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Case Reviews in Pain
Hiding in Plain Sight: A Case of Tarlov Perineural Cysts
Reta Honey Hiers, Donlin Long, Richard B. North, and Anne Louise Oaklander
Key words: Tarlov cyst, chronic pelvic pain, perineural and sacral nerve root cyst, neuropathic pain, treatment, mechanisms.
Reta Honey Hiers, Donlin Long, Richard B. North, and Anne Louise Oaklander
Key words: Tarlov cyst, chronic pelvic pain, perineural and sacral nerve root cyst, neuropathic pain, treatment, mechanisms.
A 52-year-old woman sought help for intractable lumbosacral pain, which began after she lifted a heavy object and fell onto her back more than
2 decades ago. Additional symptoms included burning, numbness, tingling, and pain in her right hip, posterior thigh, leg, and toes, and diminished sensation and sensi- tivity throughout her right leg and foot. Muscle spasms/ cramps, which often interrupted sleep, were intermit- tently present in her right buttock and right lower ex- tremity. Right-foot drop impaired her ability to walk, and she used a wheeled walker with a seat because she could not walk more than a few steps without sitting. Other problems included: Severe pressure-type headaches, chronic abdominal and pelvic pain, cervical and thoracic back pain, frequent urinary tract infections, and urinary incontinence. Her pain increased with sitting, standing, and walking, and had been refractory to ibuprofen 800 mg tid, gabapentin 300 mg tid, oxycodone/acetamino- phen 5/325 mg q4h PRN, and cyclobenzaprine 10 mg tid.
Her medical history was unremarkable and her family history was notable for above-average height; most women in her paternal family are 5’10’’ to 6’ tall, and most men are 6’4’’ and taller. Many died in their 40s, and her brother and sister had been diagnosed with pos- sible multiple sclerosis.
Magnetic resonance imaging (MRI) of her pelvis re- vealed sacral nerve root cysts that were more completely imaged by sacral MRI (Fig 2). An MRI of the cervical spine from 2007 showed only mild C4-5 disc protrusion, but a repeat MRI in 2009 noted multilevel mild degenerative changes and small (#.6 cm) perineurial cysts at C4-5, C5-6, C6-7, C7-T1. In 2007, an MRI of the thoracic spine was inter- preted as normal.
The patient stated, ‘‘Everything in my life has been destroyed by these symptoms. It took over 2 decades
Address reprint requests to Dr J.A. Paice, Northwestern University Medical School, 676 North St Clair Street, Suite 850, Chicago, IL 60611- 2927. E-mail: j-paice@northwestern.edu
1526-5900/$36.00a 2010 by the American Pain Society doi:10.1016/j.jpain.2010.07.007
2 decades ago. Additional symptoms included burning, numbness, tingling, and pain in her right hip, posterior thigh, leg, and toes, and diminished sensation and sensi- tivity throughout her right leg and foot. Muscle spasms/ cramps, which often interrupted sleep, were intermit- tently present in her right buttock and right lower ex- tremity. Right-foot drop impaired her ability to walk, and she used a wheeled walker with a seat because she could not walk more than a few steps without sitting. Other problems included: Severe pressure-type headaches, chronic abdominal and pelvic pain, cervical and thoracic back pain, frequent urinary tract infections, and urinary incontinence. Her pain increased with sitting, standing, and walking, and had been refractory to ibuprofen 800 mg tid, gabapentin 300 mg tid, oxycodone/acetamino- phen 5/325 mg q4h PRN, and cyclobenzaprine 10 mg tid.
Her medical history was unremarkable and her family history was notable for above-average height; most women in her paternal family are 5’10’’ to 6’ tall, and most men are 6’4’’ and taller. Many died in their 40s, and her brother and sister had been diagnosed with pos- sible multiple sclerosis.
Magnetic resonance imaging (MRI) of her pelvis re- vealed sacral nerve root cysts that were more completely imaged by sacral MRI (Fig 2). An MRI of the cervical spine from 2007 showed only mild C4-5 disc protrusion, but a repeat MRI in 2009 noted multilevel mild degenerative changes and small (#.6 cm) perineurial cysts at C4-5, C5-6, C6-7, C7-T1. In 2007, an MRI of the thoracic spine was inter- preted as normal.
The patient stated, ‘‘Everything in my life has been destroyed by these symptoms. It took over 2 decades
Address reprint requests to Dr J.A. Paice, Northwestern University Medical School, 676 North St Clair Street, Suite 850, Chicago, IL 60611- 2927. E-mail: j-paice@northwestern.edu
1526-5900/$36.00a 2010 by the American Pain Society doi:10.1016/j.jpain.2010.07.007
to finally get the diagnosis of Tarlov/perineural cysts.’’
