An arachnoid cyst is a fluid filled sac that develops primarily in the uterus during the development of the brain and skull. The arachnoid membrane of the brain splits, and the split space fills with fluid known as cerebral spinal fluid. The fluid will enter the split area, but it cannot escape at the same rate as it enters. Because of this, the cyst will grow over time. The growth rate depends on many factors, but even as it grows, more times than not, the cyst will remain asymptomatic. This means that generally, an arachnoid cyst will not cause any symptoms.
Arachnoid cysts can grow anywhere on the brain with the primary areas being the side of the brain, and the top of the brain. When a cyst forms on the back of the brain, this is called a posterior fossa arachnoid cyst. A posterior fossa arachnoid cyst can create pressure on the brain stem and the cerebellum. These are extremely vital organs of the brain and they both produce tremendous functions that are required to live.
The brain stem controls a lot of our everyday functions that we do not even think about. One thing it controls is our body temperature. It controls our diaphragm for breathing, and it is where our hunger and thirst are controlled. It is also the path in which all our nerves leave the brain and travel throughout the body. The brain stem controls our pain, it is also where the nausea center is based, and it plays a role in the regulation of our hearts.
The cerebellum; on the other hand, helps control our balance. It plays a role in the reflex of our muscles, and plays a major role in our motor skills. Both parts of the brain have their very specific tasks, and when either one is compromised, it can reek havoc on the entire body.
If treatment is needed for an arachnoid cyst, usually the first choice is a fenestration of the cyst. This means going into the brain with a wand and opening up any walls that may have formed inside the cyst. These walls trap the fluid inside the cyst. The idea of this procedure is to get all the cerebral spinal fluid flowing in and out of the cyst efficiently so that the cyst does not continue to grow. If this procedure does not work, a neurosurgeon may decide to put a shunt in. A shunt helps to keep the cyst draining and not allow fluid to build up inside. If the cyst is small enough and in a space on the brain that is not too dangerous to remove, the neurosurgeon may be able to remove it altogether.
Symptoms can show themselves in many ways; from balance problems, nausea, vomiting, headaches, even seizures. Many cysts are discovered on accident when having a scan for another reason. They can be seen on Cat Scan, but the preferred diagnostic test for a brain cyst, is an MRI.
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my posterior fossa arachnoid cyst has been growing. I have had this cyst show up on mris since i had two terrible seizures on june 18th 2015. every mri seems to show different types of arachnoid cysts. i have had constant seizures showing up on eegs since then. i have seen two neurosurgeons and told this is congenital. i do not understand why the cyst has never shown up before? i feel as if the cysts are causing all my seizures. the doctors feel i need a left temporal lobectomy. i need help, my memory, speech, and cognitive skills have been greatly effected. not to mention my behavior changes. i am being reffered to a neuro oncologist now. if the doctors insist it is not cancerous why do i need to see a neuro oncologist? please help me?
March 31, 2017 - 10:02pmThis Comment
Hi there, I was just reading all these posts because my 16 year old daughter has this lump at the base of her skull....she has been suffering from severe migraines, constant dizziness, constant nausea, black outs, blurry vision and then no vision at all and her memory loss. When she texts me at school because she can't remember how to hold a pencil, it was awful. She is an A and B student, though failed her finals because she couldn't remember things....where her eyes are open though she sees all black! She also goes into major shaking and can't control it. We finally got our insurance and she is getting this EEG test done for a syncope. I am trying not to be all worried because she would know and it would really affect her, so I just tell her we are getting the tests done to find out whats going on and that we will get answers... I appreciate reading your posts...it does help me a bit knowing that there are others who have and are going through the same things.
January 31, 2017 - 6:56pmThanks all,
Kristi
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Used a great surgeon in NYC....Dr. Bederson....chief of neurosurgery at Mount Sinai Hospital. LIsten to your gut it definitely saved a life here.
