Intradural spinal arachnoid cysts in adults

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.

Spinal Arachnoid Cyst Analysis of Surgical Experience in a Single Tertiary Care Centre and Review of Literature

OBJECTIVE

To study patients with spinal arachnoid cysts, who underwent cyst excision with dural defect repair or marsupialization, and their outcomes.

METHODS

The retrospective analysis involved reviewing the records of 38 patients who underwent surgical treatment for spinal arachnoid cysts in the Department of Neurosurgery at Christian Medical College, Vellore, between August 2004 and December 2022. The study examined the demographics, clinical presentation, imaging, surgical intervention, and outcomes of these patients.

RESULTS

The majority of patients in the study were male (29/38, with 76.3%) and the thoracic region was the most common location for the cyst (17, with 44.7%). Weakness was the primary complaint and 94.7% of patients had myelopathy. The bladder was affected in 13 patients (34.2%). Of the 38 patients, 26 (71%) had cysts in extradural locations, while the rest were intradural. In total, 45.5% of intradural cysts were located in the ventral region. Seventeen (65.4%) had dural defects along the root sleeve and 29 (76.3%) underwent complete excision. All extradural cysts underwent complete excision and repair of the dural defect. Thirty patients (78.9%) experienced improved outcomes with reduced spasticity and improved weakness. One patient developed new-onset weakness postoperatively due to epidural hematoma. The mean follow-up period was 41 months and one patient experienced a recurrence.

CONCLUSIONS

Spinal arachnoid cyst is a rare benign spinal condition that is typically treated with surgery in symptomatic patients. Surgical intervention may involve either the excision of the cyst or marsupialization.

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.

Scalpel sign: Dorsal thoracic arachnoid web, thoracic arachnoid cyst and ventral cord herniation

The “Scalpel sign” is a radiological sign which can be identified on magnetic resonance imaging and indicates dorsal compression of the spinal cord [1]. Prior descriptions of a “Scalpel sign” have been reported in the literature and the awareness and identification of this pathognomonic sign may aid in the rapid diagnosis and treatment of patients with dorsal arachnoid web, dorsal arachnoid cyst or ventral cord herniation. We describe 3 cases which highlight these rare conditions for which this sign is pathognomonic and summarize the pertinent literature related to these disorders [1,2].

Cine MRI Is Useful for the Diagnosis of Intradural Arachnoid Cyst with Spinal Arachnoid Web: A Case Report

CASE

A 28-year-old woman developed gait disturbance due to lower limb weakness 3 years before presentation. Conventional magnetic resonance imaging (MRI) findings were inconclusive; therefore, we performed cine MRI, which confirmed the presence of a pulsatile cyst on the posterior thoracic spinal cord. The cyst compressed the spinal cord, and its pulsations synchronized with the patient's heartbeats. We resected the intradural arachnoid cyst and thickened arachnoid membrane. The gait disturbance improved after surgery.

CONCLUSIONS

Cine MRI can be used to identify a pulsating arachnoid cyst that cannot be visualized with a conventional MRI. Cine MRI is useful in patients with unexplained spinal symptoms.

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.

Ventral Intrameningeal Cyst Treatment and Management: Technical Note

BACKGROUND

Intrameningeal cysts are rare lesions without definitive etiologies that can involve the dura or arachnoid mater. Spinal arachnoid cysts have been described, and several different etiologies have been hypothesized. This includes one-way valve mechanisms, traumatic herniation of arachnoid through the dura, and abnormal arachnoid membrane proliferation. To the authors' knowledge, no such descriptions exist regarding purely dural-based cystic lesions; however, the authors hypothesize similar mechanisms may be involved. Most notably, a traumatic injury to the dura leading to a one-way valve mechanism may allow for egress of cerebrospinal fluid (CSF) between the dural layers, splitting them open. This progressive enlargement can lead to displacement of neural elements and subsequent neurological compromise.

METHODS

We describe a 17-year-old girl who presented with progressive neck and back pain, left-upper extremity numbness, bilateral lower-extremity weakness, paresthesias, and numbness without obvious etiology despite an extensive neurologic investigation. She had undergone conservative management options including multiple medications, physical and chiropractic therapy, and epidural steroid injections. Computed tomography myelography revealed a CSF leak into the lumbar epidural space for which surgical exploration was performed. Despite utilizing fluoroscopy and intrathecal fluorescein, no leak source was identified. Fluid collection was found contained within the dural layers rather than the epidural space.

RESULTS

An intracystic blood patch was performed with near-complete resolution of the lesion by 6-week follow-up and near-complete return of neurologic function.

CONCLUSION

Ventral panspinal cysts are an exceedingly rare cause of radiculopathy and myelopathy that can be resolved by an intracystic blood patch.

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.

Neuropathic pain after spinal intradural benign tumor surgery: an underestimated complication?

Neuropathic pain presents a burdening and impairing condition which may occasionally occur after spinal tumor surgery. While it has been described in peripheral nerve sheath tumors, data on other intradural tumor patients is sparse. We hereby present a large cohort population undergoing different intradural spinal tumor surgery with assessment of early postoperative and follow-up outcomes, focusing on the occurrence of neuropathic pain. We performed a retrospective monocentric study including all patients treated for intradural spinal tumors between 2009 and 2020. We extracted surgical aspects as well as pre- and postoperative clinical courses from the records. Statistical analysis of potential contributing prognostic factors was performed including matched pair analysis. In total, 360 patients were included for analysis. At a median follow-up of 2 years, 26/360 patients complained of a neuropathic pain syndrome (7.2%) requiring continuous medication. Of these patients only 50% complained preoperatively of pain. Tumor entity did not significantly influence the incidence of postoperative neuropathic pain (p = 0.91). Sacrifice of the tumor carrying nerve root and tumor recurrence also did not increase the risk for this condition. Persistent neuropathic pain requiring continuous treatment occurred in 7.2% of patients undergoing intradural spinal surgery in our cohort. This frequently underestimated postoperative adverse event represents a disabling condition leading to a substantial impairment in the quality of life among the affected patients.

