Datasets:

---

LLMDH

/

OpenScience

like 0

Follow

LLM - Digital Humanities 16

ERROR: type should be string, got "https://doi.org/10.1590/0004-282X20200038 https://doi.org/10.1590/0004-282X20200038 ARTICLE RESUMO Introdução: A distonia cervical (DC) é a forma mais comum de distonia focal. Não se sabe exatamente se posturas anormais da cabeça na \nDC causam problemas de equilíbrio. A execução de duas tarefas simultaneamente é situação comum da vida cotidiana. Objetivo: Avaliar \na estabilidade postural (EP) em pacientes com DC e o efeito da tarefa cognitiva na EP. Como objetivo secundário, avaliamos o efeito da \ntoxina onabotulínica A (BoNT) na EP. Métodos: Foram incluídos 24 pacientes com DC em tratamento com BoNT por pelo menos um ano e \n23 controles saudáveis. As análises posturográficas foram realizadas em todos os sujeitos na plataforma de posturografia estática sob \nquatro condições diferentes: olhos abertos, olhos fechados, postura tandem e tarefa cognitiva. Nos pacientes, a análise posturográfica \nfoi realizada imediatamente antes das injeções de BoNT e após quatro semanas. Resultados: Antes do tratamento, a oscilação ântero-\nposterior era significativamente maior nos pacientes com DC com os olhos abertos quando comparados aos controles (p=0,03). A tarefa \ncognitiva interferiu significativamente nas velocidades de oscilação. A postura tandem afetou significativamente muitos parâmetros de \noscilação, enquanto a condição de olhos fechados não. Após o tratamento, apenas dois parâmetros na posição tandem e um na tarefa \ncognitiva melhoraram no grupo de pacientes. Conclusões: O controle postural é prejudicado em pacientes com DC, provavelmente devido \nà comprometida integração proprioceptiva e sensório-motora. Em referência às teorias de dupla-tarefa, possivelmente devido à atenção \ndividida e à priorização de tarefas, a dupla-tarefa cognitiva e a tarefa postural mais difíceis perturbam o EP nesses pacientes. Palavras-chave: Toxinas Botulínicas; Torcicolo; Cognição; Postura; Equilíbrio Postural. ABSTRACT Background: Cervical dystonia (CD) is the most common form of focal dystonia. It is not known exactly whether abnormal head postures \nin cervical dystonia cause balance problems. Dual-tasking is a common every-day life situation. Objective: We aimed to evaluate postural \nstability (PS) in patients with CD and the effect of cognitive task on PS. As a secondary aim, we evaluated the effect of onabotulinum toxin \nA (BoNT) injection on PS. Methods: A total of 24 patients with CD who were on BoNT treatment for at least one year and 23 healthy controls \nwere included. Posturographic analyses were carried out in all the subjects on static posturography platform under four different conditions: \neyes open, eyes closed, tandem stance and cognitive task. In patients, posturographic analysis was carried out just before the BoNT \ninjections and was repeated four weeks later. Results: Before treatment, the anterior-posterior sway was significantly higher in CD patients \nwith the eyes open condition compared to the controls (p=0.03). Cognitive task significantly affected several sway velocities. Tandem stance \nsignificantly affected many sway parameters, whereas the eyes closed condition did not. After treatment, only two parameters in tandem \nstance and one in cognitive task improved within the patient group, in a pairwise comparison. Conclusions: Postural control is impaired in \nCD patients probably due to the impaired proprioceptive and sensorimotor integration. In reference to dual task theories possibly due to \ndivided attention and task prioritization, cognitive dual-task and harder postural task disturbes the PS in these patients. Keywords: Botulinum Toxin; Torticollis; Cognition; Posture; Postural Balance. Subjects Twenty-four patients with CD who were followed-up for at \nleast one year in our movement disorders unit were enrolled \nin this prospective study. Inclusion criteria required patients \nhaving received BoNT injection every three months regularly \nfor at least one year. Patients on any other treament for CD, \nwith mental retardation or dementia, with comorbid neuro-\nlogical disorders that may affect posture and balance, such \nas polyneuropathy, ataxia, cerebrovascular disease, multiple \nsclerosis, rheumatologic or orthopedic problems, vestibulop-\nathy or otological disease, severely blurred vision, on seda-\ntive drugs or substances were excluded. Written informed \nconsent was obtained from all participants before enroll-\nment. This study was approved by the Ethics Committee of \nÇukurova University, Faculty of Medicine. There are some studies on postural balance in CD. Barr \net  al. compared the functional measures of mobility, gait, \nreaction time, and postural balance in ten people with CD \nand ten healthy controls. They reported that CD patient \nswayed more than controls, with poor postural control18. De Pauw et al. compared postural control during quiet sitting \nin 23 patients with CD and 36 healthy controls. They reported \nincreased postural sway and impaired PS in CD patients5. Bove et al. studied PS in 16 CD patients and 12 healthy con-\ntrols, CD