Inclusion Criteria:

• Adults aged 18 to 75 years old.
• Meet the criteria for 1.3 chronic migraine based on ICHD3 criteria.
• Currently receiving onabotulinumtoxinA per PREEMPT protocol for the treatment of chronic migraine.
• Have remained stable on their current headache medication for a minimum of 8 weeks.
• Patient is willing and able to comply with the protocol to the satisfaction of the investigator.
• Patient has the capacity to provide written, informed consent for themselves.

Exclusion Criteria:

• Participants with an active implanted electrical and/or neurostimulator device (e.g., cardiac pacemaker, cochlear implant).
• Participants with congestive heart failure (CHF), severe cardiac or cerebrovascular disease.
• Participants with uncontrolled epilepsy.
• Change in migraine preventive medications (type or dose) in the last two months prior to recruitment and/or during the study.
• Pregnant, trying to get pregnant or breastfeeding female participants.
• Subjects participating in any other interventional clinical study.
• Participants with other significant pain, medical or psychological problems that in the opinion of the investigator may confound the study assessments.
• Participants who have previous experience with the device.
• Patients with cranial deformities, prior cranial surgeries with violation of the calvarium, or shunt placement.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 10/11/22. Questions regarding updates should be directed to the study team contact.