You can show him to a neurologist
along with all the previous reports. The symptoms suggest towards Alzheimer disease(AD) how ever other diseases should be excluded for which Neurologist may also suggest CT angiogram of brain.
Alzheimer Disease does not have a cure at present however treatments for symptoms are available. You may also think of trying stem cell therapy
for AD if it is diagnosed however it is in research phase only with encouraging results which are not proven as of now