ACTA NEUROCHIRURGICA 9 by Springer-Verhg 1979
ActaNeurochirurgica 51, 91--96 (1979)
Institute of Neurosurgery, Santiago, Chile
Diastematomyelia R e p o r t of 10 Cases By
L. Basauri, A. Palma, A. Zuleta, F. Holzer, and R. Poblete
With 3 Figures Summary The diagnostic and therapeutic aspects of 10 cases of diastematomyelia are reported. The cutaneous, orthopaedic, neurological, and radiological signs and symptoms are discussed and emphasized. Different embryological and physiopatho-
logical aspects are commented on. Surgical treatment is recommended in all cases. Diastematomyelia is a rare malformation of the posterior midline due to the presence of a spicule of bone, fibrous tissue, or cartilage in the spinal canal. The hypothesis generally accepted is that of a division of the cord in two hemicords with independent dural sac. For some authors the presence of a bifid cord, or diplomyelia, is mandatory 5, 11 During the past 10 years 10 cases of this deformity have been treated at the Institute of Neurosurgery, Santiago, Chile. Material
Ten cases of diastematomyelia with ages ranging between 4 months and 10 years are analyzed. Eight of them were females and two males. The most usual location was the lumbar region with seven cases. Two cases were located in the dorsal region, and one was dorsolumbar. In four cases the spicule touched the laminae and divided the spinal canal completely. In eight patients the deformity was associated with other malformations, the most frequent being hemivertebra, spina bifida, megacanal, meningocoele ar myelomeningo0001-6268/79/0051/0091/$ 01.20
92
L. Basauri et al.:
code, and malformations of costal segmentation. During the first months of life only feet deformities or cutaneous stigmata were present, and the diagnosis was rarely suspected. Parents began to worry when the child started walking, because of feet deformities or weakness of the lower limbs, paraesthesiae, or progressive spinal deformities.
Fig. 1. Plain X-ray of the spine. Spicule of bone ar L2-L~ level
Signs and Symptoms The signs and symptoms of diastematomyelia can be divided into cutaneous, orthopaedic, neurological, and radiological. Cutaneous: These were present in five patients of this series. The most frequent were hypertrichosis, pilonidal cyst, lipomas, closed fistulous tract, and the external manifestation of meningo- or myelomeningocoele.
Diastematomyelia
93
Orthopaedic: The most frequent were malformations of the feet, such as valgus or varus deformities, or clubfoot. Usually the patient was taken to the orthopaedic surgeon for progressive kyphoscoliosis, generally accompanied by limping, secondary to a difference in the length of the limbs. Six patients had malformation of the feet,
Fig. 2. Myelogram with heavy contrast media. The negative image of the spicule at T 6, and malformations of costal segmentation can be seen
scoliosis, or kyphosis. Neural artropathy, which is rare, was present in one of the cases in the present series. Neurological: Eight of the 10 cases had some neurological impairment. All of them showed a paraparesis, more marked in one limb. Two children had sphincter dysfunction, and in only one was it possible to show sensory deficiency. Neurological impairment was usually slowly progressive, and in one of the present cases the only
94
L. Basauri
e t aI. :
complaint was enuresis, in a girl with kyphoscoliosis. The motor impairment varied between one patient with paraplegia to others with alterations of walking. RadiologicaI: Radiological examination must be very searching, in a child with spinal deformities or feet deformities, and must in-
Fig. 3. Photograph through the operating microscope (magnification 12 • 24) showing the two hemicords separated by a fibrous-cartilagenous septum
clude an exhaustive study of the complete spine, orientated to search for the spicule, a megacanal, or an associated malformation. In the present series plain radiographs were positive in all the cases, showing the spicule very clearly (Fig. 1). There was only one case without an associated malformation of the spine, or costal segmentation, or feet deformities. In one patient the spicule was located at the L,-L4 level and was
Diastematomyelia
95
associated with vertical astragalus, hemivertebrae L~ Ls, and spondylolisthesis LJS 1. Clinically the patient had enuresis, encopresis, and abnormal gait. Myelography was positive in all cases, disclosing very distinctly the central negative image of the spicule (Fig. 2). It showed associated malformations, mainly meningo- or meningomyelocoeles and lipomas.
