Increased interhemispheric resting-state functional connectivity in paroxysmal kinesigenic dyskinesia: A resting-state fMRI study

• We initially explored the voxel-mirrored homotopic connectivity (VMHC) in PKD.
• We found increased VMHC mainly in the basal ganglia-thalamo-cortical circuitry.
• We initially discovered increased VMHC in the cerebellum.
• We detected a negative correlation between VMHC and illness duration in PKD.

PurposeParoxysmal kinesigenic dyskinesia (PKD) is a rare movement disorder. The underlying neural mechanisms have not been fully understood. This study aimed to examine the alteration of resting-state functional connectivity (RSFC) between interhemispheric homotopic regions in PKD using a technique called “voxel-mirrored homotopic connectivity” (VMHC).MethodsThe VMHC analysis was performed on resting-state functional MRI data from 11 PKD patients and 17 age and gender matched healthy subjects. Comparison between the two groups was conducted. The correlation relationship between VMHC and illness duration was analyzed.ResultsCompared with healthy subjects, PKD patients showed increased interhemispheric RSFC in bilateral putamen, primary motor cortex, supplementary motor area, dorsal lateral prefrontal cortex, primary somatosensory cortex, superior and middle occipital gyri, as well as cerebellar tonsil. Besides, negative correlation was detected between illness duration and VMHC in bilateral putamen and the insular cortex.ConclusionThe present study provided preliminary evidence of increased interhemispheric RSFC in PKD mainly in the basal ganglia-thalamo-cortical circuitry and cerebellum. A negative correlation between VMHC and illness duration was also detected. These findings could further enhance our understandings of the pathophysiology of PKD.