Iatrogenic Spinal Deformity Following Spinal Intradural Arachnoid Cyst Fenestration Despite Minimal Access With Laminoplasty and Endoscopy in a Pediatric Patient

Spinal intradural arachnoid cysts (SAC) are non-neoplastic lesions that can cause spinal cord compression and present with myelopathy, radiculopathy, and/or back pain. Because these cysts typically span multiple levels, endoscopy could be a useful tool to avoid wide exposure. We present an 8-year-old patient with a history of gait imbalance and urinary incontinence who was found to have a SAC spanning C7 to T6 causing spinal cord compression. An osteoplastic laminoplasty was performed from T4 to T7 followed by ultrasonic verification of intracystic septations, dural opening, and cyst fenestration. A flexible endoscope was then introduced into the cystic cavity to guide complete rostral and caudal decompression of the arachnoid cyst. At six months follow-up, the patient was able to ambulate independently, but his urinary incontinence remained unchanged. Despite the combination of ultrasound and neuroendoscopy to minimize exposure, our patient suffered from worsening kyphosis from 36 degrees preoperative to 55 degrees postoperative and worsening scoliosis from 17 to 39 degrees which required treatment with a thoracolumbar sacral orthosis. Preoperative imaging demonstrated a reverse S-shaped scoliosis with the apex at T6 and T7 which were the levels included in the laminoplasty. This illustrates the need for careful preoperative risk stratification to avoid this postoperative complication.

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.

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.

The management of Chiari malformation type 1 and syringomyelia in children: a review of the literature

In anticipation of the "Chiari and Syringomyelia Consensus Conference" held in Milan in 2019, we performed a systematic literature review on the management of Chiari malformation type 1 (CM1) and syringomyelia (Syr) in children.We aimed to summarize the available evidence and identify areas where consensus has not been reached and further research is needed.In accordance with PRISMA guidelines, we formulated seven questions in Patients-Interventions-Comparators-Outcomes (PICO) format. Six PICOs concerned CM1 children with/without additional structural anomalies (Syr, craniosynostosis, hydrocephalus, tethered cord, and cranio-vertebral junction anomalies), and one PICO Syr without CM1. We searched Medline, Embase, Cochrane, and NICE databases from January 1, 1999, to May 29, 2019. Cohort studies, controlled and randomized clinical trials (CCTs, RCTs), and systematic reviews were included, all pertinent only to patients ≤ 18 years of age.For CM1, 3787 records were found, 460 full texts were assessed and 49 studies (46 cohort studies, one RCT, and two systematic reviews) were finally included. For Syr, 376 records were found, 59 full texts were assessed, and five studies (one RCT and four cohort studies) were included. Data on each PICO were synthetized narratively due to heterogeneity in the inclusion criteria, outcome measures, and length of follow-up of the included studies.Despite decades of experience on CM1 and Syr management in children, the available evidence remains limited. Specifically, there is an urgent need for collaborative initiatives focusing on the adoption of shared inclusion criteria and outcome measures, as well as rigorous prospective designs, particularly RCTs.

Spinal Arachnoid Web: A didactic report of two cases with clinical, radiological, surgical and pathological correlations

BACKGROUND

Arachnoid web (AW) is a rare but probably underestimated cause of spinal cord injury that is complex to diagnose due to subtle MRI findings and similarities to other better-known diseases such as arachnoid cyst (AC) or transdural spinal cord herniation (TSCH). Increased recognition of AW is mandatory since delay in diagnosis can lead to potentially serious neurological sequelae.

CASE PRESENTATIONS

We report two additional cases of AW for didactic purposes, with special emphasis on the distinctive MRI and intraoperative findings. Both patients presented with progressively worsening neurological symptoms, including proprioceptive ataxia, motor weakness, numbness and neuropathic pain. The diagnosis of AW was suspected on the basis of specific MRI criteria, especially the so-called "scalpel sign". Formal confirmation of the diagnosis was obtained in two patients that were managed surgically. Postoperative follow-up demonstrated significant functional recovery.

DISCUSSION

There is a need for better recognition of AW by the medical community. Careful analysis of MRI semiology is crucial for the distinction between AW, AC and TSCH. Prompt and accurate diagnosis is mandatory to conserve functional prognosis, since appropriate surgical treatment with AW resection is curative, halting or even resolving the neurological symptoms.

Enhanced Safety of Pedicle Subtraction Osteotomy Using Intraoperative Ultrasound

BACKGROUND

Pedicle subtraction osteotomy (PSO) can improve sagittal alignment but carries risks, including iatrogenic spinal cord and nerve root injury. Critically, during the reduction phase of the technique, medullary kinking or neural element compression can lead to neurologic deficits.

METHODS

We describe 3 cases of thoracic PSO and evaluate the feasibility, findings, and utility of intraoperative ultrasound in this setting.

RESULTS

Intraoperative ultrasound can provide a visual assessment of spinal cord morphology before and after PSO reduction and influences surgical decision making with regard to the final amount of sagittal plane correction. This modality is particularly useful for confirming ventral decompression of disc-osteophyte complex before reduction and also after reduction maneuvers when there is kinking of the thecal sac but uncertainty about the underlying status of the spinal cord. Intraoperative ultrasound is a reliable modality that fits well into the technical sequence of PSO, adds a minimal amount of operative time, and has few limitations.

CONCLUSIONS

We propose that intraoperative ultrasound is a useful supplement to standard neuromonitoring modalities for ensuring safe PSO reduction and decompression of neural elements.