Treatment Treatment was surgical in all cases. It consisted in the exposure of the deformity through a laminectomy (Fig. 3), resection of the spicule, freeing of adhesions, and plastic repair of the dural sac with suture of the anterior and posterior defects. The filum terminale was routinarily sectioned. Only in one case was it impossible to dissect the neural elements; this was a patient operated on for a ruptured myelomeningocoele at the moment of birth, when the diastematomyelia was not obvious. She was four years old when operated on because of enuresis, scoliosis, and a progressive right leg paresis. During recent years the use of the surgical dissecting microscope has become obligatory. In the majority of the present cases the treatment was prophylactic in order to secure the normal "migration" of the cord and to prevent further impairment of the neural elements. The results were satisfactory in all but one case. There was no mortality or morbidity, except for transient sphincter paresis.
Embryological Aspects According to Brenner 1 the theory most commonly accepted is that of the division of the cord in two hemicords with an independent dural sac. Vandresse and Cornelis 11 accept the idea of a bifid cord, or diplomyelia. The defect is probably due to a deficient closure of the embryological neural groove because of the interposition of endodermal and ectodermal material between the two neural crests.
Remarks Diastematomydia is a rare condition dominated by the presence of a septum in the spinal canal. The symptomatology is mainly caused by the compression exerted by the spicule. The lower the location of the deformities the earlier the symptoms will appear, since the lumbar cord grows more slowly than the thoracic cord. Normally the ilium terminale anchors the cord in the spinal canal. It is generally accepted that a low lumbar cord is secondary either to a diastematomyelia or a spinal tumour after the age of 5 ~, 4, 7, 8, 11
96
L. Basauri
et al.:
Diastematomyelia
Other authors believe that the main cause of symptoms is the solidly fixed filum terminale alone. It is possible, too, that the compression and stenosis of the arterial spinal axes play a role in the pathogenesis of symptoms. The deformity must be suspected in children below 15 years 6, 9, 10 of age, with spinal or feet deformities and walking alterations 2.6, 8, 11 associated with paresis and atrophy of one lower limb, the presence of cutaneous stigmata, or the external manifestation of meningo- or myelomeningocoele. A careful radiological investigation of the spine very often gives the diagnostic clue, and myelography confirms the abnormalities. Treatment must be surgical, and it is m a n d a t o r y in the presence of progressive neurological deficits. It is prophylactic in the presence of progressive spinal deformities and mild neurological manifestations, such as enuresis or abnormal gait. It is obviously required in cases associated with myelo- or meningomyelocoeles. The surgical indication is clearer the lower the location of the spinal malformation. References
1. Bremer, J. L., Dorsal intestinal fistula, accesory neurenteric canal, diastematomyelia. Arch. Path. 54 (1952), 132--138. 2. Dale, A. J. D., Diastematomyelia. Arch. Neurol. 20 (1969), 309--117. 3. Gold, L. H. A., Kieffer, S. A., Peterson, H. O., Lipomatous invasion of the spinal cord associated with spinal dysraphism: myelographic evaluation. Amer. J. Roentgen. 107 (1969), 479--485. 4. Harris, H. W, Miller, O. F., Midline cutaneous abnormalities associated with occult spinal disorders. Arch. Dermatol. 112 (1976), 1724--1728. 5. Herren, R. Y., Edwards, J. E., Diplomyelia (duplication of the spinal cord). Arch. Path. 30 (1940), 1203--1214. 6. Matson, D. D., Woods, R. P., Campbell, J. B., Ingraham, F. D., Diastematomyelia (congenital clefts of the spinal cord). Diagnosis and surgical treatment. Pediatrics (Springfield) 6 (1950), 98--112. 7. Obrador, S., Villarejo, F., Displasias raqui-medulares de la regi6n lumbo-sacra. Rev. Clin. Espafiola 139 (1975), 17--25. 8. Palma, A., Colin, E., Diastematomyelia: a prop6sito de un caso. Neurocirugfa 31 (1973), 189--193. 9. Perret, G., Diagnosis and treatment of diastematomyelia. Surg. Gynec. Obstet. 1957 69--83. 10. Rigault, P., Pouliquen, J.-C., Guyonvarch, G., Durand, Y., Quatre cas de diast~matomy~lie. Rev. Chirur. orthop. 58 (1972), 33--50. 11. Vandresse, J. H., Cornelis, G., Diastematomyelia: report of eight observations. Neuroradiology 10 (1975), 87--93. Authors' address: Dr. L. Basauri, Institute of Neurosurgery~ Casilla 3717-Correo 9, Santiago, Chile.
