流感病毒為一種RNA病毒，易傳播且感染力強，藉由飛沫傳染，但是往往以呼吸道症狀為主，較少造成神經學上的改變，也很少看到腦部影像學的變化，目前於日本所報告的案例較多流感與可逆性腦病變的個案，但是也大多都是A型流感，其中也都以幼童為主。在此報告一個20 歲軍人個案，也同樣得到流感後發生神經學症狀，而且影像學上也發現類似的胼胝體可逆性腦病變病灶，在間隔1 週的兩次腦部核磁共振可明顯觀察到變化。特別的是此個案為B型流感患者，而且年齡較大，因此我們不能以為只有A型流感才會造成，更不能以為成人就不會發生。於醫療上的貢獻為其大多可自行恢復，因而減少非必要之侵入性檢查或治療。

Influenza is a kind of RNA virus. It often leads symptoms of upper airway, but there are less neurological problems. The images finding of brain lesion are also rare. These rare cases are reported from Japan mostly. We can review more cases of influenza related brain reversible lesion, and the most of them are influenza A. The members of cases are almost young children. There is a case as a soldier, who was 20 years old, suffered from
influenza infection with neurological symptoms. The brain image as MRI revealed reversible lesion in the splenium of the corpus callosum, and lesion got recovered by itself about 1 week later. This case is special due to he is case of influenza B with older age from children. Therefore we must consider not only influenza A can lead brain reversible lesion, and adult can also causes the same problem. The symptoms often got improved without specific treatment.