patients were found to sway definitely more than \ncontrols7. Lekhel et al.19 and Moreu et al.20 reported no dif-\nferences in postural sway in stance between healthy controls \nand patients with CD. These studies all have different meth-\nodological approaches and the results were controversial. Furthermore, 23 healthy controls were included. The patients and the controls were similar in age and gen-\nder distribution. Neurological examination was performed \nin all subjects. Except for dystonia, CD patients were neu-\nrologically normal. Dystonia severity was assessed with \nthe Toronto Western Spasmodic Torticollis Rating Scale \n(TWSTRS); dystonia severity, disability and pain scores were \ndetermined24. The presence of dystonic head tremor was \nnoted. Patients received BoNT injections as needed. All of \nthem received onabotulinumtoxin A (BOTOX®, Allergan, Inc., \nIrvine, CA, USA), and the muscles to be treated were selected \nbased on the neurological examination and electromyogra-\nphy (EMG), according to each patient’s needs. Evaluations \nof patients including TWSTRS and static posturographyic \nmeasurements were repeated four weeks after the injection, \nwhich is when the highest treatment effect is expected25. Dual-tasking, a common every-day life situation, is the \nability to coordinate performance on two functional activ-\nity performing simultaneously21. METHODS Postural control and balance are provided by somato-\nsensory integrations as well as the integration of vestibular \nand visual inputs5. In CD, sensorimotor integration deficits \ndetected by motor-evoked potentials with transcranial stim-\nulation have been reported6. It is emphasized that sensorim-\notor integration deficits seen in these patients are related to \nimpaired neck proprioception, and impaired neck proprio-\nception leads to balance and posture impairments7,8,9,10,11. Mild deficits in vestibular reflexes have been defined in \npatients with CD12. The vestibular system has complex con-\nnections within the brain stem, thalamus and cortex. In CD, \nit is possible that there is a defect in these central connec-\ntions and in their relation with other modalities that control \nhead and eye movements in particular13. However, studies \nhave controversial results on this subject13,14,15,16,17. Subjects During daily activities, \nhumans involuntarily perform dual tasks without any prob-\nlem. Daily activities, such as listening to music while walking \nor running, writing while listening or answering questions, \nare examples of dual-tasking. Healthy people can provide \npostural control while performing another motor or cogni-\ntive task22. There are no studies in literature evaluating the \nPS under dual task condition in CD patients. Furthermore, \nto the best of our knowledge, there is only one study on the \neffect of BoNT treatment on PS in these patients. Müller et al. reported no beneficial effects of BoNT on dynamic balance \nin phasic CD23. Arq Neuropsiquiatr 2020;78(9):549-555 INTRODUCTION It causes involuntary contraction of neck muscles, leading to \ntonic or clonic head movements, subsequently resulting in \nsustained abnormal head postures. It has several types: torti-\ncollis, laterocollis, anterocollis and retrocollis. Most patients Cervical dystonia (CD) is the most common form of focal \ndystonia. Its prevelance ranges from 20‒4,100 cases/million1. 1Çukurova University, Faculty of Medicine, Department of Neurology, Adana, Turkey. 2Çukurova University, Faculty of Medicine, Movement Disorders Unit, Department of Neurology, Adana, Turkey. Turgay DEMİR \n https://orcid.org/0000-0002-7076-8571; Mehmet BALAL \n https://orcid.org/0000-0001-8320-6597; \nMeltem DEMİRKİRAN \n https://orcid.org/0000-0002-4649-5315\nCorrespondence: Turgay Demir; E-mails: drtdemir@gmail.com, tdemir@cu.edu.tr \nConflict of interest: There is no conflict of interest to declare. Ethical approval: Cukurova University, Faculty of Medicine Ethics Committee approved the study protocol (protocol number: 78-2016.06.01_32). Informed consent: Informed consent was obtained from all participants included in the study. Received on September 21, 2019; Received in its final form on November 29, 2019; Accepted on March 24, 2020. 1Çukurova University, Faculty of Medicine, Department of Neurology, Adana, Turkey. 2Çukurova University, Faculty of Medicine, Movement Disorders Unit, Department of Neurology, Adana, Turkey. Turgay DEMİR \n https://orcid.org/0000-0002-7076-8571; Mehmet BALAL \n https://orcid.org/0000-0001-8320-6597; \nMeltem DEMİRKİRAN \n https://orcid.org/0000-0002-4649-5315\nCorrespondence: Turgay Demir; E-mails: drtdemir@gmail.com, tdemir@cu.edu.tr \nConflict of interest: There is no conflict of interest to declare. Ethical approval: Cukurova University, Faculty of Medicine Ethics Committee approved the study protocol (protocol number: 78-2016.06.01_32). Informed consent: Informed consent was obtained from all participants included in the study. Received on September 21, 2019; Received in its final form on November 29, 2019; Accepted on March 24, 2020. 