One of the difficulties encountered at times when discussing migraines occurs when a migraineur is given a diagnosis that isn't actually accurate in diagnostic terms, but is really a descriptive term.
Such terms may be used fairly frequently, but they fall short of a diagnosis and may also be used differently from one doctor to another. That's one reason why most doctors diagnose based in the International Headache Society's International Classification of Headache Disorders, 3nd Edition (ICHD-III). A "standard" diagnosis also makes communications and transitions easier when patients need to consult other doctors or change doctors.
This is the case with the terms "acephalgic migraine" and "silent migraine." In this case, the two terms are generally accepted to mean a migraine attack without a headache. Any type of migraine can be acephalgic. There are four potential phases of a migraine attack (for a description of the four phases, see Anatomy of a Migraine):
Not all migraineurs experience all four phases, and one migraine attack can be different from the next. Simply put, an acephalgic migraine skips the headache phase. Any type of migraine can be acephalgic.
A patient who is diagnosed with migraine should be fully diagnosed as to what type of migraine they have, whether they're acephalgic or include the headache phase:
There is no diagnostic test to confirm migraine disease. Diagnosis is achieved by reviewing both family and patient medical history, evaluating the symptoms, and performing an examination to rule out other causes of the symptoms. If there is any alteration in consciousness, seizure disorders should also be ruled out.
For infrequent migraine attacks, even without the headache phase, medications used for other forms of Migraine are often employed to relieve the other symptoms. These medications can include NSAIDs, antinausea medications, ergotamines the triptans. The choice of medications is somewhat affected by the age of the patient. When migraines are frequent, the same preventive therapies used for other migraines can be explored.