risk of falls.In multivariate analyses, vestibular dysfunction was associated with a twofold increased odd of driving difficulty (odds ratio 2.16, 95% CI 1.57, 2.98). Among participants with vestibular dysfunction, concomitant driving difficulty predicted an increased risk of falls that was significantly higher than in participants with vestibular dysfunction only (odds ratio 13.01 vs. 2.91, p < 0.0001).This study suggests that difficulty driving may be a real-world manifestation of impaired spatial cognition associated with vestibular loss. Moreover, driving difficulty may be a marker of more severe vestibular dysfunction.

    View details for DOI 10.3389/fneur.2017.00557

    View details for PubMedID 29089924

    View details for PubMedCentralID PMC5650982