MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis

Surgical treatment for recurrent thoracic ventral intradural arachnoid cyst secondary to tuberculous meningitis: a case report

INTRODUCTION

Spinal intradural arachnoid cysts (SIACs) are rare spinal entities that are categorized as primary or secondary pathologies. Secondary cysts can arise from various traumatic or inflammatory causes including subarachnoid hemorrhage, intrathecal injection or surgery, and infectious meningitis/arachnoiditis. Only a few cases of SIAC secondary to tuberculous meningitis have been previously reported, without details of the surgical treatment.

CASE PRESENTATION

A 27-year-old woman diagnosed with tuberculous meningitis developed myelopathy caused by thoracic ventral SIAC and intradural abscess. The patient underwent abscess evacuation and cyst fenestration; however, cyst recurrence occurred. The 2nd surgery consisted of cyst resection via a posterolateral approach with expansive duraplasty and spinal arthrodesis. Re-recurrence occurred, and at the 3rd surgery, cyst-subarachnoid bypass was performed. One year after the 3rd surgery, the myelopathic symptoms recovered, and MR images demonstrated a decreased cyst size.

DISCUSSION

Here, we report a rare case of recurrent thoracic SIAC secondary to tuberculous meningitis and arachnoiditis. Simple fenestration is associated with a high risk of recurrence in this pathology. Ventrally located thoracic cysts can be approached with posterolateral approach with pedicles resected followed by instrumented arthrodesis. Even in cases involving gross total resection of the cyst wall, there is a risk of recurrence. In such cases, cyst-subarachnoid bypass with a large-diameter tube can be effective.

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.

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.

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.

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.

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.

Tuberculous meningomyelitis in magnetic resonance imaging: A Chinese case report

Tuberculous meningomyelitis is a relatively rare but serious type of nervous system tuberculosis. This disease is caused by invasion of the spinal cord or the spinal meninges tuberculosis. The early symptoms are not typical and lack specificity. It can cause early changes in the MRI. Analysis of the MRI manifestations combined with the clinical manifestations and cere- brospinal fluid examination can facilitate accurate diagnosis of the disease. Early treatment has a clear effect, we want to increase knowledge of the dis- ease by sharing this case in order to reduce clinical misdiagnosis and allow more patients to be treated in time.

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.

Spinal cord involvement in tuberculous meningitis

OBJECTIVES

To summarize the incidence and spectrum of spinal cord-related complications in patients of tuberculous meningitis.

SETTING

Reports from multiple countries were included.

METHODS

An extensive review of the literature, published in English, was carried out using Scopus, PubMed and Google Scholar databases.

RESULTS

Tuberculous meningitis frequently affects the spinal cord and nerve roots. Initial evidence of spinal cord involvement came from post-mortem examination. Subsequent advancement in neuroimaging like conventional lumbar myelography, computed tomographic myelography and gadolinium-enhanced magnetic resonance-myelography have contributed immensely. Spinal involvement manifests in several forms, like tuberculous radiculomyelitis, spinal tuberculoma, myelitis, syringomyelia, vertebral tuberculosis and very rarely spinal tuberculous abscess. Frequently, tuberculous spinal arachnoiditis develops paradoxically. Infrequently, spinal cord involvement may even be asymptomatic. Spinal cord and spinal nerve involvement is demonstrated by diffuse enhancement of cord parenchyma, nerve roots and meninges on contrast-enhanced magnetic resonance imaging. High cerebrospinal fluid protein content is often a risk factor for arachnoiditis. The most important differential diagnosis of tuberculous arachnoiditis is meningeal carcinomatosis. Anti-tuberculosis therapy is the main stay of treatment for tuberculous meningitis. Higher doses of corticosteroids have been found effective. Surgery should be considered only when pathological confirmation is needed or there is significant spinal cord compression. The outcome in these patients has been unpredictable. Some reports observed excellent recovery and some reported unfavorable outcomes after surgical decompression and debridement.

CONCLUSIONS

Tuberculous meningitis is frequently associated with disabling spinal cord and radicular complications. Available treatment options are far from satisfactory.

