Spinal arachnoid cysts in adults: diagnosis and management. A single-center experience

Extradural spinal cyst in a pediatric patient: A case report

Background

Spinal extradural arachnoid cysts comprise <1% of all spinal lesions and are rare findings in pediatric patients. The pathogenesis of spinal extradural arachnoid cysts is not well known but is thought to most commonly be due to congenital dural defects. Other origins include trauma, inflammation, or infection, such as arachnoiditis. Spinal magnetic resonance imaging is the gold standard for diagnosis, showing a fluid-filled space dorsal to the spinal cord with signal intensity akin to cerebrospinal fluid (CSF) and often the site of dural defect with CSF leak. While most spinal extradural arachnoid cysts are asymptomatic, large cysts can compress the spinal cord or nerve roots, leading to myelopathy, radiculopathy, or focal pain symptoms. In such cases, surgical management is indicated.

Case Description

Here, we present a case of a 15-year-old female who presented with lower back pain radiating to her bilateral posterior thighs and knees, with imaging indicating a thoracolumbar spinal extradural arachnoid cyst. After failed conservative treatment, surgical intervention in the form of laminectomy, fenestration of the arachnoid cyst, and repair of the dural defect was required, resolving the patient's symptoms with no recurrence of the cyst.

Conclusion

Complete resolution of pain in our patient following surgical management of spinal arachnoid cyst suggests that treatment of the arachnoid cyst can be achieved through minimal exposure to the site of the CSF leak to fenestrate the cyst and repair the leak.

Multiple spinal extradural arachnoid cysts presenting as compressive myelopathy in a teenager: case report and literature review with special emphasis on postoperative spine deformity in the current minimally invasive era

INTRODUCTION

Multiple synchronous spinal extradural arachnoid cysts are extremely rare in children and can lead to cord compression and disability. Multiple spinal extradural arachnoid cysts (SEDACs) in children with immature and growing spine need to be studied separately from multiple SEDACs in adults with mature and fully grown spine because of multiple surgical limitations in children (blood loss, surgery duration, long-term spinal stability after long segment exposure, etc.).

MATERIAL AND METHODS

We planned a non-systematic literature review of similar cases described in literature to analyse the pattern of presentation, management, and outcome of this surgically curable disease.

RESULTS

A total of 28 cases of paediatric multiple SEDACs in the age range of 5 months to 17 years and mean age of 11.54 years were analysed. Exposure was achieved by laminectomy in 9, laminoplastic laminotomy in 13, laminectomy in first surgery followed by laminoplasty in second surgery (re-exploration) in 1, hemilaminectomy in 2, and technique "not reported" in 3 children. Complete/near-complete recovery was seen in 27 (96.42%) children. Postoperative spine deformity was reported in 7 (25%) children and was progressive in 2 children during serial follow-up.

CONCLUSIONS

Symptomatic multiple synchronous SEDACs in children is a rare surgically curable condition. Sincere attempt to find out a dural defect in all cysts is a very important step in multiple SEDAC surgery. Total cyst wall excision with closure of all dural defects is the gold standard treatment for symptomatic cases. Laminoplasty is preferred for excision of multiple SEDACs in children to prevent postoperative spine deformity during long-term follow-up. Long serial follow-up for postoperative spine deformity is necessary.

Structural Myelopathies

OBJECTIVE

This article illustrates the clinical importance, diagnosis, and management of degenerative and nondegenerative structural myelopathies. It also aims to create a diagnostic approach for the evaluation of patients with suspected degenerative myelopathies.

LATEST DEVELOPMENTS

There is considerable interest in developing diagnostic methods that can assist in deciding if surgery is indicated in patients with structural myelopathy and the optimal timing for surgery. Diffusion tensor imaging has emerged as a promising imaging modality although it is not used routinely in clinical practice. Neuroprotective medications and interventions are being studied in patients with degenerative myelopathies.

ESSENTIAL POINTS

Structural myelopathies and particularly degenerative myelopathies are common disorders that are routinely encountered in clinical practice, with symptoms that frequently overlap with other neurologic disorders. The prompt diagnosis and treatment of patients are essential in achieving good functional outcomes.

Long-term outcomes following surgical treatment of spinal arachnoid cysts: a population-based consecutive cohort study

BACKGROUND CONTEXT

Spinal arachnoid cysts (SACs) are rare, cerebrospinal fluid-filled sacs lined by an arachnoid membrane in the spinal canal. Symptoms can develop due to pressure on the spinal cord or adjacent spinal nerves by the cyst itself or by interrupted flow of cerebrospinal fluid. If noninvasive management fails or neurological deterioration occurs, surgical treatment is recommended. However, data is lacking on long-term outcomes after surgery.

PURPOSE

To determine long-term outcomes in patients surgically treated for SACs.

STUDY DESIGN

Population-based cohort-study.

PATIENT SAMPLE

All consecutive patients treated for either intra- or extradural SACs with surgery between 2005 and 2020 at the author's institution were included.

OUTCOME MEASURES

American Spinal Injury Association Impairment Scale (AIS) and modified Japanese Orthopedic Association score (mJOA).

METHODS

Data was primarily extracted from electronic patient medical notes. Telephone interviews were performed to assess long-term postoperative outcomes. All analyses were conducted using the statistical software program R version 4.0.5. Statistical significance was set at p<.05.

RESULTS

Thirty-four patients were included. Cyst excision was performed in 11 (32%) cases, and fenestration in the remaining 23 (68%). The median follow-up time was 8.0 years. Surgery resulted in a significant long-term improvement in both AIS (p=.012) and mJOA (p=.005). Sensory deficit was the symptom that most often improved (81%), followed by pain (74%) and motor function (64%). AIS deteriorated in two patients, of which one case was attributed to a surgical complication. Local cyst recurrence requiring reoperation was seen in 4 (12%) cases, all of them following cyst fenestration. One patient (3%) required reoperation for progression of the cyst progression at a different level.