Reta Honey Hiers, BS, RN-C Tarlov Cyst Disease Foundation Knoxville, TN
Pathogenesis, Diagnosis, and Medical Management of Tarlov Cysts
This case describes a woman with multilevel symptom- atic perineurial Tarlov cysts (TCs). TCs were identified from cadaver study and described (by American neuro- surgeon Tarlov in 1938 and independently by Swedish anatomist Bror Rexed in 1947) without any knowledge of their clinical effects.11,12 Tarlov soon realized that, like herniated intervertebral discs, some cysts cause surgically treatable radiculopathy.13 But his initial paper was the only one widely read and cited, and his mistaken first impression of clinical irrelevance persisted. TCs occur most often in women (for unknown reasons), and mutual reluctance to discuss pelvic TC symptoms on the part of woman and spine specialists (usually men) has undoubt- edly contributed to the misperception of the medical significance of TCs.
TCs are created when cerebrospinal fluid (CSF) is trap- ped in the sensory nerve root sleeves. They form most of- ten at the sacral level under high hydrostatic pressure and only on sensory roots (Fig 1). CSF is presumably forced distally during transient pressure increases and sometimes blocked from returning by one-way valves or other obstructions. Cysts with free subarachnoid commu- nication are usually asymptomatic.3 High pressure causes gradual cyst enlargement, and CSF infiltration into the roots and sensory ganglia destroys axons and neurons. Large cysts can compress adjacent structures, including other nerve roots and bone. TCs are readily visible by conventional MRI or computerized tomography (CT) (Fig 2). MRI is more sensitive and recommended, particu- larly since repeated imaging is likely to be required.15 Tarlov cysts usually appear as low-intensity intraspinal masses on T1-weighted and high-intensity on T2-weighted
Reta Honey Hiers, BS, RN-C Tarlov Cyst Disease Foundation Knoxville, TN
Pathogenesis, Diagnosis, and Medical Management of Tarlov Cysts
This case describes a woman with multilevel symptom- atic perineurial Tarlov cysts (TCs). TCs were identified from cadaver study and described (by American neuro- surgeon Tarlov in 1938 and independently by Swedish anatomist Bror Rexed in 1947) without any knowledge of their clinical effects.11,12 Tarlov soon realized that, like herniated intervertebral discs, some cysts cause surgically treatable radiculopathy.13 But his initial paper was the only one widely read and cited, and his mistaken first impression of clinical irrelevance persisted. TCs occur most often in women (for unknown reasons), and mutual reluctance to discuss pelvic TC symptoms on the part of woman and spine specialists (usually men) has undoubt- edly contributed to the misperception of the medical significance of TCs.
TCs are created when cerebrospinal fluid (CSF) is trap- ped in the sensory nerve root sleeves. They form most of- ten at the sacral level under high hydrostatic pressure and only on sensory roots (Fig 1). CSF is presumably forced distally during transient pressure increases and sometimes blocked from returning by one-way valves or other obstructions. Cysts with free subarachnoid commu- nication are usually asymptomatic.3 High pressure causes gradual cyst enlargement, and CSF infiltration into the roots and sensory ganglia destroys axons and neurons. Large cysts can compress adjacent structures, including other nerve roots and bone. TCs are readily visible by conventional MRI or computerized tomography (CT) (Fig 2). MRI is more sensitive and recommended, particu- larly since repeated imaging is likely to be required.15 Tarlov cysts usually appear as low-intensity intraspinal masses on T1-weighted and high-intensity on T2-weighted
833
834 The Journal of Pain Hiding in Plain Sight
Figure 1. Diagram and legend from Tarlov’s last manuscript classifying spinal cysts; reproduced with publisher’s permission.14 Dia- gram illustrating various types of non-neoplastic, non-parasitic cysts, and diverticula of meninges and nerve roots. Top: Extradural meningeal cyst, usually midline, covered by markedly thinned dura, or it may represent herniated arachnoid through dural defect. Leptomeningeal cyst, seen below cord figure, composed of arachnoid. Upper left: Normal nerve root. Note that arachnoid continu- ation is perineurium and that subarachnoid space at root sleeve is continuous with potential space beneath perineurium, accounting for occasional myelographic filling of perineurial cysts. Middle left: Perineurial cyst. Note that this lies at level of posterior root gan- glion. Cyst wall contains neural elements. Space within cyst may have potential communication with subarachnoid space, as shown, allowing for delayed but not immediate myelographic filling. Lower left: Extradural meningeal cyst. Note that this lies proximal to posterior root ganglion. Bottom: Meningeal diverticulus. Sealing off neck of diverticulum produces cyst. Lower right: Extradural men- ingeal (false) cyst. May arise from rupture of extradural meningeal cyst, produced at operation by nicking the dura. Middle right: Men- ingeal diverticulum. Lies proximal to posterior root ganglion. Ordinarily of no pathological significance, but if communication with subarachnoid space becomes sealed off may form symptomatic extradural meningeal cyst. Upper right: Prolongation of subarachnoid space over nerve root, a rather frequent finding of no pathological significance.
