Introduction: The foot or lower extremity is rarely the initial site in adult-onset dystonia, and isolated lower extremity dystonia in adults is rarely on a primary basis. Botulinum toxin injections have been reported as beneficial in treatment of limb dystonia. In this report, we describe a case of primary focal foot dystonia which showed further improvement after applying a new simple ankle-foot orthosis.
Case report: A 58-year-old female was referred to the Department of Rehabilitation for the left toe curling movement while walking. It began 2 years ago when she had a minor trauma of left foot. When she visited our clinic, she complained abnormal curling movement of all left toes while walking and limited walking distance due to foot pain. In detail, toe curl amount decreased during stance phase when walking with usual speed, and toe curl was observed at swing phase. And walking in slow speed, there was no curl in stance phase, but toe curl was observed in swing phase. Neurological examination was otherwise unremarkable, and no joint contracture was noted. There were no significant abnormalities in MRI of foot and brain, electrophysiological study and all laboratory studies. It was concluded that the patient had a rare case of primary adult-onset primary focal foot dystonia. The patient was initially prescribed baclofen and clonazepam with limited success. She received the botulinum toxin (BTX) injections five times under EMG guidance in the left tibialis posterior, flexor digitorum longus, and flexor halluces longus muscles. At first time, she showed immediate improvement of dystonic movement and pain after the BTX injection. But, the 5th injection was less effective than the previous. At the follow up visit, surprisingly, she found that the toe clawing was reduced when she clang a jumping rope on her big toe during walking. We planned to create an ankle-foot brace (Figure 1) that could force the big toe in the direction of extension using ankle straps. With this new ankle-foot orthosis, there was no dystonic movement at any speed.
Conclusion: This case demonstrates that adult-onset primary focal foot dystonia can be managed by using the new orthosis we suggest. We believe that this new orthosis seems to be effective in suppressing the initiation of dystonic movement by providing extension moments to the big toe.
Keywords: Dystonia; Focal; Foot; Adult-onset; Orthosis; |