CONCLUSION

This study reports outcomes of surgically treated SACs with the longest follow-up time to date. Microsurgical cyst excision or fenestration were safe treatment options, and the neurological improvements seen in the immediate postoperative phase were maintained at long-term follow-up.

Cystic dilatation of the ventriculus terminalis: A narrative review

Introduction

The terminal ventricle, also known as the fifth ventricle, is a tiny relic cavity in the conus medullaris of the human spinal cord. Our purpose in bringing attention to this condition is to get the word out about the signs and symptoms, diagnostic hurdles, and therapeutic options available for it.

Methods

All relevant studies involving patients diagnosed with ventriculus terminalis (VT) were retrieved from PubMed, Google Scholar, and Scopus. Studies published in complete English language reports were included. The terms VT, terminal ventricle, and 5th ventricle. Age, gender, presenting symptoms, magnetic resonance imaging findings, treatment, and outcome of patients with ventriculus terminalis were all included and recorded.

Results

The average age of the patients was 39 years, and there were 13 men among them (14.4%). Motor deficits and sciatica were the most commonly reported symptoms in 38 and 34 patients (42.2%, 37.7%), respectively. In 48 patients (53.3%), cyst fenestration was performed, and in 25 patients (27.7%), myelotomy was performed. Fifty-eight patients (64.4%) saw a reduction in cyst size after surgery. The majority of patients reported an improvement in their symptoms in 64 cases (51.1%), with only three cases (3.3%) reporting a worsening.

Conclusions

In cases where the VT is the source of symptoms such as motor, sensory, or bladder dysfunction, surgical intervention is recommended. This review compiles information from the available literature to shed light on the anatomy, clinical presentation, imaging, and treatment options for this variant. It also aims to pinpoint any potential drawbacks or restrictions connected to the surgical techniques.

Diagnostic dilemma in acute neurological presentation of spinal arachnoid cysts: A case report

Background

Spinal arachnoid cysts are relatively uncommon, cerebrospinal fluid-filled sacs formed by arachnoid membranes that can be either idiopathic or acquired. The neurological presentation of these cysts is varied. Advances in imaging techniques have allowed an improved characterization of these entities and excluded other possible causes of clinical manifestation. Their presentation remains varied, ranging from pain to progressive neurological deficits. Here, we present two cases of patients with thoracic arachnoid cysts that posed a diagnostic dilemma at initial presentation because of their acute neurological deficit, and their eventual recovery after surgical intervention.

Case description

The first case is of a patient with end-stage renal failure, which prevented the administration of contrast during the workup. The differential diagnosis ranged from intradural abscess to arachnoid cyst. The second patient presented with non-remitting back pain that progressed to an acute neurological deficit. Both patients recovered well after decompression of the cyst.

Conclusion

The decision to intervene is still patient-dependent and based on the extent of neurological deterioration at the time of presentation due to the relatively benign nature and lack of understanding of the temporal presentation of neurological symptoms, which are rapidly and almost completely reversed after surgery. However, further studies need to be done to understand the acute presentation of these cysts, which are apparently long-standing.

How to locate the fistula orifice of spinal extradural arachnoid cyst: Surgical experience and clinical outcome

BACKGROUND

In clinical practice, spinal extradural arachnoid cysts (SEAC) are relatively rare. The key to the treatment of SEAC is recognize and close the dural defects (fistula orifice), but there is currently no convenient method to locate and identify the fistula. We propose a method for predicting the location of lumbar/thoracolumbar SEAC fistula based on surgical experience, subsequently closing the fistula through posterior unilateral interlaminar fenestration. Evaluating its surgical efficacy and investigated its effect on patient prognosis.

METHODS

A stepped approach based on clinical experience is proposed. A retrospective analysis was performed on 6 patients diagnosed with thoracolumbar SEAC disease and treated with posterior unilateral interlaminar fenestration through the position by pre-estimated fistula orifice in our hospital's Department of Neurosurgery between January 2017 and January 2022.

RESULTS

All patients who received this treatment experienced significantly lower postoperative VAS pain scores and ODI index compared to their corresponding preoperative values (P < 0.01). During the ongoing follow-up after surgery, no unstable vertebral column, adverse effects, or complications were reported.

CONCLUSIONS

The use of posterior unilateral interlaminar fenestration for the treatment of large SEAC in the adult lumbar/thoracolumbar segment can reduce spinal cord manipulation and enhance spine stability. The disease can be treated by sealing the fistula orifice through a small fenestra, the position of which is assessed before surgery. This surgical method reduces trauma and improves the prognosis of patients with large SEAC.

Familial and syndromic forms of arachnoid cyst implicate genetic factors in disease pathogenesis

Arachnoid cysts (ACs) are the most common space-occupying lesions in the human brain and present significant challenges for clinical management. While most cases of ACs are sporadic, nearly 40 familial forms have been reported. Moreover, ACs are seen with increased frequency in multiple Mendelian syndromes, including Chudley-McCullough syndrome, acrocallosal syndrome, and autosomal recessive primary ciliary dyskinesia. These findings suggest that genetic factors contribute to AC pathogenesis. However, traditional linkage and segregation approaches have been limited in their ability to identify causative genes for ACs because the disease is genetically heterogeneous and often presents asymptomatically and sporadically. Here, we comprehensively review theories of AC pathogenesis, the genetic evidence for AC formation, and discuss a different approach to AC genomics that could help elucidate this perplexing lesion and shed light on the associated neurodevelopmental phenotypes seen in a significant subset of these patients.

Spinal Intradural Arachnoid Cysts in Adults: An Institutional Experience and Literature Review

BACKGROUND

Adult spinal intradural arachnoid cysts are rare pathologic entities with an unclear etiopathogenesis. These lesions can be dichotomized into primary (idiopathic) or secondary (related to inflammation, intradural surgery, or trauma) etiologies. Limited series have depicted optimal management strategies and clinical outcomes.

OBJECTIVE

To illustrate our experience with spinal intradural arachnoid cysts and to present a literature review of surgically treated cysts to elucidate the clinical and anatomic differences between etiologies.

