Letters to the Editor

Indian Pediatrics 2001; 38: 1069-1070  

Split Cord Malformations

In the article on this subject(1) the author’s description of certain important aspects of Split Cord Malformations (SCM) is confusing and needs correction. In addition to the cutaneous markers of occult dysraphism, the common neurological deficit with SCM is in form of uniform thinning of one of the lower limb without any apparent weakness. Magnetic resonance imaging in such a situation demons-trates a thin hemicord on the side of thin leg. These children, despite any surgical correction of tethered cord, continue to grow with one thin lower limb(2-4). On the other hand a child born with cutaneous markers without any neurological deficit, if left untreated develops neurological deficit resulting from a tethered cord during the growth period(5). Surgical intervention in such cases prevents develop-ment of new neurological deficits.

The radiological findings described are contradictory. Of the 48 children with SCM, only 24 had tethered cord. This appears incorrect. All patients with SCM have a tethered cord at the site of bony or fibrous spur preventing normal cord movements(5,6). Further, of the 48 patients with SCM, 42 patients are mentioned to have a diastemato-myelia and 6 diplomyelia. What is the purpose of this differentiation? It is not correct to use these confusing terms as MRI clearly demons-trated both types of SCM (type I and type II SCM) and cord tethering (7,8). Further, 3D CT scan delineates the details of bony spur in type I SCM and the extent of split in type II in coronal imaging(10).

Surgical intervention involves intradural excision of the bony/fibrous spur and untethering of the cord. Author’s 4 of the 48 patients (8%) deteriorated after surgery which was aimed to prevent development of neuro-logical deficit(1). What was the cause of deterioration and what was the post operative MRI findings in these children. In our experience with 71 children, intradural exci-sion of spur with intraoperative methyl prednisolone infusion was found to be ideal with no child showing deterioration on an average follow-up of 6 years (1-13 years). The authors follow up of the patients is short and long term result of prophylactic surgery could not be drawn. Regrowth of the spur after excision and retethering is known(11).

Occult spinal dysraphism in the children can be detected before development of any neurological, musculoskeletal or urological deficit, if attention is given to cutaneous 

markers of the dysraphism at birth or in early childhood. It is difficult to predict the natural history of an untreated child with SCM and also the chances of a newborn with only the cutaneous stigmata of SCM to develop neurological deficit in his lifespan. However, significant neurological deficit following mild trauma or fall during sport in children or adults with SCM is well documented.

It is suggested that children with cutaneous markers of SCM must have an MRI and if SCM is detected, it must be operated even if asymptomic. With advances in microneuro-surgical techniques, safer pediatric neuro-anaesthesia and state of art monitoring system, prophylactic surgery in asymptomatic infants with SCM is undertaken without any risk and should be routinely undertaken as a prophy-laxis against later often irreversible neuro-logical damage.

Ajay Sharma,
Professor of Neurosurgery,
Pediatric Neurological Surgeon,
G.B.Pant Hospital,
New Delhi 110 002, India.

1. Jindal A, Mahapatra AK. Split cord malformations - A clinical study of 48 cases. Indian Pediatr 2000; 37: 603-607.

2. Andar U, Harkness WFJ, Haywards R. Split Cord malformations in the lumbar region. Pediatr Neurosci 1997; 26: 17-24.

3. Gulati P, Tripathy RP, Jena A, Sharma A. Magnetic resonance imaging in diastemato-myelia. Indian J Radiol Imag 1991; 1: 3-6.

4. Sharma A, Tyagi G, Jena A, Prakash B. Diastematomyelia in the first decade of life: Report of 15 cases. Child’s Nerv Syst 1990; 6: 296.

5. Sharma A. Management of tethered cord. Prog Clin Neurosci, 1998; 13: 197-202.

6. Pang D. Split Cord malformation: Clinical Syndrome. Neurosurgery 1992; 31: 481-500.

7. Tripathi RP, Sharma A, Jena A, Gulati P, Jain RK. Magnetic resonance imaging in occult spinal dysraphism. Australasian Radiol 1992; 36: 8-10.

8. Gupta RK, Sharma A, Jena A, Tyagi G, Prakash B, Kushu S. Magnetic resonance evaluation of spinal dysraphism in children. Child’s Nerv Syst 1990; 6: 161-165.

9. Gupta RK, Sharma A. MR demonstration of paravertebral lumbar meningomyelocele with diastematomyelia. Neuroradiology 1990; 31: 554.

10. Garg S, Sharma A. Splitcord malformation (SCM) in childhood. Neurol India 1997; 45: 13.

11. Pang D, Parrish RG. Regrowth of diaste-matomyelic bone spur after extradural resection J Neurosurg 1983; 59: 887-890.