summary Diastematomyelia is a congenital spinal condition caused by a fibrous, cartilaginous, or osseous bar creating a longitudinal cleft in the spinal cord. Diagnosis is made with a prenatal ultrasound in the 3rd trimester. Treatment is observation if patient is asymptomatic. Surgical resection is indicated if patient is symptomatic or has neurological deficits. Epidemiology Demographics typically presents in childhood adult presentation is rare Anatomic location more common in lumbar spine (L1 to L3) Etiology Pathoanatomy a congenital anomaly believed to be caused by persistence of neuroenteric canal present during 3rd and 4th week of gestation leads to sagittal division of the spinal cord or cauda equina if the cord does not reunite distally to the spur, it is considered a diplomyelia (true duplication of the cord) Associated conditions congenital scoliosis as high as 79% in some series tethering of cord Presentation Symptoms muscle atrophy weakness bladder or bowel incontinence Physical exam sensory loss reflex asymmetry spinal cutaneous manifestations (>50% of patients) hairy patch (hypertrichosis) dimple subcutaneous mass teratoma lower extremity deformity cavus foot club foot 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 by plain radiographs or CT, especially if they are fibrous or there is rotation from concomitant scoliosis myelography is a useful adjuvant MRI required to evaluate degree of neurologic compression Treatment Nonoperative observation alone indications may be observed if patient is asymptomatic and does not have neurologic sequelae must watch closely for progressive neurological deterioration Operative surgical resection indications surgery is indicated if patient is symptomatic or has neurologic deficits must resect diastematomyelia before correction of spine deformity must resect and repair the duplicated dural sac