Ejaz et al. (2018) are to be commended for showing no
evidence for a cortical origin of post-stroke mirror movements.
Using functional MRI during affected-finger presses
in recovering adult-onset stroke patients, they found no
consistent relationship between contralesional sensorimotor
cortex (cSM1) activation and quantitative indices of mirror
movements; specifically, mirror movements were not linked
to the presence of cSM1 overactivation, arguing against the
classic ‘transcallosal’ mechanism heretofore widely believed
to cause mirror movements (Di Pino et al., 2014). We wish
to report findings—previously published in abstract form
(Calautti, 2008)—that further support the idea that
mirror movements are not cortically mediated. We also
present data that confirm that mirror movements can
involve the affected (i.e. paretic) hand during movement
of the unaffected (i.e. non-paretic) hand, also arguing in
favour of disruption of a bilaterally-organized system