The use of botulinum toxin type A, particularly onabotulinumtoxinA, in the treatment of chronic migraines has indeed been a significant development in headache management. Here's a summary of the key points from the passage you provided:

1. Long-standing Treatment Option: Botulinum toxin type A has been used for over a decade as a preventive therapy for chronic migraine. During this time, it has become established as a well-tolerated treatment option.

2. Unique Mechanism of Action: Botulinum toxin type A works differently from the newer monoclonal antibodies that target calcitonin gene-related peptide (CGRP) or its receptor. This distinct mechanism of action makes it less likely to be replaced by these newer treatments.

3. Coexistence of Treatment Options: Both botulinum toxin type A and CGRP monoclonal antibodies are likely to coexist as important tools for patients with chronic migraines. They offer different approaches to migraine prevention, allowing for personalized treatment choices.

4. Potential for Advancements: Ongoing research may reveal more about how botulinum toxin type A works in preventing migraines. Additionally, there is the possibility of discovering or developing new types of botulinum toxin that are more selective for sensory pain neurons. These advancements could further enhance the therapeutic usefulness of botulinum toxin in headache management.

5. Keywords: The keywords provided at the end of the passage highlight the main topics covered in the review, including chronic migraine, migraine, botulinum toxin, onabotulinumtoxinA, erenumab (a CGRP monoclonal antibody), and CGRP.

In summary, botulinum toxin type A has a well-established role in the preventive treatment of chronic migraine, and its unique mechanism of action sets it apart from newer CGRP-targeted treatments. Ongoing research and potential advancements in toxin selectivity may continue to make it a valuable tool in headache management.