Sural nerve abnormalities in sacral perineural (Tarlov) cysts

Management of Tarlov cysts: an uncommon but potentially serious spinal column disease-review of the literature and experience with over 1000 referrals

Tarlov cysts were thought to be anatomic variants of uncertain etiology and clinical significance when initially described over 80 years ago. They are often detected in routine lumbosacral imaging and generally not reported in a differential diagnosis. There is increasing evidence that at least some Tarlov cysts are symptomatic and can have a significant adverse impact on patients' health and well-being. Women are disproportionately affected with this condition, often presenting with long-standing pain and neurological dysfunctions. Significant gender bias has been a concern in the management of these patients. Unfortunately, there is no consensus on patient selection or management approaches for symptomatic Tarlov cysts. This review article updates information on the prevalence, diagnosis, clinical significance, and treatments of these cysts. Based on these findings and experience with over 1000 patient referrals, a treatment decision algorithm for symptomatic Tarlov cysts was constructed to provide guidance for appropriate management of patients with these complex cysts.

Giant Tarlov Cyst presenting as pelvic mass: Often doing less is better

Background

Tarlov cysts are sacral perineural cysts arising between the peri and endoneurium of the posterior spinal nerve root at the Dorsal Root Ganglion and have a global prevalence rate of 4.27%. These are primarily asymptomatic (only 1% with symptoms) and typically arise in females between the ages of 50-60. Patients' symptoms include radicular pain, sensory dysesthesias, urinary and/or bowel symptoms, and sexual dysfunction. Non-surgical management with lumbar cerebrospinal fluid drainage and computerized tomography-guided cyst aspiration typically provide only months of improvement before recurring. Surgical treatment includes a laminectomy, cyst, and/or nerve root decompression with fenestration of the cyst and/ or imbrication. Early surgery for large cysts provides the longest symptom-free periods.

Case Description

A 30-year-old male presented with a very large magnetic resonance-documented Tarlov cyst (Nabors Type 2) arising from bilateral S2 nerve root sheaths with marked pelvic extension. Although he was initially treated with a S1, S2 laminectomy, closure of the dural defect, and excision/marsupialization of the cyst, he later required placement of a thecoperitoneal shunt (TP shunt).

Conclusion

A 30-year-old male with large Nabors Type 2 Tarlov cyst arising from both S2 nerve root sheaths required a S1-S2 laminectomy, dural closure/marsupialization, and imbrication of the cyst, eventually followed by placement of a TP shunt.

Symptomatic Tarlov cysts are often overlooked: ten reasons why-a narrative review

PURPOSE

Tarlov cysts (TCs) are dilations of nerve roots arising from pathologically increased hydrostatic pressure (HP) in the spinal canal. There is much controversy regarding whether these cysts are a rare source of pain or often produce symptoms. The aim of this review was to identify the reasons that symptomatic TCs (STCs) are easily overlooked.

METHODS

The literature was searched for data regarding pathogenesis and symptomatology.

RESULTS

TCs may be overlooked for the following reasons: (1) STCs are considered clinically irrelevant findings; (2) it is assumed that it is clinically difficult to ascertain that TCs are the cause of pain; (3) MRI or electromyography studies only focus on the L1 to S1 nerves; (4) TCs are usually not reported by radiologists; (5) degenerative alterations of the lumbosacral spine are almost always identified as the cause of a patient's pain; (6) it is not generally known that small TCs can be symptomatic; (7) examinations and treatments usually focus on the cysts as an underlying mechanism; however, essentially, increased HP is the main underlying mechanism for producing symptoms. Consequently, STCs may relapse after surgery; (8) bladder, bowel and sphincter dysfunction are not inquired about during history taking. (9) Unexplained pain is often attributed to depression, whereas depression is more likely the consequence of debilitating neuropathic pain. (10) The recognition of STCs is subject to gender bias, confirmation bias and cognitive dissonance and unconscious bias in publishing.

CONCLUSION

There are several reasons STCs are underdiagnosed, mostly due to persistent misconceptions and biases. These slides can be retrieved under Electronic Supplementary Material.

Prevalence of simple and complex sacral perineural Tarlov cysts in a French cohort of adults and children

OBJECTIVE

To determine the prevalence of simple and complex sacral perineural Tarlov cysts (TCs) in a cohort of children and adults.