METHODS

Institutional review revealed 29 patients. Various data were extracted from the medical record. Initial and follow-up symptomatologies of the surgical cohort were compared. The literature review included case series describing cysts managed surgically.

RESULTS

From patients treated surgically at our institution (22), there was a significant reduction in thoracic back pain postoperatively ( P = .034). A literature review yielded 271 additional cases. Overall, primary and secondary lesions accounted for 254 and 39 cases, respectively. Cysts of secondary origin were more likely localized ventral to the spinal cord ( P = .013). The rate of symptomatic improvement after surgical intervention for primary cysts was more than double than that of secondary cysts ( P < .001). Compared with primary etiologies, the rates of radiographic progression ( P = .032) and repeat surgery ( P = .041) were each more than double for secondary cysts.

CONCLUSION

Surgical intervention for spinal intradural arachnoid cysts improves thoracic back pain. The literature supports surgical intervention for symptomatic primary spinal intradural arachnoid cysts with improved clinical outcomes. Surgery should be cautiously considered for secondary cysts given worse outcomes.

Spinal arachnoid webs in adults: Clinical and imaging features in a multicenter study

BACKGROUND AND PURPOSE

Spinal arachnoid webs (SAWs) are rare and can present with myelopathic symptoms. This study aims to add 85 more cases of SAWs to the literature so we can continue to analyze clinical and imaging trends of SAWs to better understand this entity and its natural history.

METHODS

An institutional review board-approved retrospective review of SAW cases between 2016 and 2022 within a metropolitan, multihospital network was performed, searching for MR and CT reports that included "arachnoid web." Of 108 identified reports, 85 patients had imaging and/or pathologically proven arachnoid webs. Demographic and clinical data were collected. Images were analyzed for SAW level, point of maximum kyphosis, presence of cord expansion, and signal intensity. The electronic medical record (EMR) was reviewed for age, sex, symptom presentation and duration, management, and outcomes.

RESULTS

Of 85 cases, the most common presenting chief complaint was back pain and weakness. All (100%) SAWs were in the dorsal thoracic subarachnoid space, with 87% (74/85) located from thoracic (T) 2 to T6. Spinal cord expansion and signal abnormality were present in 54.1% and 23.5%, respectively. Twenty-six underwent surgical resection with 20 showing improvement of at least one symptom.

CONCLUSION

We present 85 additional cases of SAWs to the existing literature. Our cases all occurred in the dorsal thoracic subarachnoid space, predominantly from T2 to T6. Patients present with symptoms like other causes of cord compression, and spinal MR studies should be evaluated routinely for the findings of SAWs. Further research could focus on understanding SAW prevalence, risk factors, and pathophysiology.

Spinal extradural arachnoid cysts: A novel formation mechanism and dural defect location technology

Purpose

The formation mechanism of spinal extradural arachnoid cysts (SEACs) remains unclear. There are several hypotheses for the formation of SEACs, but none of them can fully explain its pathological findings and surgical procedures. In this study, we retrospectively analyzed the cases of SEACs, aiming to clarify the formation mechanism of SEACs. In addition, we summarize a concise method for locating dural defects preoperatively and formulate a putative explanation of this method.

Methods

The clinical data of 14 patients with SEACs underwent surgery in our hospital from January 2017 to December 2021 were retrospectively analyzed.

Results

Fourteen patients were identified during the study period. The cysts all spanned the T12/L1 segment, and dural defects were also located at the T12/L1 level (2 cases not recorded) as well as the middle or the upper-middle level of the cysts. Nine cases were treated with total cyst excision, 2 cases were treated with dural defect closure only, and 3 cases were treated with total cyst excision and dural defect closure. Histopathological examination demonstrated that the cyst wall contained both the arachnoid epithelial and compact fibrous connective tissue. The symptoms were relieved in all patients, and no recurrence was observed.

Conclusions

According to intraoperative and pathological findings, the dural outer layer cyst (DOLC) is a more reasonable hypothesis about SEACs formation. When CT myelography or cinematic MRI cannot determine the location of the dural defect preoperatively, it can be located according to the middle level of the SEACs with high accuracy.

Arachnoid webs causing rostral syrinx due to ball-valve effect: an illustrative report of two cases

An arachnoid web is a pathological formation of the arachnoid membrane. It is a rare phenomenon but is known to lead to syrinx formation in the spinal cord along with pain and neurological deficits. On imaging, the 'scalpel sign' is pathognomonic for an arachnoid web. The etiology of syrinx formation from an arachnoid web is currently unknown. This report documents the only two cases of arachnoid webs with an extensive syrinx in which a likely pathophysiologic mechanism is identified. Both cases presented with motor deficits. The patients had no history of trauma or infection. After extensive workup in both patients and observation of the scalpel sign an arachnoid web was suspected. In both cases, the patients were treated surgically after an arachnoid web was suspected. Intra-operative ultrasound visualized in both cases demonstrates a fenestration in the web that allowed passage of cerebrospinal fluid in a rostral-caudal direction due to a ball-valve effect.

Case of incidental thoracic spinal dumbbell hemorrhagic arachnoid cyst and tentorial metastasis from breast carcinoma

Background

Spinal arachnoid cysts (SACs) in adults are typically acquired dural defects following trauma, inflammation, or infection. Brain metastases from breast cancer account for 5-12% of all CNS metastases and are mostly leptomeningeal. Here, the authors reported a 50-year-old female treated for a tentorial metastasis from breast carcinoma that underwent chemotherapy and radiotherapy. Three months later, she presented with a thoracic spinal extradural dumbbell hemorrhagic arachnoid cyst.

