錢幣型頭痛是一個新型之頭痛症候羣，初於2002年被正式報告，由於其獨特之臨床特徵，即被收錄在國際頭痛分類2004年出版之第二版中，歸類為顱神經痛及其他中樞性臉痛，成為一個獨立的頭痛症侯羣。錢幣型頭痛異於其他頭痛症候羣，在於其疼痛位置、形狀和大小，在每一次發作皆相同；另外，其疼痛區塊之邊緣非常清晰，病人可以明顯地將疼痛區塊從非疼痛區塊分隔出來。錢幣型頭痛較常被報告在西班牙裔病人，而亞洲少有被提及。從世界文獻中，可得出錢幣型頭痛之特性為女性較多、平均年齡約為43.7歲、疼痛位置幾乎集中在頂部處，即在三义神經第一分枝之區域內、有雙局部疼痛、和疼痛範圍最大直徑由2至10公分。錢幣型頭痛被歸類為原發性頭痛，但是亦有顱內腦膜瘤和蜘蛛網下水囊之次發性疾病之報告。基於致病機轉，有週邊性理論和中樞性理論，兩者皆可以成立。錢幣型頭痛之診斷，是依據國際頭痛分類於2004年所建立之準則。目前醫學界對錢幣型頭痛之治療並沒有任何指引，在急性期時可先試用非類固醇抗發炎性藥品；在長期慢性疼痛病人，可嘗試加巴噴丁、抗憂鬱藥品、或肉毒桿菌。穿皮電神經刺激或可幫助。目前對錢幣型頭痛病人之預後並不清楚。

Nummular headache, or coin-shaped headache, is a new headache syndrome. It was firstly reported in 2002. Because of its characteristic picture, it was rapidly adopted into the International Classification of Headache Syndromes, 2nd edition, in 2004. Nummular headache is categorized into the title of "Cranial neuralgias and central causes of facial pain". Nummular headache is hallmarked by a consistent location, shape and size of painful area without change in each attack. Additionally, the margin of painful area is well lineated. Nummular headache is usually reported in Spanish, and is rarely mentioned in Asian. In the world literature, we review and summarize the following results: female preponderance, average age of 43.7 years, location of painful area exclusively at the parietal area which is innervated by the ophthalmic branch of the trigeminal nerve, bifocal headache, and the maximal diameter of painful area ranging from 2 to 10 cm. Although nummular headache is classified into a primary headache, meningioma and intracranial arachnoid cyst have been reported in a few patients. The peripheral and central theory of pain are both encouraged by different clinical findings. The clinical diagnosis of nummular headache is adopted to the diagnostic criteria suggested by the International Classification of Headache Syndromes, 2nd edition. Till now, there is no guideline for the treatment strategy for nummular headache. In acute phase of pain, nonsteroidal anti-inflammatory drugs can be tried. In chronic pain patient, treatment choice includes gabapentin, antidepressants, or botulinum toxin treatment. Trancutaneous nerve electrical stimulation may benefit also. The prognosis of nummular headache is still unknown.