Migratory schwannoma of the cauda equina with a change in radicular pattern: illustrative case

BACKGROUND

Intradural spinal tumors are an uncommon entity with a variety of pathologies and symptom patterns. Few cases reports in the literature have described tumor migration within the spinal canal.

OBSERVATIONS

A 38-year-old male presented with bilateral upper lumbar radicular symptoms of anterior thigh pain, with an enhancing tumor of the cauda equina initially located at L1-2. He declined surgery initially, and at a follow-up 3 years later, his symptoms were unchanged but the tumor was now located at T12-L1. He again declined surgery, but 3 months later, he had a significant change in his pain distribution, which was now along his posterolateral right leg to his foot with associated dorsiflexion and extensor hallicus longus weakness. At this time, the tumor had migrated to L2-3. He underwent laminectomy and tumor resection with resolution of his radicular symptoms and improvement in his strength back to baseline by the 1-month follow-up. Pathology was consistent with a World Health Organization grade I schwannoma.

LESSONS

Migratory schwannoma is a rare entity but should be considered when radicular symptoms acutely change in the setting of a known intradural tumor. Repeat imaging should be performed to avoid wrong-level surgery. Intraoperative imaging can also be used for tumor localization.

Primary cauda equina lymphoma confirmed by autopsy: A case report

Compared with those involving the central nervous system, lymphomas involving the peripheral nervous system, namely neurolymphomatosis, are extremely rare. Neurolymphomatosis is classified as primary or secondary; the former is much rarer than the latter. Herein, we present an autopsied case of primary cauda equina lymphoma (PCEL), a type of primary neurolymphomatosis, with a literature review of autopsied cases of PCEL as well as primary neurolymphomatosis other than PCEL (non-PCEL primary neurolymphomatosis). A 70-year-old woman presented with difficulty walking, followed by paraplegia and then bladder and bowel disturbance. On magnetic resonance imaging, the cauda equina was diffusely enlarged and enhanced with gadolinium. The brainstem and cerebellum were also enhanced with gadolinium along their surface. The differential diagnosis of the patient included meningeal tumors (other than lymphomas), lymphomas, or sarcoidosis. The biopsy of the cauda equina was planned for a definite diagnosis, but because the patient deteriorated so rapidly, it was not performed. Eventually, she was affected by cranial nerve palsies. With the definite diagnosis being undetermined, the patient died approximately 1.5 years after the onset of disesase. At autopsy, the cauda equina was replaced by a bulky mass composed of atypical B-lymphoid cells, consistent with diffuse large B-cell lymphoma (DLBCL). The spinal cord was heavily infiltrated, as were the spinal/cranial nerves and subarachnoid space. There was metastasis in the left adrenal. The patient was finally diagnosed postmortem as PCEL with a DLBCL phenotype. To date, there have been a limited number of autopsied cases of PCEL and non-PCEL primary neurolymphomatosis (nine cases in all, including ours). The diagnosis is, without exception, B-cell lymphoma including DLBCL, and the histology features central nervous system parenchymal infiltration, nerve root involvement, and subarachnoid dissemination (lymphomatous meningitis). Metastases are not uncommon. All clinicians and pathologists should be aware of lymphomas primarily involving the peripheral nervous system.

Lightning strike‑induced cauda equina syndrome: a case report

Peripheral nerve injuries after being struck by lightning have been documented. Here, we report a case of cauda equina syndrome induced by lightning. A 27-year-old man presented with numbness, a burning sensation in the saddle region, and increased urinary urgency after being struck by lightning. He had absent Achilles reflexes and paresthesia in the saddle region upon neurological examination, and magnetic resonance imaging of the spine was normal. Electrophysiological studies indicated involvement of bilateral L5, S1, and S2 myotomes and revealed cauda equina lesions. 
Peripheral nerve injury induced by lightning is rare, and the evaluation of people with neurological complaints using electromyography will help determine the true incidence.

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Severe low back pain with mild leg symptoms due to lumbar spine stenosis

BACKGROUND

Some patients with lumbar spine stenosis (LSS) have severe low back pain (LBP) with only mild leg symptoms. The effects of decompression surgery for such patients remain unknown.

METHODS

Of 818 patients with LSS who underwent surgical treatment in our institution from 2011 to 2019, eight patients had a numeric rating scale (NRS) score of ≥7 for LBP and 3≤ for leg pain. The patients' age, sex, clinical characteristics, preoperative leg symptoms, and level of LSS were investigated. The detailed characteristics of LBP, such as the disease duration, location of LBP, and exacerbating factors, were obtained from each patient. The NRS and Japanese Orthopaedic Association (JOA) scores for LBP were evaluated on admission, at 1 and 3 months postoperatively, and at the final follow-up (>1 year postoperatively).

RESULTS

All patients were male with a mean age of 71.5 years (range, 57-82 years). LBP was exacerbated during walking in six patients and during an extension posture in three patients. The median duration of LBP was 2.9 years (range, 0.3-7 years). The stenosis was located at L2/3 in three patients, L3/4 in five patients, and L4/5 in seven patients. The stenosis involved one level in three patients and more than two levels in five patients. Other pathologies, such as sacroiliac joint lesions, facet pain, superior/middle cluneal nerve pain, and discogenic pain, were excluded by diagnostic anesthetic block and detailed physical examination. All patients underwent posterior decompression surgery without fusion. In all eight patients, the NRS score for LBP significantly improved from 7.6 (range, 7-10) to 1.7 (range, 0-3) and the JOA score improved from 13.1 (range, 4-19) to 21.8 (range, 18-27).

CONCLUSION

A low proportion of patients showed walking-evoked severe LBP with mild leg symptoms due to lumbar spine stenosis. The patients' pain was improved by decompression surgery with satisfactory results.

Rosai-Dorfman disease of the cauda equina: illustrative case

BACKGROUND

Rosai-Dorfman disease (RDD) is a rare, nonmalignant histiocytosis. It typically occurs in lymph nodes, skin, and soft tissues, but numerous reports of central nervous system involvement exist in the literature. The peripheral nervous system has rarely been involved. In this study, the authors present a case of RDD isolated to the cauda equina. The presentation, management, surgical technique, and adjunctive treatment strategy are described.

OBSERVATIONS

A 31-year-old female presented with 6 months of progressive left lower-extremity numbness involving the lateral aspect of the foot and weakness of the left toes. Magnetic resonance imaging of the lumbar spine demonstrated a homogeneously enhancing intradural lesion involving the cauda equina at the L2-3 levels. Histopathology after resection revealed a histiocytic infiltrate, positive for CD68 and S100, and emperipolesis consistent with RDD. No adjuvant therapy was administered, and the patient had full remission at the 1-year follow-up. Only five other cases of intradural RDD lesions of the cauda equina have been reported in the literature.

LESSONS

RDD of the cauda equina is an especially rare and challenging diagnosis that can mimic other dura-based lesions, such as meningiomas. A definitive diagnosis of RDD relies on pathognomonic histopathological and immunohistochemical findings.

Intramedullary Epidermoid Cyst of the Conus Medullaris: A Case Report and Literature Review

Background

Central nervous system tumors are usually located in the brain, and spinal cord tumors account for approximately 20% of central nervous system tumors. Epidermoid cysts constitute <1% of all intraspinal tumors. It consists of squamous epithelial-lined cysts containing keratin, cholesterol, and cellular granules. Epidermoid cysts can be classified as congenital, acquired, extradural, extramedullary, or intramedullary according to etiology and location. The intradural intramedullary type is uncommon.

