The thalamic ultrastructural abnormalities in paroxysmal kinesigenic choreoathetosis: a diffusion tensor imaging study.

Paroxysmal kinesigenic choreoathetosis (PKC) is a rare neurologic disorder. There are not apparent morphological changes in patients with idiopathic PKC. The purpose of this study is to determine whether ultrastructural changes are in the brain of patients with idiopathic PKC using diffusion tensor imaging. From May 2007 to August 2008, seven patients with idiopathic PKC were included. The mean age at initial onset was 11.7 +/- 3.1 (range 8-17) years, and the mean disease duration was 6.9 +/- 5.1 (range 1-14) years. Seven subjects of an age- and sex-matched control group were recruited. DTI data were obtained with a 3-T scanner. Fractional anisotropy (FA) and mean diffusivity (MD) were obtained in eight brain regions of interest. Patients with idiopathic PKC had significantly higher FA values than controls in the right thalamus (P < 0.05 Bonferroni corrected). Patients also had lower MD values than controls in the left thalamus (P < 0.05 Bonferroni corrected). FA and MD values were not significantly correlated with age of onset, gender, frequency of attack and duration of the disease. The results showed that in patients with idiopathic PKC, diffusion tensor imaging discloses distinct ultrastructural abnormalities in the thalamus. DTI is a sensitive neuroradiologic technique for detecting cerebral alterations in patients even without visible lesions on conventional MRI.