My 80 Yr Old Husband Has Spinal Stenosis, But In

My 80 yr old husband has spinal stenosis, but in the last 4 weeks has deteriorated considerably in his ability to walk , with upper thigh pain in either or both legs....moving daily. This morning I noticed a heavily twitching muscle in his outer left thigh, even when he was standing still. He is not aware of it unless he touches it. Thankyou for any help.