ANTERIOR TEMPORAL WHITE-MATTER LESIONS IN MYOTONIC-DYSTROPHY WITH INTELLECTUAL IMPAIRMENT - AN MRI AND NEUROPATHOLOGICAL STUDY

We studied 12 patients with myotonic dystrophy using MRI and the Mini- mental state examination (MMSE), to see it specific MRI findings were associated with intellectual impairment. We also compared them with th e neuropathological findings in an autopsy case of MD with intellectua l impairment. Mild intellectual impairment was found in 8 of the 12 pa tients. On T2-weighted and proton density-weighted images, high-intens ity areas were seen in cerebral white matter in 10 of the 12 patients. In seven of these, anterior temporal white-matter lesions (ATWML) wer e found; all seven had mild intellectual impairment (MMSE 22-26), wher eas none of the four patients with normal mentation had ATWML, In only one of the eight patients with intellectual impairment were white-mat ter lesions not found. Pathological findings were severe loss and diso rdered arrangement of myelin sheaths and axons in addition to heteroto pic neurons within anterior temporal white matter. Bilateral ATWML mig ht be a factor for intellectual impairment in MD. The retrospective pa thological study raised the possibility that the ATWML are compatible with focal dysplasia of white matter.