CEREBRAL ABNORMALITIES IN MYOTONIC-DYSTROPHY - CEREBRAL BLOOD-FLOW, MAGNETIC-RESONANCE-IMAGING, AND NEUROPSYCHOLOGICAL TESTS

Objective.-To study cerebral abnormalities in myotonic dystrophy (MD) and determine the different patterns of cerebral function in patients with MD with maternal (mMD) vs paternal (pMD) inheritance. Design.-Pat ients with MD and normal controls were studied with neuropsychological testing, magnetic resonance imaging, and single photon emission compu ted tomography. Setting.-Studies were done at Harbor-UCLA Medical Cent er, Torrance, Calif. Patients and Other Participants.-Twenty-two conse cutive patients with MD, 11 of whom had pMD and eight mMD, and 10 norm al controls were studied. Diagnoses were made on the basis of family h istory, electromyography, and clinical examinations. Normal subjects i n the same age distribution were studied for comparisons. Results.-We found significantly lower neuropsychological performance and cerebral blood flow in the patients with MD compared with the controls. Patient s with mMD had statistically lower scores on IQ tests and more extensi ve cerebral hypoperfusion when compared with those with pMD. Changes i n cerebral blood flow were most severe in the frontal and temporoparie tal association cortex. Cerebral blood blow measures strongly correlat ed with IQ. Conclusions.-Patients with mMD had earlier onset of diseas e and lower IQs than the pMD group. The pattern of cerebral perfusion in the mMD group was consistent with a diffuse brain injury, while cer ebral perfusion in pMD showed more minor changes. These findings empha size the cognitive differences between mMD and pMD.