The main objective in the rehabilitation of the comatose patient is the regaining of consciousness. This is the first step in a life of relationship. After this objective has been achieved, the quality of the rehabilitation project is heightened, and the therapeutic relationship between the therapist and the patient is transformed from a one-way to a two-way relationship. The patient begins to participate, to seek to communicate, to move autonomously, and to take up an independent daily life. Failing to achieve contact with the surroundings, on the other hand, means being doomed to a life of vegetative perceptions and expression, and a negative rehabilitation prognosis.

Due precisely to this aspect of “promotion” or “failure”, the definition of the state of consciousness of an individual recovering from a coma is a potential source of conflict between rehabilitation staff and the patient's family. Staff must avoid the formulation of superficial judgments, judgments based on hasty observations, or worst of all, judgments made by inexpert personnel (Zasler, 1997). Currently, a vegetative state (VS) diagnosis is based essentially on clinical observation (Andrews, 1996), and requires the clinical experience of a multidisciplinary team that works well together and that places adequate importance on the family's observations (Giacino et al., 2002; Jennet, 2002). In this realm of extremely complex interests, significant errors of misdiagnosis are still made today (Andrews et al., 1996; Cranford, 1996).