Spinal arachnoid cysts: clinical and radiological correlation with prognosis

Scalpellum occulta: A rare case of dorsal spinal arachnoid web without the scalpel sign

Spinal arachnoid web is a rare condition characterized by extramedullary bands of arachnoid tissue at the level of the dorsal thoracic spinal cord that may lead to progressive, permanent neurological deficits. To date, this condition has been radiographically characterized by a scalpel sign, which has been pathognomonic in all reported cases of spinal arachnoid webs. In this case, we report the first known patient with confirmed spinal arachnoid web without radiographic evidence of the scalpel sign. In reporting our finding, we encourage a higher clinical suspicion for spinal arachnoid web in patients presenting with progressive thoracic myelopathy following trauma, and radiographic evidence of ventrally displaced spinal cord and turbulent cerebrospinal fluid flow, even in the absence of a scalpel sign.

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.

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.

Chronic renal failure revealing a spinal arachnoid cyst, a case report with literature review

INTRODUCTION

Extradural arachnoid cyst (KAED) is a rare and benign condition, accounting for approximately 1 % of all spinal expansive lesions. The pathogenesis of KAED is uncertain and appears to be multifactorial. Spinal compression symptoms are rarely indicative, and KAED is usually discovered incidentally. MRI is the radiological test of choice as it allows for precise characterization of the cyst. Early identification and management of KAED is crucial to prevent complications and ensure timely intervention.

CASE PRESENTATION

A 7-year-old girl with a nomadic lifestyle presented with sphincterian disorders without any other neurological abnormalities. Further investigation, including biological tests, revealed chronic kidney failure. A spinal MRI identified an intra-spinal extradural dorso-lumbar arachnoid cyst extending from D10 to L1, located posteriorly. The cyst was promptly removed with favorable postoperative outcomes. The patient was discharged with a treatment of vitaminocalcic and martial supplementation for his chronic renal insufficiency and a regular follow-up in consultation.

CLINICAL DISCUSSION

Arachnoid cyst is a rare benign condition that can be discovered incidentally (Agnoli et al., 1982; Chan et al.; 1985). The symptoms are the results of compression exerted by the cyst on the cord and they vary according to the level of compression of the spinal cord or the nerve roots, but the symptomatic form is a situation which remains rarely described (Charisseauj et al., 1992). In this particular case, the cyst was identified due to a series of symptoms related to acute renal insufficiency, which exacerbated pre-existing chronic renal insufficiency. This was further complicating untreated sphincter disorders. This highlights the significance of timely diagnosis and treatment to prevent severe complications that may otherwise develop from a benign condition. With early intervention, favorable outcomes can be achieved in most patients (Kendall et al., 1982).

CONCLUSION

With the advancement of neuroimaging and the widespread availability of MRI as the gold standard, extradural arachnoid cysts (KAED) can now be incidentally discovered in asymptomatic patients. Once diagnosed, surgical intervention is typically recommended to prevent irreversible neurological damage. Further research is needed to better understand the pathogenesis of KAED and establish optimal diagnosis and treatment strategies, particularly in pediatric patients, for this rare condition.

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.

Clinical Profile and Treatment Outcome of Spinal Epidural Arachnoid Cysts: A Systematic Review of Case Studies and Reports

Background A spinal epidural arachnoid cyst (SEAC) is a rare clinical entity. We performed a systematic review of the literature to obtain information regarding demographics, clinical presentation, treatment modalities, and outcome of SEACs.

Methods A literature search was performed by using the databases PubMed/Medline, PubMed Central, Embase, Cochrane Library, Ovid MEDLINE, and Ovid Medline In-Process. A total of 170 articles were found on literature search. We found 575 cases of SEAC since 1904 for inclusion in the review including three cases which were operated by us. We studied the patient characteristics, clinical features, and management strategies, and evaluated their outcome.

Results The average age of presentation was 30 years with a male:female ratio of 1.03:1. They are commonly seen in the thoracic region (42.3%). The length of cyst was more than two vertebral levels in 85.81%. Mean symptom duration was 29 months, with most common presentation being that of compressive myelopathy. A good clinical outcome was present in symptomatic patients who had a shorter symptom duration and underwent complete surgical excision of the SEAC. Age, sex, length of lesion, and presence of dural defect did not have a bearing on the surgical outcome.

Conclusion For thoracic compressive myelopathy in a young patient, SEAC should be kept as a differential diagnosis. Surgical complete excision of the cyst with meticulous closure of the dural defect is the standard in management for a good clinical outcome.

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.

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.