Case Presentation

An 11-year-old female patient had back pain with radiation to both lower extremities but worsened on the left side for 5 years. On neurological examination, motor strength was 3/5 for hip flexion and knee extension bilaterally and 5/5 for other key muscle groups. Contrast-enhanced lumbosacral magnetic resonance imaging (MRI) revealed T1 hypointense and T2 hyperintense lesions in the L2-L4 intramedullary conus and cauda equina. Laminectomy and near total resection were done, and histopathological examination revealed an epidermoid cyst. On the third postoperative day, the patient was discharged with completely resolved back pain and an improvement in lower extremity motor power. At monthly follow-up visits for a further 6 months, her back pain and weakness completely resolved, and she had no neurologic deficits. A postoperative lumbosacral MRI was done and confirmed near total excision of the tumor.

Conclusion

Intramedullary conus epidermoid cysts are rare but not unknown to neurosurgeons. MRI with diffusion-weighted images (DWI) is an imaging modality of choice. Asymptomatic patients can be conservatively treated. Once the patient has progressive symptoms and signs of compression, surgical excision is recommended. Meticulous electrocauterization may help decrease tumor regrowth in the remnant capsule, which is recommended. Avoiding leakage of cyst fluid into the subarachnoid space helps to avoid postoperative chemical meningitis. Radiotherapy is an option for the management of multiple recurrences.

Anatomical considerations regarding a high-flow arteriovenous fistula below the conus medullaris in a patient with hereditary hemorrhagic telangiectasia: Case report

BACKGROUND AND IMPORTANCE

Cauda equina radicular arteriovenous fistulas are rare "low flow" shunting lesions characterized by direct communication between the radicular artery and vein of a cauda equina nerve root. None have been associated with hereditary hemorrhagic telangiectasia and a high-flow cauda equina radicular arteriovenous fistula has never been reported. We present a unique case of a high-flow cauda equina radicular arteriovenous fistula in a patient with hereditary hemorrhagic telangiectasia. Marked flow-induced vascular remodeling posed significant diagnostic and therapeutic challenges which will be highlighted in this report.

CLINICAL PRESENTATION

A 39-year-old female with genetically confirmed hereditary hemorrhagic telangiectasia presented with progressive thoracic myelopathy secondary to a high-flow single-hole arteriovenous fistula below the conus. The feeding artery, arising from the anterior spinal artery, and draining vein had a paramedian course, favoring the diagnosis of a cauda equina radicular arteriovenous fistula (supplied by a proximal radicular artery) over a filum terminale arteriovenous fistula. Transarterial embolization was attempted but significant elongation and tortuosity of the anterior spinal artery precluded microcatheter access to the fistulous point. Surgical disconnection was successfully performed. The intraoperative findings supported the diagnosis of cauda equina radicular arteriovenous fistula. Delayed neurologic deterioration secondary to overshooting venous thrombosis was observed. She recovered after the initiation of therapeutic anticoagulation.

CONCLUSION

To the best of our knowledge, we hereby report the first high-flow cauda equina radicular arteriovenous fistula. The accurate differentiation of cauda equina radicular arteriovenous fistula from filum terminale arteriovenous fistulas, while challenging, is important to avoid treatment-related complications. Careful preoperative planning, the use of specialized endovascular and surgical techniques, and meticulous postoperative care can ensure the safe and complete disconnection of high-flow cauda equina radicular arteriovenous fistulas.

Primary Malignant Lymphoma of the Cauda Equina Diagnosed after Decompression for Lumbar Spinal Stenosis: A Case Report

Primary malignant lymphoma confinement to the cauda equina is rare. Only 14 cases of primary malignant lymphoma in the cauda equina have been reported. In these cases, the clinical features were similar to those of lumbar spinal canal stenosis (LSCS). This report describes a case of diffuse large B-cell lymphoma of the cauda equina that was diagnosed after decompression surgery for LSCS. An 80-year-old man presented with gait disturbance due to progressive muscle weakness in the lower extremities over the previous two months. He was diagnosed with LSCS, and decompression surgery was performed. However, the muscle weakness worsened after surgery; therefore, he was referred to our department. Plain magnetic resonance imaging (MRI) revealed swelling of the cauda equina. It demonstrated marked homogenous enhancement by gadolinium-diethylenetriamine pentaacetic acid. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) revealed diffuse accumulation of 18F-FDG in the cauda equina. These imaging findings were consistent with those of cauda equina lymphomas. To confirm the diagnosis, we performed an open biopsy of the cauda equina. Histological examination indicated diffuse large B-cell lymphoma. Considering the patient's age and activities of daily living, further treatment was not performed. The patient died four months after the first surgery. Rapid progression of muscle weakness, which cannot be prevented by decompression surgery, and swollen cauda equina on MRI may be signs of this disorder. Gadolinium-enhanced MRI, 18F-FDG PET, and histological investigation of the cauda equina should be performed for diagnosing primary malignant lymphoma of the cauda equina.

Case Report and Literature Review: Lumbar Disc Extrusion Misdiagnosed as an Epidural Hematoma

Accurate differentiation between epidural hematomas and lumbar disc extrusion is essential due to the potential overlap in clinical presentations. We present a case report highlighting a significant challenge in which a massive lumbar disc extrusion was mistaken for an epidural hematoma. This is a case report of a 38-year-old male patient who developed cauda equina syndrome four days after experiencing an audible cracking in the lower back during weightlifting activity. Magnetic resonance imaging (MRI) was inconclusive, unable to distinguish between an extruded nucleus pulposus and a spinal epidural hematoma. Subsequently, an urgent operation revealed a large herniated disc at the L4-L5 level, ruling out any hematoma. The patient's post-operative follow-up showed significant improvement, with almost complete recovery of motor and sensory functions. This case emphasizes the challenges faced when distinguishing between epidural hematomas and lumbar disc herniations, particularly on MRI. The lumbar disc herniation's substantial size, cranial and caudal migration on multiple levels, and signal intensity contributed to the misdiagnosis, underscoring the importance of careful interpretation and awareness of such complexities.

Stereotactic body radiation therapy to the spine: contouring the cauda equina instead of the spinal cord is more practical as the organ at risk

Background

Stereotactic body radiotherapy (SBRT) is recognized as a curative treatment for oligometastasis. The spinal cord becomes the cauda equina at the lumbar level, and the nerves are located dorsally. Recently, a consensus has been reached that the cauda equina should be contoured as an organ at risk (OAR). Here, we examined the separate contouring benefits for the spinal canal versus the cauda equina only as the OAR.

Materials and methods

A medical physicist designed a simulation plan for 10 patients with isolated lumbar metastasis. The OAR was set with three contours: the whole spinal canal, cauda equina only, and cauda equina with bilateral nerve roots. The prescribed dose for the planning target volume (PTV) was 30 Gy/3 fx.

Results

For the constrained QAR doses, D90 and D95 were statistically significant due to the different OAR contouring. The maximum dose (Dmax) was increased to the spinal canal when the cauda equina max was set to ≤ 20 Gy, but dose hotspots were observed in most cases in the medullary area. The Dmax and PTV coverage were negatively correlated for the cauda equina and the spinal canal if Dmax was set to ≤ 20 Gy for both.

Conclusions

A portion of the spinal fluid is also included when the spinal canal is set as the OAR. Thus, the PTV coverage rate will be poor if the tumor is in contact with the spinal canal. However, the PTV coverage rate increases if only the cauda equina is set as the OAR.

