The botox paradox: beyond episodic and chronic migraine and theneed for a new nomenclature for treatment-induced remission

The International Classification of Headache Disorders, 3rd edition (ICHD-3), distinguishes episodic from chronic migraine mainly by headache frequency. However, increasingly effective preventive therapies have exposed a limitation of this framework: patients with chronic migraine who respond to treatment may fall below the diagnostic threshold for chronic migraine and subsequently be classified as having episodic migraine, despite requiring continued therapy to maintain this clinical state. This issue is particularly evident with onabotulinumtoxinA, whose efficacy is established in chronic but not episodic migraine. Successful treatment may therefore reclassify a patient into a diagnostic category for which the same therapy is not generally indicated—a phenomenon we term the “Botox paradox”. Similar transitions occur with calcitonin gene-related peptide-targeted preventive therapies and may become increasingly relevant as migraine treatment advances. We argue that primary episodic migraine and treatment-induced remission of chronic migraine represent clinically distinct states that should not be conflated by nomenclature. We propose that future headache classifications consider terminologysuch as “chronic migraine in remission” to preserve information about the underlying disease trajectory, improve clinical and research communication, and better reflect the dynamic nature of migraine under effective preventive treatment.