Diastematomyelia in Adults* WESLEY J. ENGLISH, M.D., A~qD GEORGE L. MALTBY, M.D. Maine Medical Center, Prrrtland, Maine HE term "diastematomyelia" in its myelography (Fig. 2) demonstrated widening strict sense refers to a developmental of the spinal canal in the lumbosaeral region, T defect in which the spinal cord, or its a bizarre termination of the dural sac, a intraspinal derivatives, is divided longitudi- filling defect in the center of the oil column nally into lateral halves. Ollivier is credited at L-5, and a partial block at the L1-2 inter- with the origination of the term in 1837, space. It was felt that the partial block was deriving it from the Greek "diastema," due to a transverse bony ridge secondary to meaning cleft, and "myelos," meaning "mar- lumbar spondylosis. row" and subsequently spinal cord or Operation. A laminectomy was performed medulla. ~ Clinical usage of the term, how- from T-9 to L-5. The spinal cord was greatly ever, has tended to designate those cases of lengthened and was divided by a bony spur cord-splitting in which the cord is transfixed projecting dorsally from the body of L-5. The by a septum. Most authors differentiate this bony spur was surrounded by a sleeve of type of malformation from diplomyelia dura mater. The nerve roots in the low lum- (double medulla) which is a true duplication bar region left the spinal cord at right angles. of the cord. Several adhesions contributed to traction on Diastematomyelia is rarely diagnosed in the cord. A transverse bony ridge was pres- adults; only four cases have been described ent at LI-s The spur and dural sleeve were in which the diagnosis was established during removed, and the adhesions were lysed. the lifetime of the patient3 ,~,s A fifth case is Postoperative Course. The patient was known to us through personal correspon- temporarily worse, developing a paraplegia dence2 Since clinical awareness of this entity and urinary and fecal incontinence. He was aroused in 1950 through articles by received intensive physiotherapy, and 20 Matson and Neuhauser, more than 100 clini- months after surgery had better bladder cal cases have been described, mostly in control and was walking with mechanical children, in whom disturbance of gait, failure aids, though he was still spastic. of bladder control, and congenital cutaneous defects are the most common features. Case 2. A 3~-year-old woman developed a We are reporting two cases of diastema- flaccid paresis of her left leg after a saddle tomyelia in adults. block anesthesia for her fourth delivery. No bowel or bladder difficulty developed. She Case Reports had had three uncomplicated saddle blocks Case 1. A 48-year-old man entered the in the past. hospital with spasmodic pain, weakness, and Examination. There was a flaccid paresis tremor in the right leg of 3 months' duration. of the muscle groups of the left leg and The symptoms began after a 50-mile ride in a sensory losses in the saddle area and along pickup truck. the medial thigh and calf. Lumbar spine Examination. Neurological examination films disclosed a spina bifida occulta at L-3 showed a spastic paraparesis, loss of pain and (Fig. 3). Myelography was carried out at the temperature sensation over the sacrum, and LI-~ interspace, revealing diastematomyelia an unusual patch of hair in the lumbosacral at L-3 (Fig. 4). It was elected to follow the region. Low back films showed a circular patient conservatively, reserving surgical calcified shadow at L-5 in the upper portion intervention until the symptoms became of a spina bifida occulta (Fig. 1). Lumbar worse. Received for publication January 27, 1967. Discussion * Presented at the Annual Meeting of the American Academy of Neurological Surgery, San Francisco, Although first described in 1837, diastema- California, October 17, 1966. tomyelia had not been identified outside the 260 Diastematomyelia in Adults ~61 FrG. 1. Case 1. Plain spine film showing calcified nodule in spina bifida defect at L-5. Fio. ~. Case 1. Myelogram showing widening of spinal canal, filling defect at L-5, and partial block at LI-~ interspace. .