NEURORADIOLOGY Parkinson disease (PD) is a neurodegenerative disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra (SN), leading to abnormalities of movement and other functions. Motor symptoms in PD onset and progression have exhibited lateral asymmetry (1), which suggests that the neuronal loss in the SN can be asymmetric, as reported in a neuropathologic study (2). In a majority of patients, symptoms begin on the side of the dominant hand (1). SPECT has demonstrated left hemispheric predominance of nigrostriatal dysfunction in patients with PD who are right handed, providing further evidence that dopaminergic denervation in the SN can be asymmetric (3). Furthermore, signal lateral asymmetry in the SN was indicated in an anatomic MRI study at 7.0 T (4) and considered in a susceptibility-weighted imaging study at 3.0 T (5). Neuroimaging evidence of underlying tissue Purpose: To investigate lateral asymmetry in the SN of patients with PD by using diffusion MRI with both Gaussian and non-Gaussian models. Materials and Methods:In this cross-sectional study conducted from March 2015 to March 2017, 27 participants with PD and 27 age-matched healthy control (HC) participants, all right handed, underwent MRI at 3.0 T. High-spatial-resolution diffusion images were acquired with a reduced field of view by using seven b values up to 3000 sec/mm 2 . A continuous-time random-walk (CTRW) non-Gaussian diffusion model was used to produce anomalous diffusion coefficient (D m ) and temporal (a) and spatial (b) diffusion heterogeneity indexes followed by a Gaussian diffusion model to yield an apparent diffusion coefficient (ADC). Individual or linear combinations of diffusion parameters in the SN were unilaterally and bilaterally compared between the PD and HC groups. Results:In the bilateral comparison between the PD and HC groups, differences were observed in b (0.67 6 0.06 [standard deviation] vs 0.64 6 0.04, respectively; P = .016), ADC (0.48 mm 2 /msec 6 0.08 vs 0.53 mm 2 /msec 6 0.06, respectively; P = .03), and the combination of CTRW parameters (P = .02). In the unilateral comparison, differences were observed in all diffusion parameters on the left SN (P , .03), but not on the right (P . .20). In a receiver operating characteristic (ROC) analysis to delineate left SN abnormality in PD, the combination of D m , a, and b produced the best sensitivity (sensitivity, 0.78); the combination of D m and b produced the best specificity (specificity, 0.85); and the combination of a and b produced the largest area under the ROC curve (area under the ROC curve, 0.73). Conclusion:These results suggest that quantitative diffusion MRI is sensitive to brain tissue changes in participants with Parkinson disease and provide evidence of substantia nigra lateral asymmetry in this disease.

Background Hyperintensities in the splenium of the corpus callosum (CCS) have been proposed as a radiographic diagnostic criterion for fragile X‐associated tremor ataxia syndrome (FXTAS). Methods Magnetic resonance images from patients with FXTAS and from nonpremutation carriers with movement disorders were viewed by a radiologist who was blinded to gene status, and radiographic criteria for FXTAS were scored. Phenotypic data used for diagnosis of FXTAS also were collected. Results Twenty‐two patients with FXTAS and 23 controls were included. Hyperintensity in the CCS (the CCS sign) was more common in men with FXTAS versus controls (87% vs. 40%) but not in women with FXTAS (100% vs. 50% in controls). The CCS sign had higher sensitivity compared with the middle cerebellar peduncle sign (white matter lesions in middle cerebellar peduncle) in both men (0.87 vs. 0.67) and women (1 vs. 0.29) with FXTAS, but it had lower specificity in both men (0.6 vs. 0.8) and women (0.5 vs. 1). Conclusions The CCS sign is common in patients with FXTAS, but it is not significantly more prevalent in women with FXTAS compared with controls. This may be due to small sample sizes in the current study. Other signs, such as brainstem white matter disease, were more common in women with FXTAS and differed from those in men with FXTAS. This finding suggests that additional studies evaluating the diagnostic criteria for FXTAS need to be conducted, ideally with neuropathological confirmation of the disease.

Objective Assess MDS-UPDRS items for gender-, age-, and race/ethnicity-based Differential Item Functioning. Background Assessing Differential Item Functioning is a core rating scale validation step. For the MDS-UPDRS, Differential Item Functioning occurs if item-score probability among people with similar levels of parkinsonism differ according to selected covariates (gender, age, race/ethnicity). If the magnitude of Differential Item Functioning is clinically relevant, item-score interpretation must consider influences by these covariates. Differential Item Functioning can be Non-uniform (covariate variably influences an item-score across different levels of parkinsonism) or Uniform (covariate influences an item-score consistently over all levels of parkinsonism. Methods Using the MDS-UPDRS translation database of over 5,000 PD patients from fourteen languages, we tested gender-, age-, and race/ethnicity-based Differential Item Functioning. To designate an item as having clinically relevant Differential Item Functioning, we required statistical confirmation by two independent methods, along with a McFadden pseudo-R2 magnitude statistic greater than “negligible.” Results Most items showed no gender-, age- or race/ethnicity-based Differential Item Functioning. When Differential Item Functioning was identified, the magnitude statistic was always in the “negligible” range, and the scale level impact was minimal. Conclusions The absence of clinically relevant Differential Item Functioning across all items and all Parts of MDS-UPDRS is strong evidence that the scale can be used confidently. As studies of Parkinson's disease increasingly involve multinational efforts and the MDS-UPDRS has several validated non-English translations, the findings support the scale's broad applicability in populations with varying gender, age, and race/ethnicity distributions.

Use of telehealth has grown substantially in recent times due to the COVID-19 pandemic. Remote care services may greatly benefit patients with disabilities; chronic conditions; and neurological, musculoskeletal, and pain disorders, thereby allowing continuity of rehabilitation care, reducing barriers such as transportation, and minimizing COVID-19 exposure. In March 2020, our rehabilitation hospital, Shirley Ryan AbilityLab, launched a HIPAA-compliant telemedicine program for outpatient and day rehabilitation clinics and telerehabilitation therapy programs. The objective of this study was to examine patients' experiences and satisfaction with telemedicine in the rehabilitation physician practice, including novel virtual multidisciplinary evaluations. The present study examines survey data collected from 157 patients receiving telemedicine services at Shirley Ryan AbilityLab from December 2020–August 2021. Respondents were 61.8% female, predominantly White (82.2%) with ages ranging across the lifespan (69.4% over age 50 years). Diagnostic categories of the respondents included: musculoskeletal conditions 28%, chronic pain 22.3%, localized pain 10.2%, neurological conditions 26.8%, and Parkinson's and movement disorders 12.7%. Survey responses indicate that the telemedicine experiences were positive and well received. The majority of participants found these services easy to use, effective, and safe, and were overall satisfied with the attention and care they received from the providers—even for those who had not previously used telehealth. Respondents identified a variety of benefits, including alleviating financial and travel-related burdens. There were no significant differences in telehealth experiences or satisfaction across the different clinical diagnostic groups. Respondents viewed the integrated physician and rehabilitation therapist telehealth multidisciplinary model favorably, citing positive feedback regarding receiving multiple perspectives and recommendations, feeling like an integrated member of their healthcare team, and having a comprehensive, holistic team approach along with effective communication. These findings support that telemedicine can provide an effective care model in physiatry (physical medicine and rehabilitation) clinics, across different neurological, musculoskeletal, and pain conditions and in multidisciplinary team care settings. The insights provided by the present study expand our understanding of patient experiences with remote care frameworks for rehabilitation care, while controlling for institutional variation, and ultimately will help provide guidance regarding longer term integration of telemedicine in physiatry and multidisciplinary care models.

No abstract