Vasoconstriction commands from the brain → Nerve doesn’t get enough blood → abnormal nerve firing → muscle spasm
Vasoconstriction commands from the brain → Muscle doesn’t get enough blood → muscle has insufficient oxygen, buildup of waste products, ion imbalance, etc. → muscle spasm
Hmm. Speculating on some possibilities:
Vasoconstriction commands from the brain → Nerve doesn’t get enough blood → abnormal nerve firing → muscle spasm
Vasoconstriction commands from the brain → Muscle doesn’t get enough blood → muscle has insufficient oxygen, buildup of waste products, ion imbalance, etc. → muscle spasm
Skeletal muscle commands from the brain → “chronic, excessive muscle tone” → muscle spasm
(I’m speculating that 1 and/or 2 might be real things, on the basis that you can get muscle spasms after a really intense workout.)
I know very little about the physiology of muscle spasms. But it’s fun to speculate! And thanks for your comment :)