Foreign bodies in the brain can only be removed by surgery, but the general principle of surgery is not life-threatening, so it seems that this small bone fragment may remain in the brain for a lifetime. There is a large amount of fluid between the cerebral cortex and the skull. May move, there is a certain risk. If it doesn't move, there is no need for surgery.
The most authoritative brain surgery in China is in Beijing Tiantan Hospital and its derived brain research institute. If you have any questions, you can send information to their website.
I hope it can inspire you. Tell my brother not to do strenuous exercise before diagnosis, in case of danger. Uncle Charlie Young