images, like CSF. Communication between cyst and sub- arachnoid space, traditionally investigated with plain or CT-myelography, can now be studied with flow- sensitive MR sequences that detect fluid motion within the cyst. X-rays detect only TC-associated sacral erosion and fractures.3 About 1.5% of MR imaging performed for low-back-pain reveal TCs, but as with herniated discs, not all are symptomatic at the time of imaging.7 Most ra- diologists are taught that TCs are incidental and lack clin- ical significance, and many radiologists omit mention of TCs in their reports, obscuring the diagnosis, as occurred in this case. Even when TCs are accurately reported, they usually remain untreated.
TC patients with chronic moderate or severe pain, such as the woman in this case, should be offered medical management. Because of the absence of clinical trial in- vestigation for this particular condition, randomized controlled trials (RCT) for similar neuralgias must be con- sulted for guidance. There is no RCT for treatment of rad-
TC patients with chronic moderate or severe pain, such as the woman in this case, should be offered medical management. Because of the absence of clinical trial in- vestigation for this particular condition, randomized controlled trials (RCT) for similar neuralgias must be con- sulted for guidance. There is no RCT for treatment of rad-
iculopathy from TC, so I rely on studies of postherpetic neuralgia (PHN), another regional neuralgia that is caused by neuronal injury to the DRG and nerve roots, most often on the torso. A superb meta-analysis of all medication trials for treating PHN enables comparison of medication safety and efficacy.4 To summarize, the tricyclics (particularly nortriptyline and desipramine) have the highest therapeutic index and are inexpensive. For patients with contraindications to tricyclics (prior myocardial infarction, 2nd or higher degree heart- block, narrow-angle glaucoma, prostatic hypertrophy), gabapentin and opioid medications rise to the fore. Opi- oids have similar efficacy and adverse-effect profiles as other treatment options. Several of these medications should be tried for pain treatment. Medication will be the main treatment for patients who are not surgical candidates, who decline surgery, or who have residual pain after surgery. Neither exercise, physical therapy, diet, nor any alternative treatment has been shown to
Hiers et al The Journal of Pain 835
Figure 2. Sacral magnetic resonance imaging of Tarlov cysts. Magnetic resonance imaging of the sacrum performed without in- jected contrast using standard protocols demonstrated mild L3-4 and L4-5 intervertebral disk loss of height, bulging, and T2 signal- intensity changes with no substantial central canal or neural foraminal narrowing. Centered at S2 and S3, there is a lobulated col- lection of low T1 signal intensity, high T2 signal intensity structures most compatible with perineural cysts. The conglomerate mea- sures approximately 2.9 cm transverse by 2.2 cm anteroposterior by 1.4 cm craniocaudal. The collection of cysts displaces the right S3 and S4 nerve roots and contacts the left S3 and left S4 nerve roots. Additionally, there is right S1 intraforaminal perineural cyst. Limited visualized portions of the pelvis are unremarkable. Panel A is a sagittal T2 weighted image. Panel B is an axial T2 weighted image.
reduce neuropathic pain.6 A study on self-hypnosis train- ing in patients with pain from spinal-cord injury due to multiple sclerosis found efficacy but there are no data on cognitive-behavioral therapies specifically for TC. Ex- ercise and mobilization, however, have the secondary benefits of maintaining strength and flexibility and com- bating disuse, weight gain, and depression. A placebo- controlled trial found acupuncture ineffective for PHN.8
TCs can cause other disabilities including radicular foot-drop, treatable by an ankle-foot orthotic to ease walking and prevent falls.1 This patient’s urinary inconti- nence and infections suggest neurogenic bladder, a clas- sic sign of sacral radiculopathy. Urological consultation and urodynamic testing are indicated to treat inconti- nence and to prevent secondary damage to the bladder, ureters, and kidney. It is possible that her frequent head- aches reflect abnormal intracranial pressure associated with cysts—this should be clarified prior to treatment. This woman also needs genetic evaluation. TCs are linked to inherited collagen weakness, as in the Ehlers-Danlos syndromes.5 A tall woman with multiple TCs and a family history of unusual height and premature death probably has Marfan’s syndrome. A firm diagnosis and preventive care might protect her and other family members from potentially fatal complications (eg, aortic dissection, aneurysm).
