Functional connectivity of the motor system in dystonia due to PKAN.

PURPOSE

To demonstrate deviations of functional connectivity within the motor system in dystonic patients suffering from Pantothenate Kinase Associated Neurodegeneration, a genetic and metabolic disease, which is characterized by a primary lesion in the globus pallidus.

MATERIAL AND METHODS

Functional Magnetic Resonance Imaging data were measured during resting state in 12 patients suffering from a confirmed mutation of the PANK2 gene. In this region-of-interest based analysis, data were evaluated in respect to correlation of signal time course between basal ganglia, motor-related cortical regions and cerebellum, were related to clinical data and were compared to a control group of 20 healthy volunteers.

RESULTS

During resting state, correlation coefficients within the motor system were significantly lower in patients than in controls (0.025 vs. 0.133,  < 0.05). Network analysis by Network Based Statistics showed that these differences mainly affected the connectivity between a sub-network consisting of the basal ganglia and another one, the motor system-related cortical areas ( < 0.05). 6 out of 12 connections, which correlated significantly to duration of disease, were connections between both sub-networks.

CONCLUSION

The finding of a reduced functional connectivity within the motor network, between the basal ganglia and cortical motor-related areas, fits well into the concept of a general functional disturbance of the motor system in PKAN.