Case Description

A 50-year-old female underwent a left retrosigmoid suboccipital craniectomy for microsurgical removal of a tentorial metastasis attributed to poorly differentiated breast carcinoma (i.e., comedonic pattern). The patient subsequently underwent both chemotherapy and radiotherapy for accompanying bony metastases. Three months later, she experienced the onset of severe posterior thoracic pain. When the thoracic magnetic resonance imaging revealed a hyperintense "dumbbell" extradural T10-T11 lesion, she underwent a T10-T11 laminectomy for marsupialization and excision of the hemorrhagic lesion. The histological examination revealed blood and arachnoid tissue within a benign SAC, without accompanying tumor. Her postoperative course was uneventful, and she was discharged on postoperative day 3.

Conclusion

A 50-year-old female underwent a left retrosigmoid suboccipital craniectomy for removal of a tentorial metastasis from breast carcinoma, followed by radiation/chemotherapy. Three months later, she hemorrhaged into an MR-documented T10-T11 dumbell extradural SAC that was successfully treated with laminectomy, marsupialization, and excision.

Cervical spine arachnoid cyst complicated by spontaneous intracystic hemorrhage: Case report and review of the literature

Background:

Spinal intradural extramedullary arachnoid cysts represent about 1–3% of all primary spinal space-occupying lesions often causing spinal cord and/or radicular nerve compression. Spontaneous intralesional hemorrhages are extremely rare and are typically found within intracranial arachnoid cysts. Here, a 55-year-old female presented with a spontaneous hemorrhage into a cervical spine arachnoid cyst warranting surgical intervention (i.e., fenestration/excision/occlusion).

Case Description:

A 55-year-old female presented with 3 weeks of dull pain in the cervicothoracic region. She subsequently developed paresthesias and progressive lower extremity weakness with (urinary incontinence. The cervical magnetic resonance revealed a right anterolateral intradural extramedullary “cystic” lesion extending from C7 to T2; it contained a heterogeneous signalon T2W sequences, and a fluid-fluid level was documented on the T2-GRE and FLAIR sequences. At surgery, consisting of a laminectomy, two hemorrhagic cystic lesions were identified and removed. Histological findings were consistent with hemorrhagic into an arachnoid cyst.

Conclusion:

Only rarely hemorrhages develop in intraspinal intradural extramedullary spinal arachnoid cysts.

Clinical and imaging features of spinal extradural arachnoid cysts: a retrospective study of 50 cases

PURPOSE

Spinal extradural arachnoid cysts (SEDACs) are thought to arise from leakage of CSF through a spinal dural defect. This study investigates the demographics and imaging spectrum of SEDACs at our academic institution and compares them with those reported in the literature.

METHODS

Fifty cases with documented MRI diagnosis of SEDAC, Nabors criteria type I meningeal cyst (MC), were identified from retrospective review of imaging records between 1999 and 2020. Patient demographics, presenting symptoms, cyst characteristics, and management outcomes were studied. Statistical analysis was performed to determine associations between maximum cyst size and presenting symptoms along with other imaging findings.

RESULTS

In all 50 subjects, SEDACs were solitary (single) and sporadic (non-familial). The majority were incidental (62%), located posteriorly (92%) and laterally (80%) in the thoracic and thoracolumbar regions (34%, 30%). They were associated with mild mass effect upon the thecal sac (50%) and bone remodeling (92%). Among symptomatic SEDACs, back pain and radiculopathy were the most reported (68%). Larger cysts were located caudally in the spinal canal, and were associated with greater thecal mass effect, bone remodeling, and septations. Four out of six subjects who underwent surgical management had complete or partial remission. One had cyst recurrence.

CONCLUSION

In this largest series of SEDACs, most were discovered incidentally, stable over time, and located in the thoracic spine dorsal to the thecal sac. When symptomatic, back pain and radiculopathy were the most common presenting symptoms. Treatment with complete surgical excision may yield the best results for symptomatic lesions.

Imaging of Common Spinal Cord Diseases

Spinal cord evaluation is an integral part of spine assessment, and its reliable imaging work-up is mandatory because even localized lesions may produce serious effects with potentially irreversible sequelae. Spinal cord alterations are found both incidentally during spine evaluation in otherwise neurologically asymptomatic patients or during neurologic/neuroradiologic assessment in myelopathic patients. Myelopathy (an umbrella term for any neurologic deficit that refers to spinal cord impairment) can be caused by intrinsic lesions or extrinsic mechanical compression, and its etiology may be both traumatic and/or nontraumatic. The symptoms largely depend on the size/extension of lesions, ranging from incontinence to ataxia, from spasticity to hyperreflexia, from numbness to weakness. Magnetic resonance imaging is the reference imaging modality in spinal cord evaluation, ensuring the best signal and spatial resolution. We provide an overview of the most common spinal cord disorders encountered by radiologists and describe the technical measures that offer optimal spinal cord visualization.

Impact of Surgical Timing on Neurological Outcomes for Spinal Arachnoid Cyst: A Single Institution Series

Objective

Spinal arachnoid cysts (SACs) are rare lesions that often present with back pain and myelopathy. There is a paucity of literature evaluating the impact of surgical timing on neurological outcomes for primary SAC management. To compare long-term neurological outcomes in patients who were managed differently and to understand natural progression of SAC.

Methods

We conducted a retrospective analysis of adult patients treated for SAC at our institution from 2010 to 2021, stratified into 3 groups (conservative management only, surgical management, or conservative followed by surgical management). Study outcome measures were neurological outcomes as measured by modified McCormick Neurologic Scale (MNS), postoperative complications, and cyst recurrence. Nonparametric analysis was performed to evaluate differences between groups for selected endpoints.

Results

Thirty-six patients with SAC were identified. Eighteen patients were managed surgically. The remaining 18 patients were managed conservatively with outpatient serial imaging, 7 of whom (38.9%) ultimately underwent surgical treatment due to neurological decline. Most common presenting symptoms included back pain (50.0%), extremity weakness (36.1%), and numbness/paresthesia (36.1%). Initial/preoperative (p = 0.017) and 1-year postoperative (p = 0.006) MNS were significantly different between the 3 groups, but not at 6 weeks or 6 months postoperatively (p > 0.05). Additionally, at 1 year, there was no difference in MNS between patients managed surgically and those managed conservatively but ultimately underwent surgery (p > 0.99).