Ancient Schwannoma Presenting at the Cauda Equina: A Report of a Rare Case

Ancient schwannoma is an uncommon variant of schwannoma. While many reports have presented defining histologic and clinical features of ancient schwannoma, there are only a very few cases in the literature, to our knowledge, of ancient schwannoma presenting at the cauda equina. The current report of ancient schwannoma presenting at the cauda equina adds to the literature and discusses the identification of specific histologic characteristics, the role of conservative medical management, surgical resection, and prognostication in this select subset of patients.

Acute Necrotizing Encephalitis Due to Influenza B in a Child: A Case Report

Acute necrotizing encephalitis (ANE) is a rare and life-threatening form of encephalitis associated with influenza virus and other pathogens. It is characterized by a rapid onset of neurological symptoms and has been linked to a cytokine storm within the brain. We present a unique case of an eight-year-old female with influenza B-associated ANE, involving multiple brain areas including the cerebellum and brainstem and cauda equina involvement. The patient had a rapid neurological deterioration, and MRI findings revealed extensive multifocal areas of abnormal brain parenchyma and inflammation with Guillain-Barre appearance in the cauda equina. To the best of our knowledge, this is the first reported case of ANE with cauda equina involvement leading to neurological deficits. Despite treatment with oseltamivir, steroids, and intravenous immunoglobulins, the patient had poor neurological outcomes, similar to those reported in the literature.

Cholesterol granuloma associated with degenerative neuropathy in the cauda equina of a dog

An 8-y-old Labrador Retriever dog had mild ataxia of the hindlimbs 4 mo after lumbosacral dorsal laminectomy for intervertebral disk disease. Ataxia of the hindlimbs gradually worsened over the next 6 y. On autopsy, gross lesions were not recognized in the spinal cord. Histopathology revealed an intradural extraparenchymal cholesterol granuloma in the cauda equina associated with remnant nerve roots. Nerves associated with the cholesterol granuloma had axonal degeneration, myelin vacuolation, and edema. In those foci, macrophages were increased in number between nerve fibers. Immunohistochemistry for neurofilament protein and Luxol fast blue staining highlighted the presence of remnant axons and myelin sheaths within the granuloma. Inflammatory cell infiltrates in the granuloma were mainly macrophages and CD3- or CD20-immunopositive T or B lymphocytes, respectively. We conclude that the cholesterol granuloma likely formed subsequent to degenerative neuropathy in the cauda equina.

Lumbar Schwannoma as a Rare Cause of Radiculopathy in the Chiropractic Office: A Case Report

Cauda equina tumors are rare, slow-growing, and typically benign. These tumors present with low back pain resembling disc displacement with radiculopathy and thus may go undiagnosed for months. A 52-year-old, otherwise healthy man presented to a chiropractor with a one-year history of worsening low back pain radiating to the right lower extremity, rated an 8/10 in severity and aggravated by recumbency. Previously, his primary care physician had ordered radiographs revealing mild lumbar degenerative changes, prescribed a non-steroidal anti-inflammatory medication, and referred him to an orthopedist and physical therapist. There had been no change in symptoms. Upon examination by the chiropractor, the patient had neurologic deficits, and due to progressive worsening, the chiropractor recommended magnetic resonance imaging (MRI), which the patient deferred due to cost. The chiropractor initiated a trial of care, with initial success; however, the patient's symptoms recurred, and he consented to an MRI. MRI revealed an intradural extramedullary lumbar tumor, and the chiropractor referred the patient to an oncologist, who referred the patient to a neurosurgeon. The neurosurgeon surgically removed the mass, with a biopsy confirming a schwannoma. The patient had significantly improved six weeks after surgery. This case highlights a patient with chronic low back pain for whom a chiropractor identified a cauda equina tumor and referred him for further evaluation and surgery. Clinicians should consider night pain and persistent symptoms, despite conservative care, as red flags warranting further investigation in those with low back pain. Providers should refer for neurosurgical evaluation when clinical and radiological findings suggest a cauda equina tumor.

Iatrogenic CSF Leak from CT Myelogram Leading to Cauda Equina Compression: A Case Report

Introduction

Although magnetic resonance imaging (MRI) is the preferred imaging modality for diagnosing cauda equina syndrome (CES), computerized tomography (CT) myelogram may be used in patients who are unable to undergo MRI. When inserting the needle for CT myelogram, there is a risk of cerebrospinal fluid (CSF) leak, which theoretically could lead to CES. To the best of our knowledge, there are no reports of CT myelogram resulting in cauda equina compression.

Case Report

We report the case of a 38-year-old man who underwent surgical decompression for CES and developed an iatrogenic CSF leak from a pre-operative CT myelogram causing recurrent thecal sac compression requiring repeat surgery and dural repair.

Conclusion

Although CT myelogram may be used to aid in the diagnosis of CES, consideration should be given to the potential risk for causing a CSF leak and resultant thecal sac compression.

The brain of the tree pangolin (Manis tricuspis). X. The spinal cord

The spinal cord of the tree pangolin is known to be very short compared to the overall length of the body and tail. Here, we provide a description of the tree pangolin spinal cord to determine whether the short length contributes to specific structural, and potentially functional, differences. The short spinal cord of the adult tree pangolin, at around 13 cm, terminates at the midthoracic level. Within this shortened spinal cord, we could identify six regions, which from rostral to caudal include the prebrachial, brachial, interramal, crural, postcrural, and caudal regions, with both the brachial and crural regions showing distinct swellings. The chemoarchitecture of coronal sections through these regions confirmed regional assignation, being most readily delineated by the presence of cholinergic neurons forming the intermediolateral column in the interramal region and the sacral parasympathetic nucleus in the postcrural region. The 10 laminae of Rexed were observed throughout the spinal cord and presented with an anatomical organization similar to that observed in other mammals. Despite the shortened length of the tree pangolin spinal cord, the regional and laminar anatomical organization is very similar to that observed in other mammals. This indicates that the functional aspects of the short tree pangolin spinal cord can be inferred from what is known in other mammals.

Elsberg Syndrome, Lumbosacral Radiculopathy, and Myelitis Due to Herpes Zoster in a Patient With Smoldering Myeloma

Herpes zoster (HZ) is a common illness caused by the reactivation of latent varicella zoster virus (VZV) due to waning immunity, often secondary to old age or an underlying immunocompromised state. Its complications can manifest in variety of ways, including persistent neuralgias, vasculopathies, and stroke. Here, we describe a case of a 45-year-old man with a history of cryptogenic stroke and smoldering myeloma who was admitted with sacral HZ complicated by right lumbosacral radiculopathy and myelitis, otherwise known as Elsberg syndrome (ES). He was found to have an enhancing lesion in the peripheral conus medullaris on magnetic resonance imaging (MRI) with nonspecific inflammation and necrosis on biopsy pathology and cerebrospinal fluid (CSF) polymerase chain reaction (PCR) positive for VZV. The patient was initially treated with intravenous acyclovir and dexamethasone and discharged with a steroid taper and indefinite valacyclovir therapy. Twelve months postdischarge, the patient’s right lumbosacral radiculopathy and myelitis had almost completely resolved; however, he continued to require bladder self-catheterization. We believe that the patient’s underlying smoldering myeloma lead to an immunocompromised state, allowing for reactivation of latent VZV, resulting in both the patient’s cryptogenic stroke years earlier and recent ES.