MATERIAL AND METHODS

Retrospective observational epidemiological study assessing 1100 consecutive sacral magnetic resonance (MR) studies, including 100 children and adolescents. All patients underwent 1.5T MR imaging with T1 and T2 weighted image acquisitions in sagittal and axial planes. All perineural cysts affecting the sacral nerve roots S1-S4 were quantitatively and qualitatively assessed.

RESULTS

Two hundred and sixty-three sacral TCs were found in 132 adult patients (13.2%), with a female predominance (68%). None was found in children. The prevalence of TCs increased with age. The average number of cysts per patient was 2.0±1.2 with a maximum of 6 cysts in a single patient. Most of the cysts (87.5%) showed a homogenous central fluid collection and a parietal course of the nerve fibers. Complex patterns were present in 33 cysts (12.5%) within which 28 cysts showed endocystic crossing of nerve fibers and 5 cysts contained internal septations. Seventy cysts (26.6%) eroded the adjacent bone and 13 cysts (4.9%) extended to the pelvis.

CONCLUSION

The prevalence of sacral TCs in our cohort corresponded to 13%, with a female predominance. Interestingly no TCs were found in children or adolescents (<18 years). In relation to the non-negligible percentage of complex cysts with internal septations, or endocystic crossing of nerve fibers, pre-interventional characterization of sacral TCs might help to choose an appropriate procedure in the treatment of rare symptomatic variants.

Treatment of 213 Patients with Symptomatic Tarlov Cysts by CT-Guided Percutaneous Injection of Fibrin Sealant

BACKGROUND AND PURPOSE

There has been a steady progression of case reports and a small surgical series that report successful surgical treatment of Tarlov cysts with concomitant relief of patients' symptoms and improvement in their neurological dysfunction, yet patients are still told that these lesions are asymptomatic by physicians. The purpose of this study was to analyze the efficacy and safety of intervention in 213 consecutive patients with symptomatic Tarlov cysts treated by CT-guided 2-needle cyst aspiration and fibrin sealing.

MATERIALS AND METHODS

This study was designed to assess outcomes in patients who underwent CT-guided aspiration and injection of ≥1 sacral Tarlov cyst at Johns Hopkins Hospital between 2003 and 2013. In all, 289 cysts were treated in 213 consecutive patients. All these patients were followed for at least 6 months, 90% were followed for 1 year, and 83% were followed for 3-6 years. The aspiration-injection procedure used 2 needles and was performed with the patients under local anesthesia and intravenous anesthesia. In the fibrin-injection stage of the procedure, a commercially available fibrin sealant was injected into the cyst through the deep needle (Tisseel VH).

RESULTS

One year postprocedure, excellent results were obtained in 104 patients (54.2% of patients followed), and good or satisfactory results were obtained in 53 patients (27.6%). Thus, 157 patients (81.8%) in all were initially satisfied with the outcome of treatment. At 3-6 years postprocedure, 74.0% of patients followed were satisfied with treatment. There were no clinically significant complications.

CONCLUSIONS

The aspiration-injection technique described herein constitutes a safe and efficacious treatment option that holds promise for relieving cyst-related symptoms in many patients with very little risk.

Microsurgical excision of symptomatic sacral perineurial cyst with sacral recapping laminectomy : a case report in technical aspects

Perineurial cysts (Tarlov cysts) are lesions of the nerve root that are often observed in the sacral area. There is debate about whether symptomatic perineurial cysts should be treated surgically. We presented three patients with symptomatic perineurial cyst who were treated surgically, and introduced sacral recapping laminectomy. Patients complained of low back pain and hypesthesia on lower extremities. We performed operations with sacral recapping technique for all three. The outcome measure was baseline visual analogue score and post operative follow up magnetic resonance images. All patients were completely relieved of symptoms after operation. Although not sufficient to address controversies, this small case series introduces successful use of a particular surgical technique to treat sacral perineural cyst, with resolution of most symptoms and no sequelae.

Prevalence of spinal meningeal cyst in the sacrum

Spinal meningeal cysts in the sacrum (SMC) are known to be occasionally symptomatic with low back pain as well as leg pain, but no distinct prevalence of this pathological entity including asymptomatic lesions has been described. This prospective study investigated the prevalence of SMCs based on magnetic resonance (MR) myelography in 102 consecutive Japanese women with gynecological problems, who underwent pelvic conventional MR imaging. Ten of 102 patients were suspected of being positive for SMC (9.8%), but pseudo-positive findings were possible. A high probability of positive SMC was found in 7/102 (6.9%). MR myelography was better to detect SMCs than conventional MR imaging. Multiplicity and female preponderance may be other features of SMC. The speculated prevalence of SMCs in Japanese females ranged from 6.9% to 9.8%.

