T2 relaxometry of brain in myotonic dystrophy

We investigated the nature and extent of brain involvement in myotonic dyst rophy (DM), examining possible T2 relaxation abnormalities in the brain of 20 patients with adult-onset DM and 20 sex- and age-matched normal controls . Brain MRI was performed at 0.5 T, and T2 values were calculated from sign al intensity in two echoes. Regions of interest included: frontal, parietal , temporal, occipital and callosal (rostral and splenial) normal-appearing white matter; frontal, occipital, insular and hippocampal cortex; caudate n ucleus, putamen, globus pallidus and thalamus. All white-matter and occipit al and right frontal cortex regions showed a significantly longer T2 in the patients. Multiple regression analysis, including grey- and white-matter T 2 as dependent variables, plus age at onset and at imaging, disease duratio n, muscular disability, brain atrophy and CTG trinucleotide repeats as inde pendent variables, revealed that only white-matter T2 elongation and diseas e duration correlated positively. White-matter involvement in DM is more ex tensive than previously reported by MRI and neuropathological studies and s eems to be progressive in the course of disease.