Tarlov Cysts

Tarlov Cysts
NORD gratefully acknowledges Philip R. Weinstein, MD, Professor, University of California, San Francisco, Department of Neurological Surgery, for assistance in the preparation of this report.
Synonyms of Tarlov Cysts
  • perineural cysts
  • sacral, lumbar, thoracic or cervical nerve root cysts
Subdivisions of Tarlov Cysts
  • No subdivisions found
General Discussion
Summary
Tarlov cysts are fluid-filled sacs that affect the nerve roots of the spine, especially near the base of the spine (sacral region). Individuals may be affected by multiple cysts of varying size. In most cases, Tarlov cysts do not cause symptoms (asymptomatic). However, symptoms can occur depending upon the size and specific location of the cyst. Generally, the larger a Tarlov cyst is, the more likely it is to cause symptoms. Symptoms sometimes caused by Tarlov cysts include pain in the area served by the affected nerves, numbness and altered sensation, an inability to control bladder and bowel movements (incontinence), impotence, and, rarely, weakness in the legs. Small, asymptomatic cysts can slowly increase in size eventually causing symptoms. The exact cause of Tarlov cysts is unknown, but they may occur due to variation in normal development of the nerve sheath. Tarlov cysts were first described in the medical literature in 1938.
Signs & Symptoms
Many cases of Tarlov cysts are not associated with symptoms (asymptomatic). However, Tarlov cysts can grow in size eventually compressing or damaging adjacent nerve roots or nerves contained within the cyst (radiculopathy). The specific symptoms and their severity vary from one individual to another and with location along the spinal column.
Chronic pain is a common with symptomatic Tarlov cysts. Pain from lumbo-sacral cysts may affect the lower back, especially below the waist, and spread to the buttocks and legs. Pain may be worsened by walking (neurogenic claudication). Symptoms may become progressively worse. In some individuals sitting or standing may worsen pain; recumbency may relieve pain. In some cases, pain can also affect the upper back, neck, arms and hands if the cysts are located in the upper spine. Pain may worsen when coughing or sneezing. Affected individuals have also reported vulvar, testicular, rectal, pelvic and abdominal pain.
Because Tarlov cysts can affect the nerves, symptoms relating to loss of neurological function can also develop including leg weakness, diminished reflexes, loss of sensation on the skin, and changes in bowel or bladder function such as incontinence or painful urination (dysuria). Some individuals may have difficulty empting the bladder and constipation has also been reported. Changes in sexual function such as impotence can also occur.
Affected individuals may also develop abnormal burning or prickling sensations (paresthesias) or numbness and decreased sensitivity (dysesthesia), especially in the legs or feet. Tenderness or soreness may be present around the involved area of the spine.
Additional symptoms have been reported in the medical literature including chronic headaches, blurred vision, pressure behind the eyes, dizziness, and dragging of the foot when walking due to weakness of the muscles in the ankles and feet (foot drop). Some individuals demonstrate progressive thinning (erosion) of the spinal bone overlying the cyst.
Causes
The exact cause of Tarlov cysts is unknown. Several theories exist including that the cysts result from an inflammatory process within the nerve root sheath or that trauma injures the nerve root sheath and causes leaking of cerebrospinal fluid (CSF) into the area where a cyst forms. Some researchers believe that an abnormal congenital connection (communication) exists between the subarachnoid space, which contains cerebrospinal fluid, and the area surrounding the affected nerves (perineural region). The connection may remain or eventually close, after allowing cerebrospinal fluid to leak out and cause a cyst. Because Tarlov cysts contain cerebrospinal fluid, researchers have speculated that normal fluctuations in CSF pressure may lead to an increase in cyst size and a greater likelihood of developing symptoms.
In many cases, individuals with asymptomatic Tarlov cysts developed symptoms following trauma or activities that raise cerebrospinal fluid pressure such as heavy lifting. Some reports suggest that individuals with connective tissue disorders are at a greater risk of developing Tarlov cysts than the general population.
More research is necessary to understand the underlying mechanisms that ultimately cause the development of Tarlov cysts or the onset of their symptoms.
Affected Populations
Women are at a higher risk of developing Tarlov cysts than men. The exact incidence or prevalence of symptomatic Tarlov cysts in the general population is unknown. Because these cysts often go unrecognized or misdiagnosed, determining their true frequency in the general population is difficult. However, the total number of Tarlov cyst patients (symptomatic and asymptomatic) is estimated at 4.6 to 9 percent of the adult population.
Related Disorders
Symptoms of the following disorders can be similar to those of Tarlov cysts. Comparison of symptoms may be useful for a differential diagnosis.
Various cysts and tumors may have similar symptoms to those associated with Tarlov cysts. This group includes meningeal diverticula, meningoceles, neurofibromas, schwannoma, and arachnoid cysts. These cysts and tumors may cause compression of the spinal cord or nerve roots. (For more information on these conditions, choose the specific cyst or tumor name in the Rare Disease Database.)
Arachnoid cysts are fluid-filled sacs that occur on the arachnoid membrane that covers the brain (intracranial) and the spinal cord (spinal). There are three membranes covering these components of the central nervous system: dura mater, arachnoid, and pia mater. Arachnoid cysts appear on the arachnoid membrane, and they may also expand into the space between the pia mater and arachnoid membranes (subarachnoid space). The most common locations for intracranial arachnoid cysts are near the temporal lobe (the middle fossa), near the third ventricle (the suprasellar region), and the area that contains the cerebellum, pons, and medulla oblongata (the posterior fossa). In many cases, arachnoid cysts do not cause symptoms (asymptomatic). In cases in which symptoms occur, headaches, seizures and abnormal accumulation of excessive cerebrospinal fluid in the brain (hydrocephalus) are common. The exact cause of arachnoid cysts is unknown. (For more information on this disorder, choose “arachnoid cysts” as your search term in the Rare Disease Database.)
