There are many, many diseases caused by your own immune system attacking your body. The brain itself cannot “attack” anything unless you count seizures and the like. Maybe several forms of psychosis could fit the bill with even more stretching, but there is little your brain can do outside of interfering with bodily functions. If you seizure that hard outside of a hospital bed, you’re probably SOL in most cases.
There are many, many diseases caused by your own immune system attacking your body. The brain itself cannot “attack” anything unless you count seizures and the like. Maybe several forms of psychosis could fit the bill with even more stretching, but there is little your brain can do outside of interfering with bodily functions. If you seizure that hard outside of a hospital bed, you’re probably SOL in most cases.