February 6, 2017 - 1:50pmSymptoms are very mild... no more nausea, vomiting, numbness, tingling, loss of balance, fatigue, and can now concentrate! YOu must be an advocate for your daughter!!! GOD bless you both!!!!
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Thank you for sharing your experiences and for your references. I am an adult seeing my first neurosurgeon on Monday. This information will help me have my ducks in a row and help me make my case.
August 20, 2016 - 1:52pmThis Comment
My wife and I have been reading through some of the comments here and feel a need to share our experience as our son has just returned (today!) from endoscopic fenestration of an arachnoid cyst in the right ventricle. Many of the symptoms that have been described in the comments here are similar to those experienced by him. Was a top student, began a slow deterioration in focus and concentration, dizziness, vertigo, severe headaches and pressure in the head, possible ADD. We were also told that he may have pseudo tumour cerebra (?!). To cut a 3 year story short I found an article online by Prof Knut Wester from Norway. His group took a very liberal approach to cyst removal and/or fenestration. They found a clear improvement in cognitive tests before and after surgery in 80% of cases. They concluded that the determining factor in cyst symptoms was the intracystic pressure (pressure within the cyst) and not the intracranial pressure (CSF pressure) or size of the cyst. None of the neurosurgeons we spoke to were aware of this paper. The literature is very divided on how to approach cysts from ultra-conservative to ultra-liberal as in the Norwegian study. In my opinion the Norwegian study is a landmark study and although it is still too early to tell with our son, although he definitely feels an improvement already, there is certainly evidence to suggest that cysts may be the cause of many of the symptoms described in the comments. I personally have an Undergraduate degree in Biophysics and Masters in Physiology. I would like to see more studies done like those that the Norwegian group did. They even went as far as proposing that ALL cysts may actually be symptomatic to some degree but the brain is able to compensate for the effects of the cyst up to a certain point. Makes perfect sense to me but many doctors are unaware of this study and take a very conservative approach in order to avoid, albeit understandably, unnecessary brain surgery. To cut a long story short yes the cyst may well be the cause of many of the symptoms described here. There are neurosurgeons who are willing to operate but they will likely want to be sure that other factors are ruled out before considering surgery even though the complications involved with endoscopic fenestration are relatively low. If you have been struggling then I would advise building a case for yourself before next visiting your neurologist or neurosurgeon. Come prepared with a copy (or copies) of Prof Wester's paper and other similar ones.
June 2, 2016 - 12:39pmThis Comment
I would like to know what facilities or the names of neurosurgeons that take the more liberal approach of removing arachnoid cysts rather than the "watch and see" approach. The practices that have been adopted and proven to be successful by the Norwegian studies and the Knut Wester reports are all very pro removal of this type of cyst. We were just at a top brain facility in NY yesterday with a cutting edge surgeon on arachnoid cysts and he had never heard of the Norway studies but offered to review them. We need a Dr who will recognize that taking out brain cyst is the best option not the last option. Thank you.