CT-guided percutaneous injection of fibrin glue for the therapy of symptomatic arachnoid cysts

BACKGROUND AND PURPOSE

Although often asymptomatic, enlarging sacral arachnoid cysts can also cause significant discomfort. These symptomatic sacral arachnoid cysts require specific treatments to facilitate local decompression. The main drawback of the surgical managements is the high risk of recurrence and complications. To decrease risks, we had been attempting to seek a simple and safe method to manage the symptomatic sacral arachnoid cysts. CT-guided percutaneous fibrin glue therapy is a new nonsurgical alternative. To evaluate the efficacy of the novel nonsurgical approach, we conducted this retrospective study of 38 patients.

MATERIALS AND METHODS

Thirty-eight patients with symptomatic sacral arachnoid cysts underwent fibrin glue therapy in our hospital between June 2006 and May 2009. The clinical results of improvement in pain and neurologic function were evaluated after an average of 25 months of follow-up, and changes on the imaging findings were evaluated. Preoperative and postoperative pain severity was assessed according to a 10-cm VAS. Moreover, we also analyzed the postoperative complications.

RESULTS

Most patients experienced some degree of pain relief and functional improvement after fibrin glue therapy, with most experiencing complete or marked resolution of clinical symptoms. Twenty-one patients (55.3%) reported excellent recovery, 12 (31.5%) reported good recovery, 4 (10.5%) reported fair recovery, and 1 (2.6%) reported poor recovery. The overall percentage of positive outcomes (excellent and good recovery) was 86.8%. No serious postoperative complications were discovered.

CONCLUSIONS

CT-guided percutaneous injection of fibrin glue therapy is simple, safe, and effective for the management of symptomatic sacral arachnoid cysts.

Perineural (Tarlov) cysts mimicking adnexal masses: a report of three cases

Perineural (Tarlov) cysts are usually incidental findings during magnetic resonance imaging (MRI) performed for low back pain. However, in a tertiary women's hospital, they may present as incidental findings on gynecological ultrasound imaging. Approximately 40,000 pelvic scans are performed annually in our department. Tarlov cysts were identified in three women between August 2007 and September 2008. In two patients (Cases 1 and 3), these cysts were initially misdiagnosed as hydrosalpinges on ultrasound examination, the latter having a differential diagnosis of an ovarian cyst. Two patients (Cases 1 and 2) were symptomatic, although Case 2 had symptoms that could not entirely be accounted for by the location of the cyst. Although asymptomatic, Case 3 underwent laparoscopy with a view to salpingectomy/cystectomy. In these patients, confirmation of Tarlov cysts was subsequently made on either computed tomography (CT) or MRI. All three patients were managed conservatively. Here we describe their clinical presentation, the appearance of the cysts on ultrasound imaging and on CT or MRI, and their eventual outcomes.

Presacral mass consisting of a meningocele and a Tarlov cyst: successful surgical treatment based on pathogenic hypothesis

This illustrative case shows a meningocele created by erosion of the sacrum by a perineurial cyst. It is the first report of a large presacral mass consisting of a perineurial cyst and a meningocele simultaneously. We describe a hypothesis for the pathogenesis of this particular constellation of circumstances and present a successful surgical option based on the assumed pathogenesis.

Diagnosis and management of sacral Tarlov cysts

Perineurial (Tarlov) cysts are meningeal dilations of the posterior spinal nerve root sheath that most often affect sacral roots and can cause a progressive painful radiculopathy. Tarlov cysts are most commonly diagnosed by lumbosacral magnetic resonance imaging and can often be demonstrated by computerized tomography myelography to communicate with the spinal subarachnoid space. The cyst can enlarge via a net inflow of cerebrospinal fluid, eventually causing symptoms by distorting, compressing, or stretching adjacent nerve roots. It is generally agreed that asymptomatic Tarlov cysts do not require treatment. When symptomatic, the potential surgery-related benefit and the specific surgical intervention remain controversial. The authors describe the clinical presentation, treatment, and results of surgical cyst fenestration, partial cyst wall resection, and myofascial flap repair and closure in a case of a symptomatic sacral Tarlov cyst. They review the medical literature, describe various theories on the origin and pathogenesis of Tarlov cysts, and assess alternative treatment strategies.