1.脑干包括中脑、脑桥和延髓三部分，脑干上与间脑下与脊髓相连，内部结构主要有神经核团、上下行传导束和网状结构，神经分布十分复杂，丘脑及以上的脑干的高级神经到达丘脑下部，在丘脑下部多转到对侧神经核团，控制对侧机体的肌肉活动，所以当脑干高级神经损伤时，造成对侧机体瘫痪，即出现了交叉性瘫痪。
1. The brain stem consists of the middle brain, the bridge of the brain and the extension of the myelin, the brain stem is connected with the spinal cord under the interbrain, the internal structure is mainly neural nucleus group, upstream conduction beam and mesh structure, the nerve distribution is very complex, the thalamus and The upper nerves of the brain stem above reach the lower part of the thalamus, and in the lower part of the thalamus more to the opposite side of the nerve core group, control the muscle activity of the opposite body, so when the brain stem advanced nerve damage, resulting in the paralyzing of the opposite body, that is, cross-paralysis
2.真性球麻痹：病变部位在一侧或两侧的舌咽、迷走神经；下颌反射、咽反射消失；不出现强哭强笑；可出现舌肌萎缩；无双锥体束征。

假性球麻痹：病变部位一定在双侧皮质脑干束；下颌反射亢进；存在咽反射；出现强哭强笑；不出现舌肌萎缩；常出现双锥体束征。

2. True spherical paralysis: the lesions of the part on one or both sides of the tongue pharynx, vagus nerves; jaw reflexes, pharynx reflexes disappear; there is no strong crying and laughter; tongue muscle atrophy can occur; no double cones.

Pseudo-ball paralysis: the lesions must be in the bi-lateral cortical brain stem beam;