March 3, 2017 - 9:10amThis Comment
Thank you for your excellent analysis. It helped me to read all of the work of Professor Wester and his colleagues that I could find. My 18 year old son has a reasonably small arachnoid cyst but it is located in a very tight spot right in the middle of his cerebellum--it's a posterior fossa retrovermian arachnoid cyst. After getting a specialized set of upright MRI studies we could see the erosion of the skull wall, a bony structure that had formed around it, and shifts it had caused in the positioning of the left occipital lobe (a shift across the midline), as well as pressure on the cerebellum. I am working towards getting my son surgery for this--his primary complaint being a headache that won't quit since September 2015 and constant visual disturbances. The insurance company is balking at medical necessity which I think is totally ridiculous. I wanted to do two things in this comment on your excellent post. One was to ask you if you had considered Dr. Hrayr Shahinian who does endoscopic resection (removal) of arachnoid cysts instead of fenestration since fenestrated cysts sometimes refill? Also, I wanted to cut and paste a series of articles which have helped clarify my understanding about something that is pretty hard to understand especially when the medical establishment is basically still in denial about the havoc these cysts can wreak on the people who have them. These articles in combination with my son's outstanding neurologist/headache specialist (Dr. Mahan Chehrenama of McLean VA, a suburb of Washington DC), and several other experts who she has brought into the process, helped me see the rationale for why the cyst has to go. The recent research is really 100% pro-surgery, even in non-surgical journals. Partly because it works, and partly because the risks of surgery have gone down considerably with the newer endoscopic techniques. The Norwegian articles are outstanding and I sent them to one of the neurosurgeons I consulted who is not up to date on the latest research and was skeptical to say the least on operating. For those who have the stomach for it, doing searches on NIH's pubmed really gives one a lot of information. It is an incredible resource and is updated often on Arachnoid Cysts right now--there is almost a revolution on thinking about them--especially when they press on cerebral tissue. Interestingly there is also a revolution in thinking on the cerebellum and its wide-reaching functions beyond motor control and balance led by Dr. Jeremy Schmahmann at Harvard--his articles are on pubmed and his lectures are on you tube. I didn't include the cerebellum research here though. Included here are the articles (abstracts mostly) that I found most helpful in my thinking process about Arachnoid Cyst surgery--whether to do it.
If you can tell me your thinking on fenestration, I would very much appreciate it. Best wishes for your son's recovery--please update us on that too! I know how many times my son and I have thought something was going to work only to realize it didn't, but on AC surgery, the research shows incredibly high success with headaches and cognition. I am praying and am thinking that it worked for your son! Congrats in advance!
Here are the most important articles in my research on Arachnoid Cyst surgery...the recent ones are more and more compelling on operating vs. leaving them when there is headache and/or dizziness, and possibly just having one that is putting"tension" on any brain tissue as one article describes is enough to say it needs to go. I am in for a battle with my insurance company it looks like, but I am determined to help my son, and I am convinced that this surgery will change his life.
1. Neurosurgery, May 2016: Surgical Decompression of Arachnoid Cysts Leads to Improved Quality of Life: A Prospective Study. Mørkve SH1, Helland CA, Amus J, Lund-Johansen M, Wester KG.
http://www.ncbi.nlm.nih.gov/pubmed/26540351
Knut Wester, MD, PhD, Professor Emeritus, University of Bergen, Norway, Past Professor and Chairman, Department of Neurosurgery, Haukeland University Hospital, Norway, has been the leader in studying Intracranial Arachnoid Cysts (IACs), their impact on the brain, and the results of removing them.
2. Journal of Neurology, Neurosurgery, and Psychiatry, October 2007: A population based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in adults
Christian A Helland and Knut Wester
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2117571/
Key point from article: “….The treatment of such cysts, particularly in the majority of the patients with moderate and unspecific symptoms, has been controversial.11,12,13,14,15 Many authors have expressed a reluctance to operate on these patients unless the symptoms are dramatic. This was also the initial attitude of the senior author. However, based on several observations of our own and those of others, we have gradually changed our view. When we encountered patients that were severely impaired, with symptoms such as headache or dizziness, and who also had radiologically expansive cysts, we found it logical to attempt to alleviate the complaints by surgical cyst decompression. It has been our accumulated experience that surgical decompression yields clinical improvement in most patients with arachnoid cysts. Also, a growing literature indicates that cyst decompression improves the function of neighbouring cerebral tissue, thus supporting the view that patients with unspecific symptoms and “clinically silent” cysts may also profit from surgical cyst decompression.4,6,7,8,9,10,16”
3. Neurology, 2005: Arachnoid cysts cause cognitive deficits that improve after surgery.
Raeder MB1, Helland CA, Hugdahl K, Wester K.
http://www.ncbi.nlm.nih.gov/pubmed/15642927
Point of article: self-explanatory!
