Attention-Demanding Cognitive Tasks Worsen Postural Control in Patients With Cervical Dystonia: A Case-Control Study

Abstract

Background: Patients with cervical dystonia (CD) show impaired postural control, balance, and gait, likely due to abnormal head postures and sensorimotor disturbances. However, until now no study has investigated whether attention-demanding activity worsens postural control and balance in CD patients.Objective: To investigate whether patients with CD show cognitive-motor interference (CMI), a specific kind of dual-task interference that occurs during the simultaneous execution of a cognitive and motor task. This information may be useful to determine whether performing activities of daily living worsens postural control and balance in CD patients.Methods: We performed a pilot case-control study. Twenty-two patients affected by CD and 19 healthy controls were enrolled in order to test CMI. Each subject was evaluated during the execution of a cognitive task while postural stability was assessed through a stabilometric platform.Results: CD patients showed impaired postural control compared to healthy controls, with instability increasing with increasing cognitive task complexity. No relationships were found between stabilometric parameters and clinical characteristics of CD.Conclusions: Our hypothesis is that CMI in CD patients derives from deranged network connectivity when activated simultaneously during the performance of two tasks that interfere with each other and “compete” for the same resources within the cognitive system.

Variability of Postural Stability and Plantar Pressure Parameters in Healthy Subjects Evaluated by a Novel Pressure Plate

“…Eventually, on both feet, a larger Pmax on the Rf area (left = 67.3 KPa; right = 63.3 KPa) with respect to the Ff one was found in agreement with [ 29 ], while a larger Pmean in Ff with respect to other two regions was found with a median value of 59.1 KPa on the left side and 69.9 KPa on the right one. Finally, normal median values of CoPsa (28.8 mm2), LSF (4.7 m−1), and CP speed (3.4 mm/s) in OE condition confirmed the normal 244 range values found in [ 30 , 31 , 32 ], respectively, in healthy, young subjects.…”

Cognitive and Neuropsychiatric Impairment in Dystonia

“…Dual tasking is also dependent on higher cognitive processes such as executive functions required for planning and executing complex task, suggesting prominent cortical involvement, with some suggesting that impaired dual tasking suggests a reduction in contingency or reserve in those regions involved in dual tasking. Again, most studies have focused on AOIFCD, identifying impaired postural control with increasing cognitive task complexity compared to controls (p < 0.0001) with neither dystonia motor severity nor the presence of a tremor being significantly associated with the degree of impaired stability [59]. Further studies have extended this to evaluate the impact of dual tasking on both balance and gait, again examining those with AOIFCD (n = 17), compared to controls (n = 19), at normal walking speed, fast walking, cognitive dual task, and obstacle negotiation.…”

Dual task gait deteriorates gait performance in cervical dystonia patients: a pilot study

“…In idiopathic dystonia, difficulties in performing DT were firstly observed by Jahanshahi et al ( 2003 ) where patients showed a decrement of tapping task during a concurrent task performed with the other hand. Two recent studies (Demir et al 2020 ; Baione et al 2021 ) also reported cognitive DT interference in CD subjects, showing a decrement of postural control during the concomitant execution of an attention-demanding tasks. In line with these results, here we found that the ability to walk while carrying out another task is impaired in CD subjects, suggesting that there are fewer attentional resources available for simultaneous performance of secondary tasks.…”

“…Conversely, only two studies investigated cognitive-motor interference in CD patients (Demir et al 2020 ; Baione et al 2021 ). As an example, Baione et al ( 2021 ), based on the hypothesis that balance disturbances in CD may be associated with a reduction of the attentional resources available for simultaneous performance of secondary tasks, investigated whether postural control would be worsened by a concomitant execution of attention-demanding cognitive task.…”

“…Conversely, only two studies investigated cognitive-motor interference in CD patients (Demir et al 2020 ; Baione et al 2021 ). As an example, Baione et al ( 2021 ), based on the hypothesis that balance disturbances in CD may be associated with a reduction of the attentional resources available for simultaneous performance of secondary tasks, investigated whether postural control would be worsened by a concomitant execution of attention-demanding cognitive task. Results demonstrated that in CD patients postural control deteriorates while performing a cognitive DT with further decline associated with increase task difficulty These preliminary findings support the idea that, similarly to other movement disorders, also in CD, balance problems are not entirely due to dystonic posture but are associated with a reduction of functional reserve.…”