Multiple Developmental Abnormalities
Spina bifida (occulta) and situs inversus are two distinct anomalies of anatomic structure which result from abnormal embryological development. Type one, or insulin dependent, diabetes mellitus (IDDM) is a disease which may occur at any age, but typically makes its initial presentation in adolescents and young adults. Chromatopsia is a visual disturbance sometimes associated with retinal pathology.
The term "dysraphism" refers to any lack of closure of two structures which are normally fused (18:349). Spina bifida involves dysraphism of the bones that enclose the vertebral canal. Typically this occurs posteriorly and usually involves the neural arches of the vertebrae (pedicles, laminae, articular processes and spinous processes) (18:349).
It has been estimated that in the United States, two out of every 1,000 babies born have some sort of neural tube defect (NTD) (16:791). In Britain, this incidence has been reported to be as high as 7 to 8 per 1,000 births. Half of these defects involve anencephaly, or the congenital absence of the brain and spinal cord (16:791). The remainder consist of overt and occult spinal dysraphism. James and Lassman found a 5% incidence of spina bifida in autopsied adults (18:350).
Overt spinal dysraphism, or spina bifida cystica, is the well known myelomeningocele or meningocele that typically protrudes grotesquely through a defective vertebral column (18:349). The less common, spina bifida occulta, results from a similar vertebral defect; however, there is no visible exposure of the meninges or neural tissue.
Thus, spina bifida occulta can be more significant clinically. Symptoms of the abnormality may present at any time from birth to adulthood (16:791 792). Furthermore, while no particular ethnic group seems more predisposed to the condition, spina bifida occulta does occur more frequently in females than males: The sex ratio is s...