Practical approach to a patient with chronic pain of uncertain etiology in primary care.

Chronic pain of uncertain etiology often presents a challenge to both patients and their health care providers. It is a complex condition influenced by structural and physiological changes in the peripheral and central nervous systems, and it directly influences, and is modulated by, psychological well-being and personality style, mood, sleep, activity level and social circumstances. Consequently, in order to effectively treat the pain, all of these need to be evaluated and addressed.

Mechanism of action of botulinum toxin type A in migraine prevention: a pilot study.

Objective: The main objective of this study is to determine whether change in migraine frequency is correlated with a denervation pattern of the corrugator muscle after local botulinum toxin type A injections.

Background: Recent studies suggest botulinum toxin type A is effective in preventing migraine. Relaxation of the corrugator muscle may be one of multiple targets of botulinum toxin type A in relieving migraine pain.