Symptomatic spinal intradural arachnoid cyst development after lumbar myelography. Case report and review of the literature

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.

A Rare Diagnosis of Paraesthesia in the Pediatric Age Group: Unmasking the Male Factor

Spinal extradural arachnoid cysts are an uncommon condition and their exact causative triggers are still unclear. They appear to be extradural arachnoid outpouchings that connect to the intraspinal subarachnoid region via a little dura defect. These cysts are most commonly seen in the thoracic spine, followed by the lumbosacral junction. Compression of the spinal cord or nerve roots leads to the development of the symptoms. The most morbid symptom associated with these compressing extradural cysts is paresthesia. Numerous theories have been proposed about their origins, and the related conditions include spinal trauma, spina bifida, and the lymphedema-distichiasis syndrome. Their position in the spine influences the symptoms manifested. The diagnosis is made via MRI. Surgery is only performed on individuals with neurological impairment, and treatment is based on the clinical presentation. The preferred course of therapy is total surgical excision. We present a case that involves the successful surgical removal of an extradural spinal arachnoid cyst in a 10-year-old girl. Given the rarity of this pathology, its wide array of presenting symptoms, and the successful therapeutic protocol that was followed in this particular case, we believe this article shall prove beneficial to the medical fraternity.

Post-Spinal Anesthesia Intradural Extramedullary Arachnoid Cyst Formation: A Case Report

The formation of an intradural extramedullary arachnoid cyst is a rare complication of spinal anesthesia. We present a case of a 34-year-old female patient who developed neurological symptoms including a bilateral reduction in sensation and strength in the lower limbs following a C-section under spinal anesthesia. MRI of the thoracic spine revealed a lesion at the level of T11/T12 and the upper limit of the L1 vertebral body, which was pushing the cord to the side, and a diagnosis of the intradural extramedullary arachnoid cyst was established. The prognosis for this condition is good and surgical excision leads to resolution of the symptoms. Proper and prompt diagnosis is crucial to rule out other differentials and prevent permanent neurological damage in these patients.

Symptomatic secondary spinal arachnoid cysts: a systematic review

BACKGROUND

Secondary spinal arachnoid cysts have rarely been reported but present significant challenges for management. These cysts could be anteriorly located with long rostral-caudal extensions and many are related to arachnoiditis, leading to difficult-to-treat disorders. Thus far, due to the scarcity of reports, the features of the disease and the optimal therapeutic strategies remain unclear.

PURPOSE

To investigate clinical features and the optimal treatment modalities of secondary spinal arachnoid cysts compared to primary spinal arachnoid cysts STUDY DESIGN: Systematic review PATIENT SAMPLE: Systematic review identified 103 secondary cases from 80 studies and reports; OUTCOME MEASURES: Condition of symptom relief and duration of treatment response were analyzed.

METHOD

An electronic literature search of the PubMed database was conducted for studies on secondary spinal arachnoid cysts between 1990 to 2022. Non-English publications, non-human studies, reports of a primary cyst, studies not including case details, and studies of non-symptomatic cases were excluded.

RESULTS

This systematic review included 103 secondary cases. The most commonly reported etiologies were iatrogenic factors, trauma, and subarachnoid hemorrhage, accounting for 88 intradural extramedullary, 11 extradural, 1 intradural/extradural, 1 interdural, and 1 intramedullary spinal arachnoid cyst after a median duration of 30, 12, and 9 months, respectively. Extradural cysts were more prone to occur at dorsal locations and affect thoracic segments (mean cyst length: 3.4 segments). Intradural cysts showed a relatively higher ventral/dorsal ratio (1:1.09, 1.75:1, and 3.50:1 for cysts occurring from iatrogenic factors, trauma, and subarachnoid hemorrhage, respectively) and thoracic distribution, with a mean cyst length of 4.3 segments (5.1 for ventral and 3.5 for dorsal cysts). For intradural cysts, recurrence risk was lower after surgical resection than after fenestration/marsupialization (12-month recurrence risk: 21.43% vs. 50.72%, log-rank test: P = 0.0248, Gehan-Breslow-Wilcoxon test: P = 0.0126). In cases treated with shunting, one recurrence (1/8 cases) was noted after external shunting and two recurrences (2/5 cases) after internal shunting at a median follow-up of 12 months.

