Deans' stroke musings: Stroke Neuromuscular Fatigability Differs Significantly Between Sexes

Changing stroke rehab and research worldwide now.Time is Brain! trillions and trillions of neurons that DIE each day because there are NO effective hyperacute therapies besides tPA(only 12% effective). I have 523 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there.

What this blog is for:

My blog is not to help survivors recover, it is to have the 10 million yearly stroke survivors light fires underneath their doctors, stroke hospitals and stroke researchers to get stroke solved. 100% recovery. The stroke medical world is completely failing at that goal, they don't even have it as a goal. Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It lays out what needs to be done to get stroke survivors closer to 100% recovery. It's quite disgusting that this information is not available from every stroke association and doctors group.

Sunday, December 7, 2025

Stroke Neuromuscular Fatigability Differs Significantly Between Sexes

TO EXPLORE sex specific effects of stroke on motor performance, investigators studied 41 chronic stroke survivors at least six months after stroke and 23 age matched neurotypical adults. Participants completed a sustained submaximal isometric knee extension contraction at 30% of maximal voluntary strength using the paretic leg for stroke survivors and the dominant leg for controls. Task duration in seconds indexed stroke neuromuscular fatigability, with shorter duration indicating greater fatigability during isometric exercise. Potentiated quadriceps twitch responses and surface electromyography were recorded to characterize muscle contractile properties and neuromuscular activation during the fatiguing task.

Stroke survivors showed shorter task duration than neurotypical controls, confirming greater overall neuromuscular fatigability after stroke. Across all participants, males exhibited shorter task duration than females. However, a significant interaction between group and sex showed that stroke related increases in fatigability were specific to females.

Sex Differences in Stroke Neuromuscular Fatigability

Female stroke survivors demonstrated markedly shorter task duration than neurotypical females, whereas task duration was similar in male stroke survivors and neurotypical males. Among neurotypical adults, females sustained the contraction longer than males. Within the stroke group, task duration did not differ significantly between males and females, suggesting that stroke removed the usual female advantage in neuromuscular fatigability during isometric exercise.

Neuromuscular measurements supported distinct mechanisms in women and men. Stroke survivors showed smaller reductions in potentiated twitch force and smaller increases in electromyography amplitude than controls during the fatiguing contraction, consistent with altered neuromuscular activation and contractile responses. In female stroke survivors, shorter task duration correlated with less reduction in potentiated twitch, whereas in male stroke survivors shorter duration correlated with greater reduction in potentiated twitch.

Clinical Implications for Rehabilitation

These findings suggest that stroke neuromuscular fatigability may arise from different central and peripheral mechanisms in females and males. For clinicians, sex specific assessment of neuromuscular fatigability during isometric exercise may help tailor stroke rehabilitation strategies and exercise prescriptions for chronic stroke survivors. Recognizing that stroke can preferentially increase fatigability in females may prompt closer monitoring of effort, rest intervals, and task progression to optimize functional recovery and motor related outcomes over the long term.

Reference: Zhou Z et al. Stroke Increases Neuromuscular Fatigability in Females but not Males During Isometric Exercise. Med Sci Sports Exerc. 2025;doi:10.1249/MSS.0000000000003914.