This study was a chart review study that involved 335 migraine surgery patients. Two hundred forty-five subjects received stepwise diagnostic injections of BTX, and 90 subjects in
the control group received no BTX or only therapeutic BTX. It is unclear what is implied by therapeutic BTX, and why any patients in the control group received any BTX. In the review, there is no mention of how many units were utilized. The injections were performed at the sites deemed by the evaluating surgeon to be migraine trigger sites. The preoperative and 12-month postoperative migraine headache frequency, duration, and intensity were compared to determine the success of the operations. Seventy-two of 90 control subjects experienced a decrease of at least 50% in migraine headache frequency, duration, or intensity at 12 months after surgery. Twenty-nine of 90 ABT-263 control subjects reported complete elimination. Of the 245 in the BTX group, 207 experienced http://www.selleckchem.com/products/obeticholic-acid.html a decrease of at least 50% in migraine headache frequency, duration, or intensity at 12 months after surgery. Of the 245 in the BTX group, 89 experienced complete elimination. It is unclear whether the term
complete elimination is referring to just migraine or all types of headache. The surgical success rate of the BTX group was not significantly higher than that of the control group.[16] In clinical practice, it is unclear why patients who respond to 25 units of BTX proceed Edoxaban to surgery, rather than receiving higher doses of BTX. According to the Phase III Research Evaluating Migraine Prophylaxis Therapy 2 Trial (PREEMPT-2), which was a phase 3, double-blind, placebo-controlled trial addressing the use of BTX for chronic migraine, 155-195 units of BTX was found to be effective for the prophylaxis of headache in adults with chronic migraine. Repeated BTX treatments were found to be safe and well tolerated.[17] In addition, many of the subjects in migraine surgical studies had episodic migraine, and it has been demonstrated
that BTX is not effective for the treatment of episodic migraine.[18] Although peripheral nerve blocks target peripheral nerves, these procedures likely also have effects on central pain modulating structures. For example, studies have demonstrated that after performing occipital nerve blocks, migraine pain, brush allodynia in the trigeminal nerve distribution, and photophobia tend to improve.[19] These data suggest that peripheral nerve blocks may modulate pain transmission at peripheral and central targets. Thus, using peripheral nerve blocks as a confirmation of nerve compression would potentially create false positives when used as a migraine surgery screening tool. In clinical practice, nerve blocks can also at times be utilized for headache prophylaxis.