Fox, Susan H.

ObjectivesTo evaluate the effect of Alzheimer's disease (AD) ‐related biomarker change on clinical features, brain atrophy and functional connectivity of patients with corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP).MethodsData from patients with a clinical diagnosis of CBS, PSP, and AD and healthy controls were obtained from the 4‐R‐Tauopathy Neuroimaging Initiative 1 and 2, the Alzheimer's Disease Neuroimaging Initiative, and a local cohort from the Toronto Western Hospital. Patients with CBS and PSP were divided into AD‐positive (CBS/PSP‐AD) and AD‐negative (CBS/PSP‐noAD) groups based on fluid biomarkers and amyloid PET scans. Cognitive, motor, and depression scores; AD fluid biomarkers (cerebrospinal p‐tau, t‐tau, and amyloid‐beta, and plasma ptau‐217); and neuroimaging data (amyloid PET, MRI and fMRI) were collected. Clinical features, whole‐brain gray matter volume and functional networks connectivity were compared across groups.ResultsData were analyzed from 87 CBS/PSP‐noAD and 23 CBS/PSP‐AD, 18 AD, and 30 healthy controls. CBS/PSP‐noAD showed worse performance in comparison to CBS/PSP‐AD in the PSPRS [mean(SD): 34.8(15.8) vs 23.3(11.6)] and the UPDRS scores [mean(SD): 34.2(17.0) vs 21.8(13.3)]. CBS/PSP‐AD demonstrated atrophy in AD signature areas and brainstem, while CBS/PSP‐noAD patients displayed atrophy in frontal and temporal areas, globus pallidus, and brainstem compared to healthy controls. The default mode network showed greatest disconnection in CBS/PSP‐AD compared with CBS/PSP‐no AD and controls. The thalamic network connectivity was most affected in CBS/PSP‐noAD.InterpretationAD biomarker positivity may modulate the clinical presentation of CBS/PSP, with evidence of distinctive structural and functional brain changes associated with the AD pathology/co‐pathology. ANN NEUROL 2024;96:99–109

AbstractBackground and purposeSeveral clinical and demographic factors relate to anatomic spread of adult‐onset isolated dystonia, but a predictive model is still lacking. The aims of this study were: (i) to develop and validate a predictive model of anatomic spread of adult‐onset isolated dystonia; and (ii) to evaluate whether presence of tremor associated with dystonia influences model predictions of spread.MethodsAdult‐onset isolated dystonia participants with focal onset from the Dystonia Coalition Natural History Project database were included. We developed two prediction models, one with dystonia as sole disease manifestation (“dystonia‐only”) and one accepting dystonia OR tremor in any body part as disease manifestations (“dystonia OR tremor”). Demographic and clinical predictors were selected based on previous evidence, clinical plausibility of association with spread, or both. We used logistic regressions and evaluated model discrimination and calibration. Internal validation was carried out based on bootstrapping.ResultsBoth predictive models showed an area under the curve of 0.65 (95% confidence intervals 0.62–0.70 and 0.62–0.69, respectively) and good calibration after internal validation. In both models, onset of dystonia in body regions other than the neck, older age, depression and history of neck trauma were predictors of spread.ConclusionsThis predictive modeling of spread in adult‐onset isolated dystonia based on accessible predictors (demographic and clinical) can be easily implemented to inform individuals’ risk of spread. Because tremor did not influence prediction of spread, our results support the argument that tremor is a part of the dystonia syndrome, and not an independent or coincidental disorder.

Abstract Background : Non‐motor symptoms are well established phenotypic components of adult‐onset idiopathic, isolated, focal cervical dystonia (AOIFCD). However, improved understanding of their clinical heterogeneity is needed to better target therapeutic intervention. Here, we examine non‐motor phenotypic features to identify possible AOIFCD subgroups. Methods : Participants diagnosed with AOIFCD were recruited via specialist neurology clinics (dystonia wales: n = 114, dystonia coalition: n = 183). Non‐motor assessment included psychiatric symptoms, pain, sleep disturbance, and quality of life, assessed using self‐completed questionnaires or face‐to‐face assessment. Both cohorts were analyzed independently using Cluster, and Bayesian multiple mixed model phenotype analyses to investigate the relationship between non‐motor symptoms and determine evidence of phenotypic subgroups. Results : Independent cluster analysis of the two cohorts suggests two predominant phenotypic subgroups, one consisting of approximately a third of participants in both cohorts, experiencing increased levels of depression, anxiety, sleep impairment, and pain catastrophizing, as well as, decreased quality of life. The Bayesian approach reinforced this with the primary axis, which explained the majority of the variance, in each cohort being associated with psychiatric symptomology, and also sleep impairment and pain catastrophizing in the Dystonia Wales cohort. Conclusions : Non‐motor symptoms accompanying AOIFCD parse into two predominant phenotypic sub‐groups, with differences in psychiatric symptoms, pain catastrophizing, sleep quality, and quality of life. Improved understanding of these symptom groups will enable better targeted pathophysiological investigation and future therapeutic intervention.

ABSTRACT Introduction The aim of this study was to test the clinimetric properties of the Comprehensive Cervical Dystonia Rating Scale. This is a modular scale with modifications of the Toronto Western Spasmodic Torticollis Rating Scale (composed of three subscales assessing motor severity, disability, and pain) now referred to as the revised Toronto Western Spasmodic Torticollis Scale‐2; a newly developed psychiatric screening instrument; and the Cervical Dystonia Impact Profile‐58 as a quality of life measure. Methods Ten dystonia experts rated subjects with cervical dystonia using the comprehensive scale. Clinimetric techniques assessed each module of the scale for reliability, item correlation, and factor structure. Results There were 208 cervical dystonia patients (73% women; age, 59 ± 10 years; duration, 15 ± 12 years). Internal consistency of the motor severity subscale was acceptable (Cronbach's alpha = 0.57). Item to total correlations showed that elimination of items with low correlations (<0.20) increased alpha to 0.71. Internal consistency estimates for the subscales for disability and pain were 0.88 and 0.95, respectively. The psychiatric screening scale had a Cronbach's alpha of 0.84 and satisfactory item to total correlations. When the subscales of the Toronto Western Spasmodic Torticollis Scale‐2 were combined with the psychiatric screening scale, Cronbach's alpha was 0.88, and construct validity assessment demonstrated four rational factors: motor; disability; pain; and psychiatric disorders. The Cervical Dystonia Impact Profile‐58 had an alpha of 0.98 and its construction was validated through a confirmatory factor analysis. Conclusions The modules of the Comprehensive Cervical Dystonia Rating Scale are internally consistent with a logical factor structure. © 2016 International Parkinson and Movement Disorder Society