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Suggest Treatment For Arachnoid Cyst At The Back Of The Brain
Question: I am a female in my 40s with chronic migraines for 20+ years. In 2011, a brain MRI showed an arachnoid cyst at the back of my brain. Repeat MRIs for 2 years showed no change to the cyst so my neurologist said I do not need to have a MRI yearly. The past 6 months my migraine pattern has changed (from my forehead) to the back of my head-occipital pain/pressure- and it has been 3 years since the last MRI. A MRI was suggested. This MRI (2016) showed no sign of the cyst- and otherwise unremarkable MRI from 2013. How can the disappearance of the cyst be explained without my knowing of it? Can the newly-found headaches/ pressure in the back of my head be related? From what I've read about rupture of arachnoid cysts, they typically require some kind of intervention?
Thank you.
Thank you.
Brief Answer:
Read below
Detailed Answer:
I read your question carefully and I understand your concern.
Spontaneous resolution of an arachnoid cyst is possible. It is rare, most cases it remains the same. In a few cases it may rupture in the subdural space or cause hemorrhage inside the cyst which would require intervention (but is not your case). In even fewer cases there can be a spontaneous resolution like in your case, it is very rare but it has been reported. It doesn't need any intervention as long as there is no blood or fluid collection there is no compression and nothing to operate upon fortunately.
As to why it happens that is not very clear. One hypothesis is that there might be a minor trauma causing a small tear and leak in the cyst wall which doesn't produce any symptom and the fluid is gradually drained and disappears. However cases with no reported trauma have been reported so this remains only a hypothesis. Because it is something rare and also asymptomatic discovered only in later MRIs by chance, the mechanism is hard to elucidate.
One could in theory think of such a small tear causing a small fluid collection 6 months ago and causing your pain, but since now there is no such fluid collection found on MRI the headache should have resolved as well.
Anyway from a practical point of view, whichever the mechanism of the disappearance was, there is no need for any intervention, no risk involved. So you need not to worry and consider it actually a good news.
I remain at your disposal for other questions
Read below
Detailed Answer:
I read your question carefully and I understand your concern.
Spontaneous resolution of an arachnoid cyst is possible. It is rare, most cases it remains the same. In a few cases it may rupture in the subdural space or cause hemorrhage inside the cyst which would require intervention (but is not your case). In even fewer cases there can be a spontaneous resolution like in your case, it is very rare but it has been reported. It doesn't need any intervention as long as there is no blood or fluid collection there is no compression and nothing to operate upon fortunately.
As to why it happens that is not very clear. One hypothesis is that there might be a minor trauma causing a small tear and leak in the cyst wall which doesn't produce any symptom and the fluid is gradually drained and disappears. However cases with no reported trauma have been reported so this remains only a hypothesis. Because it is something rare and also asymptomatic discovered only in later MRIs by chance, the mechanism is hard to elucidate.
One could in theory think of such a small tear causing a small fluid collection 6 months ago and causing your pain, but since now there is no such fluid collection found on MRI the headache should have resolved as well.
Anyway from a practical point of view, whichever the mechanism of the disappearance was, there is no need for any intervention, no risk involved. So you need not to worry and consider it actually a good news.
I remain at your disposal for other questions
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
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