Congenital Spinal Cysts: An Update and Review of the Literature

Congenital spinal cysts are rare and encompass a wide variety of diseases including arachnoid, enterogenous, teratomatous, neurenteric, foregut, bronchogenic, epithelial, ependymal, dermoid, and epidermoid cysts. Here, we elucidate the epidemiology, pathology, pathogenesis, and diagnostic findings of the most common congenital spinal cysts, followed by a discussion of their presentation and treatment options. Differentiating the cause of each lesion is crucial for targeted clinical and surgical management for the patient. Our review describes how arachnoid cysts can be observed, fenestrated, percutaneously drained, or shunted; however, the primary goal for neurenteric, dermoid, and epidermoid cysts is removal. Further, we discuss how patient presentation is dependent on the rate of growth and location of compression on the spinal cord and nerve roots. However, although many of these lesions are discovered incidentally on imaging, the spectrum of possible symptoms include pain, weakness, ataxia, bladder incontinence, and progressive or acute neurologic deficits. We present and review the histology and imaging of a variety of cysts and discuss how although the goal of treatment is resection, the risks of surgery must be considered against the benefits of complete resection in each case.

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.

Unexplained paraparesis following subarachnoid haemorrhage

Spinal arachnoid cysts (SAC) are rare in isolation and the exact aetiology is still debated. Primary (congenital) cysts are caused by structural abnormalities in the arachnoid layer and largely affect the thoracic region. Secondary cysts are induced by a multitude of factors, infection, trauma or iatrogenic response, and can affect any level of the spinal cord. While subarachnoid haemorrhage (SAH) is a relatively common condition with significant repercussions, it is extremely uncommonly associated with SAC. When present, it may develop in the months and years after the original bleed, giving rise to new neurological symptoms. Prompt treatment is needed to halt or reverse the worsening of symptoms and questions are still being asked about how best to approach this condition. A 42-year-old man presented with chronic back pain, severe worsening ataxia and numbness below the umbilicus, 7 months after treatment for a World Federation of Neurosurgical Societies grade five (WFNS V) SAH. Imaging revealed a SAC extending from T12 to L4 and causing thecal compression. This was treated with a L3 laminectomy andmarsupialisation. An improvement in neurological function was observed at 6 months. Aetiology of the SAC and its association with SAH are discussed and a review of the relevant literature is provided.

Ventral Craniovertebral Junction Arachnoid Cyst in an Elderly Patient-A Case Report of a Unique Occurrence at Extremes of Age

BACKGROUND

Craniovertebral junction arachnoid cysts are uncommon. Among those reported, ventrally located arachnoid cysts at the extremes of age have been even rarer. We report a successfully managed case of a ventrally placed arachnoid cyst in an 88-year-old man using an unconventional surgical approach.

CASE DESCRIPTION

An 88-year-old man presented to us with complaints of tingling and numbness in both upper and lower limbs. He had a weak handgrip on both sides. Spinal magnetic resonance imaging (MRI) showed a non-contrast-enhancing cystic lesion over the anterior lip of the foreman magnum that had displaced the cervicomedullary junction posteriorly. The lesion was homogenously hypointense on T1-weighted MRI and hyperintense on T2-weighted MRI. The lesion was excised using a posterior approach. The cyst contents were drained, followed by complete wall excision. Complete improvement in clinical symptoms and an absence of neurological deficits were noted in the patient.

CONCLUSION

Arachnoid cysts are congenital lesions and can present at the extremes of age. Ventrally placed small symptomatic arachnoid cysts can be managed successfully through the posterior approach, especially in the elderly population.

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.

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.

Clinical and Radiographical Differences Between Thoracic Idiopathic Spinal Cord Herniation and Spinal Arachnoid Cyst

STUDY DESIGN

A retrospective, multicenter, case-controlled study.

OBJECTIVE

The aim of this study was to investigate the clinical and radiographical differences between thoracic idiopathic spinal cord herniation (ISCH) and spinal arachnoid cyst (SAC).

SUMMARY OF BACKGROUND DATA

ISCH and SAC are relatively rare diseases. Preoperative misdiagnose was frequently reported in both; however, these clinical and radiographical differences remain unclear.

METHODS

Of 30,469 patients who underwent spinal surgery, 18 (0.059%) and 22 (0.072%) patients were diagnosed as ISCH or SAC at nine hospitals, respectively, and their clinical and radiographical data were retrospectively evaluated. The spinal cord kink angle was measured on magnetic resonance or computed tomography myelography sagittal images; the kink angle was the exterior angle formed between the two tangents to the dorsal-side inflection points at the maximally affected level.