549 of cognitive task on PS in patients with CD. We also seek \nto analyze whether BoNT has any effect on the PS of these \npatients. Therefore, our secondary aim was to evaluate the \neffect of BoNT on PS, within the patient group. with CD have mixed type postures2. In addition to abnormal \npostures, some patients have clonic head movements result-\ning in dystonic tremor. Botulinum toxin (BoNT) treatment is \nthe first line treatment for CD and is reported to be effec-\ntive in 70‒92% of patients3,4. Whether abnormal head posture \ncause balance problems in CD is unknown. Participants Demographic features of the subjects are shown in \nTable 2. The most common CD type was torticollis and was \npresent in 83.3% (n=20) of patients. Dystonic head tremor \nwas present in 37.5% (n=9) of them (Table 3). RESULTS RESULTS Statistical analysis All analyses were performed using the SPSS® for Windows \nsoftware package (Version 20.0. Armonk, NY: IBM  Corp.). Continuous variables were summarized as means and stan-\ndard deviation. The normality of distribution for continu-\nous variables was confirmed with the Shapiro Wilk test. For variables with a normal distribution, a parametric test, \nsuch as Student’s t-test was used. Variables without a nor-\nmal distribution were evaluated using the nonparamet-\nric Mann-Whitney U test. For comparison of two related \n(paired) continuous variables, paired samples Student’s \nt-test for variables with a normal distribution or Wilcoxon \nSigned Rank test for variables without a normal distribu-\ntion was used. Pearson’s coefficient was used in the correla-\ntion analysis of numeric variables with a normal distribu-\ntion, and  Spearman’s correlation coefficient was used for \nthe analysis of numerical variables without normal distri-\nbution. The hypothesis tests were conducted to verify the Posturographic parameters With the baseline EO condition, only A-P sway and sway path \nvelocity were significantly higher in CD than in controls. EC did \nnot have any effect on PS, whereas TAN affected almost all sway \nparameters in CD significantly (Table 4). The effect of cognitive \ndual task was more prominent in the sway velocities (Table 4). BoNT treatment did not lead to a significant reduction in the \nsway parameters. Only a few parameters get better after the injec-\ntion. A-P sway in EO, lateral sway and sway path in TAN and lat-\neral sway velocity in cognitive dual tasking improved significantly \nafter BoNT injection (Table 5). Age, disease duration and TWSTRS \nscore did not correlate with any posturographic parameters. he \ny \nCD patients \n(n=24) \nControls \n(n=23)\nAge (years)\n48±14.5 (range 20‑72) 49.3±13.8 (range 22‑72)\nGender (F/M)\n14/10\n14/9\nDisease \nduration (years)\n13.1±9.9 (range 1‑32)\n_\nTWSTRS score\n12.3±6.1 (range 5‑27)\n_\nTable 2. Demographic and clinical characteristics \nof participants. CD: cervical dystonia; F: Female; M: Male; TWSTRS: Toronto Western \nSpazmodic torticollis scale\nn\n%\nDHT\nn (%)\nTWSTRS\nPure Type\n14\n58.3\n7 (29.4)\n11.7\nTorticollis\n10\n41.6\nLaterocollis\n3\n12.5\nAnterocollis\n1\n4.2\nMixed Type\n10\n41.6\n2 (8.3)\n21.3\nTorticollis-Laterocollis\n3\n12.5\nTorticollis-Retrocollis\n4\n16.6\nTorticollis-Anterocollis\n2\n8.3\nTorticollis-Laterocollis-\nAnterocollis\n1\n4.2\nTable 3. Types of cervical dystonia. DHT: dystonic head tremor; TWSTRS: Toronto Western Spasmodic \nTorticollis Scale CD patients \n(n=24) \nControls \n(n=23)\nAge (years)\n48±14.5 (range 20‑72) 49.3±13.8 (range 22‑72)\nGender (F/M)\n14/10\n14/9\nDisease \nduration (years)\n13.1±9.9 (range 1‑32)\n_\nTWSTRS score\n12.3±6.1 (range 5‑27)\n_\nTable 2. Demographic and clinical characteristics \nof participants. CD: cervical dystonia; F: Female; M: Male; TWSTRS: Toronto Western \nSpazmodic torticollis scale Table 2. Demographic and clinical characteristics \nof participants. Posturography protocol Patients and controls underwent static posturography \n(SPG). SPG was carried out just before a new injection of \nBoNT in CD and was repeated four weeks later in these \npatients. It was performed on a force platform (Lucerne II, \nOtopront®, Germany) in a quiet room. The subjects were \ntold to stand on the platform in an upright position as sta-\nble as possible, barefoot, with their feet 4 cm apart. The \narms were held alongside the body. Each recording lasted \n30 seconds. The first recording was done with the patient \nwith eyes open (EO); the second, with the eyes closed (EC); \nthe  third,  with tandem stance with eyes closed (TAN); \nand the last, with the EO producing words starting with “K” Considering the currently available data from the liter-\nature, we hypothesized that CD patients may have postural \ninstability due to abnormal head and neck postures and a \ncognitive dual-task may affect PS in these patients. In this \nsense, the primary aim of our study was to evaluate the effect 550 Arq Neuropsiquiatr 2020;78(9):549-555 nullity of the correlation coefficients. The statistical level of \nsignificance for all tests was considered as 0.05. nullity of the correlation coefficients. The statistical level of \nsignificance for all tests was considered as 0.05. (COG). The cognitive performance of participants was