However, although no structural brain damage occurs according to the classic definition, some researchers have included injuries in which structural damage has occurred and the National Institute for Health and Clinical Excellence definition includes physiological or physical disruption in the brain's synapses.
Men selvom der ingen strukturel hjerneskade sker i følge den klassiske definition, har nogle forskere inkluderet skader i hvilke strukturelle skader er opstået, og National Institute for Health and Clinical Excellences definition inkluderer fysiologiske eller fysiske ødelæggelser af hjernens synapser.