Reply: Contributions of visual and motor signals in cervical dystonia

Patients with Cervical Dystonia Demonstrated Decreased Cognitive Abilities and Visual Planning Compared to Controls

Background

Cervical dystonia (CD) involves clinical and motor manifestations, and visual and cognitive dysfunctions may also be frequent.

Objective

To evaluate functional vision, visual attention, and cognitive aspects in patients with CD compared with a control group.

Methods

Fifty patients with CD were assessed using the Useful Field of View Test (UFOV), the Mini Mental State Examination (MMSE), and the Trail Making Tests (TMT-A and TMT-B), and compared with an identical number of health controls matched by sex, age, and educational level.

Results

No differences were seen between the groups in terms of MMSE score (P = 0.481), but the CD patient group had poorer scores for the TMA-A (P = 0.004) and TMT-B (P = 0.004). For the UFOV subtests, a decrease was found for visual processing speed (P < 0.001), divided attention (P < 0.001), and selective attention (P = 0.001), as well as higher frequency in the categories with higher risk index in the UFOV test (P < 0.001).

Conclusion

Patients with CD may exhibit decreased functional vision and visual attention, as well as higher risk in performing complex activities.

Visual compensation in cervical dystonia

Introduction: Visual-spatial processing can be affected in people with cervical dystonia (CD). These impairments have almost exclusively been observed in laboratory studies, but the impact of visuo-spatial impairments on daily activities is unclear. Here, we investigated how people living with CD visually explore the environment. Method: 21 participants (10 patients and 11 controls) walked a designated course searching for targets while their eye movements were tracked by the means of eye tracking glasses. In addition, all participants performed an extensive battery of spatial neglect tests. Results: People with CD visually compensated for their lateral head position. That is, they made more eye movements towards the side opposite their lateral head position. No evidence for or against spatial asymmetries were detected in a range of behavioral measures (target detection, standard neglect battery tests) on a group level. Yet, single patients showed a neglect-like pattern. One patient with a right torticollis failed to detect most left-sided targets when walking. Conclusion: In general, participants seem to adequately compensate for the deviated head posture when judging spatial stimuli. However, the insufficient spatial exploration in one patient with a valid driving license should raise awareness in clinicians to potential visuo-spatial problems in people living with CD. An interesting question arising from our findings is whether people with CD and marked visuo-spatial deficits would benefit from scanning training, as is employed in stroke rehabilitation.

Reduced vision-related quality of life in people living with dystonia

Purpose: Dystonia is a neurological movement disorder with negative impact on function and quality of life. It is currently unclear whether vision-related quality of life is affected. The aim of this study was to determine whether vision-related quality of life is reduced by dystonia.Materials and methods: A vision-related quality of life questionnaire was delivered online to probe visual function in people living with dystonia. Scores for each of six domains were compared to normative data of 819 healthy participants using one sample t-tests. Respondents were divided into two groups based on whether they had botulinum toxin injections and compared using independent samples t-tests.Results: There were 42 completed responses. There was a difference from norm for two domains; ocular symptoms (t(41) = 2.31, p = 0.026) and role performance (t(41) = 2.85, p = 0.007). There was variation in responses for all six domains. No difference in scores for the botulinum toxin injection group was found for either domain (both p > 0.74).Conclusions: Some people with dystonia experience reduced vision-related quality of life, which has potential to contribute to their disability. Health professionals should be aware of vision-related issues when managing people with dystonia and consider appropriate rehabilitative interventions to reduce disability and enhance quality of life.Implications for rehabilitationDystonia is a neurological movement disorder resulting in abnormal postures and movements.Vision-related quality of life is reduced by dystonia which may contribute to disability and reduced function.Strategies to improve vision-related quality of life should be included in rehabilitation programmes for people living with dystonia.