not \nevaluated during the cognitive task. In TAN, one foot is in \nfront of the other, and the arms lifted up and extended in \nfront of the body. Sway path, anterior-posterior (A-P) sway, \nlateral sway, sway area, as well as the velocity of all of these \nsway values (sway path/time, A-P sway/time, lateral sway/\ntime, sway area/time) were recorded. Definition of SPG \nparameters are shown in Table 1. Posturographic parameters Parameter\nDefinition\nSway path\nSum of the movements of the \ncentre of pressure during the whole \nexamination time (cm)\nWay velocity\nAverage speed of the movement \nof the centre of pressure (cm/sec) \n(way velocity)\nSway Area (SA)\nCalculation of the sway area \nacording to the formula of Diener/\nDichgans/Bacher (cm2), xi and y iare \nthe coordinates at the time i of the \ncentre of pressure)\n\t\n n-1\nSA = ½ Σ I xi+1 yi+1 xi I\n\t\n i = 1\nSA velocity\nArea divided by time (cm2/sec) (Sway \narea velocity)\nAnterior-posterior (A-P) \nSum of the y components of the \nmovement vectors (cm/s)\nΣ I yi+1-yi I\nA-P sway velocity\nQuotient of Antero-Posterior ant \ntime (cm/s) (Anterior-posterior sway \nvelocity)\nLateral \nSum of the x components of the \nmovement vectors (cm)\nΣ I yi+1-yi I\nLateral sway velocity\nQuotient of lateral and time (cm/s) \n(lateral sway velocity)\nTable 1. Definiton of the static posturography parameters. n\n%\nDHT\nn (%)\nTWSTRS\nPure Type\n14\n58.3\n7 (29.4)\n11.7\nTorticollis\n10\n41.6\nLaterocollis\n3\n12.5\nAnterocollis\n1\n4.2\nMixed Type\n10\n41.6\n2 (8.3)\n21.3\nTorticollis-Laterocollis\n3\n12.5\nTorticollis-Retrocollis\n4\n16.6\nTorticollis-Anterocollis\n2\n8.3\nTorticollis-Laterocollis-\nAnterocollis\n1\n4.2\nTable 3. Types of cervical dystonia. DHT: dystonic head tremor; TWSTRS: Toronto Western Spasmodic \nTorticollis Scale Demir T et al. Postural stability in cervical dystonia. 551 DISCUSSION A-P: antero-posterior; COG: cognitive task; EO: eyes open; EC: eyes closed; \nLS:lateral sway; SA:sway area; SP sway path; SD: standard deviation; \nTAN: tandem stance\nPosturographic \nparameters \nand TWSTRS\nBefore \nBoNT\n(mean±SD)\nAfter BoNT\n(mean±SD)\np-value\nTWSTRS score\n12.3±6.1\n8.8±4.6\n<0.001\nEO\nA-P sway (cm)\n28.2±11.7\n24.9±7.1\n0.012\nLS (cm)\n21.5±11.5\n20.1±8.2\n0.169\nSP (cm)\n40.3±17\n36.7±11\n0.071\nSA (cm2)\n6.6±6.2\n5.2±3.1\n0.146\nA-P sway velocity (cm/s)\n0.5±0.5\n1±0.001\n0.987\nLS velocity (cm/s)\n0.8±0.5\n0.5±0.5\n0.426\nSP velocity(cm/s) \n1.4±0.6\n1.2±0.4\n0.135\nSA velocity (cm2/s)\n0.008±0.2\n0.01±0.01\n0.162\nEC\nA-P sway (cm)\n43.8±31.2\n39.1±16.8\n0.153\nLS (cm)\n25.5±12.5\n23.7±10.5\n0.193\nSP (cm)\n56.6±34.3\n51.3±20.1\n0.149\nSA (cm2)\n12.2±13.4\n10.9±9.2\n0.810\nA-P sway velocity (cm/s)\n1±0.5\n1.3±0.5\n0.059\nLS velocity (cm/s)\n1.5±1.1\n0.7±0.5\n0.257\nSP velocity(cm/s) \n1.8±1.1\n1.7±0.6\n0.439\nSA velocity (cm2/s)\n0.2±0.5\n0.1±0.3\n0.083\nTAN\nA-P sway (cm)\n97.1±67.6\n96.1±60.7\n0.225\nLS (cm)\n80.7±44.2\n76.7±40.4\n0.038\nSP (cm)\n140±86.2\n136.9±78.4\n0.048\nSA (cm2)\n54.1±.60.1\n53.8±62.2\n0.478\nA-P sway velocity (cm/s)\n3.4±2.5\n3.1±2\n0.314\nLS velocity (cm/s)\n3.3±2.2\n2.6±1.3\n0.289\nSP velocity(cm/s) \n4.6±1.8\n4.5±2.6\n0.309\nSA velocity (cm2/s)\n7.5±9.1\n6.9±2.2\n0.582\nCOG\n A-P sway (cm)\n36.1±19.1\n35.1±16.5\n0.396\nLS (cm)\n25.2±15.3\n24.2±15\n0.073\nSP (cm)\n49.2±25.6\n48.1±23.9\n0.278\nSA (cm2)\n11.1±15.6\n12.9±16\n0.276\nA-P sway velocity (cm/s)\n0.8±0.6\n0.8±0.4\n0.655\nLS velocity (cm/s)\n1.2±0.6\n0.7±0.6\n0.046\nSP velocity(cm/s) \n1.6±0.9\n1.6±0.9\n0.987\nSA velocity (cm2/s)\n0.4±0.6\n0.2±0.5\n0.164\nTable 5. Pairwise comparisons of mean postural sways, \nvelocities and TWSTRS scores before and after BoNT. A-P: antero-posterior; BoNT: botulinum toxin; COG: cognitive task; EO: eyes \nopen; EC: eyes closed; LS:lateral sway; SA:sway area; SD: standard deviation; \nSP :sway path;TWSTRS:Toronto-Western Spazmodic Torticollis Rating Scale Table 5. Pairwise comparisons of mean postural sways, \nvelocities and TWSTRS scores before and after BoNT. DISCUSSION CD compared to the healthy controls under baseline EO con-\ndition. EC condition does not have any effect, whereas TAN, \nwhich is the harder postural task, affected PS of CD patients \nmore prominently than the other conditions. Cognitive task This is the first study to investigate PS in patients with \nCD under cognitive dual task condition. One of the results of \nour study is that postural control is impaired in patients with Posturographic \nparameters \nand TWSTRS\nBefore \nBoNT\n(mean±SD)\nAfter BoNT\n(mean±SD)\np-value\nTWSTRS score\n12.3±6.1\n8.8±4.6\n<0.001\nEO\nA-P sway (cm)\n28.2±11.7\n24.9±7.1\n0.012\nLS (cm)\n21.5±11.5\n20.1±8.2\n0.169\nSP (cm)\n40.3±17\n36.7±11\n0.071\nSA (cm2)\n6.6±6.2\n5.2±3.1\n0.146\nA-P sway velocity (cm/s)\n0.5±0.5\n1±0.001\n0.987\nLS velocity (cm/s)\n0.8±0.5\n0.5±0.5\n0.426\nSP velocity(cm/s) \n1.4±0.6\n1.2±0.4\n0.135\nSA velocity (cm2/s)\n0.008±0.2\n0.01±0.01\n0.162\nEC\nA-P sway (cm)\n43.8±31.2\n39.1±16.8\n0.153\nLS (cm)\n25.5±12.5\n23.7±10.5\n0.193\nSP (cm)\n56.6±34.3\n51.3±20.1\n0.149\nSA (cm2)\n12.2±13.4\n10.9±9.2\n0.810\nA-P sway velocity (cm/s)\n1±0.5\n1.3±0.5\n0.059\nLS velocity (cm/s)\n1.5±1.1\n0.7±0.5\n0.257\nSP velocity(cm/s) \n1.8±1.1\n1.7±0.6\n0.439\nSA velocity (cm2/s)\n0.2±0.5\n0.1±0.3\n0.083\nTAN\nA-P sway (cm)\n97.1±67.6\n96.1±60.7\n0.225\nLS (cm)\n80.7±44.2\n76.7±40.4\n0.038\nSP (cm)\n140±86.2\n136.9±78.4\n0.048\nSA (cm2)\n54.1±.60.1\n53.8±62.2\n0.478\nA-P sway velocity (cm/s)\n3.4±2.5\n3.1±2\n0.314\nLS velocity (cm/s)\n3.3±2.2\n2.6±1.3\n0.289\nSP velocity(cm/s) \n4.6±1.8\n4.5±2.6\n0.309\nSA velocity (cm2/s)\n7.5±9.1\n6.9±2.2\n0.582\nCOG\n A-P sway (cm)\n36.1±19.1\n35.1±16.5\n0.396\nLS (cm)\n25.2±15.3\n24.2±15\n0.073\nSP (cm)\n49.2±25.6\n48.1±23.9\n0.278\nSA (cm2)\n11.1±15.6\n12.9±16\n0.276\nA-P sway velocity (cm/s)\n0.8±0.6\n0.8±0.4\n0.655\nLS velocity (cm/s)\n1.2±0.6\n0.7±0.6\n0.046\nSP velocity(cm/s) \n1.6±0.9\n1.6±0.9\n0.987\nSA velocity (cm2/s)\n0.4±0.6\n0.2±0.5\n0.164\nTable 5. Pairwise comparisons of mean postural sways, \nvelocities and TWSTRS scores before and after BoNT. DISCUSSION A-P: antero-posterior; BoNT: botulinum toxin; COG: cognitive task; EO: eyes \nopen; EC: eyes closed; LS:lateral sway; SA:sway area; SD: standard deviation; \nSP :sway path;TWSTRS:Toronto Western Spazmodic Torticollis Rating Scale our study is that postural control is impaired in patients with \nPostural sways and \nvelocities\nCervical \nDystonia\n(mean±SD)\nControl\n(mean±SD)\np-value\nEO\nA-P sway (cm)\n28.2±11.7\n22.3±6.4\n0.039\nLS (cm)\n21.5±11.5\n19±5.7\n0.351\nSP (cm)\n40.3±17.0\n33.5±8.8\n0.095\nSA (cm2)\n6.6±6.2\n4.2±2\n0.089\nA-P sway velocity (cm/s)\n0.5±0.5\n0.7±0.4\n0.763\nLS velocity (cm/s)\n0.8±0.5\n0.9±0.2\n0.214\nSP velocity(cm/s) \n1.4±0.6\n1.1±0.3\n0.038\nSA velocity (cm2/s)\n0.008±0.2\n0.001±0.001\n0.162\nEC\nA-P sway (cm)\n43.8±31.2\n35.5±23\n0.090\nLS (cm)\n25.5±12.5\n21.5±8.4\n0.388\nSP (cm)\n56.6±34.3\n46.6±24.9\n0.166\nSA (cm2)\n12.2±13.4\n8±8.5\n0.126\nA-P sway velocity (cm/s)\n1±0.5\n0.7±0.5\n0.089\nLS velocity (cm/s)\n1.5±1.1\n1.2±0.7\n0.155\nSP velocity(cm/s) \n1.8±1.1\n1.5±0.8\n0.239\nSA velocity (cm2/s)\n0.2±0.5\n0.09±0.2\n0.250\nTAN\nA-P sway (cm)\n97.1±67.6\n35.4±19.7\n<0.001\nS (cm)\n80.7±44.2\n29.7±24.7\n<0.001\nSP (cm)\n140±86.2\n52.5±33.7\n<0.001\nSA (cm2)\n54.1±60.1\n11.3±15.5\n<0.001\nA-P sway velocity (cm/s)\n3.4±2.5\n2±0.7\n<0.001\nLS velocity (cm/s)\n3.3±2.2\n1±0.9\n0.086\nSP velocity(cm/s) \n4.6±1.8\n2.3±1.1\n<0.001\nSA velocity (cm2/s)\n7.5±9.1\n1.6±1.8\n<0.001\nCOG\nA-P sway (cm)\n36.1±19.1\n29.5±10.3\n0.163\nLS (cm)\n25.2±15.3\n19.2±6.1\n0.253\nSP (cm)\n49.2±25.6\n39.7±12.1\n0.221\nSA (cm2)\n11.1±15.6\n6.3±5\n0.234\nA-P sway velocity (cm/s)\n0.8±0.6\n0.8±0.3\n0.933\nLS velocity (cm/s)\n1.2±0.6\n0.2±0.5\n<0.001\nSP velocity(cm/s) \n1.6±0.9\n0.7±0.7\n<0.001\nSA velocity (cm2/s)\n0.4±0.6\n0.2±0.5\n<0.001\nTable 4. Comparison of mean postural sways and velocities \nbetween patients and controls. A-P: antero-posterior; BoNT: botulinum toxin; COG: cognitive task; EO: eyes \nopen; EC: eyes closed; LS:lateral sway; SA:sway area; SD: standard deviation; \nSP : sway path; TWSTRS: Toronto-Western Spazmodic Torticollis Rating Scale DISCUSSION Postural sways and \nvelocities\nCervical \nDystonia\n(mean±SD)\nControl\n(mean±SD)\np-value\nEO\nA-P sway (cm)\n28.2±11.7\n22.3±6.4\n0.039\nLS (cm)\n21.5±11.5\n19±5.7\n0.351\nSP (cm)\n40.3±17.0\n33.5±8.8\n0.095\nSA (cm2)\n6.6±6.2\n4.2±2\n0.089\nA-P sway velocity (cm/s)\n0.5±0.5\n0.7±0.4\n0.763\nLS velocity (cm/s)\n0.8±0.5\n0.9±0.2\n0.214\nSP velocity(cm/s) \n1.4±0.6\n1.1±0.3\n0.038\nSA velocity (cm2/s)\n0.008±0.2\n0.001±0.001\n0.162\nEC\nA-P sway (cm)\n43.8±31.2\n35.5±23\n0.090\nLS (cm)\n25.5±12.5\n21.5±8.4\n0.388\nSP (cm)\n56.6±34.3\n46.6±24.9\n0.166\nSA (cm2)\n12.2±13.4\n8±8.5\n0.126\nA-P sway velocity (cm/s)\n1±0.5\n0.7±0.5\n0.089\nLS velocity (cm/s)\n1.5±1.1\n1.2±0.7\n0.155\nSP velocity(cm/s) \n1.8±1.1\n1.5±0.8\n0.239\nSA velocity (cm2/s)\n0.2±0.5\n0.09±0.2\n0.250\nTAN\nA-P sway (cm)\n97.1±67.6\n35.4±19.7\n<0.001\nS (cm)\n80.7±44.2\n29.7±24.7\n<0.001\nSP (cm)\n140±86.2\n52.5±33.7\n<0.001\nSA (cm2)\n54.1±60.1\n11.3±15.5\n<0.001\nA-P sway velocity (cm/s)\n3.4±2.5\n2±0.7\n<0.001\nLS velocity (cm/s)\n3.3±2.2\n1±0.9\n0.086\nSP velocity(cm/s) \n4.6±1.8\n2.3±1.1\n<0.001\nSA velocity (cm2/s)\n7.5±9.1\n1.6±1.8\n<0.001\nCOG\nA-P sway (cm)\n36.1±19.1\n29.5±10.3\n0.163\nLS (cm)\n25.2±15.3\n19.2±6.1\n0.253\nSP (cm)\n49.2±25.6\n39.7±12.1\n0.221\nSA (cm2)\n11.1±15.6\n6.3±5\n0.234\nA-P sway velocity (cm/s)\n0.8±0.6\n0.8±0.3\n0.933\nLS velocity (cm/s)\n1.2±0.6\n0.2±0.5\n<0.001\nSP velocity(cm/s) \n1.6±0.9\n0.7±0.7\n<0.001\nSA velocity (cm2/s)\n0.4±0.6\n0.2±0.5\n<0.001\nTable 4. Comparison of mean postural sways and velocities \nbetween patients and controls. A-P: antero-posterior; COG: cognitive task; EO: eyes open; EC: eyes closed; \nLS:lateral sway; SA:sway area; SP sway path; SD: standard deviation; \nTAN: tandem stance Table 4. Comparison of mean postural sways and velocities \nbetween patients and controls. 