Surgical manifestations of thoracic arachnoid pathology: series of 28 cases

Object

Various pathologies involving the thoracic arachnoid mater uniformly manifest as thoracic myelopathy and may present a significant management dilemma. The authors undertook this study to assess outcome in cases of thoracic myelopathy due to thoracic arachnoid pathology.

Methods

The authors have cared for and followed 28 patients with thoracic myelopathy from thoracic arachnoid pathology over the last 17 years. A chart review and contemporary follow-up of these patients was performed and outcomes were reported.

Results

Patients with thoracic myelopathy from thoracic arachnoid pathology often have improvement in their condition after surgical decompression/detethering procedures. While not universal, patients in this series had improvement in mJOA scores at 1 year after surgery (p = 0.0001) and at last follow-up (p = 0.04). Results indicated that across a wide variety of pathologies the extent of thoracic spinal cord involvement is a predictor of the disease course and outcome. Comparison of the group of patients with cord involvement limited to 2 vertebral segments (short-segment pathology) versus the group with cord tethering of more than 2 segments (long-segment pathology) showed that patients in the short-segment group more frequently had ventral or dorsal arachnoid bands (p = 0.003), more frequently had signal change in the cord on MRI (p = 0.02), and less frequently presented with a syrinx (p = 0.02), and a smaller percentage of patients in this group underwent reoperation (p = 0.02). While patients with short-segment pathology typically improved after a single operative intervention, patients with long-segment pathology typically improved after multiple operations, frequently for CSF diversion.

Conclusions

Thoracic arachnoid pathology causing thoracic cord dysfunction and myelopathy is varied, has multiple etiologies, and can be difficult to treat over the long term. Surgical management, when indicated, is case specific. Serial long-term follow-up is essential to document enduring clinical and radiographic success.

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.

Spinal endodermal cyst resembling an arachnoid cyst in appearance: Pitfalls in intraoperative diagnosis of cystic lesions

BACKGROUND

Surgical treatment of endodermal cysts requires total removal of the cyst wall during the first operation to prevent recurrence. Therefore, intraoperative pathological diagnosis plays an important role in determining the optimal surgical strategy. We present a rare case of a spinal endodermal cyst and discuss its diagnostic difficulty during the intraoperative pathological examination.

CASE DESCRIPTION

An 18-year-old male presented with progressive paraparesis and precordial oppression. Magnetic resonance (MR) imaging revealed an intradural extramedullary cystic mass having the same signal intensity as cerebrospinal fluid (CSF) without gadolinium enhancement at the T1-T2 level. The preoperative diagnosis was an endodermal or arachnoid cyst. The patient underwent surgery. An intraoperative frozen section showed a cyst wall consisting of loose, thin, fibrous tissue intermittently covered by flattened epithelium. The diagnosis was an arachnoid cyst. Accordingly, partial resection of the cyst wall was performed to create CSF communication between the cyst and subarachnoid space. However, the postoperative pathological diagnosis from permanent sections was an endodermal cyst, which was lined with ciliated columnar epithelium that was immunopositive for cytokeratin and epithelial membrane antigen. Subsequent paraffin embedding and immunostaining of the intraoperative frozen sample also confirmed patchy cytokeratin expression by all flattened epithelial cells. The patient's cyst had refilled 10 months after surgery, and he subsequently underwent fenestration of the cyst wall and placement of a cyst-subarachnoid shunt.

CONCLUSION

Examination of multiple samples from multiple sites or intraoperative immunostaining of frozen sections is recommended for accurate intraoperative diagnosis of endodermal cysts.

Spinal Arachnoid Cyst as an Infrequent Cause of Spinal Cord Compression

Spinal arachnoid cysts are rare lesions that may produce symptoms by compressing the spinal cord or nerve roots. MRI is essential for diagnosing this entity. We retrospectively reviewed the medical charts, radiological examinations, and follow-up data of four adults with spinal arachnoid cysts diagnosed in our center over a two-year period (2007-2009). All cysts were located in the thoracic spine. Three were dorsolateral to the spinal cord and one was ventral. Most had multiple septa but one had a single septum. Cyst size varied greatly; one cyst extended through eight vertebral bodies. One patient treated expectantly died of cardiovascular problems one year after the cyst was diagnosed. The other three patients underwent laminectomy and cyst fenestration; two had clinical and imaging signs of relapse after surgery. One of the patients with a relapsed cyst worsened clinically, developing syringomyelia and requiring reintervention with shunting to the subarachnoid space. The outcome of the operation was good in the case of the single septum. Spinal arachnoid cyst is uncommon. Its diagnosis is complex because the symptoms are unspecific and the imaging findings are subtle. Spinal arachnoid cyst should be included in the differential diagnosis of chronic paraparesis. Imaging plays an essential role in the diagnosis, follow-up and management of spinal arachnoid cysts.

