Arachnoid cysts are benign fluid-filled sacs that form between the arachnoid membrane and the central nervous system. All together there are three protective membranes that surround the spinal cord and the brain that form the central nervous system. The fluid inside the cyst is cerebrospinal fluid and the presence of these cysts can create life-threatening situations depending on their location and the symptoms they create. The most severe form of presentation can lead to bleeding (hemorrhage), damage to the central nervous system and sometimes even death.
Some of these cysts can be congenital (primary arachnoid cysts) while others can appear before the person turns twenty years. The secondary arachnoid cysts aren’t as common as primary cysts and occur as a result of trauma to the head, tumors growing on the spinal cord or brain and meningitis infections – or as a result of botched brain or spinal surgeries.
This rare disorder is also more common in men than in women with its being four times more common in men. Even though a few people never develop symptoms of arachnoid cysts, majority of the people develop symptoms before the age of 20 years, more so in the first year of life.
Arachnoid cysts that occur around the brain typically produce symptoms of headaches, nausea, vomiting, seizures, vertigo, hearing/visual disturbances and difficulties in balancing while walking. Cysts around the spinal cord usually result in compression resulting in progressive symptoms that include back, legs or arm pain, tingling or numbness. Diagnosis is through diffusion-weighted MRI or brain CT scan which can help in distinguishing between different types of cysts.
Treatment of arachnoid cysts has been a topic for debate; it’s generally believed that treatment for the cyst should be based upon the location and cyst size. If the cyst is small and slow-growing and isn’t disturbing the surrounding tissue or producing any symptoms, it’s usually better not to disturb it. However if there are symptoms present, you will need surgical intervention; if left untreated in such a situation, it could lead to hearing or vision damage or even death in rare cases where it ruptures or causes bleeding. Traditionally, there are two methods used to treat arachnoid cysts – Needle aspiration can be used to drain the cyst off the cerebrospinal fluid; but this method isn’t always effective as the sac can fill up again. The second method is through neurosurgery which is more risky. In this case, a shunt is created to drain off the cyst and to prevent it from filling up again; this method could lead to scarring and might end in removing the whole arachnoid membrane. But with advancing technology, there are newer microneurosurgical techniques and endoscopic tools that are safer for minimally invasive surgeries so doctors are now opting for removal of the cyst membrane and allowing it to drain off, thus permanently leaving it open. The risk of surgery is far better than the risk of leaving a growing cyst untreated!Leave a reply