Gait Variability as a Potential Motor Marker of Cerebellar Disease-Relationship between Variability of Stride, Arm Swing and Trunk Movements, and Walking Speed.

Excessive stride variability is a characteristic feature of cerebellar ataxias, even in pre-ataxic or prodromal disease stages. This study explores the relation of variability of arm swing and trunk deflection in relationship to stride length and gait speed in previously described cohorts of cerebellar disease and healthy elderly: we examined 10 patients with spinocerebellar ataxia type 14 (SCA), 12 patients with essential tremor (ET), and 67 healthy elderly (HE). Using inertial sensors, recordings of gait performance were conducted at different subjective walking speeds to delineate gait parameters and respective coefficients of variability (CoV). Comparisons across cohorts and walking speed categories revealed slower stride velocities in SCA and ET patients compared to HE, which was paralleled by reduced arm swing range of motion (RoM), peak velocity, and increased CoV of stride length, while no group differences were found for trunk deflections and their variability. Larger arm swing RoM, peak velocity, and stride length were predicted by higher gait velocity in all cohorts. Lower gait velocity predicted higher CoV values of trunk sagittal and horizontal deflections, as well as arm swing and stride length in ET and SCA patients, but not in HE. These findings highlight the role of arm movements in ataxic gait and the impact of gait velocity on variability, which are essential for defining disease manifestation and disease-related changes in longitudinal observations.

Characteristics of behavioural addiction in Parkinson's disease patients with self-reported impulse control disorder and controls matched for levodopa equivalent dose: a matched case-control study.

Impulse control disorders (ICD) in Parkinson's disease (PD) frequently occur, not always as a direct consequence of dopaminergic medication. This study investigated premorbid personality traits and behavioural characteristics in non-demented PD patients with self-reported symptoms of ICD (PD-srICD). From a total of 200 non-demented PD patients who filled out questionnaires assessing symptoms and severity of ICD, those were classified as PD-srICD (n = 32) who reported current occurrence of at least one compulsive behaviour (gambling, sexual behaviour, buying behaviour, or eating). As a control group, 32 patients with no self-reported ICD symptoms were matched for levodopa equivalent daily dose. The demographic, clinical, and premorbid personality profiles were compared between both groups. Frequency of psychological characteristics indicating substance use disorder was evaluated in patients with PD-srICD. Patients with PD-srICD were more frequently male, younger at examination, had earlier PD onset, more depression, higher non-motor burden, less quality of life (p < 0.05, respectively), and more frequently reported premorbid sensation seeking/novelty orientation (p = 0.03) and joyful experience of stress (p = 0.04) than patients in the control group. Of patients with PD-srICD, 90.6% reported at least one behavioural characteristic of substance use disorder, most frequently positive expectations following ICD behaviour and illusional beliefs about its behavioural control. Signs of addiction were common among patients with PD-srICD. Therefore, the profile of psychological characteristics in patients with PD-srICD resembled that of patients with substance use disorder. It can be concluded that dopamine replacement therapy (DRT) alone does not account for PD-srICD and that thorough psychological diagnostics are recommended.

Cognitive-Driven Activities of Daily Living Impairment as a Predictor for Dementia in Parkinson Disease: A Longitudinal Cohort Study.

OBJECTIVES: One-third of Parkinson's disease (PD) patients with mild cognitive impairment (PD-MCI) convert to dementia within a few years. Markers with a high prognostic value for dementia conversion are needed. Loss of everyday function primarily caused by cognitive dysfunction is the core criterion for the diagnosis of PD dementia, with an onset of more complex instrumental activities of daily living (IADL) dysfunction in the prodromal stage. This study evaluated the phenotype associated with cognitive IADL impairment and its predictive value for defining a high-risk group for PD dementia. METHODS: An observational longitudinal study using cognitive and clinical scores in addition to genetic and CSF biomarkers was conducted. The Functional Activities Questionnaire (FAQ) quotient (cut-off ≥1), indicating more cognitive than motor-driven IADL impairment, defined cognitive IADL impairment status at baseline. Hazard ratios (HR) were used to compare the impact of baseline classifications on dementia conversion. RESULTS: Of 268 patients with PD assessed at baseline, 108 (40.3%) had PD-MCI. After a period of 3.78±0.84 years, 164 (61.2%) patients were re-assessed. At follow-up, 93 (56.7%) patients had no cognitive impairment, 54 (32.9%) fulfilled PD-MCI criteria, and 17 (10.4%) had developed dementia. The HR of baseline cognitive IADL impairment (n=37) for dementia conversion was descriptively higher than for PD-MCI, but highest in patients with both markers (HR=12.01, 95%-CI 4.47-32.22, p<0.001). In the follow-up sample, nearly half of patients (n=10, 47.6%) with baseline classification of cognitive IADL impairment and PD-MCI converted to dementia. Baseline status of cognitive IADL impairment was associated with higher non-motor burden, worse cognitive performance, and more severe IADL progression over the study period. CONCLUSION: The importance of differentiating between cognitive and motor aspects on ADL function in PD and monitoring cognitive ADL impairment in the prodromal stage of dementia is paramount. Patients with PD-MCI and cognitive IADL impairment may be a valuable target group for clinical trials aiming to slow down development of dementia. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov NCT03687203. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that impairment of cognitive activities of daily living is associated with progression from mild cognitive impairment to dementia among patients with Parkinson's disease.

Evaluation of the Dementia Apraxia Test in Parkinson's Disease Patients.

