External Factors Modulating Pain and Pain-Related Functional Impairment in Cervical Dystonia.

BACKGROUND: Little is known about factors modulating pain and pain-related functional impairment in isolated cervical dystonia (CD). OBJECTIVE: The aim was to assess the prevalence and interrelationship between pain-modulating factors and pain-related determinants of functional impairment and quality of life in CD. METHODS: We analyzed pain-aggravating and pain-relieving external factors, the degree of pain-related functional impact on routine activities, and the relationship between these and pain severity, using cross-sectional data collected using the Pain in Dystonia Scale (PIDS) from 85 participants with CD. Pairwise correlation analyses and age- and sex-adjusted linear regression models estimated the relationship between pain-modulating factors and pain severity, and the impact of pain severity, dystonia severity, and psychiatric symptoms on pain-related functional impairment and disease-specific quality of life (measured using the Craniocervical Dystonia Questionnaire-24). RESULTS: Stress and prolonged fixed position were the most frequent and impacting pain triggers, with women reporting larger impact. The average impact of pain-relieving factors was lower than that of pain triggers. Physical exercise and social gatherings were the most impacted activities by pain in CD. The intensity of external modulating factors was a predictor of pain severity. Severity of pain, CD, and psychiatric symptoms independently predicted pain-related functional impairment, whereas quality of life was predicted by pain severity, pain-related functional impairment, and psychiatric symptom severity, but not dystonia severity. CONCLUSION: The PIDS provides insight into external modulation and functional impact of pain in CD. The pattern of external modulation of pain in CD is in line with a multifactorial modulation and complex physiology.

Basal ganglia theta power indexes trait anxiety in people with Parkinson's disease.

Neuropsychiatric symptoms are common and disabling in Parkinson's disease (PD), with troublesome anxiety occurring in one-third of patients. Management of anxiety in PD is challenging, hampered by insufficient insight into underlying mechanisms, lack of objective anxiety measurements, and largely ineffective treatments. In this study, we assessed the intracranial neurophysiological correlates of anxiety in PD patients treated with deep brain stimulation (DBS) in the laboratory and at home. We hypothesized that low-frequency (theta-alpha) activity would be associated with anxiety. We recorded local field potentials (LFP) from the subthalamic nucleus (STN) or the globus pallidus pars interna (GPi) DBS implants in three PD cohorts: 1) patients with recordings (STN) performed in hospital at rest via perioperatively externalized leads, without active stimulation, both ON or OFF dopaminergic medication; 2) patients with recordings (STN or GPi) performed at home while resting, via a chronically implanted commercially available sensing-enabled neurostimulator (Medtronic PerceptTM device), ON dopaminergic medication, with stimulation both on or off; 3) patients with recordings performed at home while engaging in a behavioral task via STN and GPi leads and electrocorticography paddles over premotor cortex connected to an investigational sensing-enabled neurostimulator, ON dopaminergic medication, with stimulation both on or off. Trait anxiety was measured with validated clinical scales in all participants, and state anxiety was measured with momentary assessment scales at multiple time points in the two at-home cohorts. Power in theta (4-8 Hz) and alpha (8-12 Hz) ranges were extracted from the LFP recordings, and their relation with anxiety ratings was assessed using linear mixed-effects models. In total, 33 PD patients (59 hemispheres) were included. Across three independent cohorts, with stimulation off, basal ganglia theta power was positively related to trait anxiety (all p<0.05). Also in a naturalistic setting, with individuals at home at rest with stimulation and medication ON, basal ganglia theta power was positively related to trait anxiety (p<0.05). This relationship held regardless of the hemisphere and DBS target. There was no correlation between trait anxiety and premotor cortical theta-alpha power. There was no within-patient association between basal ganglia theta-alpha power and state anxiety. We showed that basal ganglia theta activity indexes trait anxiety in PD. Our data suggest that theta could be a possible physiomarker of neuropsychiatric symptoms and specifically of anxiety in PD, potentially suitable for guiding advanced DBS treatment tailored to the individual patient's needs, including non-motor symptoms.

