Faculty Bibliography

Introduction: Alzheimer"™s disease (AD) and Lewy body disease (LBD) are the two most common neurodegenerative dementias and can occur in combination (AD+LBD). Due to overlapping biomarkers and symptoms, clinical differentiation of these subtypes could be difficult. However, it is unclear how the magnitude of diagnostic uncertainty varies across dementia spectra and demographic variables. We aimed to compare clinical diagnosis and post-mortem autopsy-confirmed pathological results to assess the clinical subtype diagnosis quality across these factors. Methods: We studied data of 1,920 participants recorded by the National Alzheimer"™s Coordinating Center from 2005 to 2019. Selection criteria included autopsy-based neuropathological assessments for AD and LBD, and the initial visit with Clinical Dementia Rating (CDR) stage of normal, mild cognitive impairment, or mild dementia. Longitudinally, we analyzed the first visit at each subsequent CDR stage. This analysis included positive predictive values, specificity, sensitivity and false negative rates of clinical diagnosis, as well as disparities by sex, race, age, and education. If autopsy-confirmed AD and/or LBD was missed in the clinic, the alternative clinical diagnosis was analyzed. Findings: In our findings, clinical diagnosis of AD+LBD had poor sensitivities. Over 61% of participants with autopsy-confirmed AD+LBD were diagnosed clinically as AD. Clinical diagnosis of AD had a low sensitivity at the early dementia stage and low specificities at all stages. Among participants diagnosed as AD in the clinic, over 32% had concurrent LBD neuropathology at autopsy. Among participants diagnosed as LBD, 32% to 54% revealed concurrent autopsy-confirmed AD pathology. When three subtypes were missed by clinicians, "No cognitive impairment" and "primary progressive aphasia or behavioral variant frontotemporal dementia" were the leading primary etiologic clinical diagnoses. With increasing dementia stages, the clinical diagnosis accuracy of black participants became significantly worse than other races, and diagnosis quality significantly improved for males but not females. Discussion: These findings demonstrate that clinical diagnosis of AD, LBD, and AD+LBD are inaccurate and suffer from significant disparities on race and sex. They provide important implications for clinical management, anticipatory guidance, trial enrollment and applicability of potential therapies for AD, and promote research into better biomarker-based assessment of LBD pathology.

Introduction: Previous case-control studies of sudden unexpected death in epilepsy (SUDEP) patients failed to identify ECG features (peri-ictal heart rate, heart rate variability, corrected QT interval, postictal heart rate recovery, and cardiac rhythm) predictive of SUDEP risk. This implied a need to derive novel metrics to assess SUDEP risk from ECG. Methods: We applied Single Spectrum Analysis and Independent Component Analysis (SSA-ICA) to remove artifact from ECG recordings. Then cross-frequency phase-phase coupling (PPC) was applied to a 20-s mid-seizure window and a contour of −3 dB coupling strength was determined. The contour centroid polar coordinates, amplitude (alpha) and angle (theta), were calculated. Association of alpha and theta with SUDEP was assessed and a logistic classifier for alpha was constructed. Results: Alpha was higher in SUDEP patients, compared to non-SUDEP patients (p < 0.001). Theta showed no significant difference between patient populations. The receiver operating characteristic (ROC) of a logistic classifier for alpha resulted in an area under the ROC curve (AUC) of 94% and correctly classified two test SUDEP patients. Discussion: This study develops a novel metric alpha, which highlights non-linear interactions between two rhythms in the ECG, and is predictive of SUDEP risk.

