The Challenge of Pain

action activity afferent anaesthetic animals appears approach become begin behaviour block blood body brain carried cause cells central changes chronic clinical continuous damage decrease descending described developed disease dorsal drugs effects electrical evidence evoked example exciting experience fact feel felt fibres fields Figure hand important increase inhibition inhibitory injection injury input intensity involved kinds lamina later lesions limb major mechanisms Melzack methods midbrain muscle nerve fibres nerve impulses nervous system normal observed occur operation pain particular pathways patients pattern period peripheral person phantom points possible pressure problems procedures processes produce prolonged psychological reason received recent receptors relief reported response role roots sensation sensory severe shows side signals skin sometimes specific spinal cord stimulation structures suffering suggestion terminals theory therapy tion tissue treatment trigger types Wall