Idiopathic spinal cord herniation

Early detection of idiopathic thoracic ventral spinal cord herniation by using imaging: A case report

In middle-aged and older populations, clinicians often suspect lumbar spine disease when the gait is disturbed with lumbar lower extremity numbness, but spinal herniation at the thoracic level may be causal. Early detection, appropriate treatment, and minimization of complications requires understanding of characteristic magnetic resonance imaging findings of herniation.

Idiopathic Ventral Spinal Cord Hernia-A Single-Center Case Series of 11 Patients

BACKGROUND

Idiopathic spinal cord herniations (ISCH) are rare defects of the ventromedial or mediolateral dura mater with herniation of the spinal cord through the defect with approximately 350 described cases worldwide. Patients usually become symptomatic with motor or sensory neurological deficits and gait disturbances.

OBJECTIVE

To describe characteristic symptoms and clinical findings and to evaluate the postoperative course and outcomes of ISCH.

METHODS

We present a single-center data analysis of a case series of 11 consecutive patients who were diagnosed with ISCH and underwent surgery in our department between 2009 and 2021.

RESULTS

All herniations were located in the thoracic spine between T2 and T9. In most cases, gait ataxia and dysesthesia led to further workup and subsequently to the diagnosis of ISCH. A "far-enough" posterior-lateral surgical approach, hemilaminectomy or laminectomy with a transdural approach, was performed under intraoperative neurophysiological monitoring which was followed by adhesiolysis, repositioning of the spinal cord and sealing using a dura patch. After surgery, clinical symptoms improved in 9 of 11 patients (81.8%), while only 1 patient experienced deterioration of symptoms (9.1%) and 1 patient remained equal (9.1%). The median preoperative McCormick grade was 3 (±0.70), while the median postoperative grade was 2 (±0.98) ( P = .0047).

CONCLUSION

In our case series of ISCH, we found that in most patients, neurological deficits improved postoperatively. This indicates that surgery in ISCH should not be delayed in symptomatic patients.

Imaging of intraspinal cystic lesions: A review

Several distinct conditions present as cystic or pseudocystic lesions within the spinal canal. Some of the most common spinal cystic lesions include spinal meningeal cysts, juxtafacet cysts, dermoid/epidermoid cysts, nerve sheath tumors, and syringohydromyelia. Clinical presentation is usually nonspecific and imaging characteristics are frequently overlapping, which may pose a challenging presurgical diagnosis. We provide a pictorial review of cystic intraspinal lesions and discuss the main imaging features that can aid the neuroradiologist in the differential diagnosis. First, we propose a categorization of the lesions according to their location as extradural, intradural extramedullary, and intramedullary. This is a crucial initial step in the diagnostic workup and surgical planning. Second, for each of these locations, we organize the lesions according to their etiology: congenital and developmental disorders, degenerative disorders, traumatic or postsurgical collections, infectious conditions, neoplastic lesions, and other miscellaneous disorders. Finally, we summarize the clinical highlights and MR features that provide important insights for the differential diagnosis. MR is the technique of choice in presurgical evaluation and postsurgery follow-up. It provides accurate lesion localization and characterization and, most of the times, it will allow a confident differential diagnosis. High-resolution three-dimensional T2-weighted sequences and diffusion-weighted imaging can provide important hints in specific cases. Signal correlation with T1-weighted and fat-saturated sequences allows to differentiate true cystic lesions from hemorrhage or fat tissue.

Long-term Risks of Persistent Ventral Spinal CSF Leaks in SIH: Superficial Siderosis and Bibrachial Amyotrophy

BACKGROUND AND OBJECTIVES

Superficial siderosis, bibrachial amyotrophy, and spinal cord herniation are unusual but serious long-term sequelae of persistent spontaneous spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH), particularly ventral spinal CSF leaks. However, the risk of developing such sequelae has not been established in this population. We undertook this study to determine the risk of these serious complications of persistent ventral spinal CSF leaks.

METHODS

This cohort study was conducted using data from a prospectively maintained database of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. The patient population consisted of a consecutive group of patients with SIH and persistent ventral spinal CSF leaks who were first seen within 1 year of onset of SIH symptoms and who had at least 1 year of follow-up.

RESULTS

Among 51 patients with SIH and a persistent ventral spinal CSF leak, superficial siderosis developed in 6 patients and bibrachial amyotrophy in 2 patients during 280 patient-years of follow-up. The probability of these complications increased from 0% at 48 months to 4.5% (95% confidence interval [CI] 1.0%-28.0%) at 56 months, 10.5% (95% CI 3.0%-36.4%) at 96 months, 32.7% (95% CI 15.0%-62.8%) at 144 months, and 57.9% (95% CI 30.2%-87.6%) at 192 months. None of the patients developed spinal cord herniation.

DISCUSSION

Among patients with SIH and a persistent ventral spinal CSF leak, the risk of developing serious long-term sequelae is considerable. This study shows that early treatment of a ventral spinal CSF leak offers a unique opportunity to prevent neurologic disability from superficial siderosis and bibrachial amyotrophy.

Ventral Thoracic Spinal Cord Herniation: Clinical Image and Video Illustration of Microsurgical Treatment

Idiopathic spinal cord herniation is a rare cause of progressive myelopathy that can result in severe disability. In the following report, an illustrative case and associated video in the surgical management of ventral thoracic spinal cord herniation is presented and discussed. Spinal cord herniation is most commonly observed in the thoracic spine and is characterized by ventral displacement of the spinal cord through a defect in the dura. Over time ventral herniation of the spinal cord can compromise its vascular perfusion, resulting in further ischemic injury. The etiology is unclear, but suspected to be either acquired or congenital. Multiple surgical techniques have been reported with the goal of detethering the cord and taking adjunctive measures in reducing the risk for re-herniation. Surgical management of thoracic spinal cord herniation carries great risks, although neurological outcomes are generally favorable with improvements reported in the majority of cases.