Neuroimaging findings and pathophysiology of dorsal spinal arachnoid webs: illustrative case

BACKGROUND

Spinal arachnoid webs are uncommon and difficult to diagnose, especially because causative intradural transverse bands of arachnoid tissue are radiographically occult. Left untreated, arachnoid webs may cause progressive, debilitating, and permanent neurological dysfunction. Conversely, more than 90% of patients may experience rapid neurological recovery after resection, even with a prolonged duration of presenting symptoms. Indirect imaging signs such as spinal cord indentation and compression with cerebrospinal fluid (CSF) flow alteration provide crucial diagnostic clues that are critical in guiding appropriate management of such patients.

OBSERVATIONS

The authors reported a patient with no significant medical history who presented with back pain, progressive lower extremity weakness, gait ataxia, and bowel and bladder incontinence. They discussed multimodality imaging for determining the presence of arachnoid webs, including magnetic resonance imaging, phase-contrast CSF flow study, computed tomography myelography, and intraoperative ultrasound. They also discussed the detailed anatomy of the spinal subarachnoid space and a plausible pathophysiological mechanism for dorsal arachnoid webs.

LESSONS

The authors report on a patient who underwent comprehensive imaging evaluation detailing the arachnoid web and whose subsequent anatomical localization and surgical treatment resulted in a full neurological recovery.

Surgical outcome of primary intradural spinal arachnoid cysts: a series of 10 cases

Background

Primary intradural spinal arachnoid cysts are rare pathologies of uncertain etiology and variable presentation from no symptoms to myelopathy or radiculopathy according to cord or root compression. MRI with diffusion and contrast differentiates them from many pathologies. There is a lot of debate regarding when to treat and how to treat such rare pathologies.

Objective

We present a series of 10 primary intradural arachnoid cysts and evaluate outcome after surgery.

Methods

This retrospective study includes patients having primary intradural spinal arachnoid cysts operated in two tertiary care centers from October 2012 till October 2019. Symptomatic cysts were subjected to microsurgical resection or outer wall excision and inner wall marsupialization under neurophysiological monitoring. The Japanese Orthopedic Association Score was used for clinical evaluation while MRI with contrast and diffusion was used for radiological evaluation before and after surgery.

Results

This series included 10 patients, 4 males and 6 females, with mean age of 40 years. Pain was the most common presentation. The most common location was dorsal thoracic region. Total excision was achieved in 2 cases and marsupialization in 8 cases.

All symptoms improved either completely or partially after surgery. No neurological deterioration or recurrence was reported during the follow-up period in this series.

Conclusion

Treatment of symptomatic primary intradural spinal arachnoid cysts should be microsurgical resection, when the cyst is adherent to the cord, microscopic fenestration can be safe and effective.

Posttraumatic Arachnoid Cyst in the Thoracic Spine with Medullary Compression: Case Report

Arachnoid cysts are rare; they can occur at all levels of the dural sac, and can have a congenital, traumatic, iatrogenic or inflammatory origin. In the present article, we report a patient presenting a compressive thoracic myelopathy due to an unusual intradural arachnoid cyst with posttraumatic manifestation and its resolution, in addition to a literature review on the subject. These cysts mainly occur at the thoracic spine, followed by the lumbar, lumbosacral and thoracolumbar spines. Traumatic cysts are caused by an injury to the inner dural layer. These lesions produce neurological deficits through a mass effect on the spinal cord. Concomitant compressive myelopathy is even rarer. In case of myelopathy, cyst resection or drainage is the treatment of choice, and it must be performed immediately. Although rare, arachnoid cysts can be a complication of spine fractures; as such, orthopedists and neurosurgeons, who commonly see these injuries, must be prepared for this unusual situation.

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.

Upper cervical spinal bronchogenic cyst: A rare lesion at an exceptional location

An intraspinal bronchogenic cyst is a rare but important cause of compressive cord myelopathy, commonly seen in the cervicothoracic spine. We report a case of a 30-year-old female, presented with complaints of neck pain and progressive weakness of the extremities. The magnetic resonance imaging of the cervical spine revealed an intradural extramedullary, well-defined, multiloculated, cystic lesion in the upper cervical canal extending from the C2 to C5 vertebral levels. To our knowledge, only 11 cases of spinal bronchogenic cysts have been reported in the literature so far. We discuss the rare location of this unusual lesion, possible embryological reasons, and the overall surgical outcome.

Nonfusion Muscle-Sparing Technique to Treat Long-Segment Thoracolumbar Extradural Arachnoid Cyst in a Child: A Case Report and Review of the Literature

BACKGROUND

Spinal extradural arachnoid cyst is an uncommon cause of spinal cord compression. It results from a small dural defect that leads to cerebrospinal fluid (CSF) accumulation in the cyst and subarachnoid space, and the cyst can compress the spinal cord and nerve roots. Surgery is the treatment of choice in symptomatic patients, and most cases have an immediately satisfying outcome after surgery.

CASE DESCRIPTION

A 10-year-old Thai boy presented with progressive weakness in both legs. Magnetic resonance imaging (MRI) demonstrated a giant cystic lesion 23 cm in length from T1-L2 level. To our knowledge, this is the longest arachnoid cyst that has been reported in children. The operation included unilateral paraspinal muscle dissection with spinous process translation techniques, T1-L4 laminectomy, total cyst excision, and dural defect repair at the T4 level. The symptoms were fully resolved within 2 months after surgery. However, thoracic kyphosis was slightly increased, but the patient still has a normal sagittal profile.

