Neurotransmitters in disorders of consciousness and brain damage.

Restorations from disorders of consciousness such as the minimally conscious state and the vegetative state have been achieved spontaneously or by pharmacological agents such as zolpidem, baclofen, dopaminergic agents and tricyclic antidepressants in some patients. Other restoration methods have included electric and magnetic nerve stimulation, oxygen, Kreb's cycle constituent substitution and axonal re-growth. Although apparently unrelated, these methods all influence neurotransmitter availability or production within the brain. This review proposes depleted neurotransmitter function as a cause for long term brain suppression and disorders of consciousness. It unifies fundamentally different treatment approaches and explores the restoration of neurotransmitter function as a common theme to improve brain function after brain damage.