My friend is having fits when he wakes up/ falls asleep but is concious of it and gasps for air SCAREY !!.?

It started a month ago he is 40. He starts convulsing as he wakes from a dream state or drops into a sleep. He wakes and starts convulsing having no control over his rigid body, unable to move all the time he is awake and aware of convulsions and gasps for air unable to breath. His left arm seems less able. This started 1 month ago and it has happened 3 times. Yesterday he went in and out of these convulsions like state 3 times from 8am till 11am. He was petrified as he could not do anyhing, call for help or phone anyone. Tests on his heart yesterday all is ok. He is home now & has to see a neurosurgeon in a months time. I asked him "are you dreaming this?" No he is not as the first time his friend was there and all the time he was aware of everything including seeing and being aware of the panic and fear in his friend & everything that is going on as his friend tries to help him come out of the fit. All the time this is happening he is gasping struggling to breath. What is this ?