Migraine Note: the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlledUse additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)Excludes1headache NOS (R51.9)lower half migraine (G44.00)Excludes2headache syndromes (G44.-)