Tarlov cysts are fluid-filled nerve root cysts, which are most commonly found at the sacral level of the spine (the base of the spine). Tarlov cysts typically occur along the posterior nerve roots. Cysts can be valved. They can also be non-valved. The main aspect of Tarlov cysts that distinguishes Tarlov cysts from other spinal lesions is the presence of spinal nerve root fibers within the cyst wall or in the cyst cavity itself.
Due to their close proximity to the lower pelvic region, patients with Tarlov cysts can be misdiagnosed with herniated lumbar discs, arachnoiditis. In females, gynecological conditions are also a common misdiagnosis. Accurate diagnoses can be further complicated if the patient has another condition that affects the same region.
INCIDENCE AND PREVALENCE
Small, asymptomatic Tarlov cysts exist in about 5-9% of the general population. Nevertheless, large cysts that cause symptoms are relatively rare. Tarlov cysts were originally identified during 1938; however, there is still very limited scientific knowledge available.
In a recent Tarlov cyst survey, an estimated 86.6% of respondents were female, while 13.4% were male. The majority of participants were ages 31-60, with a combined total of 80.4% in that age demographic.
About 33% of participants had a cyst(s) present in other body parts, usually the abdomen or hand and wrists.
About 3% of participants experienced no pain; 4.2% had very mild pain; 7.6% mild; 31.5% moderate; 38.6% severe; and 15.1% very severe.
CAUSES
Although the exact cause is unknown, there are theories as to what can cause an asymptomatic Tarlov cyst to produce symptoms. In several documented cases, accidents or falls involving the tailbone area of the spine caused previously undiagnosed Tarlov cysts to flare up.
SYMPTOMS
An increase in pressure in or the pressure placed on the cysts can increase symptoms and cause nerve damage. Sitting, standing, walking and bending are often painful, and generally, the only position that provides relief is reclining flat on one’s side. Symptoms vary greatly per each patient. They also can flare up and then subside.
Any of the following symptoms can be present in patients that have symptomatic Tarlov cysts:
- Pain in the area of the nerves affected by the cysts, especially the buttocks
- Weakness of muscles
- Difficulty sitting for prolonged periods
- Loss of sensation on the skin
- Reflex loss
- Changes in bowel function (constipation, etc)
- Changes in bladder function (including increased frequency or incontinence)
- Changes in sexual function
DIAGNOSIS
Tarlov cysts are difficult to diagnose, due to the limited knowledge about the condition. In addition, many of their symptoms can mimic other disorders. The majority of primary care physicians would not consider the possibility of Tarlov cyst. Patients should consult a neurosurgeon who has experience in treating this condition.
Tarlov cysts can be discovered when patients with low back pain or sciatica have an MRI performed. Follow-up radiological studies like CT myelography are typically recommended.
If a patient experiences bladder problems and seeks medical help from an urologist, tests can assist in diagnosing Tarlov cyst, which help determine if the patient has a neurogenic (malfunctioning) bladder. Through urodynamics, the bladder is filled with water through a catheter and the responses are recorded. Cystoscopy involves inserting a tube containing a miniature video camera into the bladder through the urethra. A neurogenic bladder displays excessive muscularity. Another potential test is a kidney ultrasound, which is used to see if urine is backing up into the kidneys.
Nonsurgical Treatment
Nonsurgical therapies include lumbar drainage of the cerebrospinal fluid (CSF), CT scanning-guided cyst aspiration and a more recent technique involving removing CSF from inside the cyst, later filling the space with a fibrin glue injection. Ultimately though, none of these procedures prevent symptomatic cyst recurrence.
Surgery
Tarlov cyst surgery involves exposing the region of the spine where the cyst is located. The cyst is opened with the fluid being drained. Then, in order to prevent the fluid from returning, the cyst is occluded with a fibrin glue injection or other matter.
Neurosurgical techniques for symptomatic Tarlov cysts include cyst and/or nerve root excision, simple decompressive laminectomy, and microsurgical cyst fenestration and imbrication.
The authors of one study found that patients who have Tarlov cysts larger than 1.5 cm and associated radicular pain or bowel/bladder dysfunction benefited the most from surgery. In all cases, the benefits of surgery should be weighed carefully against the associated risks.
OUTCOME
Postoperative CSF leak is the most common complication with Tarlov cyst surgeries In certain cases, these leaks can self-heal, though. Patients might be advised to stay in bed with the foot of the bed raised and to wear a corset that controls swelling. Although it is low, there is a risk of patients developing bacterial meningitis. Even though certain patients note a sizable decrease in pain, the most common negative outcome is the surgery’s failure to eliminate the symptoms. In some cases, the surgery can prompt existing symptoms to worsen or cause new ones.
When all treatment options have been exhausted, patients must make all necessary lifestyle changes and adopt a pain management strategy with a physician. Supervised pain management, along with support groups, can help a patient cope and improve his or her quality of life.