Diagnosis
Diagnosis
A diagnosis of Tarlov cysts may be suspected based upon a thorough clinical evaluation, a detailed patient history with identification of characteristic symptoms and a neurological examination. A diagnosis may be confirmed by a variety of specialized tests. In some cases, a diagnosis of a Tarlov cyst is made incidentally through x-ray or MRI scan investigation undertaken for other reasons.
Clinical Testing and Work-Up
Magnetic resonance imaging (MRI) of the lumbar region and computed tomography (CT) can both reveal Tarlov cysts. During MRI, a magnetic field and radio waves are used to create cross-sectional images of the organ being studied. During CT scanning, a computer and x-rays are used to create a film showing cross-sectional images of the organ’s tissue structure.
Another test, known as a myelogram, uses a special dye called contrast material and x-rays as well as a CT scan to create a picture of the subarachnoid space. During this test, the contrast fluid is injected under local anesthesia into the spinal canal through a thin needle. The dye allows certain structures such as the nerve roots and spinal canal to be seen more clearly on x-ray. The size and location of the connection between the cyst and the normal spinal fluid containing space can be demonstrated by CT scan performed after the myelogram. Erosion of the sacrum or vertebral bone by the cyst can also be shown.
Standard Therapies
Treatment
Tarlov cysts that do not cause symptoms should be monitored periodically to see whether cysts increase in size or whether symptoms develop. There is no specific, accepted therapy for individuals with symptomatic Tarlov cysts. Treatment is directed toward the specific symptoms that are apparent in each individual and may include drugs, surgery and other techniques. The response to various therapeutic options is highly individualized; what works for one person may be ineffective for another.
Certain drugs such as corticosteroid injections may provide temporary relief of pain. Some reports have indicated that epidural steroid injections can provide long-standing pain relief (up to 6 months) before the procedure needs to be repeated.
Non-steroidal anti-inflammatory drugs (NSAIDs) may be prescribed to treat nerve irritation and inflammation. A procedure known as transcutaneous electrical nerve stimulation or TENS may also be used to relieve nerve pain. During this procedure, electrical impulses are sent through the skin to help control pain.
Tarlov cysts have been treated by procedures in which cerebrospinal fluid is drained from the cyst (aspiration). Results from such procedures vary and, in most cases, the cysts eventually fill up with cerebrospinal fluid again. In some cases, symptoms can return within hours.
Several different procedures, both surgical and nonsurgical, have been used that involve draining a Tarlov cyst and then filling the cyst with another substance such as fibrin glue, fat, or muscle. This prevents cerebrospinal fluid from refilling the cysts and reduces pressure on the surrounding nerves.
A nonsurgical procedure used to treat individuals with symptomatic Tarlov cysts uses a combination of substances that mimic blood clotting (fibrin glue). Fibrin glue injection is a minimally invasive procedure that has benefited some individuals with symptomatic Tarlov cysts. After the cysts are drained, fibrin glue is used to seal or “glue” the cyst closed preventing the cysts from filling up again. Some individuals have experienced immediate relief after this procedure; others reported delayed benefit. This procedure has led to short-term and long-term relief of symptoms in some cases. Complications have been reported in cases where the cyst communicates readily with the spinal fluid containing space.
Surgical removal of Tarlov cysts may be used to treat symptomatic individuals who do not respond to other forms of therapy. Debate exists in the medical literature as to the most appropriate surgical technique to treat individuals with symptomatic Tarlov cysts. Various techniques have been used with different success rates and side effects. Surgical intervention depends upon numerous factors such as the progression of the disorder; the degree of nerve root compression; the size of the connection between the subarachnoid space and the cyst; an individual’s age and general health; and/or other factors. Decisions concerning the use of particular interventions should be made by physicians and other members of the health care team in careful consultation with the patient, based upon the specifics of his or her case. A thorough discussion of the potential benefits and risks, patient preference and other appropriate factors is needed.
Very large cysts may require direct surgical intervention to drain and then obliterate the cyst.  One surgical technique that has been used to treat symptomatic Tarlov cysts is an operation that exposes the region of the spine where the cyst is located by removal of overlying vertebral bone. The cyst is then sliced open with one or more thin cuts (fenestrations) and drained of fluid. The cyst wall is collapsed, circumferentially reinforced and sutured closed or the cavity is packed full of another substance such as fat or tissue adhesive to prevent it from refilling with cerebrospinal fluid.
In another procedure, after surgery to expose and drain the cysts, a flap of nearby muscle tissue is used to fill the cyst in order to prevent recurrence. A muscle flap is a portion of muscle that can be transferred along with its blood supply to an adjacent part of the body. The muscle flap is use to fill the decompressed cyst and to prevent it from refilling with cerebrospinal fluid. Results of treatment may be disappointing if irreversible nerve damage has already occurred.

Investigational Therapies
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: 
prpl@cc.nih.gov
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
For information about clinical trials conducted in Europe, contact:
https://www.clinicaltrialsregister.eu/
Resources
Tarlov Cysts Resources
Please note that some of these organizations may provide information concerning certain conditions potentially associated with this disorder.
NORD Member Organizations
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