後頭葉のpilocytic astrocytoma摘出により治癒し得た片頭痛の1例

Resolution of Migraine with Aura by Removing Pilocytic Astrocytoma of the Occipital Lobe

Ⅰ．は じ め に

　片頭痛は頭痛発作を繰り返す疾患で，中枢神経系の神経細胞の興奮性亢進によって起こるとされている．臨床においては比較的頻繁に遭遇する疾患であり（本邦では8.4%²²⁾，アメリカ合衆国では女性17.2%，男性6.0%¹⁵⁾），スマトリプタンの出現により，一般内科においても治療されるようになっている²⁴⁾．通常は器質的異常を伴わないが，片頭痛と脳虚血との関連に関しては比較的多くの報告があり，その発生メカニズムが議論されてきた^18,19)．また，片頭痛と頭蓋内占拠性病変の合併についても報告が散見される^{1,5,7,11,14,16,17,20,21,23,25,26,28)}が，その頻度は極めて稀である（0.2%^11,27)）．今回われわれは，典型的なmigraine with auraで発症した右後頭葉のpilocytic astrocytomaの1症例に対し，摘出術を行い，術後片頭痛の消失をみた．片頭痛と頭蓋内腫瘍との関連について，文献的な考察を加え報告する．

Migraine is one of the symptoms frequently encountered in daily neurological and neurosurgical clinical work. Here we report a case of pilocytic astrocytoma in the right occipital lobe presenting as migraine with aura. A 20-year-old female was referred to our hospital with the complaint of a migraine with visual aura. Her symptom did not respond to medical treatment. MRI of the brain disclosed a tumor involving the right occipital lobe. Total removal of the tumor (pilocytic astrocytoma,WHO grade 1) relieved her migraine completely. It has been previously reported that brain tumors are associated with migraine. But this is the first report of occipital pilocytic astrocytoma presenting as migraine with aura. As for other brain tumors manifesting migraine,all of them had focal neurological deficits or symptoms associated with increased intracranial pressure (ICP). The present case stresses the significance of exploration of brain tumor,or other organic abnormalities,even in patients suffering from migraine without neurological deficits or increased ICP symptoms.