Pyridostigmine Improves Hand Grip Strength in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, 2025, Scheibenbogen et al

[forestglip]

Hopefully the full paper describes a placebo control. Otherwise, it seems possible the hand grip strength change is placebo effect.

Yeah, no blinding.

Limitations of our study include the small sample size and the non-controlled design without randomization of the treatment order and the lack of a control group.

 

[Utsikt]

It’s a shame they go beyond the evidence and claim that PS improved the measurements. We have no way of knowing if it was actually caused by the PS.

 

[forestglip]

For reference, here is the main hand grip strength result:

As depicted in Figure 1A, HGS exhibited a linear decrease over the course of the ten measurements without PS but remained stable following PS administration. Further patients had a lower Fmax and Fmean HGS in the second session compared to the first without PS, while it increased after PS. In total, 16 of 20 patients had an improved HGS after 1 h. In four of 20 patients Fmax or Fmean did not increase following PS administration.

The light pink line is one hour after taking PS.

Figure 1. Hand grip strength (HGS) in patients with post-infectious ME/CFS (n = 20). Handgrip strength (HGS) was assessed in two separate sets, each consisting of ten consecutive measurements, with a 1 h rest period between sets. Mean and maximum HGS were calculated for each measurement set. The visit without pyridostigmine (PS) is shown in blue, while the visit with 30 mg of PS administered after the first measurement set is shown in pink. (A) Course of the single HGS values, left: without PS, right: with PS. (B) Maximum force (Fmax2) of the second HGS measurement set, with and without PS. (C) Mean force (Fmean2) of the second HGS measurement set, with and without PS. (D) Difference in maximum force (Fmax) between the first and second measurement set. Group comparisons were performed using the Wilcoxon matched paired-signed rank test with significance levels indicated as * p < 0.05, ** p < 0.01, *** p < 0.001.

 

[Formerhuman]

Am I right that if this effect is real, it is in favor of periferal mechanism of fatigability? It is strange to me that researchers in Charite didn't do for example crossover trial.

 

[Utsikt]

Am I right that if this effect is real, it is in favor of periferal mechanism of fatigability?

I think there’s a difference between muscles being unable to perform at close to max after exertion and the general feeling of fatigue.

This test focuses on the former.

It is strange to me that researchers in Charite didn't do for example crossover trial.

Yeah, it’s a shame they didn’t do any kind of placebo and blinding.

 

[EndME]

Am I right that if this effect is real, it is in favor of periferal mechanism of fatigability? It is strange to me that researchers in Charite didn't do for example crossover trial.

The only thing real here is likely the lack of a control or perhaps even worse (people participating because there's a chance they'd get the drug and being dissapointed when your in the non-drug group).