the.com/convulsing
The body staging a violent mutiny while the brain watches, locked out of the controls.
means Shaking or jerking uncontrollably, usually from muscle spasms, seizures, or overwhelming laughter.
from From Latin convellere, to tear up or wrench violently — convulsus literally means yanked apart from within.
Laughter overlapExtreme giggling triggers the same word, minus the danger.
Not voluntaryBy definition, you cannot do it on purpose.
Medical cousinA convulsion is the visible sign of many seizures.