CONCLUSION

Secondary spinal arachnoid cysts, particularly intradural cysts, are rarer and more challenging to treat than primary spinal cysts. Although fenestration/marsupialization is the commonly adopted treatment, the recurrence rate is high. For unresectable cysts, shunting procedures, particularly shunting into a body cavity (e.g., pleural or peritoneal cavity) away from the subarachnoid space, could be a therapeutic alternative besides fenestration/marupialization, yet its efficacy requires confirmation by more data.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

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.

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.

Endoscopic treatment of spinal arachnoid cysts

Background/objective

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

Material and methods

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

Results

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

Conclusion

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

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

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.

Intradural symptomatic arachnoid cyst formation following non-instrumented lumbar decompression

PURPOSE

Intradural arachnoid cyst is a rare complication of lumbar puncture, post-trauma or post-intraoperative durotomies. We aim to estimate the incidence of early intradural arachnoid cyst radiologically in non-instrumented posterior lumbar decompression among symptomatic patients, and establish clinical correlation.

MATERIALS AND METHODS

Patients who underwent lumbar decompression without instrumentation at a tertiary spinal service between December 2014 and January 2018 were identified. When MRI scans were performed post-operatively within 14 days, imaging, medical and operative records were reviewed by two consultant neuroradiologists.

RESULTS

488 operations were included. 46 operations were followed by an early MRI scan. 59% were requested to investigate new or ongoing pain. Ten demonstrated an intradural arachnoid cyst - seven had no documented durotomy. Eight were primary operations, three were emergency operations. Statistically, we have not identified durotomy, primary-vs-revision surgery, and elective-vs-emergency surgery as risk factors. Two patients required revision operations, of these, one had a repeat post-operative scan, where the cyst resolved following further decompression at the index level, without intradural exploration.

CONCLUSIONS

Intradural arachnoid cyst may complicate posterior lumbar decompression. To our knowledge, this is the first study to assess its incidence as an early post-operative radiological finding, which is likely to be commoner than we recognise. It may be a cause of persisting post-operative pain.

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.

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.

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.

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.

Spinal intramedullary arachnoid cyst: case report and literature review

BACKGROUND CONTEXT

Intramedullary arachnoid cysts are extremely rare; only 14 cases have been reported in the literature so far.

PURPOSE

We report on the case of a 31-year-old woman who presented with back pain and progressive paraparesis secondary to a dorsal intramedullary arachnoid cyst detected on magnetic resonance imaging (MRI): the surgical planning and clinico-radiological outcome are discussed along with a review of the relevant literature.

STUDY DESIGN

Case report and literature review.

PATIENT SAMPLE

One patient affected by intramedullary arachnoid cyst.

OUTCOME MEASURES

Magnetic resonance imaging and pathological findings from operative specimens were used to confirm the diagnosis.

METHODS

A 31-year-old woman presented with a 7-year history of back pain that had worsened 3 months before admission to our department; for this reason, the patient had undergone a spinal MRI revealing the presence of a 1-cm cystic intramedullary lesion at the level T11-T12, with no contrast enhancement. After 2 months, the patient presented with a worsening of clinical symptoms complaining of severe back pain radiating to the lower extremities associated with a progressive paraparesis, urinary incontinence, and abdominal pain. Referred to our department, at the time of admission the patient was bedridden because of the impossibility of maintaining a standing position. The patient underwent a T11-T12 laminectomy with fenestration of the cyst.

RESULTS

She experienced an immediate relief of pain symptoms, and by the seventh postoperative day she was able to stand without help and walk a few meters with assistance. By the sixth postoperative month, the patient had significantly improved, having gained the ability to walk alone without assistance with complete resolution of the bladder dysfunctions, with no cyst recurrence after approximately 2 years of follow-up.

CONCLUSIONS

Intramedullary arachnoid cysts should be considered in the differential diagnosis for intramedullary cystic lesions. A particular consideration deserves their occurrence in asymptomatic patients, who should be adequately informed on the possible natural evolution: when symptomatic, surgical therapy should be promptly offered, considering that a postoperative complete recovery is usually observed, regardless of the surgical technique.