Background: Why are spine surgeons sued, how successfully, and for how much? Typical bases for spinal medicolegal suits have included; the failure to timely diagnose and treat, surgical negligence, (i.e. especially resulting in significant neurological deficits), and the lack of informed consent. We reviewed 17 medicolegal spinal articles looking for additional reasons for suits, along with identifying other factors contributing to defense verdicts, plaintiffs' verdicts, or settlements. Methods: After confirming the same three most likely causes of medicolegal suits, other factors leading to such suits included; the lack of patient access to surgeons postoperatively, poor postoperative management (i.e. contributing to new postoperative neurological deficits), failure to communicate between specialists/surgeons perioperatively, and failure to brace. Results: Critical factors leading to more plaintiffs' verdicts and settlements along with higher payouts for both included new severe and/or catastrophic postoperative neurological deficits. Conversely, defense verdicts were more likely for those with less severe new and/or residual injuries. The total number of plaintiffs' verdicts ranged from 17-35.2%, settlements, from 8.3-37%, and defense verdicts from 27.7-75%. Conclusion: The three most frequent bases for spinal medicolegal suits continue to include; failure to timely diagnose/treat, surgical negligence, and lack of informed consent. Here, we identified the following additional causes of such suits; the lack of patient access to surgeons perioperatively, poor postoperative management, lack of specialist/surgeon communication, and failure to brace. Further, more plaintiffs' verdicts or settlements and greater respective payouts were observed for those with new and/or more severe/catastrophic deficits, while more defense verdicts were typically rendered for patients with lesser new neurological injuries.

IMPORTANCE/OBJECTIVE:In laboratory settings, dual-tasking is a performance strategy affected by dominance and stroke. However, the volitional use of dual-tasking has not been examined during naturalistic performance of activities of daily living (ADLs). OBJECTIVE:To examine dual-tasking in the context of ADLs and identify whether dominance and stroke influence its use. DESIGN/METHODS:Cross-sectional, observational. SETTING/METHODS:Academic medical center. PARTICIPANTS/METHODS:Forty-three participants with chronic stroke and upper extremity (UE) motor impairment and 19 control participants without stroke. OUTCOMES AND MEASURES/METHODS:We identified dual-tasking as the performance of dual-object primitives (DOPs), a functional strategy to manage two objects simultaneously. We videotaped participants performing feeding and toothbrushing tasks and identified the initiation and frequency of DOPs. We assessed whether these outcomes were influenced by UE dominance or paresis and whether among participants with stroke these outcomes were influenced by motor impairment (using the Fugl-Meyer Assessment) or cognitive impairment (using the Montreal Cognitive Assessment). RESULTS:DOP initiation was reduced on the nondominant side of control UEs and in the paretic UE of participants with stroke. After DOPs were initiated, however, their frequency was not significantly related to dominance or paresis. Among participants with stroke, DOP initiation but not DOP frequency was influenced by motor impairment, and neither were influenced by cognitive impairment. CONCLUSIONS AND RELEVANCE/CONCLUSIONS:The initiation of dual-tasking is curtailed in the nondominant and paretic UEs, extending previous laboratory-based findings to a more naturalistic setting. These results may reflect a demand on neural resources that is exceeded when these limbs are used. What This Article Adds: DOPs, a functional strategy to simultaneously engage two objects during ADLs, could serve as a behavioral marker of dual-tasking in real-world activities, supporting their investigation more broadly. Practicing DOPs in rehabilitation could also train the integration of dual-tasking strategies in activity execution.