Conclusion

Delayed surgical intervention in minimally symptomatic patients does not seem to result in worse long-term neurofunctional outcomes. At 1 year, postoperative MNS were significantly higher in both surgical groups, when compared to the conservative group highlighting worsening clinical picture regardless of preoperative observational status.

Spinal arachnoid cysts: A case series & systematic review of the literature

INTRODUCTION

Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management.

RESEARCH QUESTION

We analyzed our experiences from a case series and provide a systematic review to determine 1) Demographic and clinical features of SACs, 2) Optimal imaging for diagnosis and operative planning, 3) Optimal management of SACs, and 4) Clinical outcomes following surgery.

MATERIALS AND METHODS

A single-institution, ambispective analysis of patients with symptomatic SACs surgically managed between May 2005 and May 2019 was performed. Data were collected as per local ethics committee stipulations. A systematic review of SACs in adults was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and a preapproved protocol.

RESULTS

Our series consisted of 11 patients, M:F 8:3, mean age 47.8 years (range 18-73 years). Mean follow-up was 19 months (range 5-36 months). SACs were excised or marsupialised (7), fenestrated (3) or partially excised (1). Eight patients had expansile duroplasty, 3 primary dural closure. One patient had a cystoperitoneal shunt. All patients were AIS D preoperatively; 4 remained unchanged and 7 improved to AIS E at follow-up. Our systematic search retrieved 725 citations. Fourteen case series met the inclusion criteria. There was no evidence to support superiority of one surgical strategy over another. Surgery for symptomatic patients resulted in positive clinical outcomes.

DISCUSSION AND CONCLUSIONS

Symptomatic SACs require surgical intervention. Limited evidence suggests that decompressing the cord, breakdown of arachnoid adhesions, and establishing CSF flow by consideration of expansile duroplasty are important for positive outcomes.

Surgical management and outcomes in spinal intradural arachnoid cysts: the experience from two tertiary neurosurgical centres

PURPOSE

Evaluation of the presentation and outcomes of different surgical treatment approaches for spinal intradural arachnoid cysts (SIAC).

METHODS

Cases were identified from electronic records of two major neurosurgical centres in London over the last 10 years (October 2009-October 2019) that have been surgically treated in both institutions. Clinical findings, surgical technique, and recurrence by procedure were statistically analysed. Statistical analysis was performed with STATA 13.1 Software.

RESULTS

A total of 42 patients with SIAC were identified for this study with a mean age at the time of surgery of 53.6 years and a male:female ratio of 8:13. There were 31 patients with primary SIACs and 11 with secondary SIACs. The most common presenting symptom was paraesthesia (n = 27). The most common location of the cyst was in the thoracic region (n = 33). Syrinx was present in 26.2% of SIACs (n = 11). Resection was associated with significantly better postoperative pain compared to other surgical techniques (p = 0.01), significantly poorer postoperative urinary function (p = 0.029), and lower rates of sensory recovery in patients who presented preoperatively with sensory deficit (p = 0.041). No significant difference was seen in symptomatic outcomes between patients with primary and secondary SIACs.

CONCLUSION

Resection and drainage are both effective methods of managing SIACs. In this observational study, resection was associated with significantly reduced pain postoperatively when compared with drainage, however also with significantly less improvement in postoperative urinary function. Therefore, resection should be the gold standard management option for SIACs, with drainage as an option where resection is unsafe, and drainage should also be considered in patients presenting with urinary dysfunction.

Pulsating Spinal Arachnoid Cyst as a Hidden Aggravating Factor for Thoracic Spondylotic Myelopathy: A Report of 3 Cases

CASE

We report 3 cases of thoracic myelopathy caused by vertebral osteophytes and coexisting intradural spinal arachnoid cyst (SAC), which was difficult to diagnose on preoperative magnetic resonance imaging. Intraoperative ultrasound sonography revealed spinal cord impingement because of osteophytes and a pulsating intradural SAC. Repeated pincer compression on the spinal cord seemed to be associated with their paraparetic symptoms.

CONCLUSION

In treating patients presenting with unexplained progressive myelopathy with small ossified lesion in the thoracic spine, close attention should be paid to a coexisting SAC as a hidden aggravating factor for thoracic myelopathy.

Early microsurgery on thoracolumbar spinal extradural arachnoid cysts: Analysis of a series of 41 patients

BACKGROUND

We designed this study to share our management experiences on spinal extradural arachnoid cysts (SEACs) to add more to the body of evidence for their treatment.

METHODS

We retrospectively reviewed 41 patients who underwent microsurgery for thoracolumbar SEACs at our hospital from June 2009 to June 2019. All clinical data, including medical history, clinical features, imaging manifestation, operative findings, and prognosis, were extracted from medical records and databases. Perioperative differences of the Visual Analogue Scale (VAS), the Oswestry disability index (ODI) score, and postoperative Odom's criteria were used to assess the surgical outcome.

RESULTS

The most common and very first clinical symptom in the 41 patients was pain (VAS = 2.82 ± 0.89), and the mean ODI value was 61.7 ± 8.9%. Imaging revealed that the cystic lesions in the thoracolumbar spine involved an average of 2.85 segments. Of the 41 patients, 39 underwent total cyst excisions, and 36 had their dural defect repaired by one of three methods. The mean postoperative follow-up time was 52.3 months. Postoperatively, one case developed kyphoscoliosis and two cases experienced a recurrence. The majority of patients showed excellent outcomes according to Odom's criteria, the postoperative VAS (0.80 ± 1.08), and the ODI (15.4 ± 9.3%).

CONCLUSIONS

Themost commonclinicalsymptoms of thoracolumbar SEACs included progressive discomfort and pain around the involved spinal segments. Early surgical intervention relieved the patients from their symptoms. Microsurgery was recommended to resect the complete cyst and to repair the dural defect, but resection of the complete cyst is more necessary than just repairment of the dural defect for providing promising outcomes.