Signalment, clinical presentation, and diagnostic findings in 122 dogs with spinal arachnoid diverticula

Background

Most information about spinal arachnoid diverticula (SADs) in dogs has been retrieved from relatively small case series. The aim of this study was to describe this disease in a larger number of dogs.

Objectives

Description of the signalment, clinical presentation, and imaging findings of a large number of dogs with SADs.

Animals

One hundred and twenty‐two dogs with SADs.

Methods

Retrospective case series study. All medical records were searched for a diagnosis of SAD. The diagnosis was made based on myelography, computed tomography myelography (CT‐m), or magnetic resonance imaging (MRI).

Results

In the 122 dogs, 125 SADs were identified. Sixty‐five were located in the cervical region and 60 in the thoracolumbar region. A higher body weight was significantly associated with a cervical localization of the SAD (P < .001). Ninety‐five dogs were male and 27 dogs were female. Male dogs were significantly overrepresented (P < .0001). The most commonly affected breed was the Pug dog. Previous or concurrent spinal disorders, in the near proximity of the diagnosed SAD, were seen in 26 dogs. Eight of 13 French Bulldogs and 7 of 21 Pug dogs with SADs had a previous or concurrent spinal disease, whereas other spinal disorders occurred in only 1 of 17 Rottweilers with SADs.

Conclusions and Clinical Importance

Pug dogs and French Bulldogs might have a predisposition for SAD development. In a large percentage of these dogs, a concurrent spinal disorder, which might predispose to SAD formation, was diagnosed. The high prevalence in male dogs warrants further investigation.

Iatrogenic intradural lumbosacral cyst following epiduroscopy

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.

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.

Iatrogenic intradural spinal arachnoid cyst as a complication of lumbar spine surgery

Iatrogenic spinal arachnoid cysts are rare, but have been described as a complication of spinal injection and lumbar puncture procedures. The authors describe 2 cases of iatrogenic spinal arachnoid cyst formation that occurred after incidental durotomy during lumbar spine surgery. In both cases, postoperative MR imaging revealed compression of the cauda equina by an intradural arachnoid cyst. Intradural exploration and fenestration of the arachnoid cyst was accomplished in each case. This entity should be considered in the differential diagnosis of a patient experiencing symptoms of neurological compression after a lumbar surgery complicated by incidental durotomy.

Spinal cord compression caused by idiopathic intradural arachnoid cysts of the spine: review of the literature and illustrated case

Intradural spinal arachnoid cysts with cord compression are rare. When becoming symptomatic they cause variable symptoms involving gait disturbance, paraparesis or tetraparesis and neuropathic pain, decreasing significantly the patients' life quality. The extension of such cysts averages 3.7 vertebral bodies. The diagnosis is clinical and radiological with the use of MRI, CT myelography or a combination of both. The best treatment option is complete removal of the cyst. However, even when paresis is regressing there is no good recovery from neuropathic pain. Laminectomy approach can cause postoperative complications especially when the cyst(s) expand(s) in more than one level. Alternatively, a cyst fenestration can be performed, including the levels of the maximal spinal cord compression. The clinical outcome is as good as after the cyst resection enabling the patient to walk again. The neuropathic pain may persist and require medication. A clinical case is presented, and the literature is reviewed. In the present case we report a patient with intradural arachnoid cysts extending from T6 to L2 and causing severe gait ataxia as well as neuropathic pain and hypaesthesia. The spinal-cord was compressed at T8 and T12. Surgical treatment with partial cyst resection in the compressed levels with an interlaminar approach brought similar results as complete resection. The patient was able to walk without help which was not possible before surgery. The cysts' extension is impressive as well as the minimal operative procedure.

Thoracic intramedullary arachnoid cyst in an infant

Symptomatic intramedullary arachnoid cysts are rare, especially in children; these lesions are rarely described as a cause of spinal cord compression in this age group. The authors report on an 18-month-old boy who experienced a sudden loss of his ability to stand and walk due to a paraparesis. Magnetic resonance imaging of the spine exhibited a cystic intramedullary lesion at the level of T5-6. A hemilaminectomy was performed, and after myelotomy the cystic lesion was decompressed by fenestration to the subarachnoid space. The histopathological examination verified the diagnosis of an arachnoid cyst. In the postoperative course the boy experienced complete resolution of the initial paraparesis.

