Symptomatic interdural cerebrospinal fluid collections after surgery for idiopathic spinal cord herniation: illustrative case

BACKGROUND Idiopathic spinal cord herniation (ISCH) is very rare. Some reports have described postoperative ventral cerebrospinal fluid (CSF) collections in patients with ISCH; however, such collections are asymptomatic in most patients, and there is no consensus regarding whether they are part of the natural history or a complication. OBSERVATIONS A 30-year-old man with ISCH underwent direct closure of a duplicated dura mater. Eight months postoperatively, he developed reworsening of right lower limb paresis and new severe right arm pain and paresis. Three-dimensional magnetic resonance imaging revealed ventral CSF collections, which the authors judged as the responsible lesions. The authors initially considered these collections to be present in the epidural space, extradurally compressing the dural sac and resulting in myelopathy. An epidural blood patch failed; however, a CSF drainage test resulted in dramatic improvement. The authors therefore determined that the CSF collections were located in the interdural space, not the epidural space. A lumboperitoneal (LP) shunt was performed to reduce the CSF pressure. The patient’s symptoms improved immediately postoperatively. He had developed no recurrence of symptoms 6 months after surgery. LESSONS Ventral interdural CSF collections after ISCH surgery can cause reworsening of myelopathy and may be cured by a LP shunt to control CSF pressure.

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

Background and Objectives:Superficial siderosis, bibrachial amyotropy, 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 data base of patients who meet the modified International Classification of Headache Disorders (ICHD)-III 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 one year of onset of SIH symptoms and who had at least one year of follow-up.Results:Among 51 patients with SIH and a persistent ventral spinal CSF leak, superficial siderosis developed in six patients and bibrachial amyotropohy in two 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.

Coexisting protruding osteocyte and arachnoid cyst mimicking spinal cord herniation in a patient with Brown Sequard syndrome

This 68-year-old man presented with progressive spastic paraparesis of 2-month duration. The diagnosis was Brown-Sequard syndrome(BSS). Magnetic resonance imaging (MRI) revealed ventral displacement of the spinal cord at Th 7–8. The spinal cord deformity was dominant on the left side. He underwent surgery under the preoperative diagnosis of spinal cord herniation at Th 7–8. Intraoperatively we detected an arachnoid cyst and an osteophyte that compressed the spinal cord at Th 7–8 dorsally and ventrally rather than spinal cord herniation. Postoperative MRI showed successful spinal cord decompression. His neurological findings improved remarkably just after surgery. Although the misdiagnosis of spinal hernia in the actual presence of arachnoid cysts has been reported, ours is the first case of both, a lateralized osteophyte and an arachnoid cysts mimicking spinal cord herniation.

Minimally Invasive Approach for Dorsal Arachnoid Web: 2-Dimensional Operative Video

A 67-yr-old patient presented with severe paraparesis and lower limb spasticity. The spinal cord magnetic resonance imaging (MRI) revealed the “scalpel sign” 1,2 at the T7 level, suggesting a diagnosis of a dorsal arachnoid web. This video demonstrates a microsurgical technique for the excision of a dorsal arachnoid web with a minimally invasive approach. A paramedian skin incision, understanding the muscular aponeurosis, was performed from T7 to T8. Then, we inserted the tubular dilators until the lamina, to perform a muscle-sparing approach. An expandable tubular retractor of adequate length was passed over the widest dilator and docked into place along the subperiosteal plane. The T7 lamina was drilled, and the resection of the superior and inferior adjacent spine levels was completed with a rongeur. Additional contralateral bone resection was performed after tubular retractor tilt to the midline.3 After dura mater opening, it was carefully suspended and the dorsal arachnoid leaflet was cut to drain the dorsolateral and lateral spinal cisterns.4 The dorsal arachnoid web was, first, disconnected from its lateral anchorages. It was then gently removed with microsurgical forceps, to help its microdissection from the spinal cord surface. At this step, peculiar attention was paid to limit the traction or displacements of the spinal cord and surrounding vessels. Once the dorsal arachnoid web was removed, the quality of the spinal cord decompression was confirmed by its re-expansion. In conclusion, the minimally invasive approach is a safe and appropriate technique for dorsal arachnoid web excision.2,5,6-7 The patient gave her informed and signed consent for the writing and publication of this article. Image at 1:00 reused with permission from Castelnovo G et al, Spontaneous transdural spinal cord herniation, Neurology, 2014;82(14):1290.

Duroplasty in iatrogenic dorsal spinal cord herniation: illustrative case

BACKGROUND The case report detailed an unusual presentation of an iatrogenic dorsal cord herniation at the level of the thoracic cord after insertion of an epidural catheter 8 months before presentation to the neurosurgical clinic. OBSERVATIONS Only 13 cases of iatrogenic dorsal cord herniation, most of which occurred after spinal surgery, have been described in the literature. This was the first case of a spinal cord hernia described after the insertion of an epidural catheter. In this case study, the authors described a 38-year-old man who presented with progressive lower limb weakness, sensory deficits, perianal numbness, and urinary/fecal incontinence. He was diagnosed with a spinal cord hernia that reherniated after an initial sandwich duroplasty repair. Definitive repair was made after his re-presentation using an expansile duroplasty. LESSONS In patients with previous spinal instrumentation who present with neurological symptoms, spinal cord herniation should be considered a likely differential despite its rarity. In this case, a simple duroplasty was insufficient to provide full resolution of symptoms and was associated with recurrence. Perhaps a combination of graft and expansile duroplasty may be used for repair, especially when associated with a tethered cord and in the presence of significant adhesions.

Thoracic ventral spinal cord herniation with progressive myelopathy – A case report and review of the literature

Background: Idiopathic spinal cord herniation (ISCH) is a rare, underrecognized, and often misdiagnosed entity of unclear pathogenesis that typically presents as a slowly progressive thoracic myelopathy. There are less than 200 such cases reported in the literature. ISCH diagnosis and treatment are often delayed contributing to greater fixed neurological deficits, often leading to costly, unnecessary imaging studies, and inappropriate surgery. Case Description: Here, a 48-year-old female presented with trauma-induced ISCH characterized by gradually worsening lower extremity myelopathy. Conclusion: Idiopathic spinal cord herniation (ISCH) is rare, often underdiagnosed posttraumatic myelopathy that, when accurately diagnosed and treated, can result in good outcomes.