Studies suggest it’s possible that every [problematic] aspect of muscle activity – from oxygen uptake by the muscles, to mitochondrial functioning, to lactate build up, to the ability of the muscles to relax, to problems with the microcirculation – are present to some degree in fibromyalgia.
Every time you pick up a pen, hit a key on a keyboard, or turn on your smartphone, the premotor and supplementary motor areas of your motor cortex plan the movement first.
Then your primary motor cortex sends a message to the muscles to act.
When a muscle cell gets fatigued, the motor cortex recruits another cell to pick up the slack.
Plus the motor cortex also plays a role in pain inhibition pathways and connects to the insula – a sensory integration center and autonomic nervous system regulator.
Motor Cortex Function in Fibromyalgia: A Study by Functional Near-Infrared Spectroscopy. Gentile E, Ricci K, Delussi M, Brighina F, de Tommaso M. Pain Res Treat. 2019 Jan 16;2019:2623161. doi: 10.1155/2019/2623161. eCollection 2019.
Italian researchers had 24 people with FM do – tap their finger slowly and then more rapidly while measuring the activity of their motor cortex using functional near-infrared spectroscopy (fNIRS).
The motor cortex activity (oxyhemoglobin content) was similar between the people with FM and the healthy controls at rest during the slow tapping, but when asked to tap rapidly, the activity in the motor cortex of the FM patients faded (and so did their tapping ability).
This makes me think of the trouble I have sustaining repetitive motions. If the movement back and forth is too rapid, I lose my coordination and can’t keep it up.
I noticed this with running since I was a kid, and now I assume this is due to EDS, with its defective tissues. If I try running too fast, moving my legs too quickly, I feel my leg muscles get confused and stop working in coordination with each other, forcing me to stop running to prevent a fall.
When put under increased energy demand – a demand, it should be noted, that simply requires one to rapidly tap one’s finger – the motor cortex of FM patients “poops out”.
This pattern of doing OK while at rest but fading when put under stress has been seen in people with ME/CFS during exercise, in their immune cells, their mitochondria, etc.
Researchers have thought that reducing motor cortex metabolism could be a protective mechanism that shuts down motor cortex activity in the face of chronically activated pain circuits.
Instead, the authors suggested that, “cortical motor dysfunction and movement impairment could characterize FM at its onset“; i.e. could be an integral part of the disease.
Tying Movement to Pain
” Our study…points toward an important role for brain motor control… consistent with previous findings of altered pelvic floor muscle activity. Our results are also consistent with several studies demonstrating the importance of the primary motor cortex for pain processing. Kutch et. al. 2015“
Motor cortex problems may be present in other painful diseases.
The motor cortex is involved in movement planning, muscle activation and pain inhibition.
Studies indicate that magnetic stimulation of the motor cortex is able to relieve pain and other problems in FM.
These studies suggest that the motor cortex may play a key role, not just in the movement problems in FM, but in pain, mood, and other issues.
The motor cortex – movement connection goes both ways.
The use it or lose it adage applies to the motor cortex as well. If movements aren’t performed regularly, the pathways to produce them can be lost and must be relearned.
Just as motor cortex activity is required for exercise, exercise actually boosts the health of the motor cortex.
The activity of the motor cortex – the part of the brain responsible for planning and carrying out voluntary movements – appears to be impaired in both fibromyalgia and ME/CFS
Given that the motor cortex is also involved in sensory integration and pain modulation, it wasn’t that surprising to see motor cortex problems show up in diseases associated with pain and movement issues
studies suggest that a wide variety of muscle issues ranging from the motor cortex to the muscles themselves are present in FM.
Other pain disorders such as chronic pelvic pain syndrome and myofascial pain syndrome also feature motor cortex problems.
Here’s my theory: Pain itself shuts down the motor cortex.
In “the wild”, pain is designed to make you stop moving, rest, and attend to your injury, so it would make sense that it tries to keep you from worsening your injury by moving around.