Kyste arachnoïdien intramédullaire symptomatique. À propos de deux cas et résumé de la littérature

OBJECTIVE

The objective of this work is to present and discuss the rare situation of curable medullary compression with favorable prognosis.

MATERIAL AND METHOD

Two cases of thoracic intramedullary arachnoid cysts are described. Clinical, paraclinical, therapeutics and outcome features are discussed with a review of the literature.

RESULTS

Two children, 4 and 8 years old, with an uneventful history were admitted for progressive spastic paraparesia. MRI demonstrated a thoracic intramedullary cystic lesion at level T3-T4 in both patients. The cyst was emptied with partial cyst wall resection via dorsomedial myelotomy. The pathology examination confirmed the diagnosis of arachnoid cyst. The initial clinical signs resolved completely in both patients.

CONCLUSION

Thought in children, intramedullary arachnoidian cyst is a potential cause of medullary compression. Direct surgery is the treatment of choice.

Spinal Arachnoid Cyst Causing Paraplegia Following Skull Base Surgery-Case Report-

A 40-year-old woman presented with a right petroclival meningioma compressing the brainstem and manifesting as a 6-month history of headache and gait difficulty. The patient underwent subtotal removal of the tumor via an anterior transpetrosal approach. The postoperative course was complicated by cerebrospinal fluid rhinorrhea, bacterial meningitis, and acute hemorrhagic rectal ulcer. The patient was discharged home in good condition after prolonged medical treatment. Four months after the surgery, the patient noted recurrence of gait difficulty. Magnetic resonance (MR) imaging of the brain showed enlargement of the ventricles and no residual brainstem compression. A ventriculoperitoneal shunt was placed, but the symptoms were unchanged. The shunt was removed 2 months later because of infection. The patient's gait gradually deteriorated, although repeat brain MR imaging showed no significant increase in ventricular size. Ten months after the initial surgery she became paraplegic. MR imaging of the thoracic spine revealed a large arachnoid cyst extending from C-6 to T-6. The patient underwent T2-4 laminectomy, partial removal of the cyst wall, and duraplasty, but no clinical improvement was observed. Preexisting long-tract signs and coincidental hydrocephalus confused the neurological findings and delayed detection of the spinal lesion in this case. Neurosurgeons should be alert to the possibilities of insidious spinal lesion if the patient has progressive neurological disorder which does not match the known cranial lesion.

Extensive intradural arachnoid cyst of the lumbar spinal canal: case report

BACKGROUND

Spinal intradural arachnoid cysts are rare outpouchings of arachnoid lining occurring mainly in the thoracic and cervical regions. MRI is considered the diagnostic procedure of choice; however, some arachnoid cysts have been reported to elude diagnosis by MRI due to the similar signal intensity of the cyst and the subarachnoid space.

CASE DESCRIPTION

We present a case of a 41-year-old woman with an intradural arachnoid cyst of the lumbar spinal canal. Diagnostic studies demonstrated a herniated L4-5 disk, which led to two operations. Despite intractable pain postoperatively, the MRI failed to reveal further focal compression of the nerve root. A myelogram suggested compression of the thecal sac by a dorsal mass lesion. The patient underwent a midline durotomy that revealed two large arachnoid cysts with the nerve roots beneath them pushed ventrally and to the right. Removal of the arachnoid layer resulted in complete fenestration of the cyst and allowed the nerve roots to freely float in the spinal fluid.

CONCLUSION

In retrospect, the abnormality could be appreciated on multiple prior scans performed at another institution, demonstrating that in the patient with low back pain, degenerative disc disease is not the only diagnosis to consider.

Rarer causes of radiculopathy: spinal tumors, infections, and other unusual causes

For the physiatrist practicing musculoskeletal medicine, patients with radiculopathy are a challenging and rewarding population for whom to provide care. Despite the rarity of diseases discussed in this article, at some time in his or her career every musculoskeletal physiatrist will see patients with these diagnoses as the cause of radiculopathy or back pain. A high index of suspicion is necessary to identify these rare disease processes accurately and promptly. The patient's history, examination, and plain-film radiographic evaluations remain the best tools with which to establish a differential and working diagnosis. The most important services that the physiatrist can provide to these patients are an astute application of the differential diagnosis to identify the specific etiology and the leadership required to organize a multi-disciplinary team of specialists to address all of the patient's needs.

