- subjects with non-neuropathic pain component involvement, mononeuropathy multiplex, or more than one cause or potential cause for pain symptoms (e.g. trigeminal neuralgia, painful diabetic neuropathy, central post-stroke pain, phantom limb pain, peripheral neuropathy due to alcoholism, malignancy, HIV, syphilis, drug abuse, vitamin deficiency, hypothyroidism, liver disease, toxic exposure, or chronic neck pain);