Background: The relationship between prior trauma and primary adult-onset dystonia is not well understood. Addressing this issue, previous uncontrolled observations and exploratory case-control studies yielded contradictory results.
Objective: To analyse the association between cranial dystonia and prior head trauma.
Methods: An ad hoc multi-centre case-control study was performed using a semi-structured interview to collect detailed information on the history of head trauma prior to disease onset in 5 Italian tertiary referral centres for movement disorders. The presence of a history of head trauma and of post-traumatic sequelae (loss of consciousness, bone fractures, scalp/facial wounds) prior to disease onset was recorded from 177 case patients with primary adult-onset cranial dystonia and 217 control patients with primary hemifacial spasm matched by age strata and gender. Differences between groups were assessed by Mann-Whitney U test and Fisher’s exact test, and the relationship between prior head trauma and case/control status was analysed by multiple-variable logistic regression models.
Results: We found no association betweenvault/maxillo- facial trauma and cranial dystonia. Most reported traumas occurred several years before disease onset. None of the main post-traumatic sequelae altered the chance of developing cranial dystonia, if compared to patients with primary HFS, nor did head trauma modify the age at onset of cranial dystonia.
Conclusions: These results do not support prior head trauma as a possible environmental factor modifying the risk of developing late-onset cranial dystonia. The lack of association may have pathogenetic and medical-forensic implications.