Intelligence level of patients with the Duchenne type of progressive muscular dystrophy (pmd-d).

The I.Q. of 129 patients with PMD-D and 27 patients suffering from Werdnig-Hoffmann disease were estimated. Among the patients with PMD-D there was one group without any complicating factors and 3 other groups with additional factors that might influence the intelligence level. Comparing mean values and distribution of I.Q. for all these groups, one can conclude that, besides additional unfavourable pathological and environmental factors in all cases, PMD-D itself causes a small decrease of the I.Q. by about 1 SD. The frequent changes of the EEG record in these patients could reflect involvement of the CNS by the pathological process.