The first thing we experience about yawning is an urge to do so, one that can be so hard to suppress that we end up gulping down an extra serving of air when we’re trying to appear interested, or polite, or awake. But what if you yawned even if you weren’t tired, or bored? What if you got attacks of yawning six, seven, eight times in a row that you couldn’t stop? This can be a problem for some patients with ALS, and it’s made worse by the fact that due to weak jaw muscles they could dislocate their jaw.
That’s why I was particularly interested when a news report on PatientsLikeMe listed “increased yawning” as a symptom of ALS. It occurred to me then that we had in front of us the perfect way to investigate excessive yawning in more detail. The first step was to set up “excessive yawning” as a primary symptom in ALS, meaning that all new members would be rating whether they felt it was mild, moderate, or severe. Coincidentally, a paper had just come out which reported two patients (not with ALS) with excessive yawning after being prescibred an SSRI antidepressant drug. We now had a couple of different hypotheses we could test out; first that yawning in ALS was associated with respiratory funciton, second that it was associated with SSRI use, and third that it might be something to do with emotional lability. I took the new publication as an opportunity to write a letter to the editor on the subject. I wrote:
254 patients (47%) completed the survey on excessive yawning. Excessive yawning was reported to be absent in 75 patients (30%) mild in 75 (30%), moderate in 81 (32%), and severe in 22 (9%). Using Spearman’s Rho there was no correlation between severity of yawning and age (r = −0.63, P = 0.329, n = 244) months since diagnosis (r = −0.032, P = 0.619, n = 250), or the last recorded measurement of forced vital capacity (r = −0.136, P = 0.99, n = 148). There was no association between yawning severity and anti-depressant usage (χ2 = 3.269, P = 0.352). However, there was an association between yawning severity and site of onset (χ2 = 18.705, P = 0.028). Patients with a bulbar onset of disease were more likely (57%) to have moderate or severe yawning than patients with an arm onset (42%) or leg onset (31%).
So, from this data it looks like we can reject hypothesis one (breathing) and hypothesis two (SSRI use). But what about emotional lability? The reason I thought it might be a factor is that, much like uncontrollable laughter and crying, people yawned even when they weren’t sleepy and had difficulty with inhibition. Emotional lability is also found to be much more common in the bulbar-onset form of ALS relative to limb onset forms. Our own stats show a moderate but significant correlation between the two symptoms (r=~0.3) , and at the recent ALS/MND International Symposium in Toronto one of the speakers mentioned that they also consider yawning a sign of lability.
Why is all of this important? For one thing, the fact that yawning can be painful for ALS patients means we should try and stop it, but our discussions on PatientsLikeMe brought to light another reason entirely: people were losing friends because of it as they were intepreting their frequent yawning as a sign of boredom or rudeness! So, my interest now is for two things to happen; first for patients and healthcare professionals to be more sensitive to the presence of excessive yawning and clarify to patients that it can be a symptom, and second for researchers to investigate potential treatments that might target emotional lability and excessive yawning in order to improve the quality of life of our patients.