Neural network of primary focal dystonia by an anatomic likelihood estimation meta-analysis of gray matter abnormalities

Background: Recent voxel-based morphometry (VBM) studies have found gray matter (GM) abnormalities in primary focal dystonia (PFD) and yielded inconsistent results.

Aim: Our aim is to investigate consistent GM changes in PFD and to identify whether different subtypes of PFD share a common pathophysiological basis revealed by structural abnormalities.

Methods: A systematic search of VBM studies of patients with PFD and healthy control (HC) subjects published in PubMed, Embase, and Medline databases from January 1998 to April 2011 was conducted. We performed a voxel-wise meta-analysis of VBM studies comparing PFD to HC using the anatomic likelihood estimation (ALE) method.

Results: A total of 9 articles, which reported 11 PFD-HC comparisons including 199 PFD patients and 247 HC subjects, met the inclusion criteria. GM volume (GMV) was found to be greater in the caudate, postcentral cortex (BA2, 3, 40) and primary motor cortex, and smaller in the thalamus and putamen.

Conclusion: Our findings provide evidence for structural abnormalities within the sensorimotor network involved in the pathophysiology of PFD. However, our work could not distinguish whether the brain structural changes are primary or secondary to PFD.