An investigation of the conus medullaris and filum terminale variations in human fetuses.

The morphologic structure of the conus medullaris and filum terminale was investigated by dissection in 123 human fetuses, obtained from Selçuk University, Faculty of Medicine and Maternity hospital of Konya between 1992-1995. In 78 fetuses, the conus medullaris and filum terminale had a normal morphologic aspect, whereas there was a slight depression or groove formation in the closure region of the caudal neuropore in 45 fetuses. In 15 fetuses, important malformations of the cranium and vertebral column were observed. The morphologic aspects of the conus medullaris in 30 fetuses were abnormal in shape and position, among them 24 fetuses had an abnormal filum terminale (grooved, depressed, thickened or duplicated) whereas it was normal in 6. Deficiency of closure of the caudal neuropore was considered to have a negative effect on the fetal development of the filum terminale.