Thalamic ventral-Oralis complex/rostral zona incerta deep brain stimulation for midline tremor.

BACKGROUND: Midline Tremor is defined as an isolated or combined tremor that affects the neck, trunk, jaw, tongue, and/or voice and could be part of Essential Tremor (ET), or dystonic tremor. The clinical efficacy of deep brain stimulation for Midline Tremor has been rarely reported. The Ventral Intermediate Nucleus and Globus Pallidus Internus are the preferred targets, but with variable outcomes. Thalamic Ventral-Oralis (VO) complex and Zona Incerta (ZI) are emerging targets for tremor control in various etiologies. OBJECTIVE: To report on neuroradiological, neurophysiological targeting and long-term efficacy of thalamic Ventral-Oralis complex and Zona Incerta deep brain stimulation in Midline Tremor. METHODS: Three patients (two males and one female) with Midline Tremor in dystonic syndromes were recruited for this open-label study. Clinical, surgical, neurophysiological intraoperative testing and long-term follow-up data are reported. RESULTS: Intraoperative testing and reconstruction of volume of tissue activated confirmed the position of the electrodes in the area stimulated between the thalamic Ventral-Oralis complex and Zona Incerta in all patients. All three patients showed optimal control of both tremor and dystonic features at short-term (6 months) and long-term follow-up (up to 6 years). No adverse events occurred. CONCLUSION: In the syndromes of Midline Tremor of various origins, the best target for DBS might be difficult to identify. Our results showed that thalamic Ventral-Oralis complex/Zona Incerta may be a viable and safe option even in specific forms of tremor with axial distribution.

Loss and Return of Ticklishness in Functional Neurological Disorder.

BACKGROUND: People with functional neurological disorder (FND) have abnormalities in sensory processing. Loss of ticklishness has been rarely reported. OBJECTIVES: To describe associated clinical features in people with FND and loss of ticklishness and explore correlations with sensory changes. METHODS: Retrospective audit of clinical letters of people diagnosed with FND in a tertiary clinic and further cases identified in a general neurology clinic. RESULTS: Thirty-eight patients with loss of ticklishness are described, of which most had other functional sensory symptoms and signs. It was more often localized to one limb, rather than generalized, in those with pain or weakness. Dissociation for the affected body part was often described. CONCLUSIONS: Loss of ticklishness in FND is frequently described and offers insights into mechanisms of agency, sensory processing and interoception, which are known to be altered in FND.

Basal ganglia theta power indexes trait anxiety in people with Parkinson's disease.

Background: Neuropsychiatric symptoms are common and disabling in Parkinson's disease (PD), with troublesome anxiety occurring in one-third of patients. Management of anxiety in PD is challenging, hampered by insufficient insight into underlying mechanisms, lack of objective anxiety measurements, and largely ineffective treatments.In this study, we assessed the intracranial neurophysiological correlates of anxiety in PD patients treated with deep brain stimulation (DBS) in the laboratory and at home. We hypothesized that low-frequency (theta-alpha) activity would be associated with anxiety. Methods: We recorded local field potentials (LFP) from the subthalamic nucleus (STN) or the globus pallidus pars interna (GPi) DBS implants in three PD cohorts: 1) patients with recordings (STN) performed in hospital at rest via perioperatively externalized leads, without active stimulation, both ON or OFF dopaminergic medication; 2) patients with recordings (STN or GPi) performed at home while resting, via a chronically implanted commercially available sensing-enabled neurostimulator (Medtronic Percept™ device), ON dopaminergic medication, with stimulation both ON or OFF; 3) patients with recordings performed at home while engaging in a behavioral task via STN and GPi leads and electrocorticography paddles (ECoG) over premotor cortex connected to an investigational sensing-enabled neurostimulator, ON dopaminergic medication, with stimulation both ON or OFF.Trait anxiety was measured with validated clinical scales in all participants, and state anxiety was measured with momentary assessment scales at multiple time points in the two at-home cohorts. Power in theta (4-8 Hz) and alpha (8-12 Hz) ranges were extracted from the LFP recordings, and their relation with anxiety ratings was assessed using linear mixed-effects models. Results: In total, 33 PD patients (59 hemispheres) were included. Across three independent cohorts, with stimulation OFF, basal ganglia theta power was positively related to trait anxiety (all p<0.05). Also in a naturalistic setting, with individuals at home at rest with stimulation and medication ON, basal ganglia theta power was positively related to trait anxiety (p<0.05). This relationship held regardless of the hemisphere and DBS target. There was no correlation between trait anxiety and premotor cortical theta-alpha power. There was no within-patient association between basal ganglia theta-alpha power and state anxiety. Conclusion: We showed that basal ganglia theta activity indexes trait anxiety in PD. Our data suggest that theta could be a possible physiomarker of neuropsychiatric symptoms and specifically of anxiety in PD, potentially suitable for guiding advanced DBS treatment tailored to the individual patient's needs, including non-motor symptoms.

