Long-Segment Type 1 Split Cord Malformation with Two-Level Split Cord Malformation and a Single Dural Sac at the Lower Split

Abstract

Objective and Importance: Two-level bony spurs are rare and also a very long segment of bony spur is very rare. Bony spur with a single dural covering is not reported in the literature. Here, we report a case of prophylactic surgery performed on a patient with a bony spur with a single dural covering who showed a good postoperative outcome. This case highlights the importance of prophylactic surgery in such patients to avoid cord injuries. Clinical Presentation: Since birth a 1-year-old child had had a tuft of hair at the dorsal (D₆ and D₇) region. The patient was examined and found to have scoliosis with convexity towards the right. There was no neurological deficit. MRI and CT spine scans showed 2-level type 1 split cord malformation (SCM) and there was a low-lying conus at the L_3–4 level. Intervention: The patient was operated on at the age of 1 year and 2 separate bony septae were observed. The upper one extended from D₅ to D₉ and the lower one was at the D₁₁ level. The bony spurs were excised. The filum was sectioned at the L_4–5 level by a separate incision. The patient had a good postoperative recovery. Conclusion: With meticulous planning and careful surgery, prophylactic surgery can have a very good outcome in long-segment and two-level type 1 SCM.

Type 1.5 Split Cord Malformation : A New Theory of Pathogenesis

“…However, some authors have reported a few cases with characteristics of both types I and II SCM, meaning that the lesion incorporated the hemicords within a single dural sac and an extradural partial bony septum 1,3,5,7,8,15,18,19,21) . We reviewed the literature, and 13 pertinent cases are listed in Table 1.…”

A rare case of type 1 C split cord malformation with single dural sheath

“…Only one case of type I SCM with single dural sheath is reported in English literature to the best of our knowledge, that too by the senior author of this paper (Mahapatra). [ 2 ] In previous patient, authors reported a long-segment type 1 split cord malformation, with two-level split cord malformation and a single dural sac and the spur was at the lower end of split. There was a bony spur arising from the D 11 body level without a separate dural covering but with 2 cords.…”

“…Only one case of single dural sheath in type 1 SCM has been reported in English literature till now. [ 2 ]…”

Composite Type of Split Cord Malformation: Rare and Difficult to Explain

“…The article by Singh et al [1] entitled ‘Long-term segment type 1 split cord malformation with two-level split cord malformation and a single dural sac at the lower split’ aroused our interest when reading it. The authors report a case of two-level type 1 split cord malformation (SCM) with a low-lying conus at the L3–4 level.…”

“…One of the weak points of this theory is composite-type SCM. Although it has not been proven yet, the multiple accessory neuroenteric canal was considered to be responsible for the development of composite-type SCM [1,2,3,4,5]. However, there are two questions concerning this theory.…”