4. Journal of Neurodevelopment Disorders, 2013: Intracranial arachnoid cysts: impairment of higher cognitive functions and postoperative improvement Priyanthi B Gjerde,1 Marit Schmid,3 Åsa Hammar,3,4 and Knut Wester1,2
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3766187/
5. International Journal of Clinical and Experimental Medicine, October 2015: Analysis on clinical characteristics of intracranial Arachnoid Cysts in 488 pediatric cases. Jian-Huang Huang,1,* Wen-Zhong Mei,1,* Yao Chen,1 Jian-Wu Chen,1 and Zhi-Xiong Lin1,2
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4694337
Tension with cerebral tissue is key criterion used to recommend surgery with 80%+ good results.
6. Neurosurgery Focus, April 2016: Sport-related structural brain injury associated with arachnoid cysts: a systematic review and quantitative analysis.
http://www.ncbi.nlm.nih.gov/m/pubmed/27032926/?i=3&from=retrovermian%20arachnoid%20cyst
Kids with ACs have more problems than those without ACs after sport-related brain injuries (my son had a lot of hits to the back of his head after his first and second wrestling season which seemed to correlate with the beginning of his headaches)
7. Asian Journal Neurosurgery, Jan-Mar 2015: Posterior fossa arachnoid cysts in adults: Surgical strategy: Case series.
Srinivasan US1, Lawrence R2.
https://www.ncbi.nlm.nih.gov/pubmed/25767579
Excising and/or fenstrating posterior fossa ACs yields “excellent long-term outcome.”
8. Neurosurgery Review, July 2010: Posterior fossa arachnoid cysts and cerebellar tonsillar descent: short review.
Galarza M1, López-Guerrero AL, Martínez-Lage JF.
https://www.ncbi.nlm.nih.gov/pubmed/20480382
Possible causal relationship between posterior fossa ACs and cerebellar tonsillar descent resulting in Chiari deformations over time. [I have been told that my son's cerebellar tonsils are a bit low, but not low enough to diagnose as Chiari deformation]
9. Turkish Neurosurgery, 2012: Surgical management strategies of intracranial arachnoid cysts: a single institution experience of 75 cases. Duz B1, Kaya S, Daneyemez M, Gonul
https://www.ncbi.nlm.nih.gov/pubmed/23015336
90%+ resolution of headaches through surgery.
July 20, 2016 - 5:14pmThis Comment
My 14 year old son was recently diagnosed with a posterior fossa arachnoid cyst (3.3 cm x 3.1 cm). We began noticing behavioral problems with him (not aggressive, just major ADD and focus) when he was around 6. We also noticed for poor control when grasping and using writing utensils. He was diagnosed with ADD and so for years we had him medicated, but nothing worked. He still displayed the exact same behaviors. As he got older we realized something more than ADD was going on. Most little kids may do something you ask them not to because their attention span is so short, but our child would repeatedly do something he was told not to or if you asked him to do the simplest of chores or tasks, he would forget. Then when he would constantly get in trouble for the same things, over and over, he would seriously stare at you and ask "why are you so mad??". He REALLY did not understand the concept of we asked, you didn't do, etc. He constantly stayed grounded, had things taken from him and would get upset, yet would repeat the same behaviors. It literally was a never ending, perpetual cycle of hell in our home.
I took him to Texas Childrens Blue Bird Clinic for Neuropsychology a few months ago. I told them the NO child possibly wanted to stay in trouble constantly and I was beginning to believe that either he had a very deep rooted psychological issue that required more treatment than the basic ADD meds or something else physically was going on with him. The Neuropsychologist was excellent and did a full days clinical evaluation. She commented about a very noticeable tremor in his left hand and noted that his motor skills were lacking. I then requested and MRI and CT. They did both and sent the results to Neurology. Sure enough, they found the cyst.