CONCLUSIONS

Spinal arachnoid cyst is rare, especially in children. Early diagnosis and treatment are essential for improving the chance of full recovery, and for avoiding complication and irreparable defect. Total cyst removal with dural repair remains the best treatment alternative; however, potential complications, especially spinal malalignment after extensive laminectomy, must be considered. Postoperative MRI showed normal CSF flow and no spinal cord compression. The muscle-sparing technique with multiple-level laminectomy without spinal fusion that we used in this case provided a satisfying outcome.

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.

Diagnostic Dilemma in Discriminating Between Spinal Neurenteric Cysts and Simple Arachnoid Cysts Based on Embryogenesis and Surgical Correlation

BACKGROUND

Neurenteric cyst (NEC) is a rare intradural spinal tumor, but a correct preoperative diagnosis remains challenging. A misdiagnosis of arachnoid cyst (AC) often leads to conflicting surgical management and significantly higher recurrence.

CASE DESCRIPTION

We report the case of a 26-year-old woman who presented with progressive spastic quadriparesis with myelopathy below the C4 level, which was caused by a ventral intradural extramedullary cystic tumor at the C3-4 level. Magnetic resonance images showed the cystic content as identical to cerebrospinal fluid, which prompted the tentative diagnosis of spinal AC. Surgical fenestration was scheduled. However, intraoperative findings of a thick-walled cyst and severe adhesion to the neural structure without a history of trauma and inflammation were more compatible with the pathogenesis of an NEC. Because of the high recurrence rate after an incomplete resection of an NEC, we did a complete resection of the cyst with adhesive rootlets instead. Pathology analysis and immunohistochemical staining confirmed the diagnosis of an endodermal-derived NEC.

CONCLUSIONS

NECs must be differentiated from ACs because they are different diseases and require different surgical management. In cases with clear cystic content, however, the diagnosis is likely to be AC, but a thick cystic wall and structural adhesions should suggest the differential diagnosis of NEC. Gross total removal of NECs should be attempted to reduce NEC recurrence.

Cervical Cerebrospinal Fluid Leakage Concomitant with a Thoracic Spinal Intradural Arachnoid Cyst

We encountered a very rare case of spontaneous spinal cerebrospinal fluid (CSF) leakage and a spinal intradural arachnoid cyst (AC) that were diagnosed at different sites in the same patient. These two lesions were thought to have interfered with the disease onset and deterioration. A 30-year-old man presented with sudden neck pain and orthostatic headache. Diplopia, ophthalmic pain, and headache deteriorated. CSF leakage was confirmed in C2 by radioisotope cisternography, and an epidural blood patch was performed. While his symptoms improved gradually, paraparesis suddenly progressed. Thoracolumbar magnetic resonance imaging (MRI) revealed an upper thoracic spinal intradural AC, which was compressing the spinal cord. We removed the outer membrane of the AC and performed fenestration of the inner membrane after T3-4 laminectomy. Postoperative MRI showed complete removal of the AC and normalized lumbar subarachnoid space. All neurological deficits including motor weakness, sensory impairment, and voiding function improved to normal. We present a case of spontaneous spinal CSF leakage and consecutive intracranial hypotension in a patient with a spinal AC. Our report suggests that if spinal CSF leakage and a spinal AC are diagnosed in one patient, even if they are located at different sites, they may affect disease progression and aggravation.

Recurrence of a symptomatic spinal intradural arachnoid cyst 29 years after fenestration

Symptomatic arachnoid cysts are relatively rare, and no case reports have described recurrence of such cysts almost 30 years after surgery. We herein report a case in which a symptomatic intradural arachnoid cyst recurred 29 years after fenestration of the primary lesion. The patient was a 64-year-old woman who presented with paralysis of the left lower limb. She had undergone surgical treatment for an intradural arachnoid cyst at the T12 level 29 years previously. Magnetic resonance imaging (MRI) revealed an intradural mass at the T12–L1 level. The mass was compressing the spinal cord and cauda equina. Its localization and shape on MRI were similar to those of the primary cyst 29 years previously. Partial resection was performed under a diagnosis of a recurrent intradural arachnoid cyst. After surgery, the patient’s left lower limb paralysis improved. The pathological findings were suggestive of an intradural arachnoid cyst. The MRI findings 29 years previously provided useful information. The possibility of very late recurrence should be considered in patients who undergo surgical removal of intradural arachnoid cysts.

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

OBJECTIVEAdult spinal arachnoid cysts (SACs) are rare entities of indistinct etiology that present with pain or myelopathy. Diagnosis is made on imaging studies with varying degrees of specificity. In symptomatic cases, the standard treatment involves surgical exploration and relief of neural tissue compression. The aim of this study was to illustrate features of SACs in adults, surgical management, and outcomes.METHODSThe authors searched medical records for all SACs in adults in the 10-year period ending in December 2016. Radiology and pathology reports were reviewed to exclude other spine cystic disorders. Recurrent or previously treated patients were excluded. Demographic variables (age, sex) and clinical presentation (symptoms, duration, history of infection or trauma, and examination findings) were extracted. Radiological features were collected from radiology reports and direct interpretation of imaging studies. Operative reports and media were reviewed to accurately describe the surgical technique. Finally, patient-reported outcomes were collected at every clinic visit using the SF-36.RESULTSThe authors' search identified 22 patients with SACs (mean age at presentation 53.5 years). Seventeen patients were women, representing an almost 3:1 sex distribution. Symptoms comprised back pain (n = 16, 73%), weakness (n = 10, 45%), gait ataxia (n = 11, 50%), and sphincter dysfunction (n = 4, 18%). The mean duration of symptoms was 15 months. Seven patients (32%) exhibited signs of myelopathy. All patients underwent preoperative MRI; in addition, 6 underwent CT myelography. SACs were located in the thoracic spine (n = 17, 77%), and less commonly in the lumbar spine (n = 3, 14%) and cervical/cervicothoracolumbar region (n = 2, 9%). Based on imaging findings, the cysts were interpreted as intradural SACs (n = 11, 50%), extradural SACs (n = 6, 27%), or ventral spinal cord herniation (n = 2, 9%); findings in 3 patients (14%) were inconclusive. Nineteen patients underwent surgical treatment consisting of laminoplasty in addition to cyst resection (n = 13, 68%), ligation of the connecting pedicle (n = 4, 21%), or fenestration/marsupialization (n = 2, 11%). Postoperatively, patients were followed up for an average of 8.2 months (range 2-30 months). Postoperative MRI showed complete resolution of the SAC in 14 of 16 patients. Patient-reported outcomes showed improvement in SF-36 parameters. One patient suffered a delayed wound infection.CONCLUSIONSIn symptomatic patients with imaging findings suggestive of spinal arachnoid cyst, surgical exploration and complete resection is the treatment of choice. Treatment is usually well tolerated, carries low risks, and provides the best chances for optimal recovery.

