Idiopathic spinal cord herniation: a new theory of pathogenesis

doi:10.1016/j.surneu.2003.10.030

Surgical Neurology

Volume 62, Issue 2, August 2004, Pages 161-170

https://doi.org/10.1016/j.surneu.2003.10.030 Get rights and content

Abstract

Backgound

Idiopathic spinal cord herniation is a rare entity that has been described more frequently over the past few years. Its pathophysiology remains obscure, however.

Methods

We report a case of spinal cord herniation and review the literature extensively. In view of our review, we try to determine the clinical features of the condition and the diagnostic measures used, with emphasis on the role of magnetic resonance (MR) phase-contrast CSF study. The factors affecting the outcome of the condition are also studied including time and type of presentation, as well as the surgical procedure performed. The pathophysiological mechanisms behind spontaneous herniation are discussed, and a new hypothesis is proposed.

Results

Idiopathic spinal cord herniation occurs in the middle-aged adult, with a preponderance of patients being female. Brown-Séquard syndrome is the most common clinical presentation and usually progresses to spastic paraparesis. MRI typically shows a ventral kink in the thoracic cord, with MR phase-contrast imaging proving an important addition to exclude an arachnoid cyst. Better outcomes were noted in the patients treated earlier, and in those with no spasticity. Widening the dural defect seems to afford better results compared to grafting of the defect. The prognosis is favorable after correction, though a vertebral body herniation variant may be associated with worse outcome. In view of the chronology of events and imaging studies in our patient, we hypothesize that herniation occurs as an acquired phenomenon where an inflammatory process results in adherence between the spinal cord and the dura, with erosion, formation of a dural defect, and then later herniation occurring with cerebral spinal fluid (CSF) pulsations.

Conclusions

Idiopathic herniation of the spinal cord should be recognized and treated early to reach a favorable outcome. It seems to be an acquired condition likely caused by an inflammatory event, the nature of which is to be determined.

Section snippets

History and examination

A 32 year-old man had a history dating back to 1991, when he developed pain and hyperesthesia in the upper extremities and the right lower extremity following high-grade fever after septoplasty. He also had weakness in the hand grips bilaterally and diffusely in the right leg. Erythrocyte sedimentation rate was slightly elevated according to the old records. He was treated with nonsteroidal anti-inflammatory agents and physical therapy on the suspicion of postinfective radiculopathy. He

Pathophysiology

Spontaneous ventral herniation of the spinal cord through a previously uninjured dural defect through a dural defect is an exceptional occurrence. A striking similarity in the clinical presentation and radiologic appearance exists among the various cases reported, increasing the index of suspicion among treating physicians and thus the number of cases reported lately. Little is known of the pathophysiology of the condition, however.

We have identified 79 cases (including our case) of idiopathic

Conclusion

In summary, idiopathic or spontaneous spinal cord herniation is a rare entity that is being increasingly recognized and reported. It presents in the middle aged adult as Brown-Séquard syndrome and usually progresses into spastic paraparesis. MRI findings are typical, showing a ventral or ventrolateral kink of the spinal cord in the thoracic spine. Phase-contrast cine MR is very useful in excluding an arachnoid cyst, the most common mistaken diagnosis. The treatment is usually surgical by either

References (35)

M. Abe et al.
Spinal cord herniation into an extensive extradural meningeal cystpostoperative analysis of intracystic flow by phase-contrast cine MRI
J Orthop Sci
(1999)
T. Aizawa et al.
Idiopathic herniation of the thoracic spinal cordreport of three cases
Spine
(2001)
G.M.V. Barbagallo et al.
Thoracic idiopathic spinal cord herniation at the vertebral body levela subgroup with a poor prognosis?
J Neurosurg (Spine 3)
(2002)
A. Berbel et al.
Idiopathic spinal cord herniation. Presentation of a new case and review of the literature
Rev Neurol
(2001)
L.F. Borges et al.
Idiopathic spinal cord herniationa treatable cause of the Brown-Sequard syndrome: case report
Neurosurgery
(1995)
P. Brugières et al.
Idiopathic spinal cord herniationvalue of MR phase-contrast imaging
AJNR Am J Neuroradiol
(1999)
M. Cellerini et al.
Idiopathic spinal cord herniationa treatable cause of Brown-Séquard syndrome
Acta Neurochir(Wien)
(2002)
J.E. Dix et al.
Spontaneous thoracic spinal cord herniation through an anterior dural defect
AJNR Am J Neuroradiol
(1998)
C. Ewald et al.
Progressive spontaneous herniation of the thoracic spinal cordcase report
Neurosurgery
(2000)
O.N. Hausmann et al.
Idiopathic dural herniation of the thoracic spinal cord
Neuroradiology
(1996)

T. Isu et al.

Spinal cord herniation associated with an intradural spinal arachnoid cyst diagnosed by magnetic resonance imaging

Neurosurgery

(1991)

R. Kumar et al.

Herniation of the spinal cord. Case report

J Neurosurg

(1995)

G. Marquardt et al.

Acute posttraumatic spinal cord herniation. Case report and review of the literature

J Neurosurg (Spine 2)

(2001)

L. Marshman et al.

Idiopathic spinal cord herniationcase report and review of the literature

Neurosurgery

(1999)

E.M. Massicotte et al.