ActaNeurochirurgica 51, 91--96 (1979)
Institute of Neurosurgery, Santiago, Chile
Diastematomyelia R e p o r t of 10 Cases By
L. Basauri, A. Palma, A. Zuleta, F. Holzer, and R. Poblete
With 3 Figures Summary The diagnostic and therapeutic aspects of 10 cases of diastematomyelia are reported. The cutaneous, orthopaedic, neurological, and radiological signs and symptoms are discussed and emphasized. Different embryological and physiopatho-
logical aspects are commented on. Surgical treatment is recommended in all cases. Diastematomyelia is a rare malformation of the posterior midline due to the presence of a spicule of bone, fibrous tissue, or cartilage in the spinal canal. The hypothesis generally accepted is that of a division of the cord in two hemicords with independent dural sac. For some authors the presence of a bifid cord, or diplomyelia, is mandatory 5, 11 During the past 10 years 10 cases of this deformity have been treated at the Institute of Neurosurgery, Santiago, Chile. Material
Ten cases of diastematomyelia with ages ranging between 4 months and 10 years are analyzed. Eight of them were females and two males. The most usual location was the lumbar region with seven cases. Two cases were located in the dorsal region, and one was dorsolumbar. In four cases the spicule touched the laminae and divided the spinal canal completely. In eight patients the deformity was associated with other malformations, the most frequent being hemivertebra, spina bifida, megacanal, meningocoele ar myelomeningo0001-6268/79/0051/0091/$ 01.20
92
L. Basauri et al.:
code, and malformations of costal segmentation. During the first months of life only feet deformities or cutaneous stigmata were present, and the diagnosis was rarely suspected. Parents began to worry when the child started walking, because of feet deformities or weakness of the lower limbs, paraesthesiae, or progressive spinal deformities.
Fig. 1. Plain X-ray of the spine. Spicule of bone ar L2-L~ level
Signs and Symptoms The signs and symptoms of diastematomyelia can be divided into cutaneous, orthopaedic, neurological, and radiological. Cutaneous: These were present in five patients of this series. The most frequent were hypertrichosis, pilonidal cyst, lipomas, closed fistulous tract, and the external manifestation of meningo- or myelomeningocoele.
Diastematomyelia
93
Orthopaedic: The most frequent were malformations of the feet, such as valgus or varus deformities, or clubfoot. Usually the patient was taken to the orthopaedic surgeon for progressive kyphoscoliosis, generally accompanied by limping, secondary to a difference in the length of the limbs. Six patients had malformation of the feet,
Fig. 2. Myelogram with heavy contrast media. The negative image of the spicule at T 6, and malformations of costal segmentation can be seen
scoliosis, or kyphosis. Neural artropathy, which is rare, was present in one of the cases in the present series. Neurological: Eight of the 10 cases had some neurological impairment. All of them showed a paraparesis, more marked in one limb. Two children had sphincter dysfunction, and in only one was it possible to show sensory deficiency. Neurological impairment was usually slowly progressive, and in one of the present cases the only
94
L. Basauri
e t aI. :
complaint was enuresis, in a girl with kyphoscoliosis. The motor impairment varied between one patient with paraplegia to others with alterations of walking. RadiologicaI: Radiological examination must be very searching, in a child with spinal deformities or feet deformities, and must in-
Fig. 3. Photograph through the operating microscope (magnification 12 • 24) showing the two hemicords separated by a fibrous-cartilagenous septum
clude an exhaustive study of the complete spine, orientated to search for the spicule, a megacanal, or an associated malformation. In the present series plain radiographs were positive in all the cases, showing the spicule very clearly (Fig. 1). There was only one case without an associated malformation of the spine, or costal segmentation, or feet deformities. In one patient the spicule was located at the L,-L4 level and was
Diastematomyelia
95
associated with vertical astragalus, hemivertebrae L~ Ls, and spondylolisthesis LJS 1. Clinically the patient had enuresis, encopresis, and abnormal gait. Myelography was positive in all cases, disclosing very distinctly the central negative image of the spicule (Fig. 2). It showed associated malformations, mainly meningo- or meningomyelocoeles and lipomas.
