Cognitive and Neuropsychiatric Impairment in Dystonia

Protocol and Demographics of the RELY-CD Study: Assessing Long-Term Clinical Response to Botulinum Neurotoxin in Cervical Dystonia

The RELY-CD study investigated the long-term clinical response to botulinum neurotoxin type A in cervical dystonia within a multicenter, real-world setting. This retrospective study focused on patients treated with complex-free (incobotulinumtoxinA) and complex-containing (onabotulinumtoxinA and abobotulinumtoxinA) BoNT/A formulations over an up to 10-year period. The novel dose-effect parameter "DEff" was introduced to quantify the relationship between dose adjustments and clinical outcomes, enabling the identification of partial treatment failures. The primary endpoint was a comparison of a clinically meaningful worsening in DEff in treatment year 7 compared to year 2 between complex-free and complex-containing botulinum neurotoxin type A. The RELY-CD study provides unique insights into long-term treatment patterns, clinical resistance phenomena, and the implications of formulation differences on treatment outcomes, addressing a critical gap in the literature on real-world botulinum neurotoxin type A application. The study methodology, including the definition and calculation of the novel DEff, as well as clinical baseline characteristics, are presented.

Social Cognition, Executive Functioning, Mood, and Disability in Cervical Dystonia

BACKGROUND

Individuals with idiopathic adult-onset isolated cervical dystonia (CD) may have cognitive difficulties and increased mood challenges. Social cognition and executive functioning may be particularly affected.

OBJECTIVE

To explore social cognition and executive functioning performance in individuals with CD, using the Cambridge Neuropsychological Test Automated Battery (CANTAB), as previous research has used traditional, nondigital neuropsychological assessments. We sought to investigate the relationships between social cognition, executive functioning, mood, and disability in individuals with CD.

METHODS

We recruited 37 individuals with CD, including 26 women with an age range of 33 to 69 years (M = 56.64, SD = 8.31) from a dystonia clinic in a hospital neurology department. The individuals completed selected tasks from the CANTAB measuring social cognition and executive functioning. We compared the individuals' performance with CANTAB normative data. Depression, anxiety, disease severity, and disability were measured.

RESULTS

The individuals with CD had significantly lower scores than the CANTAB normative data in both social cognition and executive functioning tasks, with the largest differences evident in problem-solving, attention, and positive emotion bias tasks. Poorer emotion recognition was associated with increased difficulties in problem-solving tasks. The individuals demonstrated a bias toward identifying happiness in facial affect, which was related to a poorer recognition of emotions. Cognitive performance was not related to CD severity or disability or to current mood symptoms.

CONCLUSION

Difficulties with both social cognition and executive functioning were identified in the individuals with CD, and are likely important targets for clinical interventions.

The blink reflex and its modulation - Part 2: Pathophysiology and clinical utility

The blink reflex (BR) is integrated at the brainstem; however, it is modulated by inputs from various structures such as the striatum, globus pallidus, substantia nigra, and nucleus raphe magnus but also from afferent input from the peripheral nervous system. Therefore, it provides information about the pathophysiology of numerous peripheral and central nervous system disorders. The BR is a valuable tool for studying the integrity of the trigemino-facial system, the relevant brainstem nuclei, and circuits. At the same time, some neurophysiological techniques applying the BR may indicate abnormalities involving structures rostral to the brainstem that modulate or control the BR circuits. This is a state-of-the-art review of the clinical application of BR modulation; physiology is reviewed in part 1. In this review, we aim to present the role of the BR and techniques related to its modulation in understanding pathophysiological mechanisms of motor control and pain disorders, in which these techniques are diagnostically helpful. Furthermore, some BR techniques may have a predictive value or serve as a basis for follow-up evaluation. BR testing may benefit in the diagnosis of hemifacial spasm, dystonia, functional movement disorders, migraine, orofacial pain, and psychiatric disorders. Although the abnormalities in the integrity of the BR pathway itself may provide information about trigeminal or facial nerve disorders, alterations in BR excitability are found in several disease conditions. BR excitability studies are suitable for understanding the common pathophysiological mechanisms behind various clinical entities, elucidating alterations in top-down inhibitory systems, and allowing for follow-up and quantitation of many neurological syndromes.

Longitudinal predictors of health-related quality of life in isolated dystonia

OBJECTIVE

To determine longitudinal predictors of health-related quality of life (HR-QoL) in an international multicenter cohort of patients with isolated dystonia.

METHODS

Out of 603 dystonia patients prospectively enrolled in the Natural History Dystonia Coalition study, 155 were assessed three times within 2 years for HR-QoL, symptoms of depression, generalized anxiety disorder (GAD), and social anxiety disorder (SAD), as well as dystonia severity and dystonic tremor. In addition, the impact of botulinum neurotoxin (BoNT) injections on HR-QoL was evaluated after 1 year.