Short term cardiovascular symptoms improvement after deep brain stimulation in patients with Parkinson's disease: a systematic review.

BACKGROUND: Autonomic dysfunction is common and disabling in Parkinson's disease (PD). The effects of deep brain stimulation (DBS) on the cardiovascular system in PD remain poorly understood. We aimed to assess the effect of DBS on cardiovascular symptoms and objective measures in PD patients. METHODS: We conducted a systematic literature search in PubMed/MEDLINE. RESULTS: 36 out of 472 studies were included, mostly involving DBS of the subthalamic nucleus, and to a lesser extent the globus pallidus pars interna and pedunculopontine nucleus. Seventeen studies evaluated the effect of DBS on patient-reported or clinician-rated cardiovascular symptoms, showing an improvement in the first year after surgery but not with longer-term follow-up. DBS has no clear direct effects on blood pressure during an orthostatic challenge (n = 10 studies). DBS has inconsistent effects on heart rate variability (n = 10 studies). CONCLUSION: Current evidence on the impact of DBS on cardiovascular functions in PD is inconclusive. DBS may offer short-term improvement of cardiovascular symptoms in PD, particularly orthostatic hypotension, which may be attributed to dopaminergic medication reduction after surgery. There is insufficient evidence to draw conclusions on the direct effect of DBS on blood pressure and heart rate variability.

A survey-based approach on restless legs syndrome: practices and perspectives among Italian neurologists.

INTRODUCTION: Restless Legs Syndrome (RLS) is a widely prevalent and complex neurological disorder. Despite notable advancements in managing RLS, the disorder continues to face challenges related to its recognition and management. OBJECTIVE: This study seeks to gain comprehensive insights into the knowledge and clinical practices among Italian neurologists regarding RLS diagnosis, management, and treatment, comparing approaches among general neurologists, movement disorder specialists, and sleep experts. METHODS: Members of the Italian Society of Neurology, the Italian Society of Parkinson and Movement Disorders, and the Italian Association of Sleep Medicine were invited to participate in a 19-question online survey. RESULTS: Among the 343 surveyed neurologists, 60% categorized RLS as a "sleep-related movement disorder." Forty% indicated managing 5-15 RLS patients annually, with sleep specialists handling the highest patient volume. Of note, only 34% adhered strictly to all five essential diagnostic criteria. The majority (69%) favored low-dosage dopamine agonists as their first-line treatment, with movement disorder specialists predominantly endorsing this approach, while sleep experts preferred iron supplementation. Regular screening for iron levels was widespread (91%), with supplementation typically guided by serum iron alterations. In cases of ineffective initial treatments, escalating dopamine agonist dosage was the preferred strategy (40%). CONCLUSIONS: These findings underscore a lack of a clear conceptualization of RLS, with a widespread misconception of the disorder as solely a movement disorder significantly influencing treatment approaches. Disparities in RLS understanding across neurology subspecialties underscore the necessity for improved diagnostic accuracy, targeted educational initiatives, and management guidelines to ensure consistent and effective RLS management.