Treatment Treatment was surgical in all cases. It consisted in the exposure of the deformity through a laminectomy (Fig. 3), resection of the spicule, freeing of adhesions, and plastic repair of the dural sac with suture of the anterior and posterior defects. The filum terminale was routinarily sectioned. Only in one case was it impossible to dissect the neural elements; this was a patient operated on for a ruptured myelomeningocoele at the moment of birth, when the diastematomyelia was not obvious. She was four years old when operated on because of enuresis, scoliosis, and a progressive right leg paresis. During recent years the use of the surgical dissecting microscope has become obligatory. In the majority of the present cases the treatment was prophylactic in order to secure the normal "migration" of the cord and to prevent further impairment of the neural elements. The results were satisfactory in all but one case. There was no mortality or morbidity, except for transient sphincter paresis.
Embryological Aspects According to Brenner 1 the theory most commonly accepted is that of the division of the cord in two hemicords with an independent dural sac. Vandresse and Cornelis 11 accept the idea of a bifid cord, or diplomyelia. The defect is probably due to a deficient closure of the embryological neural groove because of the interposition of endodermal and ectodermal material between the two neural crests.
Remarks Diastematomydia is a rare condition dominated by the presence of a septum in the spinal canal. The symptomatology is mainly caused by the compression exerted by the spicule. The lower the location of the deformities the earlier the symptoms will appear, since the lumbar cord grows more slowly than the thoracic cord. Normally the ilium terminale anchors the cord in the spinal canal. It is generally accepted that a low lumbar cord is secondary either to a diastematomyelia or a spinal tumour after the age of 5 ~, 4, 7, 8, 11
96
L. Basauri
et al.:
Diastematomyelia
Other authors believe that the main cause of symptoms is the solidly fixed filum terminale alone. It is possible, too, that the compression and stenosis of the arterial spinal axes play a role in the pathogenesis of symptoms. The deformity must be suspected in children below 15 years 6, 9, 10 of age, with spinal or feet deformities and walking alterations 2.6, 8, 11 associated with paresis and atrophy of one lower limb, the presence of cutaneous stigmata, or the external manifestation of meningo- or myelomeningocoele. A careful radiological investigation of the spine very often gives the diagnostic clue, and myelography confirms the abnormalities. Treatment must be surgical, and it is m a n d a t o r y in the presence of progressive neurological deficits. It is prophylactic in the presence of progressive spinal deformities and mild neurological manifestations, such as enuresis or abnormal gait. It is obviously required in cases associated with myelo- or meningomyelocoeles. The surgical indication is clearer the lower the location of the spinal malformation. References
1. Bremer, J. L., Dorsal intestinal fistula, accesory neurenteric canal, diastematomyelia. Arch. Path. 54 (1952), 132--138. 2. Dale, A. J. D., Diastematomyelia. Arch. Neurol. 20 (1969), 309--117. 3. Gold, L. H. A., Kieffer, S. A., Peterson, H. O., Lipomatous invasion of the spinal cord associated with spinal dysraphism: myelographic evaluation. Amer. J. Roentgen. 107 (1969), 479--485. 4. Harris, H. W, Miller, O. F., Midline cutaneous abnormalities associated with occult spinal disorders. Arch. Dermatol. 112 (1976), 1724--1728. 5. Herren, R. Y., Edwards, J. E., Diplomyelia (duplication of the spinal cord). Arch. Path. 30 (1940), 1203--1214. 6. Matson, D. D., Woods, R. P., Campbell, J. B., Ingraham, F. D., Diastematomyelia (congenital clefts of the spinal cord). Diagnosis and surgical treatment. Pediatrics (Springfield) 6 (1950), 98--112. 7. Obrador, S., Villarejo, F., Displasias raqui-medulares de la regi6n lumbo-sacra. Rev. Clin. Espafiola 139 (1975), 17--25. 8. Palma, A., Colin, E., Diastematomyelia: a prop6sito de un caso. Neurocirugfa 31 (1973), 189--193. 9. Perret, G., Diagnosis and treatment of diastematomyelia. Surg. Gynec. Obstet. 1957 69--83. 10. Rigault, P., Pouliquen, J.-C., Guyonvarch, G., Durand, Y., Quatre cas de diast~matomy~lie. Rev. Chirur. orthop. 58 (1972), 33--50. 11. Vandresse, J. H., Cornelis, G., Diastematomyelia: report of eight observations. Neuroradiology 10 (1975), 87--93. Authors' address: Dr. L. Basauri, Institute of Neurosurgery~ Casilla 3717-Correo 9, Santiago, Chile.