Anne Louise Oaklander, MD, PhD Massachusetts General Hospital Boston, MA
Interventional Management of Symptomatic Sacral Perineural Cysts
Sacral cysts are of 3 general types. The perineural cysts described by Tarlov are most common; symptomatic dural ectasias often associated with large transsacral intraabdominal cysts are associated with known connec- tive tissue disorders, such as Marfan’s syndrome; and
TCs can cause other disabilities including radicular foot-drop, treatable by an ankle-foot orthotic to ease walking and prevent falls.1 This patient’s urinary inconti- nence and infections suggest neurogenic bladder, a clas- sic sign of sacral radiculopathy. Urological consultation and urodynamic testing are indicated to treat inconti- nence and to prevent secondary damage to the bladder, ureters, and kidney. It is possible that her frequent head- aches reflect abnormal intracranial pressure associated with cysts—this should be clarified prior to treatment. This woman also needs genetic evaluation. TCs are linked to inherited collagen weakness, as in the Ehlers-Danlos syndromes.5 A tall woman with multiple TCs and a family history of unusual height and premature death probably has Marfan’s syndrome. A firm diagnosis and preventive care might protect her and other family members from potentially fatal complications (eg, aortic dissection, aneurysm).
Anne Louise Oaklander, MD, PhD Massachusetts General Hospital Boston, MA
Interventional Management of Symptomatic Sacral Perineural Cysts
Sacral cysts are of 3 general types. The perineural cysts described by Tarlov are most common; symptomatic dural ectasias often associated with large transsacral intraabdominal cysts are associated with known connec- tive tissue disorders, such as Marfan’s syndrome; and
large midline cysts, which involve all sacral roots and are symmetrical, are probably internal meningoceles. For this discussion, we will focus on symptomatic TCs.
The key issue is determining when the cyst(s) revealed on imaging studies are the generator of the patient’s symptoms. Many perineural cysts are asymptomatic; however, many patients present with pain and signifi- cant, even progressive, neurological deficits. Because TCs generally involve sacral roots, loss of bowel, bladder, and sexual function are common. In experience with more than 400 patients, 3 separate syndromes have been identified. The most common occurs in patients with cyst(s) involving the S1 and/or S2 roots. These pa- tients typically have sciatic, pelvic, and perineal pain with sphincter disturbance, and perineal and genital sen- sory loss. Local pain over the cyst is common. A second substantial group of patients does not have sciatica but has all the local, perineal, and pelvic symptoms. A third very small group has only serious progressive bowel and bladder dysfunction. Thus, the first issue is determin- ing if the patient’s complaint matches the radicular symptoms expected from the location of the cyst(s). Neurological findings should also correlate with the location(s) of the cyst(s). In addition, before choosing a patient for an interventional procedure, always assess the lumbar spine and, in most cases, the pelvis to the sciatic notches.
When no other potential cause for the symptoms and signs is found, evaluate the likelihood that the cyst is the causative factor. Diagnostic blockade of cyst-bearing roots using only local anesthetic is one technique. Two blocks using agents of differing durations are employed, and concordant responses of pain relief for the expected duration of the block are required. Another possibility is to aspirate the cyst on a trial basis. If this temporarily relieves the pain, then direct treatment of the cyst is reasonable.
Two potential therapies are currently available: Direct surgical obliteration of the cyst, which has been
The key issue is determining when the cyst(s) revealed on imaging studies are the generator of the patient’s symptoms. Many perineural cysts are asymptomatic; however, many patients present with pain and signifi- cant, even progressive, neurological deficits. Because TCs generally involve sacral roots, loss of bowel, bladder, and sexual function are common. In experience with more than 400 patients, 3 separate syndromes have been identified. The most common occurs in patients with cyst(s) involving the S1 and/or S2 roots. These pa- tients typically have sciatic, pelvic, and perineal pain with sphincter disturbance, and perineal and genital sen- sory loss. Local pain over the cyst is common. A second substantial group of patients does not have sciatica but has all the local, perineal, and pelvic symptoms. A third very small group has only serious progressive bowel and bladder dysfunction. Thus, the first issue is determin- ing if the patient’s complaint matches the radicular symptoms expected from the location of the cyst(s). Neurological findings should also correlate with the location(s) of the cyst(s). In addition, before choosing a patient for an interventional procedure, always assess the lumbar spine and, in most cases, the pelvis to the sciatic notches.
When no other potential cause for the symptoms and signs is found, evaluate the likelihood that the cyst is the causative factor. Diagnostic blockade of cyst-bearing roots using only local anesthetic is one technique. Two blocks using agents of differing durations are employed, and concordant responses of pain relief for the expected duration of the block are required. Another possibility is to aspirate the cyst on a trial basis. If this temporarily relieves the pain, then direct treatment of the cyst is reasonable.