Arachnoiditis associated with arachnoid cyst formation and cord tethering following myelography: magnetic resonance features

The reported incidence of clinically significant arachnoiditis following oil-based contrast media myelography is approximately 1%. The incidence of arachnoiditis in the dorsal spine is even more rare. Acquired arachnoid cyst formation can occur with arachnoiditis of various aetiologies. A case is presented of a patient with chronic backache, radiculopathy, weakness and muscle wasting, who had undergone myelography with oil-based contrast media about 28 years ago. There was no history of spinal surgery, spinal canal stenosis, disc disease or trauma, all of which are known to increase the risk of arachnoiditis. Magnetic resonance imaging features are presented in this case of arachnoiditis with arachnoid cyst formation, and cord tethering.

Cystic lumbar nerve sheath tumours: MRI features in five patients

Intraspinal cystic lumbar nerve sheath tumours constitute an uncommon subset of tumours with distinct clinico-biological behaviour. The MRI findings in five such cases are presented. Four of these were cystic schwannomas and one was a cystic neurofibroma. The pathology, MRI findings and the differential diagnosis of these rare tumours are analysed.

Spinal cord herniation into an extradural arachnoid cyst

A herniation of the thoracic spinal cord into the mouth of an extradural arachnoid cyst is reported in a 37 year old man. This is the 20th case, but the first posterior herniation; all the others were anterior. He presented with progressive paraparesis and the magnetic resonance imaging (MRI) showed kinking of the cord into the cyst. Surgical release of the neck of the hernia was successful.

Anterior thoracic intradural arachnoid cysts

Anterior thoracic intradural arachnoid cysts (ATIACs) are a rare cause of spinal cord and nerve root compression, for which different treatment strategies have been proposed. Although ATIAC represents a well-known clinical entity, the choice of surgical method has not been uniform, and no study has been specifically designed to compare the results of the different treatment options adopted.

The authors report the case of a 40-year old man with a 1-year history of dorsal pain, weakness in the lower extremities, gait disturbance, and mild sexual and urinary dysfunction. On neurological examination spastic paraparesis, lower-extremity hypertonia, and hypesthesia below T-2 were demonstrated. Magnetic resonance imaging revealed the presence of an ATIAC at the T-2 level. The patient underwent complete microsurgical removal of the cyst.

The authors conducted a Medline search of the relevant literature from 1966 to 1998 and also obtained data on other cases in which patients underwent surgical treatment of ATIAC. The literature search yielded five such cases. Treatment strategies were complete excision and fenestration followed by placement of a shunt. In addition, one case was characterized by intraoperative cyst rupture during retraction of the spinal cord.

Correct preoperative workup coupled with microneurosurgical technique allow for successful removal of the lesion and excellent outcome. Based on the literature review and the results in our case, the complete excision of ATIAC is associated with an excellent outcome, which is different from results achieved using other surgical strategies.

Cauda equina syndrome due to lumbosacral arachnoid cysts in children

We describe the clinical, neuroradiological and surgical aspects of two children in whom symptoms attributable to cauda equina compression were caused by spinal arachnoid cysts. The first patient presented with recurrent urinary tract infections due to neurogenic bladder dysfunction, absent deep tendon reflexes and sensory deficit in the lower limbs. The second child presented with unstable gait as a result of weakness and diminished sensation in the lower extremities. Spinal magnetic resonance imaging revealed a lumbosacral arachnoid cyst in both patients. During surgery the cysts were identified and excised. Two years after surgery, the sensory deficits of the first patient have disappeared and patellar and ankle reflexes can be elicited, but there is no improvement in bladder function. Neurological examination of the second patient was normal. We conclude that the diagnosis of cauda equina syndrome should prompt a vigorous search for its aetiology. Lumbosacral arachnoid cysts are a rare cause of cauda equina syndrome in children.