Intradural spinal arachnoid cyst contributing to sudden paraparesis

Background:

Spinal arachnoid cysts are cystic lesions filled with cerebrospinal fluid that contributes to neurological deficits depending on their size/location within the spinal canal. Here, we report a patient with a spinal subarachnoid cyst who suddenly developed paraparesis.

CASE Description:

A 37-year-old female with a thoracic spinal arachnoid cyst at the T7 level suddenly developed lower abdominal pain followed by immediate paraparesis. Two weeks following the onset of symptoms, she underwent a T6-T8 laminectomy; this included with full cyst excision. By the 4^th postoperative week, her signs/symptoms fully resolved.

Conclusions:

A 37-year-old female with a T7 thoracic spinal subarachnoid cyst who presented with acute paraparesis regained normal function 2 weeks following a T6-T8 laminectomy.

Intramedullary bronchogenic cyst in the foramen magnum region accompanied with syringomyelia: A case report and literature review

RATIONALE

Bronchogenic cysts refer to congenital anomalies derived from the primitive foregut. Spinal bronchogenic cysts are uncommon entities, and those occurring in the intramedullary sites are extremely rare. Bronchogenic cysts involving the foramen magnum region have only been described in 2 cases; however, intramedullary bronchogenic cysts with syringomyelia have not yet been reported.

PATIENT CONCERNS

A 46-year-old woman presented with a 6-month history of pain in the posterior neck region and a 1-month history of numbness in the upper extremities. Neurological examination revealed a loss of sensation in bilateral upper extremities and sensory dissociation. Magnetic resonance imaging (MRI) showed an intramedullary cystic lesion in the foramen magnum region and syringomyelia.

DIAGNOSIS

Histopathological findings were consistent with a bronchogenic cyst.

INTERVENTIONS AND OUTCOMES

A surgical resection of the cystic lesion was performed via a posterior midline approach. Under neurophysiological monitoring, the cyst was punctured, yielding gelatinous liquid. The dorsal part of the cystic wall was removed. One month postoperatively, the symptoms were resolved completely. Three months after operation, MRI showed no recurrence of the cyst and the syringomyelia disappeared.

LESSONS

Intramedullary bronchogenic cysts with syringomyelia are extremely rare. Preoperative identification is challenging and definitive diagnosis depends on histopathological evidence. Timely surgical resection should be highlighted.

Surgical treatment of a thoracic ventral intradural arachnoid cyst associated with syringomyelia: case report

The pathogenesis of thoracic ventral intradural spinal arachnoid cyst (ISAC) is unknown due to its extremely low incidence. In addition, its surgical treatment is complicated because of the ventral location, large craniocaudal extension, and frequent coexistence of syringomyelia. The optimal surgical strategy for thoracic ventral ISAC remains unclear and continues to be a matter of debate. In this report, the authors describe an extremely rare case presenting with a compressive thoracic ventral ISAC associated with syringomyelia that was successfully treated with a simple cyst-pleural shunt. The patient’s medical history revealed bacterial spinal meningitis along with an extensive spinal epidural abscess, suggesting the incidence of extensive adhesive arachnoiditis (AA) to be a plausible cause for this pathology. Thoracic ventral ISAC reportedly occurs secondary to AA and is commonly associated with syringomyelia. Placement of a cyst-pleural shunt is an effective, safe, and uncomplicated surgical strategy, which can provide sufficient cyst drainage regardless of the coexistence of AA, and thus should be considered as primary surgical treatment. Syrinx drainage could be reserved for a later attempt in case the cyst-pleural shunt fails to reduce the extent of syringomyelia.

Symptomatic extradural spinal arachnoid cyst: More than a simple herniated sac

Introduction and Study Design:

Spinal arachnoid cyst is an uncommon entity, presenting with radiculopathy or paraparesis. These cysts are usually found in intradural extramedullary region; and the extradural region is a rare location. The exact pathogenesis in the existence of these cysts in the extradural region is still debated. In this article, we have retrospectively analyzed the clinical profile of the rare extradural arachnoid cyst (EDAC).

Methodology:

In this study, 19 patients of EDAC operated at our institute between January 2006 to June 2016 are analyzed. All patients with the Oswestry disability index score of >20 were managed surgically (open laminectomy and cyst excision). The clinical outcome was assessed at using 5-point satisfaction scale and McCormick grading.

Results:

All 13 operated patients had EDACs with communication with the intradural compartment. In 11 (84.6%) patients, cyst wall was excised completely, in 2 (15.3%) patients underwent partial excision of cyst wall; dural communication was closed in all patients (n = 13). None of the patients had clinical deterioration or radiological recurrence till the last follow-up. Mean follow-up was 52.2 months (range 1–160); all patients were satisfied after surgery (median score was 3).

Discussion:

Symptomatic EDACs account <2% of all spinal tumors. The EDACs have communication with the intradural compartment. In our article, we have discussed the approach and management of EDAC, including minimally invasive percutaneous procedures.

