ABSTRACT
The peripheral mechanism is best exemplified in the case of ephaptic Reflex Sympathetic Dystrophy (RSD). In this condition the secretion of norepinephrine, substance P, and lactic acid, as well as other noxious substances, causes stimulation of the peripheral nerve and input of pain to the central nervous system. The spinal cord plays a major role in modulation of pain and development of RSD. It can be the sole source and point of origination of RSD. The best way to manage the vicious circle is physiotherapy, which increases the proprioceptive input and inhibits the hyperactivity of the sympathetic nervous system. The brain stem originates and perpetuates RSD in head, neck, and face injuries, as well as in the rest of the body. A neurotransmitter, serotonin, plays a major role in modulation of pain, especially headache. The role of the brain stem in modulation of RSD pain is its major role in endocrine influence on pain.