Compassionate mind training for people with Parkinson's disease: A pilot study and predictors of response.

INTRODUCTION: People with Parkinson's disease (PD) often present with disabling neuropsychiatric symptoms. Compassionate mind training (CMT) is a psychological approach effective in reducing stress and promoting psychological well-being. Heart rate variability (HRV), a measure reflecting sympathovagal balance, has been associated with psychological well-being and a compassionate attitude. AIM: To assess the feasibility and effectiveness of CMT in enhancing the quality of life and psychological well-being in PD patients. Additionally, we evaluated HRV as a physiomarker for assessing the CMT outcomes. METHODS: Twenty-four PD patients participated in the study. A 6-week online CMT intervention was delivered on a weekly basis. At baseline and post-intervention patients completed questionnaires assessing depression, anxiety and quality of life. In a subsample of 11 patients, HRV was measured at baseline and post-intervention in three conditions: at rest, during stress and after 3 min of deep breathing. RESULTS: The attendance rate was 94.3%. Quality of life and perceived stigma improved post-intervention as compared with baseline (p = 0.02 and p = 0.03 for PD Questionnaire-39 total score and Stigma subscore, respectively). After CMT, patients presented better physiological regulation to stress, as measured by higher HRV as compared with baseline (p = 0.005). Notably, patients who were more resilient to stress at baseline (less decrease in HRV during stress) experienced a more substantial reduction in anxiety and depression following CMT. CONCLUSIONS: CMT is feasible and can improve quality of life and stigma in PD patients. HRV emerges as a promising physiomarker for predicting and measuring the outcomes of psychological interventions in PD.

Elderly Onset of Functional Motor Disorders: Clinical Correlates from the Italian Registry.

BACKGROUND: Functional motor disorders (FMD) are a frequent neurological condition affecting patients with movement disorders. Commonly described in younger adults, their manifestation can be also associated to an elderly onset. OBJECTIVE: To assess the prevalence and describe the clinical manifestations of FMD with elderly and younger onset and their relationship with demographical and clinical variables. METHODS: We recruited patients with a "clinically definite" diagnosis of FMD from the Italian Registry of FMD. Patients underwent extensive clinical assessments. For elderly onset, we set a chronological cut-off at 65 years or older according to WHO definition. Multivariate regression models were implemented to estimate adjusted odds ratio of elderly FMD onset related to clinical characteristics. RESULTS: Among the 410 patients, 34 (8.2%) experienced elderly-onset FMD, with a mean age at onset of 70.9 years. The most common phenotype was tremor (47.1%), followed by gait disorders, weakness, and dystonia (29.4%, 23.5%, 14.7%, respectively). Eleven elderly patients had a combined phenomenology: 9 exhibited two phenotypes, 2 had three phenotypes. Weakness was isolated in 3/8 patients and combined with another phenotype in 5/8, manifesting as paraplegia (n = 4); upper limb diplegia (n = 2), hemiparesis/hemiplegia (n = 1), and tetraparesis/tetraplegia (n= 1). Non-motor and other functional neurological disorders occurred more frequently in the younger group (89.1%) than the elderly (73.5%). Neurological and non-neurological comorbidities were more prevalent in the elderly group (82.4%) as opposed to the younger (32.7%). In a multivariate regression analysis, elderly-onset FMD was significantly associated with neurological comorbidities, including parkinsonism (OR 6.73) and cerebrovascular diseases (OR 5.48). CONCLUSIONS: These results highlight the importance of achieving an accurate diagnosis of FMD in the elderly, as it is crucial for effectively managing FMD symptoms and addressing neurological comorbidities.

