how many g's does it take to damage soft brain tissue if acceleration was linear rather than rotational?

disturbance/damage to meninges which manifest as headaches mean brain tissue damage as well?

The G forces the brain can tolerate is widely debated. Helmet manufacturers used to think 80 to 100 G's for microseconds was tolerable. As time goes on, it appears they are revising this amount downward drastically. There are many variables that can influence this value so I don't think there is a valid number.

I am asking this because as a person who has a history of concussions, a few days ago I moved my head very quickly in an attempt to avoid hitting it to the wall. I managed to avoid hitting the wall but in return the movement the I did to avoid collision was so rapid that it eventually caused relapse of some of concussion symptoms I used to suffer such as headache, mental rigidity, etc.

I tried to measure the acceleration involved in my head's sudden movement by using accelerometer of my tablet computer mimicking the same movement with my hand when holding the device. It seems that there is no way my head was subjected to more than 5G for 50-100ms which is nothing compared to the accelerations occur in MVA's..

I just can't understand how come sth like this can bring back all the symptoms all of a sudden. Isn't the in-built protection mechanism of my brain same as the that of normal people?

What in-built protection mechanism are you referring to ?

Studies show that the brain loses more tolerance for impact forces with each concussion. After my lifetime of concussions and sub-concussive impacts, I can give myself a concussion by shaking my head .

I am referring to layered-meninges which provides protection for the brain tissue.

What are you referring by 'studies'? if you support your claim showing only some statistical data, it is not scientific. Science requires explanation of the underlying mechanism of the phenomenon to be studied.

Hi there
Please remember this is a patient to patient support community, so no one has to provide any "scientific" evidence/proof etc here when sharing their experience, opinion or information, as they understand it.

Members can always investigate things further for themselves if needed, or ask if others do happen have any links to studies that may help in understanding.

In my many decades of following issues regarding concussions, I have never heard the concept you present.

The study I referred to was done by a prominent neuro-psychologist. It showed more cognitive decline following a second concussion that the cognitive decline from a first concussion. There was not an explanation of the mechanism. Call it just statistical data. Either way, it was done in a scientific process.