Foramen magnum arachnoid cyst induces compression of the spinal cord and syringomyelia: case report and literature review

It is very rare that a foramen magnum arachnoid cyst induces compression of the spinal cord and syringomyelia, and currently there are few treatment experiences available. Here we reported the case of a 43-year-old male patient who admitted to the hospital due to weakness and numbness of all 4 limbs, with difficulty in urination and bowel movement. MRI revealed a foramen magnum arachnoid cyst with associated syringomyelia. Posterior fossa decompression and arachnoid cyst excision were performed. Decompression was fully undertaken during surgery; however, only the posterior wall of the arachnoid cyst was excised, because it was almost impossible to remove the whole arachnoid cyst due to toughness of the cyst and tight adhesion to the spinal cord. Three months after the surgery, MRI showed a reduction in the size of the arachnoid cyst but syrinx still remained. Despite this, the symptoms of the patient were obviously improved compared to before surgery. Thus, for the treatment of foramen magnum arachnoid cyst with compression of the spinal cord and syringomyelia, if the arachnoid cyst could not be completely excised, excision should be performed as much as possible with complete decompression of the posterior fossa, which could result in a satisfying outcome.

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.

Cervical anterior intradural arachnoid cyst in a child

Intradural arachnoid cysts involving the spine are uncommon and especially rare in an anterior cervical location. In the literature, among 15 patients, 8 were in the paediatric age group and in 3 patients the cyst was localised to the full length of the cervical spinal canal. Although they occur secondary to trauma, haemorrhage, surgery or inflammation, most of them are known to be idiopathic or congenital. Although the disease shows a dramatic neurological course, early diagnosis and treatment could provide good results. We report a 2(1/2) year-old boy with progressive tetraparesis with a huge anterior intradural arachnoid cyst located from the cervico-medullary junction to the C7 level. In the paediatric age group, cervical anterior intradural arachnoid cyst is an unusual cause of quadriparesis. The rarity of this condition and the relevance of MRI in the accurate and early diagnosis is discussed here. A 2(1/2) year-old boy with a large intradural arachnoid cyst extending from the cervico-medullary junction to C7 situated anteriorly is reported here; diagnosis and treatment modalities are discussed.

Concurrent syringomyelia and intradural extramedullary tuberculoma as late complications of tuberculous meningitis

Tuberculous meningitis (TBM) is a common presentation of extrapulmonary tuberculosis. TBM is associated with many complications. However, concurrent syringomyelia and intradural extramedullary tuberculoma occurring in a patient treated for TBM is rare. Only one such case has been reported earlier. A 27-year-old woman presented with paraparesis of 2 months duration. She had been treated for TBM 8 months earlier. She was found to have an extensive syringomyelia from C2 to the conus medullaris and an intradural extramedullary tuberculoma at the lower thoracic levels. At surgery, a thick, granulomatous lesion was found in the intradural extramedullary plane. Following excision of the granulomatous lesion, a syringostomy was done. The patient was treated with antituberculous drugs and steroids. Six months after treatment, there was no significant change in her neurological status. Concurrent syringomyelia and intradural extramedullary tuberculoma should be entertained in the differential diagnosis when a patient presents with myelopathy following TBM. The pathogenesis of syringomyelia in this condition is discussed.

Imagerie des lésions kystiques du canal rachidien chez l’adulte

Intrarachidian cystic lesions are frequent, with highly varied causes. They can be classified according to their location into intramedullary cystic lesions and extramedullary cystic lesions. In these two categories, they can then be regrouped according to the tissue from which they develop. MRI is the first-choice examination for the study of the intracanal contents and the differential diagnosis between the various lesions.

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.