Idiopathic spinal cord herniationreport of eight cases and review of the literature

Spine

(2002)

H. Masuzawa et al.

Spinal cord herniation into a congenital extradural arachnoid cyst causing Brown-Séquard syndrome

J Neurosurg

(1981)

T. Matsumara et al.

A case of idiopathic spinal cord herniation

Rinsho Shinkeigaku

(1996)

Cited by (75)

Delayed cord tethering post-ventral dural repair of idiopathic thoracic cord herniation
2021, Journal of Clinical Neuroscience
Idiopathic spinal cord herniation
2020, Clinical Radiology
Citation Excerpt :
Ishida et al.24 have also described a case with radiological correlation, demonstrating cord herniation through the inner layer of duplicated dura on high-resolution volumetric magnetic resonance imaging (MRI), confirmed intra-operatively. Minor trauma, which may be repetitive, has been postulated to cause an occult dural tear through which the herniation occurs progressively over time.5,6,10,12,20 Disc herniation may cause direct low-grade injury that weakens the dura, leading to a focal defect.6,12,13,29
Idiopathic spinal cord herniation is a rare but important and increasingly recognised cause of myelopathy seen in the thoracic spine. The factors that contribute to the aetiology of the condition and of the dural defect through which the cord herniates remain under debate. We discuss the clinical features and proposed pathophysiology of the condition, and illustrate key imaging findings on MRI, fluoroscopy and computed tomography (CT) myelography to establish the diagnosis, and discuss relevant differential diagnoses. Awareness and recognition of the condition is key as surgical intervention can improve outcomes for patients.
Late Cervical Spinal Cord Herniation Resulting from Post-Traumatic Brachial Plexus Avulsion Injury
2020, World Neurosurgery
Spinal cord herniation (SCH) is often described as occurring spontaneously in the thoracic spine, with few cases of cervical SCH reported as a late complication of traumatic brachial plexus avulsion. We present 2 cases of nerve root avulsion and pseudomeningocele formation, resulting in delayed cervical SCH and neurologic deterioration.
Case 1: A 37-year old man presented with progressive leg weakness 2 years after experiencing traumatic C8 and T1 root avulsions. Magnetic resonance imaging (MRI) showed previously documented C8–T1 nerve avulsions with new SCH in a T1 pseudomeningocele. A C7–T1 costotransversectomy and C4–T4 instrumented fusion were completed, allowing SCH reduction and patch graft repair of the dural defects without the need for adhesiolysis. At last follow-up, the patient's leg weakness had resolved. Case 2: A 32-year old man presented with progressive right arm numbness, weakness, and signs of myelopathy 9 years after experiencing C8 and T1 root avulsions. MRI showed previously documented root avulsions and new SCH with extensive and compressive pseudomeningocele formation. A C7 transpedicular approach with C5–T1 instrumented fusion was completed for dural repair. A large pseudomeningocele was found and drained on drilling the C7 pedicle, and adhesiolysis was required at the spinal cord avulsion site to reduce the SCH and allow patch graft repair. At last follow-up, the patient's right arm weakness was improving, although numbness persisted.
SCH is a rare cause of delayed neurologic deterioration after brachial plexus avulsion, with few case reports describing its occurrence. We present 2 cases of this complication and describe its successful surgical treatment through dural repair after instrumented fusion.
Failure of Surgery in Idiopathic Spinal Cord Herniation: Case Report and Review of the Literature
2020, World Neurosurgery
Idiopathic spinal cord herniation is a disorder in which the spinal cord herniates through a dural defect. We present a case in which both the standard surgical method and a salvage method failed.
A 36-year-old man presented with 2 years of progressive numbness and proximal hip flexion weakness of both lower extremities. Magnetic resonance imaging of the thoracic spine was suggestive for a ventral spinal cord herniation at the T6/7 level. He was initially treated with reduction of his cord herniation, placement of a ventral sling of collagen matrix over the dural defect to prevent re-herniation, with a laminoplasty. He developed a blood-pressure-dependent paraparesis that did not recover despite a return to the operating room (OR) for removal of the laminoplastic bone flap. He was again taken to the OR, the sling was removed and we enlarged the ventral dural defect rostrally and caudally to prevent strangulation of the hernia as described by Watanabe. Though in the short term he was able to recover and transfer to physical therapy, after going home he developed lower extremity weakness and low-pressure headaches. Magnetic resonance imaging showed a ventral epidural cerebrospinal fluid pocket retropulsing the spinal cord, as well as pockets of ventral cerebrospinal fluid collections remote from the surgery site. The patient returned to the OR and the initial surgery with the ventral sling was re-performed with resolution of the headaches; the patient was neurologically stable and transferred to rehabilitation. Long-term he developed left intercostal pain at the level of the surgery without radiological correlate.
In this patient there was no single satisfactory surgical treatment of his ventrally herniated spinal cord—partly related to the herniated component of the cord acting as a mass within a narrow canal at the apex of the thoracic kyphosis. We encountered previously unreported complications of the ventral defect widening technique of surgical treatment.
Surgical Management of Idiopathic Thoracic Spinal Cord Herniation
2019, World Neurosurgery
Idiopathic spinal cord herniation is a rare condition that involves spinal cord herniation through a defect in the ventral dura.
We present a case of a 61-year-old woman who initially presented in 2016 with an approximately 1-year history of burning right lower extremity pain and gait instability. Her neurologic examination was consistent with thoracic Brown−Sequard syndrome, and spinal magnetic resonance imaging showed a focal defect in the ventral dura at the superior aspect of T4 with the left aspect of the cord herniating into the defect. In 2018, she underwent a T3−T4 laminectomy with T3 pedicle take down and medial facetectomy, with reduction of the herniated cord.
Idiopathic spinal cord herniation is an uncommon spinal cord disorder with a paucity of data reported. Our case report of a classic case of idiopathic spinal cord herniation presenting as Brown−Sequard syndrome and managed surgically will contribute to the data in this field.
Duplication of Ventral Dura as a Cause of Ventral Herniation of Spinal Cord—A Report of Two Cases and Review of the Literature
2019, World Neurosurgery
Idiopathic spinal cord herniation (ISCH) is a treatable spinal disease. It is rare and often misdiagnosed, causing a delay in management. The etiology is multifactorial, with one of the causes being duplication of the ventral dura. The spinal cord herniates within this defect and becomes strangulated, causing neurological deficits. We report the duplication of a ventral spinal cord as an important cause of ISCH in our review.
We present 2 cases of ISCH with duplication of the dura, including their relevant clinical and imaging features. The patients underwent surgical reduction of the herniated spinal cord with enlargement of the defect and placement of a dural substitute ventral to the cord. We have also reported the outcomes of the 2 patients, with an emphasis on the factors predictive of poor outcomes (i.e., long-standing symptoms, a delay in intervention, poor neurological status at presentation, and a thinned out atrophic spinal cord found during surgery). We also reviewed the available data for duplication of the dura with ISCH.
Very few asymptomatic patients can be treated conservatively. The surgical outcomes have been favorable for symptomatic patients. Proper exposure, gentle manipulation while reducing the herniated spinal cord, enlargement of the defect, and the use of intraoperative monitoring will help limit the postoperative deficits. Duplication of the ventral dura is an important cause of ISCH. It prevents the formation of an anterior pseudomeningocele after surgery. Owing to the rarity of the disease and the lack of follow-up data with recurrence rates, it has not been possible to form clear guidelines for management.