RESULTS

Depressive symptoms at baseline predicted lower HR-QoL on all subscales after 2 years (all p ≤ 0.001). Higher GAD scores at baseline predicted lower HR-QoL related to general health, pain and emotional well-being, whereas higher SAD scores predicted higher pain-related QoL after 2 years (all p ≤ 0.006). Dystonia severity at baseline predicted social functioning (p = 0.002). Neither dystonic tremor, age, or sex predicted HR-QoL at 2 years. Two latent categories were revealed across the three-time points: Category 1 with higher total HR-QoL scores (mean HR-QoL = 74.4% ± 16.1), susceptible to symptoms of depression and SAD, and Category 2 with lower total HR-QoL scores (mean HR-QoL = 45.5% ± 17.6), susceptible to symptoms of GAD. HR-QoL improved over the course of 1 year irrespective of the use of BoNT.

CONCLUSION

The longitudinal impact of psychiatric symptoms on HR-QoL emphasizes the importance of incorporating mental health treatment, in particular also the therapy of anxiety disorders, into treatment regimens for dystonia.

Clinimetrics of the Italian version of the Montreal Cognitive Assessment (MoCA) in adult-onset idiopathic focal dystonia

This study aimed at assessing the clinimetrics of the Montreal Cognitive Assessment (MoCA) in an Italian cohort of patients with adult-onset idiopathic focal dystonia (AOIFD). N = 86 AOIFD patients and N = 92 healthy controls (HCs) were administered the MoCA. Patients further underwent the Trail-Making Test (TMT) and Babcock Memory Test (BMT), being also screened via the Beck Depression Inventory-II (BDI-II) and the Dimensional Apathy Scale (DAS). Factorial structure and internal consistency were assessed. Construct validity was tested against TMT, BMT, BDI-II and DAS scores, whilst diagnostics against the co-occurrence of a defective performance on at least one TMT measure and on the BMT. Case-control discrimination was examined. The association between MoCA scores and motor-functional measures was explored. The MoCA was underpinned by a mono-component structure and acceptably reliable at an internal level. It converged towards TMT and BMT scores, as well as with the DAS, whilst diverging from the BDI-II. Its adjusted scores accurately detected cognitive impairment (AUC = .86) at a cut-off of < 17.212. The MoCA discriminated patients from HCs (p < .001). Finally, it was unrelated to disease duration and severity, as well as to motor phenotypes. The Italian MoCA is a valid, diagnostically sound and feasible cognitive screener in AOIFD patients.

The Impact of Non-Motor Symptoms on Quality of Life in Cervical Dystonia

Cervical dystonia (CD) is characterized by cranial muscle overactivity leading to abnormal intermittent or continuous posturing of the head. Nowadays, the treatment of patients suffering from this condition focuses principally on the motor component of the disorder, certainly the invaliding part; however, it leaves out the non-motor one that has a similarly invalidated effect on the quality of the subject's life. This review was conducted on studies investigating the impact of non-motor symptoms on levels of quality of life. We searched on the PubMed, EMBASE and Web of Science databases and screening references of included studies and review articles for additional citations. From an initial 150 publications, we included only five studies that met the search criteria. The results showed that anxiety, depression, pain and sleep quality have a great influence on patients' health and on the outcome of the disease. Future studies should focus more on investigating the non-motor components of CD as an integral part of the clinical management of dystonic patients in order to improve their well-being.

Non-Motor Symptoms and Quality of Life in Patients with PRRT2-Related Paroxysmal Kinesigenic Dyskinesia

Background

Monoallelic pathogenic variants of PRRT2 often result in paroxysmal kinesigenic dyskinesia (PKD). Little is known about health-related quality of life (HrQoL), non-motor manifestations, self-esteem, and stigma in patients with PKD.

Objectives

We investigated non-motor symptoms and how they related to HrQoL in a genetically homogeneous group of PRRT2-PKD patients. We paid special attention to perceived stigmatization and self-esteem.

Methods

We prospectively enrolled 21 consecutive PKD patients with a pathogenic variant of PRRT2, and 21 healthy controls matched for age and sex. They were evaluated with dedicated standardized tests for non-motor symptoms, HrQoL, anxiety, depression, stigma, self-esteem, sleep, fatigue, pain, and psychological well-being.

Results

Patients reported an alteration of the physical aspects of HrQoL, regardless of the presence of residual paroxysmal episodes. Non-motor manifestations were frequent, and were an important determinant of the alteration of HrQoL. In addition, patients perceived a higher level of stigmatization which positively correlated with a delay in diagnosis (ρ = 0.615, P = 0.003) and the fear of being judged (ρ = 0.452, P = 0.04), but not with the presence of paroxysmal episodes (ρ = 0.203, P = 0.379).

Conclusions

Our findings have important implications for care givers concerning patient management and medical education about paroxysmal dyskinesia. PRRT2-PKD patients should be screened for non-motor disorders in routine care. A long history of misdiagnosis may play a role in the high level of perceived stigmatization. Improving knowledge about diagnostic clues suggestive of PKD is mandatory.