A Single Vertebral Surgical Approach for Spinal Extradural Meningeal Cysts Spanning Multiple Vertebral Segments by Auxiliary Neuroendoscope

BACKGROUND

Spinal extradural meningeal cysts (SEMCs) are rare lesions, especially those spanning multiple vertebral segments, and the surgical strategy has remained controversial. In the present study, we have described the outcomes of 4 patients with SEMCs treated with dural defect repair alone assisted by neuroendoscopy.

METHODS

From January 2018 to January 2020, 4 patients with SEMCs spanning multiple vertebral segments had undergone single-vertebral laminectomy or hemilaminectomy.

RESULTS

The SEMCs in all 4 patients had spanned multiple vertebral segments, from T11 to L2. Using magnetic resonance imaging, the location of the dural defect was predicted correctly for 3 patients. Single-vertebral laminectomy was used in 2 patients and single-vertebral hemilaminectomy in 2 patients. Intraoperatively, the entire cyst, including the upper pole, lower pole, and middle segment of the cyst, was explored using neuroendoscopy. In each patient, only 1 dural defect was found, which had been located in the middle segment of the cyst (T12-L1). All cyst dural defects had been sutured under a microscope. In all cases, the cyst wall was not removed. Postoperatively, the symptoms for all the patients had improved significantly, and subsequent magnetic resonance imaging studies showed obvious cyst regression. During the follow-up period of 15-44 months, no recurrence was observed.

CONCLUSIONS

For SEMCs spanning multiple vertebral segments, dural defect repair without cyst wall resection through single-vertebral hemilaminectomy or laminectomy can be effective. Intraoperative neuroendoscopy can assist, not only in finding the dural defect, but also in avoiding the omission of multiple dural defects as much as possible.

Microsurgical treatment of symptomatic spinal extradural arachnoid cyst: a consecutive case series of 34 patients and literature review

PURPOSE

A spinal extradural arachnoid cyst (SEAC) is a rare condition with unclear etiology. Herein, we report a series of symptomatic SEACs to illustrate features of SEACs in adults, surgical management, and outcomes.

METHODS

A total of 34 consecutive patients who underwent microsurgical treatment were retrospectively reviewed. Patient characteristics were recorded in each case, including presenting symptoms, imaging findings, neurologic status, a surgical procedure performed and follow-up.

RESULTS

There were 19 (56%) male and 15 (44%) female patients, with the ages ranging from 16 to 71 years (average 45 years). The lesions were located in the cervical segment (n = 4, 12%), thoracic segment (n = 6, 18%), thoracolumbar segment (n = 10, 29%) and lumbar segment (n = 14, 41%). Clinical presentations included back pain (n = 18, 53%), sensory deficits (n = 14, 41%), weakness (n = 4, 12%) and gait ataxia (n = 4, 12%), with a mean duration of symptoms of 17 months. The lesion was hypointense with the spinal cord on T1-weighted images and hyperintense on T2-weighted images and showed no homogeneous enhancement after contrast medium injection. Communication between the cyst and subarachnoid space was found in 23 patients and the cyst was resected after fistula ligation. Postoperatively, patients were followed up for an average of 80 months. The patients' symptoms dramatically improved and follow-up radiological images showed a complete disappearance of the cyst in all patients. No recurrence was observed in the dural repair group.

CONCLUSION

Patients with symptomatic SEAC present with obvious and persistent symptoms. Complete microsurgical cyst removal with the closure of the dural defect is the standard treatment procedure with good results and a low recurrence rate.

Systematic Review of Surgical Management of Spinal Intradural Arachnoid Cysts

OBJECTIVE

Spinal intradural arachnoid cysts (SIACs) are rare pathological lesions that can arise via outpouchings of the arachnoid layer in the spinal canal that can result in neurological deficits. We performed a systematic literature review regarding the current surgical techniques used in the management of SIACs and discussed the prevailing hypotheses surrounding the etiology of SIACs.

METHODS

A systematic search of the literature was performed in December 2020 using EMBASE and MEDLINE for reports regarding the surgical management of SIACs. Data were collected regarding the demographics of the patients, classification system used, presence or absence of syrinxes, preoperative imaging modality, surgical approach and extent of resection, and postoperative outcomes and follow-up.

RESULTS

Our search yielded 19 reports for inclusion in the present study. The 19 studies included a total of 414 cases, with an overall male/female ratio of 0.93:1. The most common site for the SIACs was the thoracic spinal cord at 77.5%. The symptoms were very similar across the 19 studies. Of the 19 studies, 15 had used resection to manage the SIACs, 10 had used fenestration or marsupialization, and 4 had used cystoarachnoid or cystoperitoneal shunts.

CONCLUSIONS

SIACs are rare and debilitating spinal pathological lesions, with the etiology of primary SIACs still not fully elucidated. Multiple surgical approaches have been effective, with the optimal operative strategy largely dependent on the individual patient and cyst factors on a case-by-case basis.

Scalpel Sign in Spine Pathology: Presentation in 3 Different Rare Diagnoses

BACKGROUND

The scalpel sign is a radiological finding observed on sagittal magnetic resonance imaging and computed tomography myelography corresponding to an indentation in the dorsal aspect of the spinal cord resembling a surgical scalpel blade. It is said to be a pathognomonic imaging discovery linked to dorsal arachnoid webs. However, other spine-related conditions may mimic dorsal arachnoid webs on magnetic resonance imaging, such as spinal arachnoid cysts or ventral spinal cord herniation, leading to misdiagnosis.

METHODS

A retrospective review was performed of cases involving 3 different diagnoses at our institution in the last 5 years that shared in common the characteristic focal dorsal indentation of the spinal cord.

RESULTS

Of 7 cases identified, all but 1 were treated and confirmed intraoperatively. All lesions were located at the dorsal spinal cord. Magnetic resonance imaging was the study of choice for evaluation. Clinical manifestations included back pain and lower extremity numbness and weakness together with compressive myelopathy signs and urinary symptoms. Mean follow-up was 16.8 months with satisfactory postoperative results.