552 Arq Neuropsiquiatr 2020;78(9):549-555 function is required to provide postural control and balance in \nsuch patients under dual task conditions. affected the sway velocities in patients significantly. There are \na few studies in literature investigating PS in CD, and the \nresults are controversial7,17,19,20,22. Lekhel et al.19 and Moreau \net al.20 reported that there was no significant difference in \nlateral and A-P sways between CD patients and controls. In contrast to these studies, Bove et al.7 and Wöber et al.26 \nreported significant increase in postural sway parameters \nsuch as sway path, sway area, medio-lateral and A-P sway val-\nues in CD compared to the controls. Barr et al. reported that \nCD patients swayed more than controls, had poor postural \ncontrol and walked more slowly than controls18. De Pauw \net al. reported increased postural sway and impaired PS in \npatients with CD5. DISCUSSION For this to happen, precise data from vestibular, \nvisual, body sensory systems should be taken, reconciled, \nunnecessary information should be eliminated and selected \nactions should be made appropriate. A robust neurological \nand skeletal system is required for all this to occur. However, \nour  results suggest that visual input may not have much \neffect on PS in these patients. Therefore, we assume that \nvisual input probably has the least effect on postural balance \nin patients with CD. As suggested by some earlier studies, \nproprioceptive and sensorimotor integration are probably \nmore important components of PS in patients with CD7,8,9,10,11. Up to date, there are no studies evaluating the effect \nof dual-tasking on postural control in patients with CD. An important finding of the present study is the effect of cog-\nnitive dual-tasking in patients with CD. We found that cog-\nnitive task impaired PS in these patients more than controls. The effect was more prominent on the sway velocities in pos-\nturographic analyses. Some theories have been put forward \nto explain the difficulties in performing dual tasks. The most \nprevalent are capacity sharing, bottleneck (task  switching), \nand cross talk27. According to capacity sharing theory, which is \nthe most widely accepted, performing two tasks at the same \ntime decreases the performance of each task due to the divi-\nsion of capacity for tasks27. In bottleneck (task-switching) \nmodel, parallel processing may be impossible for some men-\ntal operations27. Some operations may simply require a single \nmechanism to be dedicated to them for some period of time. When two tasks need the mechanism simultaneously, a bot-\ntleneck occurs, and one or both tasks will be delayed or oth-\nerwise impaired. The crosstalk model is being used to refer \nto conditions in which informational code overlaps across \ntasks27. Taleli et al.28 suggested that differential cortical activa-\ntion within the higher neural centers can affect task prioritiza-\ntion, further allowing increased conscious attention while car-\nrying out cognitive or motor tasks. Therefore, we can say that \nattention is an important variable to maintain PS under dual \ntask conditions in patients with CD and an adequate attention The present study has limitations. The absence of BoNT-\nnaive patient group is one of them. We included only the \npatients who were already under treatment. The number \nof patients with dystonic head tremor was low. DISCUSSION Differences in the study protocols includ-\ning patient selection and variations in the posturographic \nprotocols may explain these discrepancies. During dual task assessment, the two tasks performed \nsimultaneously in a dual task paradigm can be two cognitive, \ntwo motor, or a motor and a cognitive task29. Dual task costs, \nthat is, decline in performance of either or both tasks can be \ndue to age or illness-related conditions30,31. Hence, patients \nwith CD may experience reduction in performance when \nperforming two activities that require attention at the same \ntime, such as finding words starting with K and maintaining \nPS, leading to dual task costs32. They may have a tendency \nto prioritize the motor task, which is PS, in the presence of a \ncognitive or another challenging motor task33,34,35,36,37. In the literature, there are contradictory results on the \neffect of BoNT on PS in CD patients. In our study, BoNT injec-\ntion had little effect on PS of CD patients; in cognitive task, only \none sway velocity (lateral sway velocity), and in TAN stance \ntwo sway parameters (lateral sway and sway path) improved. Wöber et al.26 reported that the whole-body postural control \nwas impaired in more than 75% of idiopathic CD patients and \nhad improved with local injections with BoNT-A. On the other \nhand, De Pauw et al.38 reported that BoNT injection had little \nutility on cervical sensorimotor control, postural control, and \nvisual vertical perception. In our study, as seen in the improve-\nment of TWSTRS scores, BoNT is an effective treatment for CD, \nbut it did not have much effect on PS of these patients. It affects \nthe contraction of the muscles, leading to a better posture of \nthe head and neck, but this peripherally and improved posture \nprobably does not have any retrograde effects on central mecha-\nnisms which control the PS of patients with CD. In other words, \nthe PS of CD is the result of central mechanisms. Controlling the \nperipheral mechanism, such as improving the faulty contraction \nof neck muscles, probably does not provide additional help in \nthe maintenance of PS. More data in larger series is needed on \nthis subject to fully understand the effect of BoNT on PS in CD. hh The normal balance function provides the ability to \nmaintain the erect posture of the body in motion or stable \ncondition. Demir T et al. Postural stability in cervical dystonia. DISCUSSION Therefore, \nwe were unable to analyze the effect of dystonic head tremor \non these parameters in relation to dual-tasking. Different \ntypes of CD may have different impacts on PS. Nonetheless, \nthe number of patients are not enough to evaluate the effect \nof each type of CD. For standardization, we used the same \norder of tests in the posturographic analysis in every subject. This might have had some practice effects. In conclusion, PS is impaired in patients with CD. Vision \nmay not be as essential for PS in these patients like proprio-\nceptive and sensorimotor integration are. Cognitive dual \ntask disturbes PS in CD probably due to divided attention \nand task prioritization. BoNT injection does not seem to \nhave much effect on PS in patients with CD. More compre-\nhensive studies of posturography with complex motor or cog-\nnitive tasks may provide further information on this subject. 553 Demir T et al. Postural stability in cervical dystonia. References 1988 Feb;45(2):164-9. https://doi.org/10.1001/\narchneur.1988.00520260050019 1988 Feb;45(2):164-9. https://doi.org/10.1001/\narchneur.1988.00520260050019 1. Defazio G, Jankovic C, Giel JL, Papapetropoulos S. Descriptive \nepidemiology of cervical dystonia. Tremor Other Hyperkinet Mov \n(N Y). 2013;3:tre-03-193-4374-2. https://doi.org/10.7916/D80C4TGJ 18. Barr C, Barnard R, Edwards L, Lennon S, Bradnam L. Impairments \nof balance, stepping reactions and gait in people with cervical \ndystonia. Gait Posture. 2017 Jun;55:55-61. https://doi.org/10.1016/j. gaitpost.2017.04.004 2. Albanese A, Bhatia K, Bressman SB, Delong MR, Fahn S, Fung VS, \net al. Phenomenology and classification of dystonia: a consensus \nupdate. Mov Disord. 2013 Jun;28(7):863-73. https://doi.org/10.1002/\nmds.25475 19. Lekhel H, Popov K, Anastasopoulos D, Bronstein A, Bhatia Kailash, \nMarsden CD, et al. Postural responses to vibration of neck muscles \nin patients with idiopathic torticollis. Brain. 1997;120(Pt 4):583-91. https://doi.org/10.1093/brain/120.4.583 3. Costa J, Espírito-Santo C, Borges A, Ferreira JJ, Coelho M, Moore P, \nSampaio C. Botulinum toxin type A therapy for cervical dystonia. Cochrane Database Syst Rev. 2005;1:CD003633. http://dx.doi. org/10.1002/14651858.CD003633.pub2 20. Moreau MS, Cauquil SA, Costes Salon M. Static and dynamic balance \nfunction in spasmodic torticollis. Mov Disord. 1999 Jan;14(1):87-\n94. https://doi.org/10.1002/1531-8257(199901)14:1%3C87::aid-\nmds1015%3E3.0.co;2-c 4. Marsh WA, Monroe DM, Brin MF, Gallagher CJ. Systematic \nreview and meta-analysis of the duration of clinical effect of \nonabotulinumtoxinA in cervical dystonia. BMC Neurol. 2014 \nApr;14:91. https://doi.org/10.1186/1471-2377-14-91 21. Tsang WW, Chan VW, Wong HH, Yip TW, Lu X. The effect of \nperforming a dual-task on postural control and selective attention \nof older adults when stepping backward. J Phys Ther Sci. 2016;28(10):2806-11. https://doi.org/10.1589/jpts.28.2806 5. DISCUSSION De Pauw J, Mercelis R, Hallemans A, Van Gils G, Truijen S, Cras P, \net al. Postural control and the relation with cervical sensorimotor \ncontrol in patients with idiopathic adult-onset cervical dystonia. Exp Brain Res. 2018 Mar;236(3):803-11. https://doi.org/10.1007/\ns00221-018-5174-x 22. Dault MC, Frank JS, Allard F. Influence of a visuo-spatial, verbal \nand central executive working memory task on postural control. Gait Posture. 2001 Oct;14(2):110-6. https://doi.org/10.1016/s0966-\n6362(01)00113-8 6. Abbruzzese G, Marchese R, Buccolieri A, Gasparetto B, \nTrompetto C. Abnormalities of sensorimotor integration in focal \ndystonia: a transcranial magnetic stimulation study. Brain. 2001 \nMar;124(Pt 3):537-45. https://doi.org/10.1093/brain/124.3.537 23. Müller J, Ebersbach G, Wissel J, Poewe W. Dynamic balance function \nin phasic cervical dystonia following Botulinum Mov Disord. 2001 \nSep;16(5):934-7. https://doi.org/10.1002/mds.1164 7. Bove M, Brichetto G, Abbruzzese G, Marchese R, Schieppati M. Postural responses to continuous unilateral neck muscle vibration \nin standing patients with cervical dystonia. Mov Disord. 2007 \nMar;22(4):498-503. https://doi.org/10.1002/mds.21357 24. Consky ES, Basinki A, Belle L, Ranawaya R, Lang AE. The \nToronto Western Spasmodic Torticollis Rating Scale (TWSTRS): \nassessment of validity and inter-rater reliability. Neurology. 1990;40(Suppl 1):S445. 8. De Pauw J, Mercelis R, Hallemans A, Michiels S, Truijen S, Cras P, \net al. Cervical sensorimotor control in idiopathic cervical dystonia: \na cross-sectional study. Brain Behav. 2017;7(9):e00735. https://doi. org/10.1002/brb3.735 25. Odergren T, Hjaltason H, Kaakkola S, Solders G, Hanko J, \nFehling C, et al. A double blind, randomised, parallel group study \nto investigate the dose equivalence of dysport and botox in the \ntreatment of cervical dystonia. J Neurol Neurosurg Psychiatry. 