Two potential therapies are currently available: Direct surgical obliteration of the cyst, which has been
836 The Journal of Pain
employed for more than 50 years with a number of satis- factory outcomes reported, and CT-controlled percuta- neous cyst aspiration and obliteration by injecting blood, fibrin sealant, or harvested fat. Six years ago, we began to investigate cyst aspiration followed by obliteration by injecting commercially available fibrin sealant. This 30-minute outpatient procedure is per- formed with minimal sedation, usually including a small amount of intravenous opioid. Using CT control, 1 nee- dle is placed into the cyst and, when possible, a second venting needle is also placed. The contents are aspi- rated, and if the cyst does not refill, the cyst is partially obliterated by the injection of the fibrin sealant. Pa- tients are given limited restrictions for 1 or 2 days and then return to full activity. Outcomes were deter- mined by third-party interview coupled with review of medical records. Pain relief was judged by VAS scale changes, the BenDebba-Long pain assessment tool, and improvement in neurological function. Treatment was considered successful if patients’ symptoms and signs were relieved to the degree that they did not desire further therapy and if they indicated that they would undergo the same procedure for the same result again if needed. Evaluation of the first 130 patients yielded an initial success rate of approximately 75%. The initial failure rate was 25%, and an additional failure rate of 5% occurred with time. Three patients were relieved for 1 to 2 years and underwent successful reaspiration. Onset of improvement varied from immediate to 3 months. No patient who had not begun to improve within 3 months improved later; however, some pa- tients did not reach maximum improvement for 9 to 12 months following the procedure. Complications were minimal. There were no infections and no in- stances of nerve injury. Four patients, however, re- ported substantial worsening of pain, which lasted 2 to 4 weeks and then relented. One patient who under- went the procedure subsequent to the initial group complained of worsening pain, which has persisted for 6 months now. One patient had a cutaneous aller- gic reaction to something employed during the proce- dure. The second follow-up of patients treated from 1 to 6 years ago is underway.
Surgery has been employed for more than 50 years with reasonable success. The surgical procedure in- cludes cyst exposure, opening the cyst to avoid nerve in- jury, obliteration of real or potential spinal fluid space connections, and then cyst obliteration by packing, col- lapsing, or imbrication. Most published series are small, but all reported excellent outcomes.2,9,16 My surgical series includes 75 patients over nearly 40 years. My current indications for surgery are failure of aspiration or the presence of spinal fluid fistula large enough that aspiration is not feasible. Outcomes have been approximately the same as aspiration: 75% of patients have been satisfied with their surgical outcome. There has been no incidence of nerve injury. One infection occurred in a patient with massive dural ectasia, which is not the topic of this discussion. Postoperative spinal fluid leak to subcutaneous tissues occurred in 9% of patients, half of whom required reoperation.
employed for more than 50 years with a number of satis- factory outcomes reported, and CT-controlled percuta- neous cyst aspiration and obliteration by injecting blood, fibrin sealant, or harvested fat. Six years ago, we began to investigate cyst aspiration followed by obliteration by injecting commercially available fibrin sealant. This 30-minute outpatient procedure is per- formed with minimal sedation, usually including a small amount of intravenous opioid. Using CT control, 1 nee- dle is placed into the cyst and, when possible, a second venting needle is also placed. The contents are aspi- rated, and if the cyst does not refill, the cyst is partially obliterated by the injection of the fibrin sealant. Pa- tients are given limited restrictions for 1 or 2 days and then return to full activity. Outcomes were deter- mined by third-party interview coupled with review of medical records. Pain relief was judged by VAS scale changes, the BenDebba-Long pain assessment tool, and improvement in neurological function. Treatment was considered successful if patients’ symptoms and signs were relieved to the degree that they did not desire further therapy and if they indicated that they would undergo the same procedure for the same result again if needed. Evaluation of the first 130 patients yielded an initial success rate of approximately 75%. The initial failure rate was 25%, and an additional failure rate of 5% occurred with time. Three patients were relieved for 1 to 2 years and underwent successful reaspiration. Onset of improvement varied from immediate to 3 months. No patient who had not begun to improve within 3 months improved later; however, some pa- tients did not reach maximum improvement for 9 to 12 months following the procedure. Complications were minimal. There were no infections and no in- stances of nerve injury. Four patients, however, re- ported substantial worsening of pain, which lasted 2 to 4 weeks and then relented. One patient who under- went the procedure subsequent to the initial group complained of worsening pain, which has persisted for 6 months now. One patient had a cutaneous aller- gic reaction to something employed during the proce- dure. The second follow-up of patients treated from 1 to 6 years ago is underway.
