Cranial MRI findings in myotonic dystrophy.

MRI was performed in 13 patients with the adult form of myotonic dystrophy (MD) and compared with that of sex- and age-matched normal controls. There was some cerebral atrophy in the patients and marked thickening of the skull in three of them, associated with ossification of the falx cerebri in two. We found high-signal areas on T2-weighted images in the white matter in 9 (70%) of the patients; five showed high-signal areas in the subcortical white matter of the temporal lobes. These findings were associated with intellectual impairment in only one patient, who had a history of a difficult birth and temporal lobe epilepsy.