RESULTS

There were no significant differences in age, gender, and duration of symptoms. Preoperative motor deficit was significantly higher (94.4%) and severer (manual muscle testing: 3.1 ± 1.1) in ISCH. Brown-Séquard syndrome was observed in 38.9% of ISCH, while no patients in SAC. In addition, leg sensory disorder and bladder rectal disorder were significantly more common in ISCH, while back pain was significantly frequent in SAC. With respect to radiographical findings, the length of disease (5.1 ± 2.7 levels) and altered cerebrospinal flow (CSF) (81.8%) in the lesion was significantly longer and more common in SAC. On the contrary, the kink angle was significantly greater in ISCH (54.0 ± 23.1°) than in SAC (14.1 ± 12.0°) (P < 0.001). The cut-off value of the kink angle to distinguish ISCH and SAC was 32.8°.

CONCLUSION

Patients with ISCH commonly had severe preoperative neurological deficit, Brown-Séquard syndrome, and higher kink angle, while patients with SAC had back pain, longer length of disease, and altered CSF in the lesion.

LEVEL OF EVIDENCE

4.

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.

Excision of an anterior intradural arachnoid cyst of the cervical spine through central corpectomy approach

Anterior cervical intradural arachnoid cyst is a rare entity which has been mostly approached posteriorly, commonly resulting in incomplete resection. Incomplete resection is associated with recurrence; hence, we describe the anterior central corpectomy approach with complete neurologic recovery in a twenty year old with an anterior cervical intradural arachnoid cyst in front of the third and fourth cervical vertebra, who had presented with spastic quadriparesis.

Magnetic Resonance Imaging of an Epidural Spinal Arachnoid Cyst

The myelography, CT and MR imaging findings in a patient with an epidural spinal arachnoid cyst are discussed. MR imaging excellently demonstrated cyst size, cyst location and cord compression, and should be the method of choice in these cases.

Extensive spinal intradural arachnoid cyst exhibiting a "double cord sign" on magnetic resonance imaging

STUDY DESIGN

Retrospective case study.

OBJECTIVE

To report on a case with an extensive intradural arachnoid cyst that caused left hemiparesis.

SUMMARY OF BACKGROUND DATA

Intradural arachnoid cysts are not common causes of spinal cord compression and myelopathy. Although arachnoid cysts of the spine have been occasionally reported, cases with extensive intradural arachnoid cysts associated with hemiparesis are rarely reported.

METHOD

The patient was a 43-year-old woman who had cervical myelopathy symptoms, including radiating pain and left limb hemiparesis with gait disturbance. Magnetic resonance imaging revealed an extensive intradural extramedullary multi-septated cyst from the C6-T12, exhibiting a double cord sign on the T2-weighted axial image of the spine. The mass blocked normal cerebrospinal fluid flow, which led to cord compression. Two stages of operations were planned because of the patient's health status. The patient underwent laminectomy and cyst wall resection on the level of the T5-T7, which had the most compressed lesion. From C6-T2, a right side unilateral laminectomy was performed to resolve the right limb's neurology after the first operation.

RESULT

Hypoesthesia and the radiating pain were improved immediately postoperatively; however, motor power at the C8-T1 level of the right unaffected side was impaired and included finger abduction and finger flexion, which decreased to 4/5. During the second operation, the arachnoid cyst was exposed by performing a right unilateral laminectomy. The patient's neurologic symptoms were improved without neurologic sequelae.

CONCLUSION

In the case of an extensive cyst that exhibits a double cord sign, an intradural arachnoid cyst should be suspected as a differential diagnosis. Without radical excision of all lesions, neurologic symptoms can be recovered by performing selective resection and CSF normalization can be achieved even at extensive levels.

Cystic Abnormalities of the Spinal Cord and Vertebral Column

Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions.

Clinical characteristics and treatment strategies for idiopathic spinal extradural arachnoid cysts: a single-center experience

BACKGROUND

Idiopathic spinal epidural arachnoid cysts (SEACs) are relatively rare lesions with diverse clinical manifestations depending on the affected spinal region and nerve roots. To assess the relationship between clinical presentation and surgical outcome, we conducted a retrospective review of medical records and neuroimages from idiopathic SEAC patients.

METHODS

Of 15 consecutive patients with idiopathic SEACs, 14 underwent surgical treatment at the Beijing Tiantan Hospital between January 2008 and July 2013. Case histories, clinical presentations, imaging findings, operative findings, and surgical outcomes were reviewed.

