So Mi Lee MD, Presenter: Nothing to Disclose

Jung-Eun Cheon MD, Abstract Co-Author: Nothing to Disclose

Younghun Choi MD, Abstract Co-Author: Nothing to Disclose

In-One Kim MD, Abstract Co-Author: Nothing to Disclose

Woo Sun Kim MD, Abstract Co-Author: Nothing to Disclose

Hyun-Hae Cho MD, Abstract Co-Author: Nothing to Disclose

Su-Mi Shin MD, Abstract Co-Author: Nothing to Disclose

Ji Young Kim MD, Abstract Co-Author: Nothing to Disclose

Sun Kyoung You MD, Abstract Co-Author: Nothing to Disclose

Limited dorsal myeloschisis (LDM) is characterized by fibroneural stalk that links the midline cutaneous lesion to the underlying cord. That is a distinctive form of spinal dysraphism, similar radiologic appearances with congenital dermal sinus (CDS). The aim of this study was to compare the neuroimaging findings between these two disease entities.

We retrospectively reviewed the MR and US findings in 22 patients (12 LDM and 10 CDS) with surgically proven LDM (M: F = 2: 10, age range 15 days – 4years) and CDS (M: F = 6: 4, age range 7 days – 16 months) from January 2012 to March 2014. The following imaging features were evaluated: location of the skin lesion, visibility of the tract along its subcutaneous and intrathecal course, ending point of the tract in the spinal canal, change in the cord location and shape, and presence of an intradural abscess or a dermoid-epidermoid tumor.

All of the skin lesions in both groups were located at the lumbosacral region. In ten (83%) of twelve patients with LDM, both subcutaneous and intrathecal portion of the tract were clearly visualized, while in nine (90%) of ten patients with CDS, the tract was indistinct in the intrathecal portion. In all 12 LDM patients, the tracts ended with attachment to the spinal cord just above the conus, while in eight patients with CDS, the tract ended within the spinal canal; dermoid-epidermoid tumors (n=5), filum terminale (n=1), conus medullaris (n=2). In the remaining two patients with CDS, the tract did not extended into the spinal canal ; ended at the dura without passing through it (n=1), end blindly in the subcutaneous fat layer (n=1). In the LDM group, the conus medullaris was lying below L2 in nine (75%) patients and the cord showed dorsal tenting at the level of the tract attachment in ten (83%) patients. The level of the conus medullaris in the CDS was obscured by an intraspinal abscess or an infected dermoid-epidermoid in four (40%) patients and was low-lying in three (30%) patients with CDS. None of the LDM patients had an intradural infection or a dermoid-epidermoid tumor.

LDM showed a clearly visible intrathecal tract that was attached to the spinal cord just above the conus and dorsal tenting of the cord at the tract attachment site. LDM was not associated with an intradural infection or a dermoid-epidermoid, unlike CDS.

MRI can be helpful in differential diagnosis of LDM and CDS.

Lee, S, Cheon, J, Choi, Y, Kim, I, Kim, W, Cho, H, Shin, S, Kim, J, You, S, Imaging Findings of Limited Dorsal Myeloschisis: Comparison with Congenital Dermal Sinus.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14012035.html