My Husband Is Having Severe Head Pain After Climax, We

My husband is having severe head pain after climax, we have been married twenty five years and this just came about the last few months, not every time but the more aroused and better the climax the worse the pain. It is in the front of his head between the temples, his neck cramps also. The pain is severe and lasts around three to four minutes with him thinking he is going to die. He is 58 years old in good health. he does not use any medications.
Thank you for any help.
Regards,
Maureen