symptoms, treatment, operation and progress

Tarlov cysts are most often asymptomatic. But in some cases, they can cause pain and require treatment. Explanations from Dr Sylvia Morar, lead neurosurgeon at the Rare Disease Reference Center at Bicêtre C-MAVEM Hospital.

What is a Tarlov cyst?

Tarlov cysts, or perineural cysts, are pockets filled with cerebrospinal fluidtransparent liquid in which the brain and spinal cord bathe. They correspond to a local dilation of the subarachnoid space forming in contact with a nerve root. Most often, they are located at the level of the sacral vertebrae (at the bottom of the back). We speak of meningeal or radicular cysts when they are located on the rest of the spine (cervical or lumbar cysts). “Tarlov cysts are extremely common, their prevalence is estimated at 5% in the general population. In the majority of cases, they are discovered accidentally during an MRI performed for other reasons. Of all the patients who present this image on medical imaging, only 1 in 100 risks seeing their Tarlov cyst become symptomatic. informs Dr. Sylvia Morar. We owe the first description of Tarlov cysts to the American neurosurgeon Isadore Tarlov in 1938.

Tarlov cysts fill with cerebrospinal fluid and grow very slowly, until they compress the nerve fibers. Nevertheless, their evolution is not systematic. “If they grow, it is extremely slow, over decades. Tarlov cysts are not serious in themselves, but they can be bothersome when they become symptomatic. Their origin remains poorly known, even if the traumatic cause is mentioned. indicates the referring neurosurgeon at the Rare Disease Reference Center at Bicêtre C-MAVEM Hospital. Most Tarlov cysts are just an anatomical variant that is not serious.

Symptoms: Can a Tarlov cyst hurt your back?

In most cases, Tarlov cysts are asymptomatic. Symptomatic cysts mainly cause pain in the coccyx with radiation into the pelvis. Pain can also be lumbar, abdominal, pelvic, perianal, vaginal or even testicular. Loss of muscle strength et urinary problems can also be observed.

“The pain is very low because the location is mainly at the lumbosacral level. There is also some in the cervical and dorsal areas but this remains exceptional. 95% of this pain increases after prolonged sitting or orthostatic position and improves after walking, in other words, is the opposite of lumbar and spine pathologies. specifies Dr Sylvia Morar.

Imaging: CT and MRI

The diagnosis is mainly based on MRI. (magnetic resonance imaging) or thoracolumbar scanner. An electromyography is also often performed but it generally does not show anything specific. Perineal electrophysiological exploration also contributes to the differential diagnosis by possible demonstration of denervation in the bulbocavernosus muscles, the anal sphincter and the striated-urethral sphincter. “The prevalence of Tarlov cysts is more important in womenwhich can make the diagnosis difficult since from a certain age, there are other problems that can arise (perineal, gynecological disorders, endometriosis, etc.) and which lead to symptoms identical to those caused by Tarlov cysts. Hence the importance of analyzing the patient carefully to ensure that it is really the perineural cyst which is responsible for her symptoms and not other problems. specifies the specialist.

“Most Tarlov cysts do not evolve at all, neither morphologically nor symptomatically. Those that evolve win about 1 millimeter every 5-10 yearsit is extremely slow so frequent monitoring by MRI would be useless”, reassures Dr. Sylvia Morar.

The treatment is symptomatic and not curative. It aims to relieve patients’ pain, which is most often neuropathic, using analgesics of different levels, non-steroidal anti-inflammatories, muscle relaxants, certain antidepressants and local topicals. Surgical treatment remains rare. and must always be the subject of a Multidisciplinary Consultation Meeting (RCP) composed of neurosurgeons, neurologists, neuro-urologists and neuro-radiologists. “Surgery offers quite poor results and risks causing more problems than there already are. It is therefore very rare to operate on a Tarlov cyst”notes our expert.

Several methods can be proposed:

• Cyst diversion: the fluid is diverted to the abdominal cavity using a catheter. This technique is rarely used because it poses a risk of intracranial hypotension. Pain relief and improvement of symptoms help confirm the diagnosis;
• Drainage of the cyst: Once the fluid is removed, glue is injected inside the cyst to strengthen its wall and prevent fluid from getting back inside. Unfortunately, this technique is not viable in the long term;
• In surgery: it consists of opening the wall of the cyst, relieving it of its fluid and replacing it with fat or muscle in order to close the communication orifice. This technique poses risks of complications, including leakage of cerebrospinal fluid (CSF), vomiting and headaches;
• Cyst puncture: the neurosurgeon punctures the cyst using a needle and reinforces its wall with synthetic dura mater, so that it can no longer fill.