The thesis of Maraike Coenen focuses on the cognitive processes in patients with dystonia and ataxia, disorders characterized by involuntary and uncoordinated movements. Both disorders occur in children and adults and are caused by a variety of factors, such as genetic mutations, inborn errors of metabolism, lack of oxygen during birth or abnormalities in brain development. The brain structures that are involved in the involuntary uncoordinated movements are also important for cognition, for example for fast information processing, planning ahead, learning, and emotion recognition.
The thesis investigated whether cognition is also affected in children and adults with dystonia and ataxia. The results were positive for the patients with dystonia as children and adult had mostly intact cognition. Exceptions included adult patients with deficits in planning and children with deficits in social cognition. Across age groups it was found that additional neurological abnormalities were associated with more severe cognitive deficits. Ataxia patients had a similar cognitive profile, but deficits were more outspoken.
We also tested the effect of Deep Brain Stimulation (DBS) on the cognition in patients with disabling medication refractory dystonia. Based on the results of this dissertation, patients with dystonia who undergo DBS often have executive dysfunctions, but Deep Brain Stimulation does not change cognition in these patients. This research underscores the importance of neuropsychological assessments in patients with movement disorders, because the results can help clinicians to advise their patients.
