Delayed-onset focal dystonia of the leg secondary to traumatic brain injury

A 42-year-old man presented with action-induced, stereotyped posturing of the left leg with task specificity following major traumatic brain injury less than a year earlier. Although adult onset primary leg dystonia is a recognised entity, our patient is unusual in that dystonia was an isolated abnormality without associated spasticity, was not preceded by ipsilateral hemiparesis and remained focal without progression to involve other body regions. MRI brain showed a small area of gliosis in the left frontal subcortical white matter but with no lesions in the basal ganglia or thalamus. The dystonia in our patient almost completely resolved with botulinum toxin therapy.