N of 1 means only one patient in a research trial, acting as their own control….for those who care!
Hugh appeared in another story with his Parkinson’s. Much later, he came in to see me about fatigue. He had gone to his neurologist and talked about severe fatigue. The neurologist had done a good job of diagnosis, and referred Hugh for sleep lab testing. He had very severe obstructive sleep apnea, and was told he had to have CPAP: Continuous Positive Airway Pressure. Wearing a mask with an air pump attached all night, sleeping on his back.
“I don’t want to wear a mask with a damn machine! Isn’t there anything else I can do?”
The first sleep specialist in town had grown his practice so large that he ran out of capacity, and taught me to try three tricks before referral to him for sleep apnea. I had been using those for years by then. Trick one: Wear breathe-right adhesive strips on your nose to reduce air flow resistance. Those do work, a little. Second, elevate the head of the bed on blocks 6 inches, so the nose tissue drains and swells less (this is about the water pressure on the venous side of circulation, but do you really care?). That helps a little also. Extra pillows do not. The third trick requires acquiring three expensive pieces of equipment, but you can do it!: Tennis ball, sock, diaper pin.
Got it yet?
Push the tennis ball down the sock. Pin the sock with the diaper pin to the back of pajamas or a T-shirt in the middle of your back. No, next to the ball, dummy! You’re not playing tether ball! Now you’ll never sleep on your back again! You see, they make you lie on your back for sleep testing BECAUSE that is the very worst position, and if you sleep on your side it’s much better or gone. We move a lot while sleeping (no, you can search YouTube yourself for a fast forward video of somebody sleeping if you don’t believe this).
So Hugh agreed to try my tricks. He came back promptly: “You CURED ME!! I’m not even tired anymore!!” “Really? So you tried my three tricks?” “No, just the tennis ball!”
Poor Hugh! I did not believe him. I had NEVER seen such dramatic results. So I sent him back to be studied WITH the tennis ball. His index number of apnea episodes dropped from well over 20/hour to zero!!! He went from “severe” to “none”.
Then I realized he was a binary. Off, or on. It’s the Parkinson’s. At night, falling asleep on his back, his medicine would wear off and disappear, and he COULDN”T move! So on his back (standard testing start) he STAYED on his back and had severe apnea. Starting on his side with the tennis ball, he STAYED on his side and had NO apnea. He was right. Cured with a sock, diaper pin, and tennis ball.
Ain't family medicine grand? Can a doc have more fun than this? And is there need of more proof than this clean N of 1 research trial?