Now my question is, could the cyst account for his behavior? I will literally tell him "Don't touch that button". Two seconds later, he is touching the button and seriously confused as to what he did wrong. Or day to day he has chores. I get home and they aren't done and he says "mom, I forgot". How do you forgot to feed 5 horses, two dogs and two cats that you see daily? The litter box for the cats (they're his cats) stay in his section of the house. He walks right by the box daily. I walked into the living area near his room and almost gagged. I asked when the last time was that he cleaned it and he was like 3 days ago. I'm like how do you not smell that? He says he didn't notice. If I don't make him, he won't bathe for days. He says he's not dirty even though he's been out with the horses, riding his four wheeler and hunting. I don't know if some of this is just sheer laziness or he really doesn't remember or doesn't care.
We are scheduled to go see Neurosurgery at TCH in January. All I want is for them to recommend a safe treatment plan. I feel like my child's quality of life is terrible because of his behavior, but I don't know the cause of the behavior.
FYI... this is the same child who through the 3rd grade was in gifted and talented classes. He is now a freshman in high school and I have recently pulled him out of school to home school him. He cannot function in a normal environment. His grades suffer, he makes poor decisions which earned him 45 days in alternative school recently (took his ADD meds to school and took them in class - nurse didn't have a valid prescription for him to have them on campus), he does the same thing repeatedly when feeding horses that gets him in trouble (spills feed all over the floor, instead of one pad of hay he feeds however much he can grab and then proceeds to spill half of that from the hay storage to stalls), has used my credit card for Itunes purchases repeatedly to the tune of almost $1,000 in one year. But he has this look when he gets in trouble like he truly DOES NOT understand what he's done wrong or why we are so frustrated!
Thanks for letting me vent and please let me know if you have any ideas or suggestions.
December 28, 2015 - 8:46amThis Comment
Have you looked at Dr. Schmahmann's research on the cerebellum and the impacts of problems with it? It is my view that some of my son's ADD is caused by the pressure of his AC right on the posterior side of the cerebellum--where they now have proved both executive functioning and possibly volition itself originates! Your son's problems seem so related to what Dr. Schmahmann's symptoms of cerebellum problems state. Look him up on wikipedia or you tube and you will see what I mean. I am so sorry for your son, but he is very lucky to have you. I am sure he does not mean to do what he is doing, why would he?
July 20, 2016 - 5:20pmThis Comment
Hello. Im 32 years old and have been experiencing symptoms since 2007 when my arachnoid cyst was discovered. Mine is 3cm by 2cm by 2 cm and is in the dorsal aspect of the tentorium in the left cerebral area. I have constant nausea extreme fatigue trouble understanding and comprehending simple things which is not like me trouble with vision at times pain in my spine lung and torso area but that may be because Ive had pleurisy 4 times. It hurts when i breathe it hurts to turn my head right or left . i think those symptoms may be from the inflammation from pleurisy but not sure. I have no motivation depression like symptoms memory issues sometimes feels spaced out or lost in the middle of a conversation or while doing tasks around the house or shopping etc. I dont feel like myself at all. My personality feels flat. I have no desire to do anything and usually im outgoing sociable and love to have fun. Lately between the pain nausea and confusion etc and not feeling like myself i dont feel like doing anything but sleeping. My Neurologist says my cyst isnt causing any of my symptoms but I find that hard to believe. I feel like im slowly physically and mentally crumbling and at a young age dont see what else could be causing my symptoms. Any thoughts? I also have tachycardia which was recently discovered and asthma. I have loud painful crepitus in my joints near my spine and rib cage so every breathe i take or anytime i move my arms or turn my head etc youll hear loud joint popping and cracking noises that are loud enough to hear just from sitting next to me. The doctors dont know what the crepitus is from or why its painful. I'm now being sent to a rheumatologist but im afraid some of my symptoms are from my cyst. Read so many articles where people have similar symptoms as I and all the doctors say the cyst isnt causing tbe symptoms. Its so frustrating and Ive been living like this for 7 years and its just getting worse and worse.
December 28, 2015 - 12:50amThis Comment