Subjective Cognitive Complaints in Parkinson's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Subjective cognitive complaints (SCCs) in Parkinson's disease (PD) are reported frequently, but their prevalence and association with changes on objective testing are not fully known. OBJECTIVE: We aimed to determine the prevalence, clinical correlates, and predictive value of SCCs in PD. METHODS: We conducted a systematic review and meta-analysis. From 204 abstracts, we selected 31 studies (n = 3441 patients), and from these, identified the prevalence, clinical features, associations with neuropsychiatric symptoms, and predictive values of SCCs in PD. RESULTS: The meta-analysis showed an SCC prevalence of 36%. This prevalence, however, was significantly moderated by study heterogeneity regarding female sex, disease severity, levodopa equivalent daily dosage, exclusion from the overall sample of patients with objective cognitive impairment, and measurement instrument. SCC prevalence did not differ between de novo and treated PD patients. SCCs were weakly and negligibly associated with cognitive changes on objective testing in cross-sectional studies. However, in cognitively healthy patients, SCCs had a risk ratio of 2.71 for later cognitive decline over a mean follow-up of 3.16 years. Moreover, SCCs were moderately related to co-occurring symptoms of depression, anxiety, or apathy and were more strongly related to these neuropsychiatric symptoms than objective cognitive functioning. CONCLUSION: Our analyses suggest that SCCs in patients with and without objective cognitive impairment are frequent, occurring in more than one third of PD patients. Establishing uniform measurement instruments for identifying PD-related SCCs is critical to understand their implications. Even in cases lacking evidence of objective cognitive impairment and where SCCs might reflect underlying neuropsychiatric symptoms, the possibility of later cognitive deterioration should not be excluded. Therefore, SCCs in PD patients warrant close monitoring for opportunities for targeted and effective interventions. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Radiofrequency thalamotomy for tremor produces focused and predictable lesions shown on magnetic resonance images.

Radiofrequency thalamotomy is a neurosurgical management option for medically-refractory tremor. In this observational study, we evaluate the MRI features of the resultant lesion, their temporal dynamics, and how they vary depending on surgical factors. We report on lesion characteristics including size and location, as well as how these vary over time and across different MRI sequences. Data from 12 patients (2 essential tremor, 10 Parkinson's disease) who underwent unilateral radiofrequency thalamotomy for tremor were analysed. Lesion characteristics were compared across five structural sequences. Volumetric analysis of lesion features was performed at early (<5 weeks) and late (>5 months) timepoints by manual segmentation. Lesion location was determined after registration of lesions to standard space. All patients showed tremor improvement (clinical global impressions scale) postoperatively. Chronic side-effects included balance disturbances (n = 4) and worsening mobility due to parkinsonism progression (n = 1). Early lesion features including a necrotic core, cytotoxic oedema and perilesional oedema were best demarcated on T2-weighted sequences. Multiple lesions were associated with greater cytotoxic oedema compared with single lesions (T2-weighted mean volume: 537 ± 112 mm³ versus 302 ± 146 mm³, P = 0.028). Total lesion volume reduced on average by 90% between the early and late scans (T2-weighted mean volume: 918 ± 517 versus 75 ± 50 mm³, t = 3.592, P = 0.023, n = 5), with comparable volumes demonstrated at ∼6 months after surgery. Lesion volumes on susceptibility-weighted images were larger than those of T2-weighted images at later timepoints. Radiofrequency thalamotomy produces focused and predictable lesion imaging characteristics over time. T2-weighted scans distinguish between the early lesion core and oedema characteristics, while lesions may remain more visible on susceptibility-weighted images in the months following surgery. Scanning patients in the immediate postoperative period and then at 6 months is clinically meaningful for understanding the anatomical basis of the transient and permanent effects of thalamotomy.

Dyskinesia and impulsive compulsive behaviour in Parkinson's disease are not related: Insights from a study with a wearable sensor.

