Cervical dystonia : assessment and rehabilitation

Abstract

This thesis addresses isolated cervical dystonia (iCD) assessment and rehabilitation by integrating motor and non-motor symptom management through scalable, evidence-based rehabilitation strategies. Despite advancements in iCD management, such as Botulinum neurotoxin (BoNT) injection, substantial numbers of patients continue to experience clinical burden from pain, disability, sleep disturbances, and neuropsychiatric symptoms. Limited access to specialist services, particularly in low-resource settings, further underscores the necessity for standardized and remotely accessible clinical approaches. To address these gaps, this research systematically evaluated the reliability of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and its revised version (TWSTRS-2) for remote and multidisciplinary use. Furthermore, it investigated the effectiveness of adjunctive physiotherapy and peripheral stimulation alongside primary BoNT therapy. Moreover, we examined the effect of BoNT on non-motor symptoms across Chapter 2 through 5. To ensure reliable tracking of clinical changes, Chapter 2 evaluated 89 video recordings from 27 patients, demonstrating good overall inter-rater reliability for the TWSTRS. The TWSTRS-2 exhibited superior precision and clinical usability, although sub-items capturing rare or mild phenomena such as sagittal shift, duration factor, and sensory tricks remained susceptible to interpretive ambiguity. These findings are essential for establishing a standardized pathway for telemedicine integration, thereby supporting equitable care delivery in resource-limited regions. A systematic review and meta-analysis of 14 interventional studies (Chapter 3) established that adjunctive physiotherapy provides clinically meaningful benefits over standalone BoNT, significantly reducing pain, disease severity, and disability. Findings of meta-analysis showed an improvement in TWSTRS pain scores mean difference (MD) = -5.00, 95% CI (-6.26, -3.74) strongly supports incorporating individualized, multimodal physiotherapy into routine care to enhance global accessibility and reduce long-term care burdens. Evaluation of peripheral stimulation (Chapter 4), including conventional transcutaneous electrical nerve stimulation (TENS), neuromuscular electrical stimulation (NMES), and muscle vibration applied alternatively in 15 patients revealed immediate but transient improvements in cervical range of motion (CROM) and pain. Neck rotation improved in 33.3% of patients after TENS and in 42.1% after NMES or muscle vibration, while sagittal flexion and extension improved in more than half of the participants (55.6% after TENS, 53.3% after NMES, and 46.7% after muscle vibration). Nevertheless, improvements in rotational CROM were modest, ranging between 1 and 18. Despite these limited motor effects, the safety, portability, and non-invasive nature of these neuromodulatory interventions support their potential as accessible, home-based rehabilitation strategies. However, their clinical efficacy and long-term therapeutic value require further investigation in larger and more rigorously designed clinical trials. Furthermore, the longitudinal evaluation of 29 patients at six weeks post-BoNT injection (Chapter 5) highlighted that primary pharmacological therapy has a selective impact on non-motor symptoms (NMS). While patient sleep quality improved significantly (MD = 2.65, P < 0.001), reductions in anxiety and depression failed to reach statistical significance. This divergence indicates that psychiatric symptoms do not necessarily improve alongside motor symptom relief, underscoring the limitations of standalone pharmacotherapy and the necessity of holistic, biopsychosocial care models. The clinical insights of this thesis are supported by strong methodological foundations, including an independent systematic review process, assessments by experienced movement disorder specialists, and standardized, calibrated protocols that enhance internal validity and reproducibility. Nevertheless, future randomized controlled trials are needed to validate the long-term effectiveness and therapeutic synergy of combining BoNT with physical therapy, peripheral stimulation, and psychological interventions.