Abstract Objectives: Evaluate feasibility and preliminary efficacy of remotely supervised transcranial Direct Current Stimulation (RS-tDCS) interventions for persistent post-traumatic headache (PPTH) secondary to mild TBI (mTBI).
Method(s): Veterans with PPTH completed a 28-day baseline observation of headache days and received either active or sham RS-tDCS paired with mindfulness meditation. This 4-week intervention of 20-minutes daily (M-F) RS-tDCS (anodal stimulation dlPFC) was monitored via VA Video Connect. Feasibility was determined by the number of participants completing >=80% of the intervention. Efficacy was measured by changes in number of moderate/severe headache days from baseline period to the end of treatment phase, and 4-week post-treatment follow-up. Secondary endpoints included total number of headache days, acute pain medication use, as well as headache- and mTBI-related disability.
Result(s): Twenty-six veterans (46.6+/-8.7 years) with PPTH completed baseline observations and were randomized to either active (n=13) or sham (n=13) treatment groups. A total of 22/25 (88%) participants fully completed either active (10/12) or sham (12/13) interventions (p=.0.59). Within-group analyses reveled significant reductions in moderate/severe headache days in the active (p=0.04) but not sham (p=0.54) groups. This resulted in a trend towards significant reductions in moderate/severe headache days in the active vs. sham groups (p = 0.07). Active participants also demonstrated a reduction in total number of headache days during treatment (p=0.04) where the sham group did not (p=0.70). There is statistically significant reduction in total number of headache days during treatment for active vs. sham participants (p=0.03). No significant differences were maintained during the 4-week post-treatment follow-up (p's>0.05).
Conclusion(s): RS-tDCS treatment feasible with high adherence and effective for veterans with PPTH. Findings suggest that active RS-tDCS via dlPFC reduce headache frequency and improve clinical outcomes. A larger phase II study is warranted to confirm these findings and inform evaluation for clinical use. Research Category and Technology and Methods Clinical Research: 9. Transcranial Direct Current Stimulation (tDCS) Keywords: tDCS, Persistent Post-traumatic headache, Veterans, mTBI
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Abstract Background: Loss of hand dexterity is disabling and reduces quality of life. People living with progressive forms of MS have marked neurologic disabilities but limited rehabilitation options. Transcranial direct current stimulation (tDCS) is a method of noninvasive brain stimulation in which stimulation delivered during motor training can strengthen outcomes. We have established a remotely supervised tDCS (RS-tDCS) protocol that delivers multiple stimulation sessions paired with training to participants at home.
Objective(s): To evaluate a blinded randomized sham-controlled clinical trial of active vs. sham tDCS paired with manual dexterity training for people with progressive MS.
Method(s): We recruited right-hand dominant individuals with progressive MS and hand dexterity impairment. Participants completed 20 sessions of daily (M-F) manual dexterity and were randomized to either active (2.0 mA) or sham primary motor cortex (M1-SO) tDCS. Manual dexterity was measured with the Nine-Hole Peg Test (9HPT) and Dellon-Modified Moberg Pick-Up test (MMPUT) at baseline and study end and transformed to normative z-scores for comparison.
Result(s): Participants were n=60 with primary (32%) or secondary (68%) progressive MS (52% female, ages 37-72 years, and a median Expanded Disability Status Scale (EDSS) score of 5.0 [1.5-7.5]). The intervention was safe and well tolerated, with n=59/60 (98%) completing 18/20 daily sessions. Combining hands and tasks, the full group improved following the manual dexterity training (mean z-score improvement 1.64+/-9.53, p=0.016). Active tDCS led to greater improvement (mean z-score improvement 4.51+/-8.78, p=0.001). Analyzing those with right- or left-hand impairment at baseline, the active tDCS group had significant improvement on the 9HPT (Right: p=0.036, Left: p=0.028) and trended towards significant improvement for the MMPUT (Right: p=0.071, Left: p=0.079).
Conclusion(s): At-home manual dexterity training paired with tDCS is a safe, tolerable, and feasible intervention for people with progressive MS and hand impairment. Training outcomes are augmented with simultaneous M1-SO tDCS. Research Category and Technology and Methods Clinical Research: 9. Transcranial Direct Current Stimulation (tDCS) Keywords: tDCS, motor training, multiple sclerosis, teleintervention
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BACKGROUND: Multiple sclerosis (MS) is a degenerative disease with typical onset between 20 and 50 years of age. An increase in MS cases has been found in the adolescent US population. Adolescents require fine motor manipulation skills for their functional and academic performance. Deficits in the major components of manipulation skills may result in insufficient function. This study examined the 2-point, 3-point, and lateral pinch strength of adolescents diagnosed as having MS. METHODS: Seventy-four adolescents, 37 with a diagnosis of relapsing-remitting MS and a control group of 37 age-matched peers, participated in this study. Data on 2-point, 3-point, and lateral pinch strength in both hands were collected using a pinch meter. Analyses of covariance were used to describe differences across the 2 groups, and effect sizes (Cohen d) were calculated by finding the mean difference between the study groups divided by the pooled SD. RESULTS: A significant difference was found in the 2-point pinch strength of the right hand of participants with pediatric MS compared with age- and sex-matched control participants. There were no significant differences in 2-point pinch strength of the left hand or in 3-point or lateral pinch strength of the right and left hands. CONCLUSIONS: Pinch grasp strength was differentially affected in adolescents with MS. Pinch strength should be assessed and considered in adolescents with MS for a better understanding of their functional performance of fine motor tasks in activities of daily living and academics.