1998 \nJan;64(1):6-12. https://doi.org/10.1136/jnnp.64.1.6 9. Vuillerme N, Pinsault N. Experimental neck muscle pain impairs \nstanding balance in humans. Exp Brain Res. 2009 Feb;192(4):723-9. https://doi.org/10.1007/s00221-008-1639-7 26. Wöber E, Schnider P, Steinhoff N, Trattnig S, Zebenholzer K, Auff E. Posturographic findings in patients with idiopathic cervical dystonia \nbefore and after local injections with botulinum toxin. Eur Neurol. 1999;41(4):194-200. https://doi.org/10.1159/000008050 10. Treleaven J, Jull G, LowChoy N. The relationship of cervical joint \nposition error to balance and eye movement disturbances in \npersistent whiplash. Man Ther. 2006 May;11(2):99-106. https://doi. org/10.1016/j.math.2005.04.003 27. Pashler H. Dual-task interference in simple tasks: data and theory. Psychol Bull. 1994 Sep;116(2):220-44. https://doi.org/10.1037/0033-\n2909.116.2.220 11. Field S, Treleaven J, Jull G. Standing balance: a comparison between \nidiopathic and whiplash-induced neck pain. Man Ther. 2008 \nJun;13(3):183-91. https://doi.org/10.1016/j.math.2006.12.005 28. Talelli P, Ewas A, Waddingham W, Rothwell J, Ward N. Neural \ncorrelates of age-related changes in cortical neurophysiology. Neuroimage. 2008 May;40(4):1772-81. https://doi.org/10.1016/j. neuroimage.2008.01.039 12. Münchau A, Bronstein AM. DISCUSSION Role of the vestibular system in the \npathophysiology of spasmodic torticollis. J Neurol Neurosurg \nPsychiatry. 2001 Sep;71(3):285-8. https://doi.org/10.1136/\njnnp.71.3.285 29. Saxena S, Cinar E, Majnemer A, Gagnon I. Does dual tasking ability \nchange with age across childhood and adolescence? A systematic \nscoping review. Int J Dev Neurosci. 2017 May;58:35-49. https://doi. org/10.1016/j.ijdevneu.2017.01.012 13. Bronstein AM, Rudge P. Vestibular involvement in spasmodic \ntorticollis. J Neurol Neurosurg Psychiatry. 1986 Mar;49(3):290-5. https://doi.org/10.1136/jnnp.49.3.290 14. Stejskal L, Tománek Z. Postural laterality in torticollis and torsion \ndystonia. J Neurol Neurosurg Psychiatry. 1981 Nov;44(11):1029-34. https://doi.org/10.1136/jnnp.44.11.1029 30. Bekkers EMJ, Dockx K, Devan S, Van Rossom S, Verschueren SMP, \nBloem BR, et al. The ımpact of dual-tasking on postural stability in \npeople with Parkinson’s disease with and without freezing of gait. Neurorehabil Neural Repair. 2018 Feb;32(2):166-74. https://doi. org/10.1177/1545968318761121 15. Stell R, Bronstein AM, Marsden CD. Vestibulo-ocular abnormalities \nin spasmodic torticollis before and after botulinum toxin injections. J Neurol Neurosurg Psychiatry. 1989 Jan;52(1):57-62. https://doi. org/10.1136/jnnp.52.1.57 31. Liu YC, Yang YR, Tsai YA, Wang RY. Cognitive and motor dual task \ngait training improve dual task gait performance after stroke - A \nrandomized controlled pilot trial. Sci Rep. 2017;7(1):4070. https://doi. org/10.1038/s41598-017-04165-y 16. Huygen PL, Verhagen WI, Van Hoof JJ, Horstink MW. Vestibular \nhyperreactivity in patients with idiopathic spasmodic torticollis. J Neurol Neurosurg Psychiatry. 1989 Jun;52(6):782-5. https://doi. org/10.1136/jnnp.52.6.782 32. Krampe RT, Schaefer S, Lindenberger U, Baltes PB. Lifespan changes \nin multi-tasking: concurrent walking and memory search in children, \nyoung, and older adults. Gait Posture. 2011 Mar;33(3):401-5. https://\ndoi.org/10.1016/j.gaitpost.2010.12.012 17. Diamond SG, Markham CH, Baloh RW. Ocular counterrolling \nabnormalities in spasmodic torticollis. Arch Neurol. 554 Arq Neuropsiquiatr 2020;78(9):549-555 33. Brown LA, Sleik RJ, Polych MA, Gage WH. Is the prioritization \nof postural control altered in conditions of postural threat in \nyounger and older adults? J Gerontol A Biol Sci Med Sci. 2002 \nDec;57(12):M785-92. https://doi.org/10.1093/gerona/57.12.m785 36. Li KZH, Lindenberger U, Freund AM, Baltes PB. Walking while \nmemorizing: age-related differences in compensatory behavior. Psychol Sci. 2001 May;12(3):230-7. https://doi.org/10.1111/1467-\n9280.00341 37. Rapp M, Krampe RT, Baltes PB. Adaptive task prioritization in aging: \nselective resource allocation to postural control is preserved in \nAlzheimer disease. Am J Geriatr Psychiatry. 2006 Jan;14(1):52-61. https://doi.org/10.1097/01.JGP.0000192490.43179.e7 34. Doumas M, Rapp M, Krampe RT. Working memory and postural \ncontrol: adult age differences in potential for improvement, task-\npriority and dual-tasking. J Gerontol B Psychol Sci Soc Sci. 2009 \nMar;64B(2):193-201. https://doi.org/10.1093/geronb/gbp009 38. DISCUSSION De Pauw J, Cras P, Truijen S, Mercelis R, Michiels S, Saeys W, et al. The effect of a single botulinum toxin treatment on somatosensory \nprocessing in idiopathic isolated cervical dystonia: an observational \nstudy. J Neurol. 2018 Nov;265(11):2672-2683. https://doi. org/10.1007/s00415-018-9045-y 35. Doumas M, Smolders C, Krampe RT. Task prioritization in aging: \neffects of sensory information on concurrent posture and memory \nperformance. Exp Brain Res. 2008 May;187(2):275-81. https://doi. org/10.1007/s00221-008-1302-3 555 Demir T et al. Postural stability in cervical dystonia."