I mentioned the 20% thing, and my response. While I was holed up under my desk, I took some time to read up on current medical literature to figure out how that 20% was derived. By the way, morbidity is a fancy word for occurence. No one died.
Once you get the headache, the dura needs to heal so the CSF will stop leaking and the headache will stop. Roughly 24% of PDPHs clear up in 1-2 days, another 29% in 3-4 days, and another 19% in 5-7 days. By two weeks, a total of 80% of PDPHs have resolved themselves.
In any population, there are people who have issues and people who don’t. Over the whole population, you can get a general risk factor. But.. certain parts of the population are probably going to be more at risk that others. In my case, I hit the jackpot.
There are three significant studies of the morbidity of PDPH in dural puncture patients. The earliest and most quoted is from the late 1950s, and already a disturbing trend was evolving: there’s something about Mary, and it’s not her hairdo. After controlling for the possibility that women are simply over-reported (due to punctures during attempted epidurals on the delivery table), it was becoming clear even back then that being female is a clear risk for PDPH. Being female raises the risk to close to 40%, effectively doubling it. The two later studies looked at other physical factors, such as weight, physical health, physical fitness, and age. Again, the studies were controlled for the potential over-reporting of females of childbearing age, but an even scarier, and more complete, picture emerged: physically active females with lower body mass indices and age from 18 to 40 years old were shown to have a morbidity rate of 70%. Interestingly, being obese and having high blood pressure cuts the risk to nearly zero. There you have it, donuts are your friend.
It turns out that those of us who love our yoga, our running, our daily attack on fat molecules, also maintain very healthy and flexible tendon and ligament tissue. The dura is just one big ligamentous envelope. One big slow-to-heal ligamentous envelope. Healthy ligaments are stretchy and under some tension, so the small tear that the needle makes pulls open. Less healthy ligaments don’t stretch, they just kind of sag there, so the sides of the tear do not pull apart at all. The pulled-apart opening takes longer to heal, because the little ligament fibres have to reach the other side to join up and patch themselves together. Curse the situps and the sun salutations!
Ouch. That would be me, right there, physically fit skinny chick. Had I known about the 70%, I still would have gone through with the puncture, but I think I would have been less surprised by the onset of what turned out to be the most miserable week of my life so far. I would have been more prepared for the disruption. I might have even taken the pain more seriously when it started and just laid down. But I didn’t, and I didn’t. Ouch.