Hemangioblastoma of the Cauda Equina : A Case Report and Review of the Literature

Introduction : Hemangioblastoma in the spine mainly occurs at the cervical and thoracic levels and is often associated with von Hippel-Lindau (VHL) syndrome. Here, we reported a quite rare case of spinal sporadic hemangioblastoma arising from the cauda equina. Case presentation : A 66-year-old woman presented with a 5-year history of low back and leg pain. Imaging revealed a hypervascular intradural extramedullary tumor in the lumbar region. Preoperative angiography helped to identify the feeding arteries and draining vein, and so facilitated subsequent tumor resection. The pain was dramatically improved but weakness of the left tibialis anterior and left extensor hallucis longus muscles persisted. Discussion : We reported a rare case of spinal hemangioblastoma arising from the cauda equina. Preoperative angiography may be useful for diagnosis and understanding of the anatomy of feeding veins. J. Med. Invest. 69 : 312-315, August, 2022.

Jmjd3 Mediates Neuropathic Pain by Inducing Macrophage Infiltration and Activation in Lumbar Spinal Stenosis Animal Model

Lumbar spinal stenosis (LSS) is a major cause of chronic neuropathic back and/or leg pain. Recently, we demonstrated that a significant number of macrophages infiltrated into the cauda equina after compression injury, causing neuroinflammation, and consequently mediating neuropathic pain development and/or maintenance. However, the molecular mechanisms underlying macrophage infiltration and activation have not been elucidated. Here, we demonstrated the critical role of histone H3K27 demethylase Jmjd3 in blood-nerve barrier dysfunction following macrophage infiltration and activation in LSS rats. The LSS rat model was induced by cauda equina compression using a silicone block within the epidural spaces of the L5-L6 vertebrae with neuropathic pain developing 4 weeks after compression. We found that Jmjd3 was induced in the blood vessels and infiltrated macrophages in a rat model of neuropathic pain. The blood-nerve barrier permeability in the cauda equina was increased after compression and significantly attenuated by the Jmjd3 demethylase inhibitor, GSK-J4. GSK-J4 also inhibited the expression and activation of MMP-2 and MMP-9 and significantly alleviated the loss of tight junction proteins and macrophage infiltration. Furthermore, the activation of a macrophage cell line, RAW 264.7, by LPS was significantly alleviated by GSK-J4. Finally, GSK-J4 and a potential Jmjd3 inhibitor, gallic acid, significantly inhibited mechanical allodynia in LSS rats. Thus, our findings suggest that Jmjd3 mediates neuropathic pain development and maintenance by inducing macrophage infiltration and activation after cauda equina compression and thus may serve as a potential therapeutic target for LSS-induced neuropathic pain.

Intradural lumbar radicular arteriovenous malformation mimicking perimedullary arteriovenous malformation of the conus medullaris: illustrative case

BACKGROUND

Intradural radicular arteriovenous malformation (AVM) of the cauda equina is a rare entity of spinal AVMs. Because of the specific arterial supply of the conus medullaris and cauda equina, AVMs in this area sometimes present with confusing radiological features.

OBSERVATIONS

The authors reported a rare case of intradural radicular AVM arising from the lumbar posterior root. The patient presented with urinary symptoms with multiple flow void around the conus medullaris, as shown on magnetic resonance imaging. Digital subtraction angiography demonstrated arteriovenous shunt at the left side of the conus medullaris fed by the anterior spinal artery via anastomotic channel to the posterior spinal artery and rich perimedullary drainers. There was another arteriovenous shunt at the L3 level from the left L4 radicular artery. Preoperative diagnosis was perimedullary AVM with radicular arteriovenous fistula. Direct surgery with indocyanine green angiography revealed that the actual arteriovenous shunt was located at the left L4 posterior root. The AVM was successfully treated by coagulation of feeding branches.

LESSONS

Unilateral arteriovenous shunt fed by either posterior or anterior spinal artery at the conus medullaris may include AVM of the cauda equina despite abundant perimedullary venous drainage. Careful pre- and intraoperative diagnostic imaging is necessary for appropriate treatment.

Platelet-Rich Plasma for the Treatment of Degenerative Lumbosacral Stenosis: A Study with Retired Working Dogs

Traditionally, canine degenerative lumbosacral stenosis (DLS) has been defined as a multifactorial syndrome characterized by lumbosacral pain triggered by the compression of the nerve rootlets of the cauda equina. There is still no consensus on the treatment of this condition, probably because there are a plethora of possible causes. In addition to compression, inflammation is a very important factor in the physiopathology of the disorder. Platelet-rich plasma (PRP) consists of an increased concentration of autologous platelets suspended in a small amount of plasma. Platelets are a source of several growth factors. Growth factors were shown to help in wound healing and biological processes, such as chemotaxis, neovascularization and synthesis of extracellular matrix, and growth factors were used to improve soft tissue healing and bone regeneration. PRP also facilitates the restoration of the structural integrity of the affected anatomy. Fourteen dogs diagnosed with DLS were treated with three epidural injections of PRP on days 0, 15 and 45. All dogs showed clinical improvement 3 months after the initial treatment. Gait was also objectively assessed by means of the use of force platform analysis before and after treatment, showing significant improvement. The results show that PRP may provide a good alternative to other nonsurgical treatments, such as prednisolone epidural injection.

Perineural spread of peripheral neurolymphomatosis to the cauda equina

OBJECTIVE

Neurolymphomatosis (NL) is a rare manifestation of lymphoma confined to the peripheral nervous system that is poorly understood. It can be found in the cauda equina, but extraspinal disease can be underappreciated. The authors describe how extraspinal NL progresses to the cauda equina by perineural spread and the implications of this on timely and safe diagnostic options.

METHODS

The authors used the Mayo Clinic medical records database to find cases of cauda equina NL with sufficient imaging to characterize the lumbosacral plexus diagnosed from tissue biopsy. Demographics (sex, age), clinical data (initial symptoms, cerebrospinal fluid, evidence of CNS involvement, biopsy location, primary or secondary disease), and imaging findings were reviewed.

RESULTS

Ten patients met inclusion and exclusion criteria, and only 2 of 10 patients presented with cauda equina symptoms at the time of biopsy, with 1 patient undergoing a cauda equina biopsy. Eight patients were diagnosed with diffuse large B-cell lymphoma, 1 with low-grade B-cell lymphoma, and 1 with mantle cell lymphoma. Isolated spinal nerve involvement was identified in 5 of 10 cases, providing compelling evidence regarding the pathophysiology of NL. The conus medullaris was not radiologically involved in any case. Lumbosacral plexus MRI was able to identify extraspinal disease and offered diagnostically useful biopsy targets. FDG PET/CT was relatively insensitive for detecting disease in the cauda equina but was helpful in identifying extraspinal NL.

CONCLUSIONS

The authors propose that perineural spread of extraspinal NL to infiltrate the cauda equina occurs in two phases. 1) There is proximal and distal spread along a peripheral nerve, with eventual spread to anatomically connected nerves via junction and branch points. 2) The tumor cells enter the spinal canal through corresponding neural foramina and propagate along the spinal nerves composing the cauda equina. To diffusely infiltrate the cauda equina, a third phase occurs in which tumor cells can spread circumdurally to the opposite side of the spinal canal and enter contralateral nerve roots extending proximally and distally. This spread of disease can lead to diffuse bilateral spinal nerve disease without diffuse leptomeningeal spread. Recognition of this phasic mechanism can lead to identification of safer extraspinal biopsy targets that could allow for greater functional recovery after appropriate treatment.

