Age

18–60

Sex

ALL

Healthy volunteers

Accepted

For patients:
Overuse of acute medications for headache;
Continuous or daily headache;
Other primary headache disorders, with the exception of infrequent tension-type headache.
For healthy controls:
Any subject with frequent tension type headache, migraine, cluster headache, other pain syndromes or neurological conditions.
For both patients and healthy controls:
Allergy to nitroglycerin;
Major psychiatric disorders such as bipolar affective disorder and schizophrenia;
Cardiovascular diseases that contraindicated the use of nitroglycerin;
Intracranial hypertension;
Cerebral haemorrhage;
Cerebral trauma;
Pulmonary toxic oedema;
Closed angle glaucoma;
Anaemia;
Pregnancy and breastfeeding;
Aortic stenosis or significant hypotension (SBP\<90mmHg or \<100mmHg and symptomatic) precluding nitroglycerin administration;
Use of sildenafil;
Any person unable to lie still within the environment of the MRI scanner for the required period to perform the study;
Any person where MRI scanning is contraindicated (metal implants, pacemaker, claustrophobia, etc.);
Use of illicit drugs;
MRI head showing any brain pathology, such as space-occupying lesions;
Any person unable to understand and follow the instructions of the investigators.

Study of the Glymphatic System in Migraine