View all citing articles on Scopus

View full text

SpineIdiopathic spinal cord herniation: a new theory of pathogenesis

Abstract

Backgound

Methods

Results

Conclusions

Section snippets

History and examination

Pathophysiology

Conclusion

J Orthop Sci

Idiopathic herniation of the thoracic spinal cordreport of three cases

Spine

Thoracic idiopathic spinal cord herniation at the vertebral body levela subgroup with a poor prognosis?

J Neurosurg (Spine 3)

Idiopathic spinal cord herniation. Presentation of a new case and review of the literature

Rev Neurol

Idiopathic spinal cord herniationa treatable cause of the Brown-Sequard syndrome: case report

Neurosurgery

Idiopathic spinal cord herniationvalue of MR phase-contrast imaging

AJNR Am J Neuroradiol

Idiopathic spinal cord herniationa treatable cause of Brown-Séquard syndrome

Acta Neurochir(Wien)

Spontaneous thoracic spinal cord herniation through an anterior dural defect

AJNR Am J Neuroradiol

Progressive spontaneous herniation of the thoracic spinal cordcase report

Neurosurgery

Idiopathic dural herniation of the thoracic spinal cord

Neuroradiology

Spinal cord herniation associated with an intradural spinal arachnoid cyst diagnosed by magnetic resonance imaging

Neurosurgery

Herniation of the spinal cord. Case report

J Neurosurg

Acute posttraumatic spinal cord herniation. Case report and review of the literature

J Neurosurg (Spine 2)

Idiopathic spinal cord herniationcase report and review of the literature

Neurosurgery

Idiopathic spinal cord herniationreport of eight cases and review of the literature

Spine

Spinal cord herniation into a congenital extradural arachnoid cyst causing Brown-Séquard syndrome

J Neurosurg

A case of idiopathic spinal cord herniation

Rinsho Shinkeigaku

Spine
Idiopathic spinal cord herniation: a new theory of pathogenesis