Microsurgical resection of giant T11/T12 conus cauda equina schwannoma

In this video, we highlight the anatomy involved with microsurgical resection of a giant T11/T12 conus cauda equina schwannoma. Spinal schwannoma remains the third most common intradural spinal tumor. Tumors undergoing gross total resection usually do not recur. To our knowledge, this is the first video case report of giant cauda equina schwannoma resection. A 55-year-old female presented with paraparesis and urinary retention. Lumbar spine MRI revealed a contrast-enhancing intradural extramedullary tumor at the T11/T12 level. Surgery was performed in the prone position with intraoperative neurophysiology monitoring (somatosensory and motor evoked potentials-SSEPs and MEPs). T11/T12 laminectomies were performed. After opening the dura and arachnoid, the tumor was found covered with cauda equina nerve roots. We delineated the inferior pole of the tumor, followed by opening of the capsule and debulking the tumor. Subsequently, the cranial pole was dissected from the corresponding cauda equina nerve roots. Finally, the tumor nerve origin was identified and divided after nerve stimulation confirmed the tumor arose from a sensory nerve root. The tumor was removed; histological analysis revealed a schwannoma (WHO Grade I). Postoperative MRI revealed complete resection. The patient fully recovered her neurological function. This case highlights the importance of careful microsurgical technique and gross total resection of the tumor in the view of favorable postoperative neurological recovery of the patient. Intraoperative use of ultrasound is helpful to delineate preoperatively tumor extension and confirm postoperative tumor resection.

Acute neurologic decline in a patient with spinal stenosis: blame it on the epidural fat

Spinal epidural lipomatosis [SEL] is defined as an excessive accumulation of extradural normal adipose tissue. This condition may be idiopathic or acquired. Surgical decompression is considered the gold standard treatment in patients presenting with progressive neurologic deficit. We report a case of a 69-year-old male patient presented with neurogenic claudication and lower left limb radiculopathy. The magnetic resonance imaging (MRI) revealed a L5-S1 epidural compression sustained by a large epidural plaque whose signal was consistent with adipose tissue. A conservative approach, including weight loss attempt, revealed unsuccessful and the patient presented some months after the diagnosis at the emergency department with acute onset bilateral drop foot, more severe on the right side and urinary disturbances. Microsurgical decompression via L5 laminectomy and partial L4 laminectomy and fatty plaque debulking was performed. The post operative course was uneventful and at the two months post operative follow up the patient reported a significative improvement of the pre operative neurological signs and symptoms and of pain control. SEL deserves attention as an identifiable cause of radiculopathies, typically attributed to spinal stenosis, with a higher incidence than previously reported. Moreover cases of acute onset of cauda equina like syndrome were reported in patent affected by SEL, probably related to a local venous engorgement with stasis and edema. Therefore it should be considered as a possible diagnosis not only in patients complaining of stenosis-type symptoms but also in cases of acute neurological decline with cauda equina like syndrome, especially when provided with a "benign" imaging reading.

Prevalence of lumbosacral transitional vertebrae in dogs in Berlin

Lumbosacral transitional vertebrae (LTV) are abnormally formed vertebrae of congenital origin. Dogs with LTV are predisposed to premature degeneration of the lumbosacral spine and hip dysplasia due to a weakened sacroiliac attachment. Moreover, LTV has been discussed as a cause of cauda equina syndrome. To date, LTV remain poorly understood and a diagnostic standard is yet to be established. This study examines prevalence, types and breed predispositions for LTV in the canine population in Berlin. The diagnostic value of laterolateral radiographs of the lumbosacral region, in addition to ventrodorsal radiographs, was also evaluated. The prevalence of LTV was assessed by reviewing ventrodorsal pelvic radiographs of 1030 dogs. LTV were detected in 95 (9.2%) dogs. The prevalence was higher in Pugs (63.6%) and Jack Russel Terriers (27.6%) than in the other breeds. The most common type of LTV was type II (37.9%), showing separation of the first sacral segment from the sacrum, the presence of a rudi-mentary intervertebral space between the first sacral segment and the rest of the sacrum, and symmetrically formed transverse processes. Laterolateral radiographs were available for 66 of 95 dogs with LTV and provided evidence of a rudimentary intervertebral disc space between the first and second sacral vertebrae in all cases of LTV type II and III (100%). The results of this study contribute to a better understanding of the condition. Furthermore, they demonstrate that laterolateral radiographs are a valuable addition to standard ventrodorsal radiographs and should be included in routine LTV screening protocols to provide a complete evaluation.

A Systematic Review of the Value of a Bladder Scan in Cauda Equina Syndrome Diagnosis

Cauda equina syndrome (CES) is one of the emergency conditions that can lead to devastating permanent functional disabilities, if misdiagnosed. Multiple studies have questioned the reliability of clinical assessment in diagnosing CES, whether some of the features should be considered to be potential red flags. Bladder dysfunction can reflect CE compromise. The post-void residual (PVR) volume bladder scan is useful in CES diagnosis, but to date there has been no single systematic review supporting its use. Furthermore, there is no clear cut-off point to consider PVR statistically significant. The aim of the study is to perform a systematic review of the current evidence behind the use of the PVR bladder scan as a diagnostic tool for CES diagnosis. This was a comprehensive search using Medline, PubMed and Embase. All articles included post-void bladder scans with the mentioned clear cut-off volume as a diagnostic parameter. A total of five study articles from 1955 fit with our inclusion and exclusion criteria. The total number of patients who had a bladder scan was 531. CES was confirmed in 85 cases. Bladder scan diagnosed 70 cases and excluded 327. The best results for both sensitivity and specificity in correlation with the sample of the study were for PVR more than 200 ml. Measuring the post-void urine volume using a bladder scan is an essential tool in the diagnosis of CES. There is a significant correlation between the PVR volume more than 200 ml and higher sensitivity and specificity.

Soft Tissue Extramedullary Plasmacytoma Leading to Cauda Equina Syndrome: Case Presentation and Clinical Considerations

Cauda equina syndrome (CES) is a rare neurological emergency that requires prompt diagnosis and immediate surgical intervention for the best potential patient outcome. CES results from the compression of spinal roots along the lower spine usually at the level of L2 or below. It typically presents with severe low back pain, pain radiating to lower extremities, motor weakness, sensory loss, saddle anesthesia, bladder and bowel dysfunction. It is most commonly caused by a large central intervertebral disc herniation or central canal spinal stenosis but can also occur on occasion from abscesses, neoplasms, and inflammatory conditions. If the patient's symptoms are overlooked and surgical intervention is delayed there is a risk for long-term damage to neurological function. Here, we will present a case of a 46-year-old female with a long-standing history of back pain that presented to her primary care office with worsening back pain symptoms as well as a new presentation of urinary incontinence. A prompt MRI confirmed CES and the patient was advised to report to the nearest ED. At the hospital, neurosurgeons performed a laminectomy and found a mass along L3 that was compressing the cauda equina and associated nerve roots. The pathology of the mass revealed an extramedullary plasmacytoma (EMP) that was later determined to originate from the right psoas muscle. The case provides insight into the patient's presentation of CES and the key differentiating factors that led the medical care team to order the appropriate work up and prevent the long-term complications associated with an untreated CES.

