Are nongenetic triggers for dystonia type-specific? A study exploring scoliosis in blepharospasm.

We previously observed that diseases of the anterior ocular segment predispose to primary blepharospasm, but not to other focal dystonias. In this multicenter study, we tested whether prior scoliosis, which increases the risk of developing cervical dystonia, is also a predisposing factor to blepharospasm. The frequency of scoliosis did not differ between blepharospasm patients and controls. This finding supports the hypothesis that environmental risk factors may be specific for a single form of adult-onset dystonia.