Well, this depends on which continuity you're talking about.
In the main continuity - first of all, Pike was a Fleet Captain, not a commander (which is rank below both Fleet Captain and Captain).
Pike was injured in a training mission with cadets. He suffered severe delta radiation poisoning. He was now relegated to an advanced life support chair, and could only respond yes or no via blinking lights on this chair. Was also severely disfigured.
Eventually, Spock took control of the Enterprise, and with the extremely disable Pike along, diverted the vessel to Talos IV, a prohibited planet in the Federation.
Spock's intention was, risking execution if caught, to deliver Pike to Talos IV, where the Talosians could tap Pike's mind with telepathy and illusions so he would be spared dying helpless in his lifeless body.
On Talos IV, with the help of the Talosians, Pike lived out a life of illusion in which his devastating handicap no longer existed. Pike went into retirement from Starfleet active duty and lived on Talos IV permanently, with no further outside contact, since the secrecy of the Talosian power made his fate largely unknown.
One could presume Pike lived out a normal lifespan on Talos IV, or one the Talosians would have extended according to their abilities. ProfessorTrek 06:39, August 8, 2011 (UTC)