Conclusion:

One should aim for preoperative or intraoperative localization of dural communication and try to disconnect the extradural cyst from the intradural connection to prevent recurrence. Surgical treatment is complete excision of the cyst.

Direct puncture for diagnosis of intradural spinal arachnoid cyst and fenestration using 3D rotational fluoroscopy: technical note and the "jellyfish sign"

The authors report on a 47-year-old woman with a symptomatic thoracic spinal arachnoid cyst (SAC) who underwent a novel procedure that involves direct puncture of the SAC to visualize, diagnose, and potentially treat these rare spinal lesions. The method described utilizes 3D fluoroscopy to gain access to the SAC, followed by injection of myelographic contrast into the cyst. A characteristic "jellyfish sign" was observed that represents the containment of the contrast within the superior aspect of the cyst and a clear block of cranial flow of contrast, resulting in an undulating pattern of movement of contrast within the cyst. Following balloon fenestration of the cyst, unimpeded flow of contrast was visualized cranially throughout the thoracic subarachnoid space. The patient was discharged the following day in good condition, and subsequently experienced 1 year free from symptoms. This is the first reported case of a successful direct puncture of an SAC with balloon fenestration, and the first noted real-time fluoroscopic "behavior" of CSF within an arachnoid cyst.

Resection of an extensive thoracic arachnoid cyst via less-invasive targeted laminoplasties

OBJECTIVE

Spinal arachnoid cysts are a known cause of spinal cord compression. When symptomatic, treatment of choice entails laminectomies over the length of the cyst in order to achieve complete cyst removal and fenestration.

METHODS

A 60-year-old woman presented with a one-year history of progressive pain between the shoulder blades, exacerbated by sitting up or standing, and relieved by lying supine. MRI imaging revealed a T3-T7 dorsal intradural arachnoid cyst. Due to extant spinal deformity and medical comorbidity, the decision was made to proceed with selective laminoplasties at the superior and inferior limits of the cyst.

RESULTS

After the dura was opened to reveal the margins, the cyst was sharply fenestrated and drained. Irrigation was passed through the cyst to ensure open communication, and a lumbar drain catheter was passed from the inferior to superior margin. The catheter was removed before closure. Postoperatively, MRI of the thoracic spine revealed decompression of the spinal cord and the patient noticed improvement in her symptoms. At 7-month follow-up, the patient remained free of symptoms and MRI demonstrated near-complete resolution of the cyst.

CONCLUSION

Although open exposure and complete resection are considered the treatment of choice for spinal arachnoid cysts, cyst fenestration through selective bony windows at the margins of the cyst represents a viable, less invasive alternative approach to effective cyst decompression, and can be considered in patients in whom a full exposure would be prohibitive.

Cord Splitting Access to Ventral Intradural Cysts of Cervicothoracic Junction and Thoracic Spine

OBJECTIVE

Surgical treatment of ventrally located intradural cysts is difficult and controversial. Laminectomy with division of the denticulate ligaments and gentle cord mobilization remains the standard approach but risks further neurologic deterioration secondary to cord manipulation. Our purpose is to evaluate the safety and effectiveness of a midline cord-splitting approach as an alternative for treating ventral thoracic intradural cysts.

METHODS

We describe 2 patients who were treated for ventral intradural cysts causing progressive and severe myelopathy. Under general anesthesia and continuous neurophysiologic monitoring, laminectomy, durotomy, and cord splitting through a midline approach gave direct access to both lesions. Cyst drainage was supplemented by a cystopleural shunt in 1 case.

RESULTS

Cyst collapse and cord reexpansion were documented in both patients with a magnetic resonance imaging scan 1 week after surgery. In both cases there was a significant neurologic improvement, which was maintained 2 years postoperatively. Intraoperative monitoring recorded no loss of somatosensory or motor potentials during surgery. Follow-up magnetic resonance imaging scans 2 years postoperatively showed no evidence of cyst recurrence, and both patients remained neurologically improved and stable.

CONCLUSIONS

We have been able to drain 2 ventral intradural cysts using a cord-splitting technique. This has allowed safe access to purely ventrally located lesions, which were inaccessible dorsally or dorsolaterally. By using this method we have been able to avoid a more invasive ventral transthoracic approach necessitating vertebrectomy and reconstruction and risking serious complications.

Clinical Outcomes of Surgical Treatment for Arachnoid Web: A Case Series

Introduction

We describe 5 patients who underwent operative treatment for arachnoid web (AW) and discuss the postoperative clinical outcome in each case. AW is an extremely rare disease that causes cord compression and syringomyelia in the thoracic spine. To date, 14 cases only of AW have been reported, and the effect of surgical intervention on clinical and radiologic outcomes is unknown.

Methods

Five patients who underwent surgical treatment for AW were retrospectively reviewed. The clinical outcomes were evaluated using the thoracic Japanese Orthopaedic Association (T-JOA) score. Preoperative and postoperative images were reviewed.

Results

All the patients presented with spastic gait and numbness in the lower extremities. Two patients also presented with bladder-bowel dysfunction (BBD). AW, or the so-called “scalpel” sign, was seen dorsally in the thoracic spine on magnetic resonance imaging in all the patients. Syringomyelia adjacent to the web was observed in 4 patients. Fenestration and web resection without instrumentation was performed in all the cases. Overall, significant improvement was seen in locomotion and the total T-JOA score postoperatively. However, numbness in the lower extremities improved in 2 patients but was unchanged in 3 cases. BBD was ameliorated in 1 patient but remained unchanged in the other patient.

Conclusions

Our experience suggests that surgical treatment, including the another patient and resection of the web, can correct the flow dynamics of cerebrospinal fluid and allow neurologic recovery, in particular locomotion, in patients with AW.