INTRODUCTION: Ideomotor apraxia, a disorder of skilled movements affecting limbs and/or face, can be seen in patients with Parkinson's disease (PD), yet tests of apraxia in PD are rare. The aim of this project was to evaluate the psychometric properties and validity of the Dementia Apraxia Test (DATE) in a PD sample. METHODS: 118 PD patients were included. Besides DATE performance, motor and non-motor burden, cognition, and activity of daily living (ADL) function were assessed. Patients were classified as cognitively impaired (n = 41) or non-cognitively impaired (n = 77). RESULTS: Interrater reliability of the DATE (sub-)scores between video ratings and on-site ratings by the investigator was good (0.81 ≤ rk ≤ 0.87). Items were mostly easy to perform, especially the buccofacial apraxia items, which had also low discriminatory power. DATE scores were associated with cognition and ADL function. DATE performance was confounded by motor impairment and patients' age; however, when analysed for both cognitive groups separately, the correlation between DATE and motor performance was not significant. DISCUSSION/CONCLUSION: The DATE seems to be an objective and predominantly valid apraxia screening tool for PD patients, with a few items needing revision. Due to the potential effect of motor impairment and age, standardized scores adjusting for these confounders are needed.

Divergence Between Informant and Self-Ratings of Activities of Daily Living Impairments in Parkinson's Disease.

OBJECTIVE: To examine the agreement between self- and informant-reported activities of daily living (ADL) deficits in Parkinson's Disease (PD) patients, and to examine factors influencing ADL ratings. BACKGROUND: In PD, the loss of functional independence is an important outcome of disease progression. The valid assessment of ADL function in PD is essential, but it is unclear to what extent informants' and patients' perceptions of their daily functions concur, and how other factors may influence both ratings. METHODS: Data of 150 PD patients who underwent cognitive and motor testing, as well as their informants were analyzed. The 10-item Functional Activities Questionnaire (FAQ), completed separately by patients (FAQ-S) and their informants (FAQ-I), assessed ADL function. Weighted κ statistics summarized level of agreement, and a discrepancy score (FAQ-I - FAQ-S) quantified agreement. Correlation analyses between FAQ total scores, patient and informant characteristics, and cognitive scores were conducted, with post hoc regressions to determine the associations between both FAQ scores and cognition, independent of patient characteristics. RESULTS: The sample included 87 patients with normal cognition, 50 with mild cognitive impairment, and 13 with dementia. Overall, there was fair to moderate agreement between patients and informants on individual FAQ items (0.27 ≤ κ ≤ 0.61, p < 0.004), with greater discrepancies with increasing cognitive impairment. Patients' age, motor severity, non-motor burden, and depression also affected both ratings (0.27 ≤ r ≤ 0.50, p < 0.001), with motor severity showing the greatest influence on both ratings. Both the FAQ-I and FAQ-S were correlated with almost all cognitive domains. Post hoc regression analyses controlling for patient characteristics showed that the attention domain was a significant predictor of both the FAQ-S and FAQ-I scores, and memory was also a significant predictor of the FAQ-I score. Only 29.3% of patients agreed perfectly with informants on the FAQ total score, with informants most commonly rating ADL impairments as more severe than patients. CONCLUSIONS: Patient and informant ratings of ADL function using FAQ items showed moderate agreement, with only few items reaching substantial agreement. Ratings of both were associated with patient cognitive status, but also other characteristics. In addition to patient and informant reports, objective measures are needed to accurately classify ADL deficits in PD.

Effect of Fear of Falling on Mobility Measured During Lab and Daily Activity Assessments in Parkinson's Disease.

In chronic disorders such as Parkinson's disease (PD), fear of falling (FOF) is associated with falls and reduced quality of life. With inertial measurement units (IMUs) and dedicated algorithms, different aspects of mobility can be obtained during supervised tests in the lab and also during daily activities. To our best knowledge, the effect of FOF on mobility has not been investigated in both of these settings simultaneously. Our goal was to evaluate the effect of FOF on the mobility of 26 patients with PD during clinical assessments and 14 days of daily activity monitoring. Parameters related to gait, sit-to-stand transitions, and turns were extracted from IMU signals on the lower back. Fear of falling was assessed using the Falls Efficacy Scale-International (FES-I) and the patients were grouped as with (PD-FOF+) and without FOF (PD-FOF-). Mobility parameters between groups were compared using logistic regression as well as the effect size values obtained using the Wilcoxon rank-sum test. The peak angular velocity of the turn-to-sit transition of the timed-up-and-go (TUG) test had the highest discriminative power between PD-FOF+ and PD-FOF- (r-value of effect size = 0.61). Moreover, PD-FOF+ had a tendency toward lower gait speed at home and a lower amount of walking bouts, especially for shorter walking bouts. The combination of lab and daily activity parameters reached a higher discriminative power [area under the curve (AUC) = 0.75] than each setting alone (AUC = 0.68 in the lab, AUC = 0.54 at home). Comparing the gait speed between the two assessments, the PD-FOF+ showed higher gait speeds in the capacity area compared with their TUG test in the lab. The mobility parameters extracted from both lab and home-based assessments contribute to the detection of FOF in PD. This study adds further evidence to the usefulness of mobility assessments that include different environments and assessment strategies. Although this study was limited in the sample size, it still provides a helpful method to consider the daily activity measurement of the patients with PD into clinical evaluation. The obtained results can help the clinicians with a more accurate prevention and treatment strategy.