Orbitofrontal cortex involvement in chronic analgesic-overuse headache evolving from episodic migraine.
The way in which medication overuse transforms episodic migraine into chronic daily headache is unknown. To search for candidate brain areas involved in this process, we measured glucose metabolism with 18-FDG PET in 16 chronic migraineurs with analgesic overuse before and 3 weeks after medication withdrawal and compared the data with those of a control population (n = 68). Before withdrawal, the bilateral thalamus, orbitofrontal cortex (OFC), anterior cingulate gyrus, insula/ventral striatum and right inferior parietal lobule were hypometabolic, while the cerebellar vermis was hypermetabolic. All dysmetabolic areas recovered to almost normal glucose uptake after withdrawal of analgesics, except the OFC where a further metabolic decrease was found. A subanalysis showed that most of the orbitofrontal hypometabolism was due to eight patients overusing combination analgesics and/or an ergotamine-caffeine preparation. Medication overuse headache is thus associated with reversible metabolic changes in pain processing structures like other chronic pain disorders, but also with persistent orbitofrontal hypofunction. The latter is known to occur in drug dependence and could predispose subgroups of migraineurs to recurrent analgesic overuse.
Fumal
Arnaud
A
Department of Neurology, University of Liège, Liège, Belgium. arnaud.fumal@ulg.ac.be
Laureys
Steven
S
Di Clemente
Laura
L
Boly
Mélanie
M
Bohotin
Valentin
V
Vandenheede
Michel
M
Coppola
Gianluca
G
Salmon
Eric
E
Kupers
Ron
R
Schoenen
Jean
J
D000328:Adult; D000368:Aged; D000700:Analgesics / Q000009:adverse effects* / Q000627:therapeutic use; D002531:Cerebellum / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D003627:Data Interpretation, Statistical; D004359:Drug Therapy, Combination; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism / Q000473:pathology*; D006261:Headache / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000378:metabolism; D019966:Substance-Related Disorders / Q000378:metabolism / Q000473:pathology
D000700:Analgesics; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18