RESULTS

Of the 15 patients, 5 were children (median age, 13 years) and 10 were adults (median age, 35 years). The male-to-female ratio was 4:1. The median disease duration was 1 year in children and 4 years in adults. The most common manifestations were progressive paraparesis (73.3 %) and radiculopathy (66.7 %). All pediatric lesions affected thoracic segments, while 80 % of adult lesions affected lumbar segments. Fourteen patients underwent microsurgical treatment, with cyst excision in nine (combined with fistula closure in four) and partial cyst excision in five (with fistula closure in three). No recurrences were observed during follow-up (average of 23 months). Excellent outcome was achieved in six cases, good outcome in four, fair in two, and poor in two.

CONCLUSIONS

Idiopathic SEAC mainly affect the thoracic segments in children and the lumbar segments in adults, and often results in progressive paraparesis and radiculopathy. Early surgical intervention is suggested for progressive symptomatic patients to restore neurological function.

Extramedullary spinal cysts in dogs

OBJECTIVE

To (1) synthesize the terminology used to classify extramedullary spinal cysts in dogs to clarify some of the commonly reported misconceptions, and (2) propose a classification scheme to limit confusion with terminology.

STUDY DESIGN

Literature review.

METHODS

An online bibliographic search was performed in January 2013 for articles relating to extramedullary spinal cysts in dogs using PubMed (http://www.pubmed.gov/) and Google Scholar (http://scholar.google.com/) databases. Only peer-reviewed clinical literature describing cystic lesions pertaining to the spinal cord and associated structures was included.

RESULTS

From 1962 to 2013, 42 articles were identified; 25 (95 dogs) reported meningeal cysts, 10 (24 dogs) described 60 extradural cysts, 3 reports (18 dogs) described discal cysts or acute compressive hydrated nucleus pulposus extrusions (HNPE). Spinal cysts were categorized by location based on cross-sectional imaging as meningeal or extradural non-meningeal. Sub-classification was then performed based on surgical findings and pathology. Meningeal cysts included arachnoid diverticulae and Tarlov (perineural) cysts. Extradural non-meningeal cysts included intraspinal cysts of the vertebral joints, ligaments and discs. Discal cysts also fit this category and have been reported extensively in humans but appear rare in dogs.

CONCLUSIONS

Extramedullary spinal cysts should be first classified according to location with a sub-classification according to pathologic and surgical findings. Previous canine cases of discal cysts appear to represent a different disease entity and the term acute compressive HNPE is therefore preferred.

Anterior cervical arachnoid cyst

This report is composed of two patients with anteriorly located cervical intradural arachnoid cyst and review of 24 cases in Englishlanguage literature. Both of our patients were in the first two decades of life with neck pain and motor weakness. With suspicious diagnosis of anterior arachnoid cyst surgery was carried out in both cases, though laminectomy in one and laminoplasty in the other. The cyst wall was widely fenestrated with subsequent subtotal excision of the cyst. Both cases had good long-term outcome. The review disclosed male predominance. 73% of the patients were diagnosed within the first two decades of life. Neck pain and motor weakness were the dominant signs and symptoms of this pathology. Magnetic resonance imaging showing a cerebrospinal fluid (CSF) containing cyst was the best mode of diagnosis. Wide cyst fenestration with waying CSF into subarachnoid cyst was the most appropriate and applied surgery with optimal outcome.

Thoracolumbar extradural arachnoid cyst--three surgical case reports

Three cases of symptomatic extradural arachnoid cyst were treated by surgery. Total excision of the cyst followed by tight closure of the fistula by suture was achieved in all 3 cases. Surgery improved the neurological deficits but urinary incontinence persisted in all three patients. Obliteration of the fistula is considered to be important at surgery from the etiological perspective of the cyst. There are many surgical options, but surgical removal of the cyst and obliteration of the communication usually leads to prompt improvement in neurological deficits. Instability, malalignment, and worsening scoliosis are well-recognized postoperative complications of excessive laminotomy, but the exposure should be wide enough to cover the cyst completely at the operation. Wide exposure of the entire cyst is preferable to avoid missing the fistula and to identify any adhesions or fistula between the cyst and the dura. Identification of the fistula location based on preoperative imaging studies is also important.

Surgical treatment of spinal extradural arachnoid cysts in the thoracolumbar spine

BACKGROUND

Because an idiopathic spinal extradural arachnoid cyst (SEAC) is rare, its optimal surgical treatment remains controversial.

OBJECTIVE

To evaluate the results of surgical treatments for SEACs and to clarify features of the disease associated with poor outcomes.

