METHODS	In the patients treated with propranolol , the mean ( + / - SD ) of monthly headache frequency declined from 5.83 ( + / -1.98 ) to 2.2 ( + / -1.67 ) per month , headache intensity lessened from 6.43 ( + / -1.6 ) to 4.13 ( + / -1.94 ) and headache duration decreased from 15.10 ( + / -6.84 ) to 7.27 ( + / -6.46 ) h ( P < 0.001 ) .\