Heatstroke with Neurological Symptoms

My brother had a heatstroke this past summer,  it was 103 outside and 110 heat index.  He went into muscle cramps that literally rolled all over his body, he fell to his knees and became ill and threw up.  His body locked up and he could not walk and had to be carried out of the heat.  He was then ice packed down, and the ice packs exploded he was so hot.  He didn't get medical care for almost 4 hours after that.  A few days after the heatstroke, he had an experience where he started to get the muscle cramps again (he was outside). He wasn't feeling well and decided to go home and take a cool shower.   When he got out of the shower, the room violently shock (am guessing a visual thing) and he doesn't remember anything after that (possibly passed out).  

Since then he has had headaches, vertigo, memory problems, and confusion. Lately he has noted  a metallic taste and sound sensitivity.  He has these "episodes" where he will get a headache, pain in his left eye (though it has happened in his right), visual changes where he will lose his peripheral vision or his vision will jump up close and then clear up, he can get a slight slur to his words, , and lately momentary shakes as though his body is shaking from lifting something very heavy.    The most concerning, is that these episodes seem to determine his mental state.  He can have one of these episodes and become very confused (he gets this lost look on his face, he doesn't interact, and can not follow conversations, or hold one very easily, and mood changes).  This state of confusion can last for minutes or weeks; OR, when he has one of these episodes, he becomes very clear and back to his old self (interacting, smiling, as though nothing had happened to him), generally this state of clarity lasts for a few days, then another episode generally takes place.  He can have headaches and dizziness almost everyday, but it is different than these episodes he has.  

My brother is a very young man and is aware in part to what is taking place with him, though his memory has been very bad since the heatstroke, and like the rest of us is very perplexed to what is happening.  All we know is that it has changed him and his life, and he needs some direction to what is taking place with him.  He saw a neurologist shortly after this happened and he had a negative MRI, and his diagnosis was post-heat stroke (though these episodes were not very clear to us at the time). The neurologist did know however of the mood changes, headaches, and memory problems, etc.  My brother  has also had his memory tested and it does show that he does have cognitive deficits.  

It has now been over six months since the heatstroke, and my brother is better in some ways and worse in others.  Any help would be greatly appreciated, because it is very hard going on like this without any answers.