METHODS

Twelve patients with SEACs who underwent surgery at our hospital between 1988 and 2008 were examined retrospectively. The mean follow-up period was 4.7 years. Total resection of the cyst was performed in 7 patients and closure of the dural defect without cyst resection in 5 patients. Surgical outcomes were evaluated with regard to the duration of symptoms, the size of the cyst, and the surgical procedure used.

RESULTS

Neurological recovery was observed in all patients, and there was no recurrence. Poor outcomes were observed in patients with a long duration of symptoms (>1 year, P < .01) and large cyst size (>5 vertebrae, P < .05). The surgical procedure had no significant association with the postoperative neurological recovery. However, there was a significant difference in the degree of the mean postoperative kyphotic angle between the patients treated by total resection of the cyst (9.7 degrees) and those treated by closure of the dural defect without cyst resection through selective laminectomy (2.2 degrees) (P < .01).

CONCLUSION

There was no significant difference in postoperative neurological recovery between the 2 surgical procedures. However, closure of the dural defect without cyst resection was less invasive, preventing postoperative kyphotic deformity of the thoracolumbar spine.

Spinal arachnoid cysts in the pediatric population: report of 31 cases and a review of the literature

OBJECT

The goal of this study was to review all cases of pediatric spinal arachnoid cysts (SACs) surgically treated at the authors' institution between 1992 and 2008 and to compare these cases to the published literature for the general population.

METHODS

The charts of all pediatric patients with SACs were reviewed for demographics, medical history, presenting symptoms, imaging findings, operative procedure(s), complications, and outcomes. Following a complete literature review, the pediatric data were compared with data from the general population and unique findings associated with pediatric patients were identified.

RESULTS

Thirty-one pediatric patients (median age 6.9 years) underwent operative intervention for SACs between 1992 and 2008 (median duration of follow-up 4.2 years). There were 17 female patients (55%) and 14 male patients (45%). Twenty-one patients (68%) presented with symptoms of radiculopathy or myelopathy. The most common presenting symptoms were pain (42%), lower-extremity weakness (39%), gait instability (32%), spasticity (19%), sensory loss (10%), and bladder dysfunction (7%). In 3 patients (10%) SACs were incidental findings. Intradural SACs were more common (18 patients, 58%) than extradural SACs (11 patients, 36%). One patient (3%) had extradural and intradural components. One patient (3%) had a purely intramedullary cyst, and 1 patient (3%) had both an intradural and intramedullary component. Of the 18 intradural SACs, 9 (50%) were located ventral to the spinal cord and 9 (50%) were dorsally situated. One dorsal intradural SAC had an intramedullary component. All extradural SACs were located dorsal to the spinal cord. Intradural SACs were primarily concentrated in the cervical and thoracic regions (67%), whereas extradural cysts were more evenly distributed between the thoracic, lumbar, and sacral regions. Of the 18 patients with intradural SACs, 13 (72%) had significant previous CNS abnormalities, compared with 3 (27%) of 11 patients with extradural SACs. There were 2 operative complications. One patient had a CSF leak treated with a lumbar drain, and the second patient had a pseudomeningocele. No patients had neurological deterioration as a result of surgical intervention. Twenty-one patients (68%) had complete remission of symptoms, 6 (19%) had improvement, 3 (10%) were stable, and 1 (3%) has worsening of symptoms with recurrence that ultimately required cystoperitoneal shunting, despite multiple failed attempts at fenestration.

CONCLUSIONS

Spinal arachnoid cysts are rare lesions in the pediatric population. Affected patients present with back pain, weakness, and/or gait instability. In children, SACs predominantly develop in the thoracic region and are more likely to occur intradurally, compared with SACs in the general population. Overall outcomes following surgical fenestration or excision of SACs are excellent, with complete remission or improvement of symptoms achieved in 87% of cases.

Thoracolumbar extradural arachnoid cysts: a study of 14 consecutive cases

BACKGROUND

To investigate characteristic clinical and radiological features of extradural arachnoid cysts (EDACs) in the thoracolumbar region, a retrospective review of medical records and imaging studies was performed. EDACs are well known but relatively rare lesions in the thoracolumbar spinal canal. The most common site is the lower thoracic spine, and it may cause neurological symptoms by compressing the spinal cord or nerve root. In this study, the pathogenesis, symptomatology, diagnostic approach, and surgical management of EDACs will be discussed.

METHODS

We studied 14 consecutive patients who were surgically treated for EDACs in the thoracolumbar region at our institute between March 2000 and January 2011. The history, clinical presentations, image findings, operative findings, and surgical outcomes of these patients were retrospectively analyzed. The mean follow-up period was 28 months (range: 6-72 months).