INTRODUCTION: Previous studies have suggested an association between Impulsive Compulsive Behaviour (ICB) and dyskinesia in Parkinson's disease (PD). However, none of these studies have employed an objective home-based measure of dyskinesia. OBJECTIVES: To evaluate in advanced PD the relationship between ICB and dyskinesia, objectively measured with a wearable device. METHODS: In this cross-sectional study, ICB and other neuropsychiatric symptoms were assessed by means of structured clinical interview and specific screening instruments. Presence and severity of motor fluctuations and dyskinesia were rated with patient's and clinician's based rating instruments. Motor fluctuations and dyskinesia were also measured at home for 5-days using a validated wearable devise, the Parkinson's KinetiGraph™(PKG). RESULTS: We included 89 subjects with PD (29 females, 62 ± 7 years, disease duration 10.3 ± 4.5), of whom 36 (40%) had ICB. Patients with and without ICB did not differ by presence and severity of dyskinesia measured by clinical scales and PKG. There was no association between the presence of ICB and dyskinesia in the whole sample. CONCLUSION: Our data suggest that ICB and dyskinesia are common but unrelated disorders in advanced PD.

Beta-triggered adaptive deep brain stimulation during reaching movement in Parkinson's disease.

Subthalamic nucleus (STN) beta-triggered adaptive deep brain stimulation (ADBS) has been shown to provide clinical improvement comparable to conventional continuous DBS (CDBS) with less energy delivered to the brain and less stimulation induced side effects. However, several questions remain unanswered. First, there is a normal physiological reduction of STN beta band power just prior to and during voluntary movement. ADBS systems will therefore reduce or cease stimulation during movement in people with Parkinson's disease and could therefore compromise motor performance compared to CDBS. Second, beta power was smoothed and estimated over a time period of 400 ms in most previous ADBS studies, but a shorter smoothing period could have the advantage of being more sensitive to changes in beta power, which could enhance motor performance. In this study, we addressed these two questions by evaluating the effectiveness of STN beta-triggered ADBS using a standard 400 ms and a shorter 200 ms smoothing window during reaching movements. Results from 13 people with Parkinson's disease showed that reducing the smoothing window for quantifying beta did lead to shortened beta burst durations by increasing the number of beta bursts shorter than 200 ms and more frequent switching on/off of the stimulator but had no behavioural effects. Both ADBS and CDBS improved motor performance to an equivalent extent compared to no DBS. Secondary analysis revealed that there were independent effects of a decrease in beta power and an increase in gamma power in predicting faster movement speed, while a decrease in beta event related desynchronization (ERD) predicted quicker movement initiation. CDBS suppressed both beta and gamma more than ADBS, whereas beta ERD was reduced to a similar level during CDBS and ADBS compared with no DBS, which together explained the achieved similar performance improvement in reaching movements during CDBS and ADBS. In addition, ADBS significantly improved tremor compared with no DBS but was not as effective as CDBS. These results suggest that STN beta-triggered ADBS is effective in improving motor performance during reaching movements in people with Parkinson's disease, and that shortening of the smoothing window does not result in any additional behavioural benefit. When developing ADBS systems for Parkinson's disease, it might not be necessary to track very fast beta dynamics; combining beta, gamma, and information from motor decoding might be more beneficial with additional biomarkers needed for optimal treatment of tremor.

Opicapone versus entacapone: Head-to-head retrospective data-based comparison of healthcare resource utilization in people with Parkinson's disease new to catechol-O-methyltransferase (COMT) inhibitor treatment.

BACKGROUND AND PURPOSE: Motor fluctuations are a significant driver of healthcare resource utilization (HCRU) in people with Parkinson's disease (pwPD). A common management strategy is to include catechol-O-methyltransferase (COMT) inhibition with either opicapone or entacapone in the levodopa regimen. However, to date, there has been a lack of head-to-head data comparing the two COMT inhibitors in real-world settings. The aim of this study was to evaluate changes in HCRU and effect on sleep medications when opicapone was initiated as first COMT inhibitor versus entacapone. METHODS: In this retrospective cohort study, we assessed HCRU outcomes in pwPD naïve to COMT inhibition via UK electronic healthcare records (Clinical Practice Research Datalink and Hospital Episodes Statistics databases, June 2016 to December 2019). HCRU outcomes were assessed before (baseline) and after COMT inhibitor prescription at 0-6 months, 7-12 months and 13-18 months. Opicapone-treated pwPD were algorithm-matched (1:4) to entacapone-treated pwPD. RESULTS: By 6 months, treatment with opicapone resulted in 18.5% fewer neurology outpatient visits compared to entacapone treatment; this effect was maintained until the last follow-up (18 months). In the opicapone group, the mean levodopa equivalent daily dose decreased over the first year and then stabilized, whereas the entacapone-treated group showed an initial decrease in the first 6 months followed by a dose increase between 7 and 18 months. Neither COMT inhibitor had a significant impact on sleep medication use. CONCLUSIONS: This head-to-head study is the first to demonstrate, using 'real-world' data, that initiating COMT inhibition with opicapone is likely to decrease the need for post-treatment HCRU versus initiation of COMT inhibition with entacapone.

