More common than locked-in syndrome is old age in a nursing home where a wheel chair is needed to get around that one needs a nurse to push. At another extreme, but not uncommon, are people who habitually project their pain onto those around them in an abusive fashion. That might be considered a "locked-out" syndrome since they have no way to suffer their pain except to cause others pain. I will be at a funeral of one member of my family tomorrow who died from pneumonia after years in a nursing home and have to face the abuse of another who will unreservedly project pain onto everyone for this death.
I am beginning to see suffering as a set of skills that needs to be developed. One of the skills is an ability to pay attention to what we are suffering, to not project it onto others and to not despair.
Although suffering can be a feedback mechanism or karma, I would agree with Job that it also occurs without any justice. Karma, or any other deterministic explanation for suffering, is not the whole explanation.
One of the things that I reject about suffering is that it implies there is something wrong with the universe. Similarly in Job's case he questions whether Yahweh is on his side or not--or even more painfully whether Yahweh loves him or not. Ultimately, Job sides with Yahweh even when he doubts if Yahweh sides with him.