Magnetic resonance tractography of the lumbosacral plexus: Step-by-step

ABSTRACT

MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).The fiber bundles reconstruction was optimized in terms of eliminating the muscle fibers contamination using the segmentation of cauda equina, the effects of the normalized quantitative anisotropy (NQA) and angular threshold on reconstruction of the LSP. In this study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA) and the regions of interest positioning was precisely adjusted bilaterally and symmetrically in each individual subject.The diffusion data were processed in individual L3-S2 nerve fibers using the generalized Q-sampling imaging algorithm. Data (mean FA, mean diffusivity, axial diffusivity and radial diffusivity, and normalized quantitative anisotropy) were statistically analyzed using the linear mixed-effects model. The MR neurography was performed in MedINRIA and post-processed using the maximum intensity projection method to demonstrate LSP tracts in multiple planes.FA values significantly decreased towards the sacral region (P < .001); by contrast, mean diffusivity, axial diffusivity, radial diffusivity and NQA values significantly increased towards the sacral region (P < .001).Fiber tractography of the LSP was feasible in all examined subjects and closely corresponded with the nerves visible in the maximum intensity projection images of MR neurography. Usage of NQA instead of FA in the proposed algorithm enabled better separation of muscle and nerve fibers.The presented algorithm yields a high quality reconstruction of the LSP bundles that may be helpful both in research and clinical practice.

[Spinal Intradural Schwannoma with Torsion: A Case Report]

Intradural schwannoma accompanied with torsion is rare. Intradural lumbar schwannoma was found in a 63-year-old man presenting with right sacral pain radiating to the lower extremity. This mass showed minimal enhancement on MRI. The tumor's location changed each time on MRI and CT-myelography. The patient underwent surgical resection and the cauda equina, linked to this schwannoma, was severely twisted.

Cauda equina syndrome after use of dural sealant in revision lumbar decompression surgery

OBJECTIVE

We report a case of cauda equina syndrome related to the use of fibrin glue dural sealant "TISSEEL".

BACKGROUND

Incidental durotomy (ID) is not uncommon in revision spinal surgery. Augmentation of the dural repair after primary closure is gaining popularity. The use of dural sealants is not risk-free.

METHOD

A 65-year old man who underwent revision lumbar decompression surgery developed postoperative cauda equina syndrome. He had urinary retention, bilateral leg pain and perianal numbness on the third postoperative day. We believe this complication was related to the use of fibrin glue to manage an ID.

RESULT

After the urgent surgical removal of the fibrin glue patch, the patient fully recovered with no residual neurological deficit.

CONCLUSION

Cauda equina syndrome development is a potential complication after the use of fibrin glue to augment intraoperative ID. Surgeons should be aware of this potential risk so it can be managed in a timely fashion.

Cauda Equina Syndrome in Neurosarcoidosis

Neurosarcoidosis (NS) is a mimicker of many infectious, neoplastic, and inflammatory diseases. It most commonly involves the cranial nerves followed by meninges, ventricles, hypothalamic-pituitary axis, spinal cord, and brainstem/cerebellum. While NS myelopathy has been increasingly recognized, pathophysiological/prognostic and management principles in NS-mediated cauda equina (CE) and conus medullaris (CM) syndromes, which constitute a small and rare minority of this subset, remain elusive. We present the case of a 49 -year-old Hispanic man who developed a peripheral facial palsy and primary hypogonadism within a span of 12 months and eventually got diagnosed with NS after he presented with CE syndrome. We also performed an extensive literature review, with a discussion on the underlying pathophysiology and current management recommendations for NS-mediated CE/CM syndrome. CE/CM syndromes in a middle-aged man should prompt the consideration of NS as a possible differential diagnosis. While steroid responsive, the majority of NS-CE/CM patients are left with residual neurodeficits with quick relapses when steroids are tapered, making the case for early institution of immunosuppressive therapies.

Microsurgical Management of a Primary Neuroendocrine Tumor of the Filum Terminale: A Surgical Technique

Neuroendocrine tumors (NETs) are benign tumors of the autonomic nervous system that rarely occur in the spinal canal. The gold standard treatment is gross total resection while preserving the patient’s neurologic functioning as complete surgical resection is curative. The surgical management of NETs could pose a challenge given their friable consistency, hypervascular nature, and proclivity to adhere to the cauda equina nerve roots.

We present a case of a 62-year-old female with an incidental primary NET arising from the filum terminale internum, review the literature, and describe the surgical technique including the benefits of using an intraoperative ultrasound and some of the pitfalls of relying “blindly” on neuromonitoring. Early identification and disconnection of the tumor’s vascular pedicle, which usually runs through the cranial filum, devascularizes the tumor, prevents systemic complications from catecholamine release, and facilitates circumferential dissection off the en passage cauda equina nerve roots. Our patient remains neurologically intact and asymptomatic two years postoperatively and neuroimaging confirmed complete resection.

Flexible endoscope visualization to assist in the removal of a string of 10 schwannomas at the cauda equina: technical case report

Bead-like schwannomas at the cauda equina are rare but benign intraspinal tumors. They can involve multiple nerve roots and spread within the spinal canal, and open resection would cause significant trauma. The authors have successfully applied a novel minimally invasive technique for the total removal of such schwannomas. A 68-year-old woman presented with a 1-month history of left waist and leg pain. MRI demonstrated multiple intraspinal lesions located from L1 to S1. The diagnosis was bead-like schwannomas at the cauda equina. Two incisions were made at the T12 and L5 levels. A flexible endoscope was introduced into the spinal canal following hemisemilaminectomy under a microscope to identify the relationship between the tumors and the carrying nerves. After dissecting both cranial and caudal ends of the carrying nerve, the string of bead-like tumors was gently pulled out from the caudal end as a whole. The endoscope was reintroduced into the spinal canal to ensure complete tumor removal. The patient recovered quickly, and no tumor residual was found at postoperative MRI. Flexible endoscope-assisted visualization plus microscopic hemisemilaminectomy via 2 incisions is a feasible minimally invasive approach for selected patients with bead-like schwannomas at the cauda equina.

Lymphomatosis cerebri with cauda equina lymphoma

PURPOSE/AIM

Lymphomatosis cerebri (LC) and cauda equina lymphoma are both rare forms of primary central nervous system lymphoma (PCNSL). LC is characterized by diffuse bilateral non-enhancing (or partially enhancing) inltrative lesions without mass effect, which can be easily confused with other forms of leukoencephalopathy and, thus, lead to delays in diagnosis.

CASE REPORT

For the first time, a case of LC concomitant with cauda equina involvement confirmed by brain stereotactic biopsy is presented.

CONCLUSIONS

This case highlights the necessity of using a multimodal strategy in diagnosing PCNSL, including multimodal magnetic resonance, cerebral spinal fluid cytology, flow cytometry and fluorodeoxyglucose positron emission tomography/computed tomography.

Acute Aortic Thrombus Presenting as Cauda Equina Syndrome

BACKGROUND

Occlusive abdominal aortic thrombus is a rare but critical clinical emergency with life-threatening consequences. Clinical presentation may mimic other diagnoses, resulting in a delay in the appropriate investigations for this condition. Spinal arterial involvement is a recognized complication of aortic thrombus and can result in pain, lower limb weakness, and loss of continence. These symptoms are usually associated with local spinal compression or stenosis manifesting as cauda equina syndrome (CES): a clinical finding of disrupted motor and sensory function to the lower extremities and bladder.

