For chronic migraine, meaning headache on fifteen or more days a month, onabotulinumtoxinA reduces the number of headache days for many people. It is not effective for episodic migraine, and it does not stop an attack that has already started. Response is judged across cycles rather than after one round.
For chronic migraine, meaning headache on fifteen or more days a month, onabotulinumtoxinA reduces the number of headache days for many people. It is not effective for episodic migraine, and it does not stop an attack that has already started. Response is judged across cycles rather than after one round.
The distinction that matters most is chronic versus episodic migraine, and it is defined by frequency rather than severity. Chronic migraine means headache on fifteen or more days per month, of which at least eight have migraine features. OnabotulinumtoxinA is licensed and used for that group. If your migraines are severe but occur on fewer days, this is not the right preventive and a different plan applies. People are often surprised by this, because intensity feels like it should be the deciding factor.
The aim is fewer headache days per month, not their elimination. A treatment that takes someone from twenty headache days to twelve has worked, even though headaches continue. This is why counting matters: judged by feel, such a change is easy to dismiss, and people abandon effective treatment as a result. Keep a simple tally on a calendar from before you start, because a comparison needs a baseline.
It is given in cycles rather than once, and benefit typically builds over more than one round. Judging it after a single treatment is the commonest reason it gets written off prematurely. If there has been no meaningful change in headache days after an adequate trial across cycles, that is a real answer and the plan should change. This treatment is given in the office; the practice operates no infusion suite, so anything requiring infusion is arranged elsewhere.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: American Academy of Neurology; MedlinePlus, National Library of Medicine; National Institute of Neurological Disorders and Stroke.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.