Intradural spinal arachnoid cyst resection: implications of duraplasty in a large case series

OBJECTIVE Optimal diagnosis and management strategies for intradural spinal arachnoid cysts (SACs) are still unresolved given the rare nature of this entity, with few large case series and virtually no statistical analyses of patient characteristics in the literature. Here, the authors studied a large patient cohort with these lesions to determine whether pre- or postoperative attributes could be used to aid in either diagnosis or prognosis. METHODS A chart review was completed at a single institution for the period from 2002 to 2016 to determine the preoperative characteristics and postoperative outcomes of 21 patients with exclusively intradural SACs. Patients were assessed for symptoms such as weakness, pain, sensory changes, bowel and/or bladder dysfunction, and gait changes. Postoperatively, patients were analyzed for symptom improvement, complication occurrence, and duration of follow-up. RESULTS Approximately two-thirds of the patients in this series had developed SACs idiopathically, and the mean duration of symptoms prior to diagnosis was 15 months among all patients. A slight majority (57%) underwent CT myelography in the course of diagnosis, and a quarter of the patients had a syrinx. There was a statistically significant association between location of the SAC and number of presenting signs and symptoms; that is, patients with cysts in the lumbosacral region had more symptoms than those with cysts at the cervical or thoracic levels (p = 0.031). Overall, outcomes were largely positive, with approximately 60%-70% of patients experiencing postoperative improvement in symptoms, with motor weakness showing the highest response rate (71%) and pain symptoms the least likely to subside (50%). In the cohort with preoperative pain, those who had undergone expansile duraplasty were significantly more likely to experience relief of their pain symptoms (p = 0.028), which may have been a result of the superior restoration of cerebrospinal fluid pathways allowing for more adequate reduction in compression. CONCLUSIONS In this large case series on intradural SACs, new light has been shed on aspects of both pre- and postoperative care for patients with these rare lesions. Specifically, the authors revealed that lumbosacral intradural SACs may be associated with a higher disease burden and that patients who undergo expansile duraplasty may have an increased likelihood of experiencing postoperative pain relief.

Surgical management of a thoracic extradural arachnoid cyst with communication to subarachnoid space through nerve root: a case report

Spinal extradural cysts are uncommon and may cause cord and nerve root compression. The cysts usually appear in thoracic spine. We report a 29-year-old man with an extradural arachnoid cyst from T4 to T6. The cyst was communicated to the subarachnoid space through a fistula at the left T6 nerve root. To access the fistula, we had to unroof the foramen of left T6 nerve root which could lead to spinal instability. We decided to save the bony and soft tissue elements of the foramen at the mentioned thoracic spine level. Therefore, the cyst walls were excised and then the ostia of the cyst at the cystic side of the fistula was tightly closed.

Postepidural Spinal Intradural Arachnoid Cyst: A Rare Case Report

Compression of the neural structures in spine by an intradural arachnoid cyst is a rare entity. At times such a cyst is an incidental finding. Spinal epidural injection is one of the few rare etiological factors for its development. Symptomatic cysts can present with variable neurological manifestations depending on the spinal level involved. This includes back pain, lower limb weakness, and sphincteric dysfunction. If asymptomatic, they can be followed radiologically. Surgical decompression along with a histological diagnosis is reserved for cysts that are enlarging, symptomatic or the ones for whom the diagnosis is uncertain. Incomplete excision of cyst wall or simple fenestration and decompression mandates close follow-up, clinically and radiologically for further recurrences.

Conventional and Advanced Imaging of Spine Oncologic Disease, Nonoperative Post-treatment Effects, and Unique Spinal Conditions

In this review, we discuss the imaging features of diseases and conditions ranging from neoplastic to nonoperative post-treatment effects to unique conditions of the spine. Additionally, advanced imaging may increase diagnostic certainty in cases where conventional imaging characteristics of benign lesions and malignant pathology are variable.

Clinical and Radiologic Outcomes After Fenestration and Partial Wall Excision of Idiopathic Intradural Spinal Arachnoid Cysts Presenting with Myelopathy

BACKGROUND

Intradural spinal arachnoid cysts (ISACs) with associated neurologic deficits are encountered infrequently. Various management strategies have been proposed with minimal data on comparative outcomes.

OBJECTIVE

We describe the clinical and radiologic presentation as well as the outcomes of 14 surgically managed patients who presented with an ISAC and associated myelopathy.

METHODS

We retrospectively reviewed the clinical course of consecutive patients presenting with neurologic deficits associated with idiopathic ISACs at our institution. The diagnoses were based on preoperative magnetic resonance imaging studies followed by intraoperative and histopathological confirmation.

RESULTS

A total of 14 consecutive patients with ISACs (1 cervicothoracic, 12 thoracic, and 1 thoracolumbar) and associated myelopathy were identified. Syringomyelia was noted in 8 patients. All ISACs were treated with cyst fenestration and partial wall resection through a posterior approach. Preoperative neurologic symptoms were noted to be stable or improved in all patients starting at 6-week postoperative follow-up. The median (interquartile range) preoperative mJOA score was 13 (12.0-14.8), whereas the postoperative median score at a mean follow-up of 22 months (range 6-50 months) was 16 (14.0-17.0), which represents a median improvement (ΔmJOA) of 2.0 (1.3-3.0) (P < 0.001). Comparison of ΔmJOA scores between cases without and with associated syrinxes did not reveal a significant difference (P = 0.23). Postoperative magnetic resonance imaging scans revealed spinal cord re-expansion at the level of the ISAC in all cases and either complete or partial syrinx resolution in 7 of 8 cases.

CONCLUSIONS

Early treatment with fenestration and partial wall resection allows for cord decompression, syrinx resolution, and gradual resolution of myelopathic symptoms in most cases.

