Artificial realities would probably come in varying degrees of realism -- to duplicate the patient's familiar world, you'd have to calculate wind currents, light reflections, gravity, friction, and so on, as well as the effect all of these have on the senses. Then you'd have to interpret activity in the motor neurons of the simulated nervous system, to update the patient's simulated body position. These will be difficult, and will never perfectly match the real world, but it is reasonable to suppose that algorithmic shortcuts will be found which generate results that are "good enough". Artificial reality would have the advantage of being able to shape the laws of physics to the programmer's whim, allowing, for example, magic spells or anti-gravity devices. However, there would be a risk of people getting addicted to direct brain stimulation, or simply getting lost in some virtual game and losing touch with reality.