英语语法分析

The main symptom of a gelastic seizure is uncontrolled laughter.

发作性痴笑的主要症状就是控制不住地大笑。

As it turned out, the pilot, who showed no other symptoms, was experiencing a rare form of epileptic episode called gelastic seizure.

原来是这样的：这位飞行员是在经历一种罕见的被称为发作性痴笑的癫痫发作，没有其他症状。