RESULTS

Progressive motor weakness was the predominant symptom in all patients. Nine patients had radicular leg pain and back pain in the thoracolumbar area. On MRI, the cyst compressed the dural sac and spinal cord posteriorly typically with bilateral foraminal extensions. On radiological study, a communication point with the subarachnoid was hardly observed. The surgical treatment of EDACs included complete resection of the walls and closing the communicating point with the subarachnoid space. All patients showed excellent outcomes according to Odom's criteria without recurrence. One CSF leakage and one postoperative hematoma were noted.

CONCLUSIONS

Thoracolumbar EDAC patients presented paraparesis and leg pain. Complete excision and closing the communicating point with the subarachnoid space were the choices of treatment, and the outcomes were favorable.

Arachnoid ossificans containing metaplastic hematopoietic marrow resulting in diffuse thoracic intrathecal cysts and severe myelopathy

OBJECTIVE

To present a rare case of multiple compressive thoracic intradural cysts with pathologic arachnoid ossification, review the literature and present the surgical options. Few reports have identified the existence of arachnoid calcifications and intrathecal cysts causing progressive myelopathy. The literature regarding each of these pathologies is limited to case reports. Their clinical significance is not well studied, although known to cause neurologic sequelae.

METHODS

An 81-year-old female clinically presents with rapidly progressive myelopathy. Pre-operative magnetic resonance imaging identified multiple compressive thoracic intrathecal cysts. Surgical exploration and decompression of these cysts identified calcified plaques within the arachnoid. Histopathologic examination revealed fibrocalcific tissue undergoing ossification with bone marrow elements.

RESULTS

Due to progressive myelopathy, the thoracic cysts were decompressed and calcified plaques were excised, once identified intra-operatively.

CONCLUSIONS

On last examination, the patient's neurologic status had not improved, but had stabilized. The rate of neurologic improvement from excision and decompression is variable, but it may still be warranted in the face of progressive neurologic deficits.

Spinal extradural meningeal cyst in klippel-trenaunay syndrome

A case of a symptomatic spinal extradural meningeal cyst (SEMC) in Klippel-Trenaunay syndrome (KTS) is introduced. A 38-year-old woman presented with right L2 radiculopathy. She underwent operations for varicose veins in both her lower extremities. She had port-wine nevi on her trunk and extremities. The edematous change in both legs had waxed and waned. Magnetic resonance imaging showed an 11.8×13 mm extradural meningeal cyst growing through the intervertebral foramen in L2-3. Multiple meningeal cysts were located in the dorsal aspect of the spinal cord from T3 to T10. A 5.8×6.2 mm cyst was also found in left pleural cavity. The extradural meningeal cyst was completely excised and the preoperative symptom was improved. KTS is a congenital disorder due to a mesodermal abnormality, which may predispose the dura to weakness. The SEMC may occur through the dural defect or weakened point.

Noncommunicating spinal extradural meningeal cyst in thoracolumbar spine

Spinal extradural meningeal cyst has been rarely reported, whose etiologies are assumed to be the communication of cerebrospinal fluid (CSF) between intradural subarchnoid space and cyst due to the congenital defect in dura mater. Although the CSF communication due to this defect can be found, in most case, few cases in which there is a lack of the communication have also been reported. We report a case of the huge extradural meningeal cyst occurring in the thoracolumbar spine (from T10 to L2) where there was a lack of the communication between the intradural subarachnoid space and cyst in a 46-year-old man who presented with symptoms that were indicative of progressive paraparesis and leg pain. The patient underwent laminectomy and cyst excision. On intraoperative findings, the dura was intact and there was a lack of the communication with intradural subarachnoid space. Immediately after the surgery, weakness and leg pain disappeared shortly.

Diffuse arachnoid ossification and multiple arachnoid cysts presenting with progressive thoracic myelopathy

An ossified arachnoid membrane combined with cystic formation is rarely reported as a cause of spinal cord compression. We report the case of a 60-year-old man who presented with diffuse ossification of the arachnoid membrane (arachnoid ossification) and multiple cystic changes (arachnoid cyst) at the thoracic and lumbar spine. The lesions were surgically removed and progressive deterioration was prevented, although no marked improvement of neurological symptoms was attained.

Insidious progression of paraparesis secondary to type III spinal meningeal cyst: a study of six difficult cases

STUDY DESIGN

Case report.

SETTING

Neuro-orthopaedic Unit, Fukui University Hospital, Japan.