CONCLUSIONS

Isolated radiological presentation of the scalpel sign is not sufficient to distinguish between dorsal arachnoid webs, arachnoid cysts, and ventral herniation of the spine. However, awareness of its importance is relevant for accurate curative surgical planning.

CT cisternography to visualize epidermoid tumors for stereotactic radiosurgery treatment planning

The visualization of intracranial epidermoid tumors is often limited by difficulties associated with distinguishing the tumor from the surrounding cerebrospinal fluid using traditional computed tomography (CT) or magnetic resonance imaging (MRI) modalities. This report describes our experience using CT cisternography to visualize intracranial epidermoid tumors in three illustrative cases. CT cisternography of the epidermoid tumor provides more clarity and precision compared to traditional neuroimaging modalities. We demonstrate the feasibility of using CT cisternography to produce high-resolution images with well-defined tumor margins that can be used effectively for precise SRS treatment planning.

Endoscopic treatment of spinal arachnoid cysts

Background/objective

Spinal arachnoid cysts (SAC) are intradural lesions, which may provoke a compression of the spinal cord and roots. Endoscopic techniques are increasingly used to minimize the surgical access and the postoperative scar tissue. Shunts may also represent an option. The aim of this paper is to illustrate the technique of endoscopic-assisted fenestration and positioning of a cysto-peritoneal diversion in a thoracic SAC using a flexible endoscope and to perform a systematic literature review on this subject.

Material and methods

We reported our case and we performed a review of the literature, searching for all the adult cases of Type III SACs in English language treated through endoscopic procedures.

Results

We found 5 articles matching our search criteria and we included 9 adult patients in our analysis. Six patients were females and the most common localization was the thoracic spine. Six patients underwent selective laminectomies followed by endoscopic fenestration without cyst wall resection. Three patients had a percutaneous endoscopic inspection of the cyst and in two cases a cysto-subarachnoid shunt space was performed. Improvement of pre-operative neurological deficit was reported in six patients, no patients experienced clinical deterioration. The mean follow-up was 22 months and no progression or recurrence was reported.

Conclusion

The implementation of endoscopy allows a minimally invasive treatments with good visualization of cyst anatomy and precise shunt positioning under real-time guidance. Endoscopy is technically demanding but it can offer similar clinical outcomes when compared to microscopic procedures with a limited rate of post-operative complications.

The long-term risk of recurrence should be established by prospective studies.

Extradural arachnoid cyst with bony erosion: a rare case report

The authors present the case of an otherwise healthy 38-year-old female with an atypical extradural arachnoid cyst with multi-level involvement in the lumbar spine leading to left quadriceps weakness and dysesthesia. Upon presentation, a lumbar spine MRI with contrast and plain radiographs revealed extensive L4 bony erosion. An MR angiogram and cervical spine MRI with contrast were then obtained in order to rule out any aortic root or cervical spine pathology. With no other apparent clinically relevant pathology revealed by these additional tests, an L3-5 posterior decompression and fusion procedure was performed. Her preoperative symptoms were successfully resolved following the procedure, with no resultant surgical complications. The cyst is atypical not only due to its size and location, but also due of the significant bony erosion of the left L4 pedicle and vertebral body. To the authors' knowledge, this is the first reported case of an extradural arachnoid cyst in the lumbar spine with bony erosion of the pedicle and vertebral body. In cases such as this, a CT myelogram may be useful in planning the operative approach through visualization of the exact communication between cyst and dura. This approach may also aid in diagnosing and identifying atypical cyst presentations such as the one presented here.

Extradural thoracic meningeal cyst without spinal dysraphism causing adulthood myelopathy: Case illustration and review of the literature

Extradural spinal meningeal cysts are rare lesions in the adult spine and are an uncommon cause of neurologic deficits. We present the case of an adult who presented with myelopathic symptoms related to a dorsally based extradural thoracic meningeal cyst in the absence of any defect in the posterior spinal elements and no history of spinal dysraphism or trauma. We also performed a review of the literature to evaluate the surgical techniques for extradural meningeal cysts. Most thoracic cysts are intradural arachnoid cysts, yet this lesion is an extradural meningeal cyst, not an intradural arachnoid cyst. Because of the rarity of this lesion, its anatomic characterization can be difficult to conceptualize. An artist's illustration helps illustrate the anatomic characteristics of this cyst and our surgical management.

Rare dorsal thoracic arachnoid web mimics spinal cord herniation on imaging

Background:

Dorsal arachnoid webs (DAWs) are rare clinical entities that can mimic other conditions on magnetic resonance imaging (MRI). Here, we present a case of DAW that was misdiagnosed on MR as a ventral cord herniation.

Case Description:

A 35-year-old female presented with a 1-year history of lower extremity weakness and numbness. The MRI of the thoracic spine showed ventral cord displacement with syringomyelia. The computed tomography myelogram demonstrated ventral cord herniation. Intraoperatively, the patient had a dorsal thoracic web in the absence of cord herniation. Within 8 postoperative weeks, the patient had improved, and the follow-up MI showed a significant reduction in the syrinx size.

Conclusion:

On MR scans, DAWs may look like ventral cord herniation. However, the positive “scalpel sign” and syrinx, the absence of an arachnoid cyst on myelography, and the findings on cine MR help differentiate DAWs from ventral cord herniation.

Spinal intradural extramedullary arachnoid cysts in adults-operative therapy and clinical outcome

BACKGROUND

Spinal arachnoid cysts (SAC) are rare mostly idiopathic intradural lesions with compression of the spinal cord and clinical signs of radiculo- and/or myelopathy. We retrospectively analyzed radiological and clinical characteristics of patients with surgical treatment of SAC including a subgroup evaluation of long-term outcome and QoL.

