- Department of Surgery, Division of Neurosurgery, Santa Casa de São Paulo Medical School, São Paulo - SP, Brazil
Correspondence Address:
Guilherme Brasileiro De Aguiar
Department of Surgery, Division of Neurosurgery, Santa Casa de São Paulo Medical School, São Paulo - SP, Brazil
DOI:10.4103/2152-7806.148042
Copyright: © 2014 De Souza RB. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.How to cite this article: De Souza RB, De Aguiar GB, Daniel JW, José Carlos Esteves Veiga. The pathophysiology, classification, treatment, and prognosis of a spontaneous thoracic spinal cord herniation: A case study with literature review. Surg Neurol Int 30-Dec-2014;5:
How to cite this URL: De Souza RB, De Aguiar GB, Daniel JW, José Carlos Esteves Veiga. The pathophysiology, classification, treatment, and prognosis of a spontaneous thoracic spinal cord herniation: A case study with literature review. Surg Neurol Int 30-Dec-2014;5:. Available from: http://sni.wpengine.com/surgicalint_articles/pathophysiology-classification-treatment-prognosis-spontaneous-thoracic-spinal-cord-herniation-case-study-literature-review/
Abstract
Background:Spinal cord herniation was first described in 1974. It generally occurs in middle-aged adults in the thoracic spine. Symptoms typically include back pain and progressive paraparesis characterized by Brown-Séquard syndrome. Surgical reduction of the hernia improves the attendant symptoms and signs, even in patients with longstanding deficits.
Case Description:A 66-year-old female with back pain for 7 years, accompanied by paresthesias and a progressive paraparesis, underwent a thoracic MRI which documented a ventral spinal cord herniation at the T4 level. Following a laminectomy, with reduction of the hernia and ventral dural repair, the patient improved.
Conclusion:Herniation of the thoracic cord, documented on MR, may produce symptomatic paraparesis which may resolve following laminectomy with ventral dural repair.
Keywords: Laminectomy, magnetic resonance imaging, microsurgery, neurosurgical procedures, spinal cord diseases
INTRODUCTION
Idiopathic spinal cord herniation (ISCH), most commonly found in the thoracic spine, was first described in 1974.[
CASE REPORT
A 66-year-old female farm worker presented with 7 years of progressive back pain and impaired motor and sphincter function. On neurological examination, she exhibited a sensory level at T4 with a spastic paraparesis and bilateral (right greater than left) muscle atrophy.[
Figure 1
Magnetic resonance of the dorsal spine [sagittal acquisition – (a and d) T1-weighted images; (b and e) T2-weighted images; (c and f) SPIR (Selective partial inversion recover) T2-weighted images] demonstrating the spinal cord herniation (a-c) and the radiological result following surgical treatment (d–f)
DISCUSSION
Clinical and diagnostic studies
Utilizing MRI, ISCH has been increasingly recognized. In one series, it was reported to occur in 0.08% of cases.[
Pathophysiology
Spontaneous ventral cord herniation usually involves the mid-thoracic spine, where the cord is naturally anteriorly situated due to the natural kyphosis.[
One author[
Other etiologies of spinal cord herniation
There are also multiple other etiological theories as to why ventral thoracic cord herniations occur. The predominant one is that the ventral position/adherence of the thoracic cord leads to compression and extrusion through ventral dural defects attributable to cardiac, pulmonary, and/or CSF pulsations.[
Value of MR in diagnosing spinal cord herniation
Although MRI is the most accurate tool for diagnosing spinal cord herniation, myelo-CT studies also prove useful.[
Classification of sagittal and axial MR types of cord herniation
Sagittal MR: In the sagittal plane, three types of thoracic MR cord herniations are identified: Type K shows an obvious ventral spinal kink; Type D, the discontinuous type, is characterized by the spinal cord completely disappearing at the herniation site; and Type P is the protrusion type wherein the anterior subarachnoid space ventral to the thoracic cord disappears, almost without a focal “kink.”[
Axial MR: Using axial images, the location of cord herniations is classified as central (Type C) and lateral (Type L) types. Furthermore, the laterality of the herniated spinal cord is classified based on its correspondence (same; Type S) or non-correspondence (opposite; Type O) with the location of the herniation.[
Surgery and outcome
Surgery for ISCH is appropriate when a progressive and/or severe neurological deficit occurs.[
Prognosis is better if the preoperative deficit is limited.[
CONCLUSION
Patients who present with slowly progressive paraparesis or Brown-Séquard syndrome may suffer from a ventral thoracic spinal cord herniation (ISCH). Surgical decompression, utilizing a laminectomy or laminoplasty, may allow for reduction of the cord herniation while facilitating ventral dural repair.
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