Is phonophobia associated with cutaneous allodynia in migraine?

Objective To determine whether phonophobia and dynamic mechanical (brush) allodynia are associated in episodic migraine (EM). Methods Adult patients with EM were prospectively recruited. A structured questionnaire was used to obtain demographic and migraine related data. Phonophobia was tested quantitatively using a real time sound processor and psychoacoustic software. Sound stimuli were pure tones at frequencies of 1000 Hz, 4000 Hz and 8000 Hz, delivered to both ears at increasing intensities, until an aversive level was reached. Allodynia was assessed by brushing the patient's skin with a gauze pad at different areas. Patients were tested both between and during acute attacks. Sound aversion thresholds (SATs) in allodynic and non-allodynic patients were compared. Results Between attacks, SATs were lower in allodynic compared with non-allodynic patients, with an average difference of -5.7 dB (p=0.04). During acute attacks, the corresponding average SAT difference (allodynic-non-allodynic) was -15.7 dB (p=0.0008). There was a significant negative correlation between allodynia scores and SATs, both within and between attacks. Conclusions The results support an association between phonophobia and cutaneous allodynia in migraine.