summary Diastematomyelia is a congenital spinal condition caused by a fibrous, cartilaginous, or osseous bar that creates a longitudinal cleft in the spinal cord Diagnosis is made with prenatal ultrasound in the 3rd trimester Treatment is observation for patients who are asymptomatic. Surgical resection is indicated for patients who are symptomatic or have neurological deficits Epidemiology Demographics typically presents in childhood adult presentation is rare Anatomic location more common in the lumbar spine (L1-3) Etiology Pathoanatomy a congenital anomaly believed to result from persistence of the neuroenteric canal present during the 3rd-4th week of gestation leads to sagittal division of the spinal cord or cauda equina if the cord does not reunite distal to the spur, considered a diplomyelia (true duplication of the spinal cord) Associated conditions congenital scoliosis as high as 79% tethering of the cord Presentation Symptoms muscle atrophy weakness bladder or bowel incontinence Physical exam sensory loss reflex asymmetry spinal cutaneous manifestations (>50%) hairy patch (hypertrichosis) dimple subcutaneous mass teratoma lower-extremity deformity cavus foot clubfoot claw toes Imaging Prenatal ultrasound may be diagnosed in utero during the third trimester Radiographs interpedicular widening is suggestive CT helpful to delineate bony anatomy Myelography spurs are often undetectable on plain radiographs or CT, particularly when they are fibrous or when concomitant scoliosis causes spinal rotation useful adjunct MRI required to evaluate the degree of neurologic compression Treatment Nonoperative observation alone indications patient is asymptomatic and has no neurologic sequelae patient must be monitored closely for progressive neurological deterioration Operative surgical resection indications patient is symptomatic or has neurologic deficits diastematomyelia causative septum must be resected before correction of a spinal deformity duplicated dural sac must be surgically addressed, with repair as indicated