CASE REPORT

We studied six patients with insidious progression of paraparesis caused by thoracic and thoracolumbar spine type III spinal meningeal cyst and intradural arachnoid cyst, who underwent microsurgical decompression. Histologically, some samples showed oedematous and hypertrophic changes of the arachnoidal tissue together with occasional tophaceous deposits and calcification. Surgical treatment was complete excision of the cyst, or wide fenestration of these membrane, and close a communicating fistula, if detectable. All patients improved neurologically after microscopic surgery.

CONCLUSION

We stress the significance of neuroimaging and neurological assessment in patients with gradual progression of paraparesis caused by intradural arachnoid cyst, but surgical procedure and timing of operative intervention require further considerations.

Multiple spinal extradural meningeal cysts presenting as acute paraplegia

✓Multiple spinal extradural meningeal cysts are rare. To the authors' knowledge, there have been only four reported cases in the world literature. The authors report a case of multiple spinal extradural meningeal cysts in a 31-year-old woman presenting with acute paraplegia. Magnetic resonance imaging of the thoracolumbar spine revealed multiple extradural cystic lesions extending from T-7 to T-8 and from T-12 to L-3. Intraoperative findings demonstrated a white, fibrous, and tense cyst filled with cerebrospinal fluid–like colorless fluid. Excision of the posterior wall of the symptomatic cyst was followed by immediate neurological improvement. The examination of the pathological specimen showed a thick duralike layer of collagen and an inner membrane of arachnoid that is often not found in these lesions. The final diagnosis was based on combined imaging, intraoperative, and histopathological findings. The authors review the literature and discuss the etiological, diagnostic, and therapeutic aspects of this lesion.

Compression médullaire par kystes arachnoïdiens

Spinal arachnoid cysts are considered to be rare entities, intradural locations are even less common. We report two cases of patients (two women aged 77- and 21-year-old) who presented spinal cord compression by intradural arachnoid cysts. For the second patient, repeated surgical procedures were necessary to improve the neurological status. After presenting the case reports, we expose the pathophysiological mechanisms and clinical features, and the surgical difficulties of treating this rare cause of spinal cord compression.

Spinal arachnoid pseudocysts in 10 rottweilers

Ten rottweilers presenting with spinal arachnoid pseudocysts were investigated. In six dogs, the lesions were localised dorsally at C2-C3; in three dogs, dorsally and ventrally at C5-C6; and, in one dog, dorsally and ventrally at C6-C7. Clinical signs were consistent with focal compression of the affected spinal cord segments. The animals showed ataxia of all four limbs, with truncal ataxia and marked hypermetria in cases of C2-C3 involvement, or ambulatory tetraparesis in cases of C5-C6 or C6-C7 involvement. Other than signs indicative of spina bifida in one dog, no abnormalities could be detected on plain radiographs. Myelography was used to define the localisation and extent of the pseudocysts. Additional information was obtained using magnetic resonance imaging in five dogs. Five dogs underwent a dorsal laminectomy; in three cases, the pseudocyst was treated by marsupialisation and, in two, by durectomy.

Spinal extradural meningeal cyst with spinal stenosis

STUDY DESIGN

Case report.

OBJECTIVE

To present a rare pathology causing a common disease.

SETTING

Spine unit of the orthopaedic surgery department of a university hospital in Berlin/Germany.

CASE REPORT

A 39-year-old female with an intraspinal extradural arachnoid cyst of the lumbar spine presented with intermittent radiating lumbar pain. The magnetic resonance imaging (MRI) showed a dorsal spinal extradural arachnoid cyst at L3/4. After wide laminotomy L3, operative cyst resection and stabilisation at L3/4 by posterior lumbar interbody fusion (PLIF), major symptom relief occurred.

CONCLUSION

Spinal extradural arachnoid cysts are a rare entity causing low back pain and intermittent radicular syndromes. They can be caused by arachnoid herniation through dural weak spots which are hereditary or occur after trauma. A ball-valve mechanism promotes growth. The main diagnostic tool for spinal extradural cysts is the MRI scan. Additionally, myelography is helpful to demonstrate fluid communication. Complete surgical removal of the cyst should be attempted to reduce risk of recurrence. If extensive decompression is needed for the surgical approach causing segmental instability, interbody fusion is recommended. The outcome depends on age, duration and degree of neurological damage.

