Drug-induced changes in cortical inhibition in medication overuse headache

• Published in: Cephalalgia Vol. 31; no. 12; pp. 1282 - 1290
• Main Authors: Currà, Antonio, Coppola, Gianluca, Gorini, Manuela, Porretta, Elisa, Bracaglia, Martina, Di Lorenzo, Cherubino, Schoenen, Jean, Pierelli, Francesco
• Format: Journal Article Web Resource
• Language: English
• Published: London, England SAGE Publications 01.09.2011; Blackwell Science
• Subjects: Adaptation, Physiological - drug effects; Adaptation, Physiological - physiology; Adaptation, Physiological/drug effects/physiology; Adult; Anti-Inflammatory Agents, Non-Steroidal - adverse effects; Evoked Potentials, Motor - drug effects; Evoked Potentials, Motor - physiology; Evoked Potentials, Motor/drug effects/physiology; Female; Headache - chemically induced; Headache - physiopathology; Headache/chemically induced/physiopathology; Human health sciences; Humans; Male; Motor Cortex - drug effects; Motor Cortex - physiopathology; Motor Cortex/drug effects/physiopathology; Neural Inhibition - drug effects; Neural Inhibition - physiology; Neural Inhibition/drug effects/physiology; Neurologie; Neurology; Sciences de la santé humaine; Transcranial Magnetic Stimulation; Tryptamines - adverse effects; transcranial magnetic stimulation; triptans; silent period; cortical inhibition; Medication overuse headache; NSAIDs
• ISSN: 0333-1024; 1468-2982; 1468-2982
• DOI: 10.1177/0333102411415877

Background: We investigated whether chronic headache related to medication overuse (MOH) is associated with changes in brain mechanisms regulating inhibitory cortical responses compared with healthy volunteers and episodic migraineurs recorded between attacks, and whether these changes differ according to the drug overused. Subjects and Methods: We studied 40 MOH patients whose symptoms were related to triptans alone, non-steroidal anti-inflammatory drugs (NSAIDs) or both medications combined, 12 migraineurs and 13 healthy volunteers. We used high-intensity transcranial magnetic stimulation over the primary motor cortex to assess the silent period from contracted perioral muscles. Results: In MOH patients the cortical silent period differed according to the type of headache medication overused: in patients overusing triptans alone it was shorter than in healthy volunteers (44.7 ± 14.2 vs. 108.1 ± 30.1 ms), but similar to that reported in migraineurs (59.9 ± 30.4 ms), whereas in patients overusing NSAIDs alone or triptans and NSAIDs combined duration of silent period was within normal limits (80.6 ± 46.4 and 103.8 ± 47.2 ms). Conclusions: Compared with episodic migraineurs, MOH patients overusing triptans have no significant change in cortical inhibition, whereas those overusing NSAIDs have an increase in cortical inhibitory mechanisms. We attribute these changes to medication-induced neural adaptation promoted by changes in central serotonin neurotransmission.