CASE REPORT

We present a case of a 60-year-old female patient presenting with back pain, leg weakness, paresthesia, and urinary incontinence. She was urgently investigated for cauda equina syndrome via a magnetic resonance imaging scan of the spine, which subsequently demonstrated a large occlusive abdominal aortic thrombus. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Nontraumatic acute thrombosis of the aorta is a life-threatening condition that may present with apparent neurological symptoms. In this patient there was both a relevant history and evolving clinical signs pointing toward a vascular etiology; however, the clinical findings were confusing and CES evaluation was prioritized. CES remains a medical emergency requiring urgent investigation and management. However, knowledge of spinal anatomy including vascular supply may help widen the differential. Physicians and associate specialists should consider this at clinical assessment and also when interpreting imaging of the spine. Any delay in diagnosing an aortic thrombosis has the potential for catastrophic clinical consequences.

Canine Degenerative Lumbosacral Stenosis: Prevalence, Impact And Management Strategies

Canine degenerative lumbosacral stenosis (DLSS) is a syndrome of low back pain with or without neurologic dysfunction associated with compression of the cauda equina. Most commonly occurring in medium- to large-breed dogs of middle to older age, German shepherd and working dogs are predisposed. Diagnosis is based on a combination of clinical signs, advanced imaging and ruling out other differential diagnoses. The volume of the intervertebral foramina at the lumbosacral junction is naturally reduced on extension but degenerative changes lead to a more marked reduction that can impinge the L7 nerve roots. Evidence is lacking on which to base decision-making for treatment of dogs with DLSS. However, surgical intervention may be indicated in dogs that do not respond to conservative management, or for dogs in which there is a requirement to work that prevents lifestyle adjustments. Improvements in electrodiagnosis and novel intra-discal treatments may improve the management of DLSS in the future.

Dynamic Changes of Cauda Equina Motion Before and After Decompressive Laminectomy for Lumbar Spinal Stenosis With Redundant Nerve Roots: Cauda Equina Activation Sign

STUDY DESIGN

Cross-sectional observational study (consecutive case series).

OBJECTIVES

The aim of this study was to define a criterion for achieving successful decompression of lumbar spinal stenosis (LSS) using intraoperative ultrasonography (IOUS) and to investigate the pathogenesis of redundant nerve roots (RNRs) based on the ultrasonographic findings.

METHODS

A total of 100 LSS patients (71 males, 29 females, mean age, 71 ± 8 years) with RNRs were enrolled as subjects in this study. IOUS was performed to evaluate pulsatile motion of the cauda equina (PMCE) just before and after decompressive laminectomy. To determine the decompression status of the cauda equina, the ultrasonographic findings were classified into 3 types on the basis of the presence or absence of PMCE: type 1, predecompression PMCE (-) to postdecompression PMCE (+); type 2, pre- and postdecompression PMCE (+); and type 3, pre- and postdecompression PMCE (-). The pathogenesis of RNRs was also investigated based on the ultrasonographic findings.

RESULTS

Around the stenosis, PMCE was almost always absent before decompression and appeared after decompression (type 1 in 94 patients, type 2 in 6, type 3 in 0). IOUS showed that, before decompression, the cauda equina was held at the stenosis and could not pulsate beyond the stenotic site, and after decompression, PMCE recovered in the craniocaudal direction, leading to the resolution of RNRs.

CONCLUSIONS

The emergence of PMCE can be a sign of successful decompression for LSS. Ultrasonographic findings support the notion that disturbance of PMCE around the stenosis is a basic component of the pathogenesis of RNRs.

A Technical Problem in Diagnosis Clarity of Solitary Spinal Cord Neurofibroma in an Eleven-month-old Boy

Spinal neurofibroma is one of the rarest of the neoplasms involving the spinal cord or roots and occurs much less often than neurinoma, meningioma or glioma. The sixth pediatric case of solitary intramedullary tumor was described in 2013, according to B. Eljebbouri et al. We present a rare, difficult to diagnose and may-be the seventh pediatric case of solitary neurofibroma of the cauda equine in an 11-month-old infant. The patient underwent a laminectomy of T12, L1, L2 and L3, extirpation of intradural, intramedullary and extramedullary spinal cord tumor. The patient is fully recovered for 5 years of monitoring. Although rare, spinal neurofibromas in children should be diagnostically considered and radically treated for a favorable outcome.

Does Surgical Intervention Help with Neurological Recovery in a Lumbar Spinal Gun Shot Wound? A Case Report and Literature Review

The third leading cause of spinal injuries are gunshot wounds to the spine, accounting for 15.2% of all spinal cord injuries. Treatment for gunshot wound spinal cord injuries (GSWSCI) remains variable, with indications for surgery being controversial. There is no clear evidence or guidelines that can help spine surgeons decide and direct surgical intervention. With the paucity of available literature, we report an interesting case of a gunshot injury to the lumbar spine at L1-L2, discuss the presentation and outcome, and evaluate relevant literature. A 27-year-old incarcerated male patient presented with a conus cauda equina asymmetrical injury involving the lower extremities and required initial medical stabilization in the intensive care unit (ICU). He subsequently underwent delayed surgical treatment with decompression and fragment resection at L1-L2. The patient improved neurologically to the American Spinal Injury Association (ASIA) Classification D and eventually regained nearly all lower extremity neurological function. Despite considerable evidence favoring the conservative management of GSWSCI and the absence of guidelines or recommendations on surgical interventions, our case report demonstrates that surgical intervention in appropriately selected patients can yield good recovery of neurological function and improvement in the quality of life. The key remains careful patient selection, the appropriate location of the retained fragment, and the extent of neurological injury that occurred. We feel surgical decompression and fragment removal, along with debridement, can result in good neurological recovery and long-term outcomes.

Are high lumbar punctures safe? A magnetic resonance imaging morphometric study of the conus medullaris

A high lumbar puncture (LP) at L2-L3 or above is often necessary to consider on technical grounds, but complications of conus medullaris (CM) damage during high LP are potentially concerning. We hypothesized that a high LP might be safer than previously thought by accounting for movements of the CM upon patient positional changes. We retrospectively reviewed standard normal supine lumbar spine magnetic resonance imaging of 58 patients and used electronic calipers on axial images at the T12-L1, L1-L2, and L2-L3 disc levels to measure the transverse diameter of the CM relative to the size of the dorsal thecal sac space (DTSS) through which a spinal needle could be inserted. On 142 axial images, the means for CM diameters were 8.2, 6.0, and 2.9 mm at the three levels, respectively. We then used known literature mean CM displacement values in the legs flexed and unflexed lateral decubitus position (LDP) to factor in CM shifts to the dependent side. We found that at all three levels, the likely positional shift of the CM would be too small and insufficient to displace the entire CM out of the DTSS. However, if needle placement could be confined to the midsagittal plane, an LP in the unflexed LDP would theoretically be entirely safe at both L1-L2 and L2-L3, and almost so at L2-L3 in the legs flexed LDP. Thus, high LPs at L1-L2 and L2-L3 are in theory likely safer than considered previously, more so in the legs unflexed than in the flexed LDP. Clin. Anat. 32:618-629, 2019. © 2019 Wiley Periodicals, Inc.

Acute Paraplegia Revealing a Hemorrhagic Cauda Equina Paragangliomas

Cauda equina paragangliomas are rare neuroendocrine benign and slow-growing tumors. Acute paraplegia, occurring because of sudden intratumoral hemorrhage, represents an extremely rare clinical picture of this disease. We report the case of a 64-year-old male presenting with a 5-day acute lower back pain, sciatica, and leg weakness. Spinal imaging showed an intradural mass of the cauda equina region and an emergent surgical treatment was achieved. The lesion was removed “en bloc,” and subarachnoid blood was noticed during surgery. The postoperative course was uneventful, with complete regression of pain and progressive motor recovery. The histological study revealed typical microscopic and immunohistochemical features of paragangliomas.

