Migraine
Table:
Migraine

Woman with migraine headache
Specialty	Neurology
Symptoms	Headaches, nausea, sensitivity to light, sensitivity to sound, sensitivity to smell[1][2]
Usual onset	Around puberty[1]
Duration	Recurrent, long term[1]
Causes	Environmental and genetic[3]
Risk factors	Family history, female[4][5]
Differential diagnosis	Subarachnoid hemorrhage, venous thrombosis, idiopathic intracranial hypertension, brain tumor, tension headache, sinusitis,[6] cluster headache[7]
Prevention	Metoprolol, valproate, topiramate[8][9]
Medication	Ibuprofen, paracetamol (acetaminophen), triptans, ergotamines[5][10]
Frequency	~15%[11]

With reference to the table, determine whether the statement is entailed, neutral, or refuted. Conclude with JSON {"answer": "YOUR ANSWER"} — nothing else.

Statement: Brain tumors are a leading cause of migraine headaches.

answer: refuted