Meta-analytical and electrophysiological evidence for executive dysfunction in primary dystonia. (September 2016)

• Record Type: Journal Article
• Authors: Lange, Florian; Seer, Caroline; Salchow, Carolin; Dengler, Reinhard; Dressler, Dirk; Kopp, Bruno
• Is Part Of: Cortex. Volume 82(2016)
• Page Start: 133
• Page End: 146
• Publication Date: 2016-09
• Subjects: Primary dystonia -- Blepharospasm -- Executive dysfunction -- Wisconsin Card Sorting Test -- Event-related potentials; ANOVA analysis of variance -- BSDI Blepharospasm Disability Index -- BSI-18 Brief Symptom Inventory-18 -- BSP blepharospasm -- EEG electroencephalogram -- ERP event-related potential -- HC healthy controls -- JRS Jankovic Rating Scale -- MCI mild cognitive impairment -- MoCA Montreal Cognitive Assessment -- PSP posterior switch positivity -- SF-36 short form 36 health survey questionnaire -- WCST Wisconsin Card Sorting Test -- WST Wortschatztest [vocabulary test]; Neuropsychology -- Periodicals; Nervous system -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Behavior -- Periodicals; Neurology -- Periodicals; 612.825
• DOI: 10.1016/j.cortex.2016.05.018
• Languages: English
• ISSNs: 0010-9452

Abstract

Abstract: Impaired motor control in primary dystonia has been linked to cortico-basal ganglia alterations that may also give rise to changes in executive functioning. However, no conclusive evidence for executive dysfunction in patients with primary dystonia has been reported yet. We conducted a meta-analysis of the relationship between primary dystonia and performance on the Wisconsin Card Sorting Test (WCST), an established test of executive functioning. Its results revealed a significant effect of medium size, indicating that primary dystonia is associated with moderate performance deficits on the WCST. Building on this finding, we conducted an event-related potential (ERP) study to elucidate the cognitive and neural mechanisms underlying executive dysfunction in primary dystonia. Eighteen patients with blepharospasm, a common form of primary focal dystonia, and 34 healthy matched controls completed a computerized version of the WCST. We specifically compared indicators of two distinct components of executive functioning: set shifting and rule inference. On a behavioral level, blepharospasm patients seemed to have particular difficulty integrating information to infer the correct task rule. In addition, P3a amplitude (as an electrophysiological marker of rule-inference processes) was selectively attenuated in blepharospasm patients. Executive dysfunction in blepharospasm can thus rather be attributed to a rule-inference deficit, whereas set-shifting abilities appear to be relatively unaffected by the disease. Moreover, P3a amplitude attenuation was related to disease duration, indicating that this ERP might serve as a neural indicator of disease progression and executive dysfunction in primary dystonia. These results demonstrate for the first time that pathophysiological alterations in primary dystonia might affect cortical activation for executive functioning.