METHOD

Patients with SAC treated between 1993 and 2017 were evaluated. Craniocaudal (c.c.) and anteroposterior (a.p) cyst diameters were measured pre- and post-OP. McCormick and Odom score for myelopathy, general outcome and QoL (SF-36, EORTC-QLQ30) were recorded.

RESULTS

A total of 72 patients (female:male = 1.9:1) were analyzed with mean FU of 44.8 ± 60 months (long-term data from 25 patients with FU 78.2 ± 63.9 months). All had surgery due to solitary cysts: 10 cervical (13.9%), 45 thoracic (62.5%), and 17 lumbosacral (23.6%), the majority (79.2%) located dorsally. Main symptoms were gait disturbance (80%), dysesthesia (64%) and paresis (80%). Patients had (hemi-)laminectomy with cyst fenestration in 48 (66.7%) and complete resection in 18 cases (25.0%). Four cases (5.5%) were treated by cystoperitoneal shunt, 2 by marsupialization (2.8%). In total, 11 revisions were necessary in 9/72 (12.5%) patients (one patient underwent 3 revisions). Two patients were reoperated for wound revision/epidural hematoma (each n = 1). Seven patients needed additional cyst wall resection after 1.5-31.0 months due to insufficient cyst shrinking and persistent clinical symptoms after first surgery; most of the cysts were multiple septated and of post-hemorrhagic origin. The mean c.c. size decreased from 5.2 ± 3.7 cm pre-OP to 2.7 ± 3.9 cm (p < 0.05); the a.p. diameter decreased from 1.0 ± 0.5 cm to 0.3 ± 0.3 cm (p < 0.0001) without significant differences between fenestration and resection. McCormick and Odom scores revealed improved symptoms, particularly of gait disturbance, sensory deficits, and general performance. Long-term FU displayed satisfying QoL performance without differences of fenestration or resection.

CONCLUSION

SAC mostly affect women and are predominantly located in the thoracic spine, becoming apparent with clinical myelopathy. For cysts without intracystic septae and compartments, both fenestration and resection of the cyst wall provided significant reduction of cyst size and clinical improvement.

Intradural Thoracic Arachnoid Cyst Fenestration for Spinal Cord Compression: A Case Illustration and Video Demonstration

Spinal intradural arachnoid cysts are rare, benign intradural lesions of the spinal cord that can arise as a primary lesion or secondary due to inflammatory processes. Symptoms can range from an asymptomatic incidental finding to progressive myelopathy, with paresthesia and neuropathic pain. We present the case of an 80-year-old female with a longstanding history of back pain, urinary incontinence, difficulty ambulating and frequent falls, with rapid progression of her symptoms prior to presentation. Physical examination revealed lower extremity weakness, decreased sensation and increased deep tendon reflexes. Thoracic spine MRI showed an extra-axial cystic lesion extending from T4 to T10, causing severe compression of the spinal cord. We performed two separate thoracic laminectomies at T4-T5 and at T9-T10, with microsurgical fenestration of the dorsal arachnoid cyst performed under continuous intraoperative neurophysiologic monitoring. Intraoperative fluoroscopy and ultrasound were used for localization purposes. The patient was discharged on postoperative day 6 to an inpatient rehabilitation facility with no neurological complications. She presented a month later with significant improvement in ambulation and lower extremity strength.

True Dural Spinal Epidural Cysts: Report of 5 Cases

BACKGROUND

Spinal arachnoid cysts are a rare cause of compressive myelopathy. Spinal extradural arachnoid cysts (SEACs) are even rarer.

METHODS

We retrospectively reviewed the SEACs operated on in our hospital between 2015 and 2019, according to their clinical and radiologic findings, treatments performed, and outcomes.

RESULTS

We identified 5 cases (2 males and 3 females), ranging in age from 21 months to 78 years. Except for the pediatric case, all patients presented with pain and 3 had some grade of neurologic impairment. Preoperative magnetic resonance imaging showed multiloculated cyst in 4 cases, and the communication with the dura was properly identified in only 1 case. The patients were operated through a laminectomy or laminoplasty and total removal of the cyst, and the communication with the dura was identified and repaired in all cases. In all cases, the defect was near the exit of a nerve root, and rootlets were seen through it, producing a ball-like valve mechanism. Histology of the cyst wall showed true dura in every case. One patient needed a reoperation for evacuation of a fluid collection (related to the dural sealant). Following Odom's criteria, 3 patients had an excellent outcome and 2 had a fair outcome.

CONCLUSIONS

Total excision of a symptomatic SEAC through either laminectomy or laminoplasty is a safe and effective treatment option. Although isolated repair of the dural communication without cyst removal may seem appealing, we have found it very difficult to identify the point of communication preoperatively.

Microsurgical excision of a compressive thoracic arachnoid cyst: Technical pearls

The key clinical message of this case is that it is critical to differentiate between arachnoid cysts and spinal cord herniation. This is performed by evaluating the ventral dura to assure that it remains intact.

Utilizing real-time contrast medium to detect the fistula of giant spinal arachnoid cyst and treat with minimal invasive surgery

BACKGROUND

Spinal arachnoid cysts are rare and have varied clinical manifestations depending on the affected spinal region and nerve roots. A complete cyst excision with fistula closure is the first choice of treatment. However, it might be difficult to localize the specific position of the fistula because previous images have no enhancements or the fistula is too tiny to be detected.

CASE PRESENTATION

This case is a giant lumbar extradural arachnoid cyst. We administered a lumbar injection with contrast medium into subarachnoid space under digital subtraction angiography (DSA) and disclosed the fistula. Confirming the location of fistula enabled us to perform minimally invasive surgery to ligate the fistula. Surgical intervention for a spinal arachnoid cyst might encounter the problem of the formation of a postoperative cerebrospinal fluid (CSF) fistula. We propose the option of detecting the fistula preoperatively for minimal invasive surgery. Recurrence depends on the long-term follow-up, and more cases are needed to further evaluate our technique.

CONCLUSIONS

The real-time contrast medium technique for spinal arachnoid cysts contributes to the complete ligation with minimally invasive surgery.