Neurolymphomatosis in the Cauda Equina Diagnosed by an Open Biopsy

Neurolymphomatosis is a rare form of extranodal malignant lymphoma defined as the infiltration of malignant lymphocytes into the central or peripheral nerve. We herein report a case of neurolymphomatosis in the cauda equina diagnosed by an open surgical biopsy. He presented with muscle weakness, atrophy, numbness and hypoesthesia in the bilateral lower extremities with the accumulation of ¹⁸fluoro-2-deoxyglucose (FDG) in the bilateral cauda equina. Cerebrospinal fluid cytology (three times) and flow cytometry (two times) and biopsies of the left sural nerve, bone marrow, paranasal sinus and left testis were all negative for malignancy, so finally we performed a surgical open biopsy of the cauda equina by laminectomy and diagnosed him with diffuse large B-cell lymphoma in the cauda equina. He was successfully treated with the disappearance of the FDG accumulation for a long time. The present case suggested that an early open biopsy of the cauda equina may be considered for cases of suspected neurolymphomatosis in the cauda equina for a good outcome.

Acellular Cauda Equina Allograft as Main Material Combined with Biodegradable Chitin Conduit for Regeneration of Long-Distance Sciatic Nerve Defect in Rats

Autologous nerve grafting (ANG), the gold standard treatment for peripheral nerve defects, still has many restrictions. In this study, the acellular cauda equina allograft (ACEA), which consists of biodegradable chitin conduit and acellular cauda equina, is developed. The cauda equina is able to complete decellularization more quickly and efficiently than sciatic nerves under the same conditions, and it is able to reserve more basal lamina tube. In vitro, ACEA shows superior guidance capacity for the regeneration of axons and migration of Schwann cells compared to acellular sciatic nerve allograft (ASNA) in dorsal root ganglion culture. In vivo, ACEA is used to bridge 15 mm long-distance defects in rat sciatic nerves. On day 21 after transplantation, the regenerative distance of neurofilaments in the grafting segment is not significantly different between the ACEA and ANG groups. At week 12, ACEA group shows better sciatic nerve repair than chitin conduit only and ASNA groups, and the effect is similar to that in the ANG group as determined by gait analysis, neural electrophysiological, and histological analyses. The above results suggest that the ACEA has the potential to become a new biological material as a replacement for autografting in the treatment of long-distance nerve defects.

An Unusual Cause of Cauda Equina Syndrome: Lumbar Epidural Venous Engorgement

BACKGROUND Epidural venous plexus (EVP) engorgement occurs due to many conditions, so it can be easily misdiagnosed. This becomes problematic when the diagnosis requires prompt treatment for a good outcome, especially when it results in cauda equina syndrome (CES). We report a case of extensive iliocaval thrombosis leading to epidural venous plexus and ascending lumbar vein engorgement as an outcome of deep venous thrombosis (DVT) due to probable adverse effects of oral combined contraceptive pills (OCCP). CASE REPORT A 42-year-old woman presented to a rural medical facility with bilateral lower-limb swelling and skin darkening for 2 days. She was transferred to a tertiary medical facility where her condition deteriorated to severe CES. A lower-limbs ultrasonography confirmed the presence of extensive DVT extending to the lower segment of the inferior vena cava. Spine magnetic resonance imaging showed abnormal enhancement of the conus medullaris with thick enhanced cauda equina nerve roots, consistent with a possible case of Guillain-Barré syndrome. However, there was engorgement of the EVP extending to the ascending lumbar, azygos, and hemiazygos veins, which was misdiagnosed. The patient was managed immediately with low-molecular-weight heparin and steroids. She died 4 weeks after admission due to hospital-acquired pneumonia and acute respiratory distress syndrome, probably due to the high dose of steroids. CONCLUSIONS Acute CES has a wide differential diagnosis. This report describes an unusual cause of CES and emphasizes the importance of early recognition to avoid misdiagnosis and management delay. Early identification of this clinical entity markedly decreases morbidity and mortality and thus improves the prognosis. Likewise, underlying causing factors such as venous congestion due to OCCP-related DVT should be considered in the diagnosis.

Analysis of stress application at the thoracolumbar junction and influence of vertebral body collapse on the spinal cord and cauda equina

The thoracolumbar junction comprises the spinal cord, nerve roots and the cauda equina, exhibiting unique anatomical features that may give rise to a diverse array of symptoms under conditions of injury, thus complicating the diagnosis of compressive disorders. The present study aimed to examine varying degrees and forms of compression at this level of the spinal cord using a two-dimensional model to calculate the relationship of these variables to injury. The degree of compression was expressed as a percentage of the spinal canal that was occupied. Results were compared with findings from clinical observations to assess the validity of the model. Analysis revealed that higher levels of compression/spinal canal occupation are associated with the presence of neurological symptoms. This finding was consistent with clinical data. Results of the present analysis warrant further research involving evaluation of compression with respect to other parameters, such as blood flow, as well as more anatomically accurate three-dimensional analysis.

Unusual cauda equina syndrome due to multifocal ependymoma infiltrated by lymphoma

Myxopapillary ependymoma is a rare tumour of the central nervous system (CNS); this subtype of ependymoma occurs most frequently in cauda equina, conus medullaris or filum terminale. The treatment consists of complete removal of the tumour including its capsule when possible since it is usually a solitary lesion. Non-Hodgkin lymphoma of the CNS is found in only 1.3% of cauda equina tumours. We report the case of a 62-year-old man who presented to our institution with progressive weakness of his right lower extremity, with numbness and paresthesia of both feet. He was suffering from one month of right sciatica. Lumbosacral MRI displayed two intradural extramedullary lesions, the first one was located posteriorly to L1-L2 and the second one was spreading from L4 to S2 presenting as a mucoid cyst in its superior part with hyperintense T2 signal, isointense on T1-weighted with high and homogeneous contrast enhancement in the inferior solid component. Imaging also found three additional intradural, extramedullary tumor formations with contrast enhancement, located respectively at C5-C6, C7 and T4. A L1-L2 and S1-S2 laminectomy was performed in emergency and total removal was achieved. Neuropathologist concluded that the tumor was a myxopapillary ependymoma infiltrated by large B-cell lymphoma. Although rare, this phenomenon (coexisting tumors within the same lesion) should be known by neurosurgeons because the occurrence of collision tumors affects the treatment and the patient's prognosis. In our case, two different types of tissue were mingled in the same location-this finding is very uncommon and has, to our knowledge, never been reported before.

PEMLIF-a tale of two stories

Intervertebral disc prolapse is a common cause of both acute and chronic low back pain. This can result in differential grades of motor and sensory disturbances in lower limbs and even cauda equina syndrome (CES). The neurological manifestations are a result of compression of the spinal cord and roots ventrally in the spinal canal due to the prolapsed disc. However, neurologic deficits owing to compression of the spinal cord dorsally as a result of migration of sequestrated disc fragments are very rare. We present two different cases of back pain with severe neurologic deficit referred to us within a short span of one month. Among them, one had long standing history of back pain while other had none. Both patients were investigated and found to have a sequestrated disc fragment which had dorsally migrated to the epidural space and was causing severe compression of the spinal cord. They underwent laminectomy and removal of the sequestrated fragment. However, they were only partially relieved of their motor and bladder weakness. We present our cases to highlight this rare form of lumbar epidural intervertebral disc migration, as well as enumerate the diagnostic challenges and discuss the differential diagnosis and treatment.