In this study, using computerized cognitive assessments combined with multi-modal neuroimaging approach investigators aim to address three specific questions on patients with cervical and myoclonus dystonia:

(i) investigate various aspects of the sense of agency and relationship to the severity of dystonia symptoms, (ii) characterize the possible link between abnormalities of movement perception and alteration of sense of agency in dystonia, (iii) (identify the neuronal underpinnings of the defective sense of agency in dystonia.

This is a single-centre, two-group ( dystonia and control), case-control study using behavioural and novel multimodal neuroimaging techniques to address the study aims.

The battery of the tasks will include explicit-agency tasks, a visual discrimination task on objects movement perception. The magnetic resonance acquisition protocol will include MP2RAGE structural (10 min duration), multi echo (3 echo times) multiband (MB factor 4) resting state functional neuroimaging (15 minutes duration) and multi shell diffusion imaging sequence (15 minutes duration)

Inclusion Criteria:

• diagnosis of isolated adult-onset cervical dystonia (CD) or myoclonus dystonia (MD);
• duration of disease of more than one year
• no botulinum toxin injection for at least three months before the study
• normal or corrected-to-normal vision.

Exclusion Criteria

• any neurological history except for dystonia,
• history of dopamine antagonist treatment,
• secondary dystonia,
• dystonia in the upper limbs,
• inability to maintain gaze straight.