Huge spinal extradural meningeal cyst in the thoracolumbar spine: a case report of a rare cause of low backpain

Symptomatic intraspinal extradural meningeal cysts are rare. We present the case of a 17-year-old female with low back pain, progressive numbness, and radiation pain to the flank and lower limbs. Magnetic resonance imaging and computed tomographic myelography revealed a huge intraspinal extradural meningeal cyst extending from T12 to L3 with cord and dural sac compression. The patient underwent surgery to open the cyst and close the connecting dural defect. Pathologic examination of the cyst disclosed non-specific fibrous connective tissue without an inner arachnoid single-cell lining. She achieved complete recovery after the operation. There was no recurrence of the cyst at a 2-year follow-up.

Spinal intradural juxtamedullary cysts in the adult: surgical management and outcome

OBJECTIVE

Intradural nonneoplastic cysts compressing the spinal cord are rare lesions. We retrospectively analyzed a series of patients harboring this entity with regard to clinical and radiological features, surgical management, and follow-up results.

METHODS

In a retrospective study, we reviewed the medical charts, radiological investigations, and follow-up data of 11 women and 10 men (mean age, 43.6 yr) with intradural juxtamedullary spinal cysts, which were consecutively treated microsurgically at our institutions between January 1995 and January 2003. All lesions were approached via a laminectomy, hemilaminectomy, or laminoplasty at the corresponding vertebral levels and histopathologically verified. The patients were routinely scheduled for clinical follow-up 2 and 6 months after surgery. Baseline postoperative magnetic resonance imaging (MRI) was ordered 6 months after surgery. Thereafter, follow-up was performed at 1-year intervals, with neurological examination and MRI.

RESULTS

According to presenting symptomatology, two main patient groups could be differentiated: one group with a myelopathic syndrome (10 patients) and another group with a predominant radicular pain syndrome (8 patients). Histopathological examination revealed 16 arachnoid cysts, 4 neuroepithelial cysts, and 1 cervical nerve root cyst. Most arachnoid cysts (12 cases) were located on the dorsal aspect of the thoracic spinal cord. The mean craniocaudal extension of these cysts was 3.7 vertebral levels, and complete resection was performed. In four patients, the arachnoid cyst was situated ventral to the spinal cord and involved up to 17 vertebral levels. These patients had a history of major spinal trauma, and the cyst was generously fenestrated at its greatest circumference as depicted on preoperative MRI scans. The four neuroepithelial cysts and the cervical nerve root cyst were located on the ventral or ventrolateral aspect of the spinal cord, and their maximum sagittal extension was two spinal vertebral levels. Symptoms in all but two patients demonstrated major improvement; in particular, radiating pain disappeared immediately after surgery. There was no cyst recurrence on MRI after a mean follow-up period of 3.2 years.

CONCLUSION

Intradural cysts should be considered in the differential diagnosis of lesions causing myelopathy and/or a radicular pain syndrome. Microsurgical resection or generous fenestration in cysts with large craniocaudal extensions effectively ameliorated patients' symptomatology. A description of the first documented case of a surgically treated intradural cervical nerve root cyst is provided.

Intradural spinal arachnoid cysts in adults

BACKGROUND

Idiopathic arachnoid cysts are rare lesions not associated with trauma or other inflammatory insults. To date, there have been few large series describing the presentation and management of these lesions.

METHODS

Twenty-one cases of intradural spinal arachnoid cysts were identified (1994-2001). Pediatric patients and cases with antecedent trauma were excluded. There were eight women and 13 men with an average age of 52 years. Follow-up averaged 17 months.

RESULTS

Cysts were most commonly found in the thoracic spine (81%). Fifteen cysts were dorsal to the spinal cord and six were ventral to the spinal cord. All patients underwent laminectomy with cyst fenestration and radical cyst wall resection. Based upon intraoperative ultrasonography, four cysts were also shunted to the subarachnoid space, and seven patients had an expansile duraplasty with freeze-dried dural allograft. Of the seven patients with syringomyelia, three resolved with extramedullary cyst resection alone. Four required syrinx to subarachnoid shunting. Follow-up MRI demonstrated cyst resolution in all cases. All seven intramedullary syrinxes were decreased in size and four resolved completely. Weakness (100%), hyperreflexia (91%), and incontinence (80%) were more likely to improve than neuropathic pain (44%) and numbness (33%). One patient had increased numbness postoperatively.

CONCLUSIONS

Ventral cysts are more likely to cause weakness and myelopathic signs. Preoperative symptoms of neuropathic pain and numbness are less likely to improve than weakness and myelopathy. Utilizing intraoperative ultrasound to guide aggressive surgical treatment with the adjuncts of shunting and duraplasty results in a high rate of cyst and syrinx obliteration.