Memory Phenotypes In Early, De Novo Parkinson's Disease Patients with Mild Cognitive Impairment.

BACKGROUND: Memory deficits in mild cognitive impairment related to Parkinson's disease (PD-MCI) are quite heterogeneous, and there is no general agreement on their genesis. OBJECTIVES: To define memory phenotypes in de novo PD-MCI and their associations with motor and non-motor features and patients' quality of life. METHODS: From a sample of 183 early de novo patients with PD, cluster analysis was applied to neuropsychological measures of memory function of 82 patients with PD-MCI (44.8%). The remaining patients free of cognitive impairment were considered as a comparison group (n = 101). Cognitive measures and structural magnetic resonance imaging-based neural correlates of memory function were used to substantiate the results. RESULTS: A three-cluster model produced the best solution. Cluster A (65.85%) included memory unimpaired patients; Cluster B (23.17%) included patients with mild episodic memory disorder related to a "prefrontal executive-dependent phenotype"; Cluster C (10.97%) included patients with severe episodic memory disorder related to a "hybrid phenotype," where hippocampal-dependent deficits co-occurred with prefrontal executive-dependent memory dysfunctions. Cognitive and brain structural imaging correlates substantiated the findings. The three phenotypes did not differ in terms of motor and non-motor features, but the attention/executive deficits progressively increased from Cluster A, through Cluster B, to Cluster C. This last cluster had worse quality of life compared to others. CONCLUSIONS: Our results demonstrated the memory heterogeneity of de novo PD-MCI, suggesting existence of three distinct memory-related phenotypes. Identification of such phenotypes can be fruitful in understanding the pathophysiological mechanisms underlying PD-MCI and its subtypes and in guiding appropriate treatments. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Pain in Dystonia Scale (PIDS)-Development and Validation in Cervical Dystonia.

BACKGROUND: A better understanding of pain in adult-onset idiopathic dystonia (AOID) is needed to implement effective therapeutic strategies. OBJECTIVE: To develop a new rating instrument for pain in AOID and validate it in cervical dystonia (CD). METHODS: Development and validation of the Pain in Dystonia Scale (PIDS) comprised three phases. In phase 1, international experts and participants with AOID generated and evaluated the preliminary items for content validity. In phase 2, the PIDS was drafted and revised by the experts, followed by cognitive interviews to ensure self-administration suitability. In phase 3, the PIDS psychometric properties were assessed in 85 participants with CD and retested in 40 participants. RESULTS: The final version of PIDS evaluates pain severity (by body-part), functional impact, and external modulating factors. Test-retest reliability showed a high-correlation coefficient for the total score (0.9, P < 0.001), and intraclass correlation coefficients were 0.7 or higher for all items in all body-parts subscores. The overall PIDS severity score showed high internal consistency (Cronbach's α, 0.9). Convergent validity analysis revealed a strong correlation between the PIDS severity score and the Toronto Western Spasmodic Torticollis Rating Scale pain subscale (0.8, P < 0.001) and the Brief Pain Inventory-short form items related to pain at time of the assessment (0.7, P < 0.001) and impact of pain on daily functioning (0.7, P < 0.001). CONCLUSION: The PIDS is the first specific questionnaire developed to evaluate pain in all patients with AOID, here, demonstrating high-level psychometric properties in people with CD. Future work will validate PIDS in other forms of AOID. © 2023 International Parkinson and Movement Disorder Society.