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.

Review/Perspective On the Diagnosis and Surgical Management of Spinal Arachnoid Cysts

Background:

Spinal arachnoid cysts (SAC) are typically congenital, spontaneous, traumatic (i.e., including iatrogenic/surgical), or inflammatory in origin. In descending order, they occur in the thoracic, lumbar, and cervical spine, and originate from focal entrapment of the arachnoid membrane. Arachnoid cysts represent 1–2% of all cystic spinal masses/tumors. The majority are extradural arachnoid cysts (EDAC) while 10% of all arachnoid cysts are intradural (IDAC) including subarachnoid, or extra-arachnoidal/subdural. Only rarely are they intramedullary in location. The clinical symptoms/signs of IDAC/EDAC include; intracranial hypotension (i.e., due to continued cerebrospinal fluid drainage), radiculopathy, and/or myelopathy.

Methods:

Magnetic Resonance Images (MR) and Myelo-Computed Tomography (Myelo-CT) studies classically document the predominant dorsal location of IDAC/EDAC. They also show their extent and severity contributing to root, cord, and/or cauda equina compression. In the cervical/thoracic spine, MR/Myelo-CT studies classically show the “double cord” or “windsock” signs, while the “fake arachnoiditis sign” may be seen in the lumbar spine. The latter sign signals the presence of a circumferential extra-arachnoidal-subdural cyst that centrally “traps” the cauda equina. Note, that this resembles and is often misinterpreted as adhesive archnoiditis.

Results:

Patients with significant SAC-related neurological deficits typically warrant early surgery. That surgery includes; partial/total resection/fenestration of cyst walls, and occlusion of communicating fistulas with or without accompanying shunts.

Conclusion:

It is critical to recognize the clinical (i.e., intracranial hypotension, radiculopathy, and/or myelopathy) and radiographic MR/Myelo-CT signs (i.e., “double cord,” “windsock signs”, or “fake arachnoiditis sign”) of IDAC, EDAC, or intramedullary spinal arachnoid cysts to appropriately offer treatment. For those with significant neurological deficits, early surgery (i.e. optimally 0-< 24 hours after the onset of symptoms/signs consisting of laminectomies, partial/total cyst resection/fenestration, and ligation/occlusion of the subarachnoid-cyst fistula with or without shunt placement), is essential to avoid significant permanent neurological sequelae.

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.

Postarachnoiditis Anterior Spinal Arachnoid Cyst Formation with Compressive Myelopathy: Report of 2 Cases

BACKGROUND

Spinal cystic arachnoiditis is a rare complication of a subarachnoid haemorrhage or infectious meningitis. The inflammatory process leads to fibrosis, adhesions, and in severe cases cyst formation. Large arachnoid cysts are an uncommon cause of compressive myelopathy. The majority are located posterior of the spinal cord at the thoracic level. Anterior cyst formation is exceptional, especially at the cervical region.

CASE DESCRIPTION

We present 2 cases of progressive myelopathy secondary to anterior arachnoid cyst formation. In a 54-year-old female a large anterior symptomatic thoracic cyst arose 4 years after rupture of a posterior inferior cerebellar artery aneurysm. The other 59-year-old-patient, however, developed an anterior cervical cyst only weeks after a varicella meningoencephalitis. Both female patients were treated with a decompressive laminectomy and wide fenestration of the cysts. Partial recovery was obtained in 1 patient, but there was no improvement in the other case.

CONCLUSIONS

Spinal cystic arachnoiditis with anterior cyst formation is an extremely rare complication of subarachnoid haemorrhage and infectious meningitis but can cause severe neurologic deficits. Clinicians should be aware of this rare complication. Due to the risk of irreversible spinal cord injury, rapid surgical intervention is recommended in most cases.

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.

An occult spinal neurenteric cyst associated with congenital hemivertebrae. A case report

We describe a case of an occult spinal neurenteric cyst associated with congenital hemivertebrae. Different intraspinal anomalies, such as neurenteric cysts (representing 0.3 to 0.5 % of all spinal tumors) have been reported in association with congenital hemivertebrae. Indeed, although CT is the best examination to study vertebral anomalies, MRI should be performed in order to exclude a more complex dysraphic condition.