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LETTER TO EDITOR
Year : 2012  |  Volume : 60  |  Issue : 3  |  Page : 342--343

Idiopathic spinal cord herniation

Manoj Choradia 
 Department of Radiology, NM Medical, Shyamsunder, Mumbai, India

Correspondence Address:
Manoj Choradia
Department of Radiology, NM Medical, Shyamsunder, Mumbai
India




How to cite this article:
Choradia M. Idiopathic spinal cord herniation.Neurol India 2012;60:342-343


How to cite this URL:
Choradia M. Idiopathic spinal cord herniation. Neurol India [serial online] 2012 [cited 2022 Aug 18 ];60:342-343
Available from: https://www.neurologyindia.com/text.asp?2012/60/3/342/98535


Full Text

Sir,

Idiopathic spinal cord hernia is a rare condition that is easy to be missed or misdiagnosed. A 48-year- woman presented with mild numbness in the anteromedial aspect of her right thigh and slight difficulty with right leg movement for the past two years. She did not have back pain or lower limb pain, nor did she have a history of trauma.

MR examination of the thoracic spine revealed anterior displacement of the spinal cord posterior the T3 vertebral body associated with a kink and flattening of the displaced cord [Figure 1]a and b. Enlarged cerebrospinal fluid space posterior to the spinal cord at the level of displacement was noted. On the basis of the MR findings, a diagnosis of idiopathic spinal cord herniation (ISCH) was made. This diagnosis was subsequently confirmed with phase-contrast cine MRI. It revealed free and turbulent flow of CSF dorsal to the herniation and no flow ventral to it [Figure 2]a and b.This ruled out presence of any filling defect or loculation in the subarachnoid space at the level of the spinal cord herniation that could have given rise to such displacement. This finding was helpful in excluding a diagnosis of arachnoid cyst which appears as a CSF signal intensity lesion. Also, the free flow of CSF excluded the possibility of arachnoiditis in which adhesions can prevent normal flow of CSF. There is limited cord motion at the level of herniation [Figure 2]c and normal motion above it [Figure 2]d.{Figure 1}{Figure 2}

The reported age range of patients with ISCH varies from 22 to 78 years, with a median age of 50 years. [1] Brown-Sequard syndrome is the most frequently described symptom of ISCH presentation [2] . Imaging is the cornerstone in the diagnosis of ISCH. On sagittal T2 weighted images, recognition of the focal ventral displacement and angulation of the thoracic spinal cord, with or without cord thinning or flattening, on the images should lead one to consider this diagnosis. It is important to exclude a cystic lesion posterior to the spinal cord, such as an intradural arachnoid cyst, because the appearance of this lesion can mimic that of cord herniation. Phase-contrast cine MR imaging can be used to rule out this possibility. [3] In this disorder, the thoracic spinal cord prolapses through an anterior or lateral dural defect. It has been suggested that close apposition of the thoracic cord to the anterior dura may be fundamental in the pathogenesis of this disease. [4] Early surgical reduction of the hernia has been recommended, as there is slow progressive deterioration in the symptoms [5] .

The aim of reporting this rare entity is to demonstrate that Phase-contrast imaging is a valuable technique for assessing the presence or absence of a dorsal lesion like posterior arachnoid cyst or arachnoiditis. Also, it provides better understanding of the pathophysiology and explains how, even in the absence of a compressive posterior lesion like an arachnoid cyst, spinal cord herniation is possible when an anterior dural defect occurs.

References

1Najjar MW, Baeesa SS, Lingawi SS. Idiopathic spinal cord herniation: A new theory of pathogenesis. Surg Neurol 2004;62:161-70.
2Ferré JC, Carsin-Nicol B, Hamlat A, Carsin M, Morandi X. MR imaging features of idiopathic thoracic spinal cord herniation using combined 3D-FIESTA and 2D-PC cine techniques. J Neuroradiol 2005;32:125-30.
3Brugieres P, Malapert D, Adle-Biassette H, Fuerxer F, Djindjian M, Gaston A. Idiopathic spinal cord herniation: Value of MR phase-contrast imaging. AJNR Am J Neuroradiol 1999;20:935-9.
4Dix JE, Griffitt W, Yates C, Johnson B. Spontaneous thoracic spinal cord herniation through an anterior dural defect. AJNR Am J Neuroradiol 1998;19:1345-8.
5Barrenechea IJ, Lesser JB, Gidekel AL, Turjanski L, Perin NI. Diagnosis an treatment of spinal cord herniation: A combined experience. J Neurosurg Spine 2006;5:294-302.