Researchers at Hallym University, Anyang, Korea investigated the clinical features of headache associated with mobile phone (HAMP) use among 247 medical students. Their median age was 23.6 years; 39.6% were women and 60.4% men. Following a 14-item questionnaire, individual telephone interviews were conducted with participants who reported HAMP more than 10 times during the previous year. HAMP was defined as a headache attack during MP use or within 1 hour after MP use. Of 214 (86.6%) students who completed the questionnaire, 40 (18.9%) experienced HAMP more than 10 times during the previous year. The majority of those affected (97.4%) reported that HAMP was triggered by prolonged MP use (mean time 49.7 +/- 36.7 minutes); 52.6% reported HAMP occurred every time they used a MP. The headache was mild in intensity, and dull or pressing in quality in 79%, ipsilateral to the side of MP use (orbital or periorbital) in 84.2%, associated with a burning sensation in 71.1% and dizziness in 39.5%. Phonophobia was more prevalent among participants with HAMP compared to those without HAMP. The proportion of HAMP participants who suffered from migraine was 10.8%, and among none-HAMP participants it was 8.4% (NS). 
COMMENT. The authors discuss the mechanism of HAMP and its possible relation to radiofrequency fields, psychological factors, temperature change, and noise. Only one participant in this cohort reported headache provocation by regular telephone use, and HAMP did not occur when using hands-free equipment. HAMP shows stereotyped clinical features.