To conduct a comprehensive analysis of cognition in cervical dystonia (CD).

Cervical dystonia is the most prevalent phenotype of the adult onset idiopathic focal dystonias (AOIFD), a group of hyperkinetic disorders. Patients with AOIFD have been shown to have varying abnormalities in cognition. This non-motor feature is under-recognised and may influence QoL.

Studies into cognition in CD have been limited by inconsistent psychological assessment tools making generalisations difficult. We selected wide ranging neuropsychological tests to create a comprehensive cognitive profile.

13 adult patients (5 male, 8 female) with idiopathic focal CD completed an extensive neuropsychological battery. Participants were screened for presence of mood disorders (HADS). All patients were receiving 3 monthly botulinum toxin treatment and were not on any medications that could influence cognition.

Cognitive domains assessed: premorbid functioning, general intellectual functioning, language, information processing speed, attention, memory, executive function and social cognition using reliable and valid standardized neuropsychological assessments.

Mean age was 60-years. Mean HADS-A= 6 and mean HADS-D=5.

CD patients showed clear evidence of cognitive dysfunction compared to normative data. The most significant impairments were noted in social cognitive measures [emotional prosody to emotional face, FAB (mean Z score: -1.75); naming emotional prosody, FAB (mean Z score: -0.81)], executive function [SWMBE468, CANTAB (mean Z score: -0.73)] and, memory [LM2, WMS (mean Z score: -0.82)]. Moderate impairments were seen in information processing speed [WAIS coding (mean Z score: -0.51)], language [Boston Naming Test (mean Z score: -0.51)] and attention and working memory [RVPA, CANTAB (mean Z score: -0.61)].

Patients performed better than controls in another aspect of social cognition [conflicting emotional prosody, FAB (Z score: 1.67)].

There is mounting evidence of cognitive deficits in CD, implicating cognitive pathways in disease pathogenesis. This non-motor aspect may influence QoL and patient satisfaction. Early recognition and neuropsychological input could improve outcomes.