My husband who is 52 has this morning suffered sudden memory losses. Whilst working on the computer, he could not remember what month we are in and had to look at his diary after a couple of minutes. It then took him 10 minutes to remember the names of our two pets. We returned from a 10 day trip to India 9 days ago, he started to have a sore throat towards the very end of the trip which has developed into coughs, he had a temperature of 100 a week ago but it has returned to normal. He is also under a lot of pressure at work struggling to catch up with things. He has Psoriatic Arthritis and injects himself with Humira and Methotrexate. What are the likely causes to his sudden memory loss please?