Emergency treatment ? .....

Hello ,
I am from Kratie Province, and I live here with a Cambodian family, and for a while, the eldest son of the family, 22 years old, has some troubles in his head, and since recently, is under stress huge, incredible anxiety attacks, and loss of memories that we really have trouble explaining.
He even happens to be unable to recognize us.
A year ago, he had been scanned in Ho Chi Minh, and these examinations did not lead to anything, except that they did say that it seemed to them that there was something, but now his behavior changes even more than before.
It is imperative that this boy now follows a treatment, because although I know nothing about medicine, I'm afraid it's more serious than I think.
Since I do not know anything about hospital specialties, I am now looking for a place where this boy could be examined and of course possibly looked after.
Khmer friends from Sihanoukville told us about a German institution that would be located near Bokor in Kampot province, I do not know more about it, but it seems that this place would be able to accommodate people with this kind problems and at a moderate cost.
If there is anyone among you who is able to give me information about this institution, and of course other places anywhere in the country, who have the equipment to detect and treat that type of disease, and it is possible that it is a brain tumor, I will be particularly grateful to them.

Sincere thanks, Christian