The pathogenesis of fetal hypokinesia. A neurological study of 75 cases of congenital contractures with emphasis on cerebral lesions.

A comprehensive prospective clinical study is presented of 75 cases of fetal hypokinesia and congenital contractures of various causes, with neuropathological investigation in 23 cases. With the data of medical history, neurological examination, laboratory tests and neuropathology an exact or probable nosological or syndromal diagnosis could be made in 61 cases. These cases were categorized by localisation of causal pathology in the subsequent levels of the developing motor system. In 14 of 61 cases developmental brain disorders (f.i. hydrocephalus, hydranencephaly, microcephaly) were the cause of fetal hypokinesia, often with perinatal death, whereas in 7 cases both cerebral and/or spinal cord lesions were found. Besides cerebral involvement was frequently present in cases with congenital contractures of other origin, concomitant or due to perinatal complications. In a large number of cases clinical evidence of spinal cord lesions, especially anterior horn cell degeneration was present. Myopathic disorders occurred in only four cases, whereas congenital myasthenia and congenital neuropathy were present in one case each. In cases without muscle weakness miscellaneous disorders including congenital skin anomalies and probably primary connective tissue disorders were encountered. The etiologic role of intrauterine viral infection is discussed.