Surgery has been employed for more than 50 years with reasonable success. The surgical procedure in- cludes cyst exposure, opening the cyst to avoid nerve in- jury, obliteration of real or potential spinal fluid space connections, and then cyst obliteration by packing, col- lapsing, or imbrication. Most published series are small, but all reported excellent outcomes.2,9,16 My surgical series includes 75 patients over nearly 40 years. My current indications for surgery are failure of aspiration or the presence of spinal fluid fistula large enough that aspiration is not feasible. Outcomes have been approximately the same as aspiration: 75% of patients have been satisfied with their surgical outcome. There has been no incidence of nerve injury. One infection occurred in a patient with massive dural ectasia, which is not the topic of this discussion. Postoperative spinal fluid leak to subcutaneous tissues occurred in 9% of patients, half of whom required reoperation.
Hiding in Plain Sight
Spinal fluid leak is the most significant complication reported.
An infrequently recognized complication of the cyst is progressive sacral thinning with or without pathologi- cal fracture. This has occurred in several patients in our series. Reconstruction of the eroded posterior sacrum has been suggested but as yet has not been tried in a significant number of patients. The typical symptomatic cyst has been 1.5 cm or larger. Multiple cysts occurred in approximately 40% of patients. Our current approach is to treat only cysts we believe to be symptomatic.
As yet, there are no epidemiological studies that allow us to determine the true incidence of symptomatic cyst, but it is important for those involved with spinal and pel- vic pain problems to understand that some sacral cysts are symptomatic and that reasonably successful treat- ments exist for them.
Donlin Long, MD, PhD Department of Neurosurgery Johns Hopkins University Baltimore, MD
Neuromodulation of TC Pain
This patient’s intractable back and pelvic pain is accom- panied by symptoms of burning, numbness, tingling, and pain in her right hip, leg, and foot. She also has a neuro- logic deficit that is manifest as right-foot drop as well as frequent urinary tract infections and urinary inconti- nence. Thus, her pain is neuropathic in nature.
Spinal cord stimulation (SCS) is a well-established treatment for neuropathic pain of spinal origin.10 SCS is not, however, a treatment for neurologic deficit, such as weakness, albeit function such as strength can improve when SCS relieves pain. As a practical matter, although the exact cause of loss of neurologic function can be difficult to determine, a patient can easily un- dergo an SCS screening trial with a temporary electrode and external pulse generator. The results of such a screen- ing trial allow us to determine if stimulation will provide pain relief and improve function.
Although SCS is used almost exclusively to treat pain, sacral root stimulation is used both for pain and to treat bladder and bowel dysfunction that results in inconti- nence and retention. Sacral nerve stimulation can be ac- complished with special electrodes or SCS electrodes, as appropriate. In the case of sacral stimulation, we are stimulating the roots, not the spinal cord. Compared with SCS, the mechanism of action of sacral stimulation might differ or be the same because the dorsal columns contain the same primary afferents that are accessible for stimulation in the roots
When we treat a patient with a neurologic deficit, such as the foot drop in this case, we must first determine if the problem is surgically remediable before we simply take steps to treat the pain with a stimulator or anything else. For this patient, we would need to determine if the foot drop is due to nerve compression by a mass lesion in the lumbosacral spine, which would be amenable to de- compression, but as Dr. Long points out, the compression
Spinal fluid leak is the most significant complication reported.
An infrequently recognized complication of the cyst is progressive sacral thinning with or without pathologi- cal fracture. This has occurred in several patients in our series. Reconstruction of the eroded posterior sacrum has been suggested but as yet has not been tried in a significant number of patients. The typical symptomatic cyst has been 1.5 cm or larger. Multiple cysts occurred in approximately 40% of patients. Our current approach is to treat only cysts we believe to be symptomatic.
As yet, there are no epidemiological studies that allow us to determine the true incidence of symptomatic cyst, but it is important for those involved with spinal and pel- vic pain problems to understand that some sacral cysts are symptomatic and that reasonably successful treat- ments exist for them.
Donlin Long, MD, PhD Department of Neurosurgery Johns Hopkins University Baltimore, MD
Neuromodulation of TC Pain
This patient’s intractable back and pelvic pain is accom- panied by symptoms of burning, numbness, tingling, and pain in her right hip, leg, and foot. She also has a neuro- logic deficit that is manifest as right-foot drop as well as frequent urinary tract infections and urinary inconti- nence. Thus, her pain is neuropathic in nature.
Spinal cord stimulation (SCS) is a well-established treatment for neuropathic pain of spinal origin.10 SCS is not, however, a treatment for neurologic deficit, such as weakness, albeit function such as strength can improve when SCS relieves pain. As a practical matter, although the exact cause of loss of neurologic function can be difficult to determine, a patient can easily un- dergo an SCS screening trial with a temporary electrode and external pulse generator. The results of such a screen- ing trial allow us to determine if stimulation will provide pain relief and improve function.
