Diastematomyelia is a congenital spinal condition in which bone, cartilage, or fibrous tissue grows inside of the spinal canal, splitting the spinal cord in two, and then most often reconnecting below the lesion. The condition is often progressive and may occur in conjunction with spina bifida or other congenital spine anomalies. The majority of people are diagnosed with this congenital condition during prenatal ultrasound or well-child doctor's visits. Symptoms vary; they may include spinal cord tethering, or fixation of the spinal column with tissue attachments, which stretch the spine and result in various neurological conditions. Treatment may be surgical or conservative depending on the symptoms.
The exact cause of diastematomyelia is unknown; scientists think that early in gestation, an embryo develops two spinal canals somewhere between the ninth thoracic and first sacral level of the spine. Below the lesion, the spinal columns may recombine, but not always. Diastematomyelia may occur in conjunction with other congenital spinal anomalies including spina bifida, butterfly vertebra, hemivertebra, or kyphoscoliosis. Girls are more often affected than boys.
The diagnosis of diastematomyelia may be made during prenatal ultrasound if the technician is able to view the fetus's back. After birth, the baby's back is routinely checked for any abnormalities. In childhood, a telling symptom of this condition is a hairy patch, dimple, or other type of stigmata at the level of spine separation. Confirmation of this condition may be made with a screening MRI and a postmyelographic CT scan. The scan provides the doctor with a very detailed picture of the bone and will reveal any associated pathology.
Spinal cord tethering, or fixation, may be responsible for neurological symptoms in diastematomyelia. Children may develop leg weakness, lower back pain, or incontinence. Foot and spinal deformities such as scoliosis may also occur. Adults often display sensorimotor problems, bladder, and bowel incontinence, impotence, pain, and symptoms impacting the autonomic nervous system. The condition may be progressive with symptoms worsening over the course of the patient's life.
There are two approaches to the treatment of diastematomyelia: surgery and observation. Patients with worsening neurological symptoms may be treated surgically. During minimally-invasive microsurgery, the bone or fibrous tissue is removed and the dural sacs are repaired. The best candidates for surgical treatment are young people who have had less severe neurological symptoms for a shorter duration of time. Asymptomatic or patients with stable symptoms may be treated conservatively by periodic visits to a neurologist. If symptoms develop or worsen, surgery may be required.