Idiopathic intradural dorsal thoracic arachnoid cysts: A case series and review of the literature

BACKGROUND

Spinal intradural arachnoid cysts (SIAC) are cerebrospinal fluid (CSF) filled sacs formed by arachnoid membranes and may be either idiopathic or acquired. Idiopathic cysts represent a separate entity and their aetiology remains uncertain. By far the most difficult differential diagnosis is distinguishing between idiopathic anterior spinal cord herniation (IASCH) and dorsal thoracic intradural arachnoid cysts (TIAC), due to their similarity in radiological appearance. Cine-mode (SSFP) is emerging as a novel technique in the diagnosis and operative planning of SIAC.

METHOD

Retrospective analysis of patients with idiopathic TIACs that were surgically managed at Royal North Shore Hospital and North Shore Private Hospital between November 2000 and November 2015.

RESULTS

Ten patients were included in this study. Age ranged from 20 to 77years with a mean age of 60years and a female preponderance. The most common clinical features were progressive gait ataxia and lower limb myelopathy. Radicular pain tends to improve following surgery, however gait ataxia may not.

DISCUSSION

While there are circumstances in which the distinction between dorsal thoracic intradural arachnoid cysts and idiopathic anterior spinal cord herniation are radiologically obvious, in cases where the appearances are less clear, cine-mode SSFP MRI imaging can provide an invaluable tool to differentiate these pathologies and lead the clinician towards the correct diagnosis and management. The mainstay of surgical management for dorsal TIACs is laminectomy and cyst excision or fenestration. Surgery for gait ataxia should be aimed towards preventing deterioration, while maintaining the potential for symptomatic improvement, whereas surgery for radicular pain should be curative.

A New Classification for Pathologies of Spinal Meninges—Part 2: Primary and Secondary Intradural Arachnoid Cysts

BACKGROUND: Spinal intradural arachnoid cysts are rare causes of radiculopathy or myelopathy. Treatment options include resection, fenestration, or cyst drainage.

OBJECTIVE: To classify intradural spinal arachnoid cysts and present results of their treatment.

METHODS: Among 1519 patients with spinal space occupying lesions, 130 patients demonstrated intradural arachnoid cysts. Neuroradiological and surgical features were reviewed and clinical data analyzed.

RESULTS: Twenty-one patients presented arachnoid cysts as a result of an inflammatory leptomeningeal reaction related to meningitis, subarachnoid hemorrhage, intrathecal injections, intradural surgery, or trauma, ie, secondary cysts. For the remaining 109 patients, no such history could be elucidated, ie, primary cysts. Forty-six percent of primary and 86% of secondary cysts were associated with syringomyelia. Patients presented after an average history of 53 ± 88 months. There were 122 thoracic and 7 lumbar cysts plus 1 cervical cyst. Fifty-nine patients with primary and 15 patients with secondary cysts underwent laminotomies with complete or partial cyst resection and duraplasty. Mean follow-up was 57 ± 52 months. In the first postoperative year, profound improvements for primary cysts were noted, in contrast to marginal changes for secondary cysts. Progression-free survival for 10 years following surgery was determined as 83% for primary compared to 15% for secondary cysts. Despite differences in clinical presentation, progression-free survival was almost identical for patients with or without syringomyelia.

CONCLUSIONS: Complete or partial resection leads to favorable short- and long-term results for primary arachnoid cysts. For secondary cysts, surgery can only provide clinical stabilization for a limited time due to the often extensive arachnoiditis.

Dorsal cervical spinal arachnoid cyst (Type III) presenting with dorsal column dysfunction: A case report

CONTEXT

Spinal arachnoid cysts are usually asymptomatic and discovered incidentally. Expansion of the cyst, whether acute, subacute or chronic, leads to neural compression resulting in radicuopathy and/or myelopathy.

FINDINGS

This case report is of a patient who presented primarily with posterior column dysfunction,subacute in onset and rapidly progressing. Images of the cervical spine showed a dorsal arachnoid cyst, causing significant cord compression and signal changes in the cord, with no scalloping of the vertebrae.

CONCLUSION

The author explains the mechanism of rapid expansion of an asymptomatic spinal arachnoid cyst, causing neural compression leading to fast progression of neurological deficits. The dorsal location of the cyst, explain the absence of radiculopathy, which is a common presenting feature of ventrally located intradural arachnoid cyst.

Intraspinal bronchogenic cyst: Series of case reports and literature review

PURPOSE

Spinal bronchogenic cysts (SBCs) are rare congenital lesions. The clinical and imaging characteristics and treatment of SBCs are not well known. We studied three cases of SBCs retrospectively, which were registered in our department and analyzed eight case reports which were all published in English, focusing on providing a deeper knowledge of SBCs.

METHODS

Three patients with SBCs registered in our department were retrospectively reviewed. Eight reported SBCs cases published from 1992 to 2015 were enrolled in our study. Imaging diagnosis was confirmed by computed tomography (CT), MRI, and computed tomography angiography (CTA). All of our patients and reviewed cases had undergone surgical resection and the final diagnosis was made by pathological examination.

RESULTS

Five lesions were located at the cervical spinal canal. Most patients presented with pain in the limbs and back, which might be related to compression of the spinal cord and the reduced blood supply of the anterior spinal artery. The signal intensity on MRI was correlated with cystic fluid traits to a large extent. Seven lesions were partially removed because of the adhesions to the nearby spinal cord. All reported cases had no recurrence in the later follow-up.

CONCLUSIONS

SBCs can occur anywhere in the spinal canal, but they are more likely to present at the cervical canal and might be present along with some developmental malformations of the spine. We emphasize the role of CT and MRI findings in the disease diagnosis. It is recommended that the lesion should be removed as completely as possible.