Although SCS is used almost exclusively to treat pain, sacral root stimulation is used both for pain and to treat bladder and bowel dysfunction that results in inconti- nence and retention. Sacral nerve stimulation can be ac- complished with special electrodes or SCS electrodes, as appropriate. In the case of sacral stimulation, we are stimulating the roots, not the spinal cord. Compared with SCS, the mechanism of action of sacral stimulation might differ or be the same because the dorsal columns contain the same primary afferents that are accessible for stimulation in the roots
When we treat a patient with a neurologic deficit, such as the foot drop in this case, we must first determine if the problem is surgically remediable before we simply take steps to treat the pain with a stimulator or anything else. For this patient, we would need to determine if the foot drop is due to nerve compression by a mass lesion in the lumbosacral spine, which would be amenable to de- compression, but as Dr. Long points out, the compression
Hiers et al
might simply be the result of infiltration by CSF under pressure. The important point is to consider surgically treating the cause of the pain before treating the symptom (pain).
Tarlov cysts and SCS are not mentioned together in the literature. Lumbosacral radiculopathy is the most com- mon indication for SCS in the United States, but this use of SCS is generally to treat persistent or recurrent pain after a lumbosacral surgical procedure (failed back surgery syndrome, ‘‘FBSS’’). Arguably, patients with FBSS are comparable to this patient with Tarlov cysts be- cause, in each case, the same structures are injured, and, furthermore, many patients with FBSS undoubtedly have incidental Tarlov cysts. Thus, the FBSS literature should
References
1. Baek WS, Rezania K, Baek WS, Rezania K: Tarlov cysts masquerading as peripheral neuropathy. Arch Neurol 63: 1804-1805, 2006
2. Caspar W, Papavero L, Nabhan A, Loew C, Ahlhelm F: Mi- crosurgical excision of symptomatic sacral perineurial cysts: a study of 15 cases. Surg Neurol 59:101-106, 2003
3. Davis SW, Levy LM, LeBihan DJ, Rajan S, Schellinger D: Sa- cral meningeal cysts: evaluation with MR imaging. Radiol- ogy 187:445-448, 1993
4. Hempenstall K, Nurmikko TJ, Johnson RW, A’Hern RP, Rice AS: Analgesic therapy in postherpetic neuralgia: a quan- titative systematic review. PLoS Med 2:e164, 2005
5. Isono M, Hori S, Konishi Y, Kinjo H, Kakisako K, Hirose R, Yoshida T: Ehlers-Danlos syndrome associated with multiple spinal meningeal cysts–case report. Neurol Med Chir (Tokyo) 39:380-383, 1999
6. Jensen MP, Barber J, Romano JM, Molton IR, Raichle KA, Obsborne TL, Engel JM, Stoelb BL, Kraft GH, Patterson DR: A comparison of self-hypnosis versus progressive muscle re- laxation in patients with multiple sclerosis and chronic pain. Int J Clin Exp Hyp 57:198-221, 2009
7. Langdown AJ, Grundy JR, Birch NC, Langdown AJ, Grundy JRB, Birch NC: The clinical relevance of Tarlov cysts. J Spinal Disord Tech 18:29-33, 2005
might simply be the result of infiltration by CSF under pressure. The important point is to consider surgically treating the cause of the pain before treating the symptom (pain).
Tarlov cysts and SCS are not mentioned together in the literature. Lumbosacral radiculopathy is the most com- mon indication for SCS in the United States, but this use of SCS is generally to treat persistent or recurrent pain after a lumbosacral surgical procedure (failed back surgery syndrome, ‘‘FBSS’’). Arguably, patients with FBSS are comparable to this patient with Tarlov cysts be- cause, in each case, the same structures are injured, and, furthermore, many patients with FBSS undoubtedly have incidental Tarlov cysts. Thus, the FBSS literature should
References
1. Baek WS, Rezania K, Baek WS, Rezania K: Tarlov cysts masquerading as peripheral neuropathy. Arch Neurol 63: 1804-1805, 2006
2. Caspar W, Papavero L, Nabhan A, Loew C, Ahlhelm F: Mi- crosurgical excision of symptomatic sacral perineurial cysts: a study of 15 cases. Surg Neurol 59:101-106, 2003
3. Davis SW, Levy LM, LeBihan DJ, Rajan S, Schellinger D: Sa- cral meningeal cysts: evaluation with MR imaging. Radiol- ogy 187:445-448, 1993
4. Hempenstall K, Nurmikko TJ, Johnson RW, A’Hern RP, Rice AS: Analgesic therapy in postherpetic neuralgia: a quan- titative systematic review. PLoS Med 2:e164, 2005
5. Isono M, Hori S, Konishi Y, Kinjo H, Kakisako K, Hirose R, Yoshida T: Ehlers-Danlos syndrome associated with multiple spinal meningeal cysts–case report. Neurol Med Chir (Tokyo) 39:380-383, 1999
6. Jensen MP, Barber J, Romano JM, Molton IR, Raichle KA, Obsborne TL, Engel JM, Stoelb BL, Kraft GH, Patterson DR: A comparison of self-hypnosis versus progressive muscle re- laxation in patients with multiple sclerosis and chronic pain. Int J Clin Exp Hyp 57:198-221, 2009
7. Langdown AJ, Grundy JR, Birch NC, Langdown AJ, Grundy JRB, Birch NC: The clinical relevance of Tarlov cysts. J Spinal Disord Tech 18:29-33, 2005
The Journal of Pain 837
be applicable to patients with Tarlov cysts who are suffer- ing from intractable pain, and we should consider treat- ing them as we would an FBSS patient: First with surgical remediation as appropriate, always considering the relative risks and benefits of surgery versus SCS and considering further that we can perform a trial of SCS.
Richard B. North, MD
Professor of Neurosurgery and of Anesthesiology and Critical Care Medicine,
The Johns Hopkins University School of Medicine (retired)
The Sandra and Malcolm Berman Brain & Spine Institute
Baltimore, MD
8. LewithGT,FieldJ,MachinD:Acupuncturecomparedwith placebo in post-herpetic pain. Pain 17:361-368, 1983
9. Mummaneni PV, Pitts LH, McCormack BM, Corroo JM, Weinstein PR: Microsurgical treatment of symptomatic sacral Tarlov cysts. J Neurosurg 47:74-79, 2000
10. North RB, Kidd DH, Farrokhi F, Piantadosi: Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial. Neurosurgery 56:98-106; discussion 106-107, 2005
11. Rexed B: Arachnoidal proliferations with cyst formation in human spinal nerve roots at their entry into the interver- tebral foramina; preliminary report. J Neurosurg 4:414-421, 1947
12. Tarlov IM: Perineurial cysts of the spinal nerve roots. Arch Neurol Psychiatry 40:1067-1074, 1938
13. Tarlov IM: Cysts (perineurial) of the sacral roots: another cause (removable) of sciatic pain. J Am Med Assoc 138: 740-744, 1948
14. Tarlov IM: Spinal perineurial and meningeal cysts. J Neu- rol Neurosurg Psychiatry 33:833-843, 1970
15. Van de Kelft E, Van Vyve M: Sacral meningeal cysts and perineal pain. Lancet 341:500-501, 1993
16. Voyadzis JM, Bhargava P, Henderson FC: Tarlov cysts: a study of 10 cases with review of the literature. J Neurosurg 95(Supp 1):25-32, 2001
be applicable to patients with Tarlov cysts who are suffer- ing from intractable pain, and we should consider treat- ing them as we would an FBSS patient: First with surgical remediation as appropriate, always considering the relative risks and benefits of surgery versus SCS and considering further that we can perform a trial of SCS.
Richard B. North, MD
Professor of Neurosurgery and of Anesthesiology and Critical Care Medicine,
The Johns Hopkins University School of Medicine (retired)
The Sandra and Malcolm Berman Brain & Spine Institute
Baltimore, MD
8. LewithGT,FieldJ,MachinD:Acupuncturecomparedwith placebo in post-herpetic pain. Pain 17:361-368, 1983
9. Mummaneni PV, Pitts LH, McCormack BM, Corroo JM, Weinstein PR: Microsurgical treatment of symptomatic sacral Tarlov cysts. J Neurosurg 47:74-79, 2000
10. North RB, Kidd DH, Farrokhi F, Piantadosi: Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial. Neurosurgery 56:98-106; discussion 106-107, 2005
11. Rexed B: Arachnoidal proliferations with cyst formation in human spinal nerve roots at their entry into the interver- tebral foramina; preliminary report. J Neurosurg 4:414-421, 1947
12. Tarlov IM: Perineurial cysts of the spinal nerve roots. Arch Neurol Psychiatry 40:1067-1074, 1938
13. Tarlov IM: Cysts (perineurial) of the sacral roots: another cause (removable) of sciatic pain. J Am Med Assoc 138: 740-744, 1948
14. Tarlov IM: Spinal perineurial and meningeal cysts. J Neu- rol Neurosurg Psychiatry 33:833-843, 1970
15. Van de Kelft E, Van Vyve M: Sacral meningeal cysts and perineal pain. Lancet 341:500-501, 1993
16. Voyadzis JM, Bhargava P, Henderson FC: Tarlov cysts: a study of 10 cases with review of the literature. J Neurosurg 95(Supp 1):25-32, 2001