It's a progressive neurological disorder

神经元逐步失调
that destroys the cells in the brain that control essential muscle activity,

导致控制肌肉运动的脑细胞受损
such as...

比如
Speaking, walking, breathing, swallowing

讲话行走呼吸吞咽
The signals that muscles must receive in order to move are disrupted.

控制肌肉运动的电信号收到了干扰
The result is... gradual muscle decay, wasting away.

结果就是肌肉逐步萎缩
Eventually, the ability to

最终彻底地
control voluntary movement is... lost... entirely.

丧失运动能力
I'm afraid average life expectancy is two years.

平均寿命是发病后两年
There's nothing I can do for you.

我也无能为力
What about the brain?

大脑呢
The brain isn't affected, you're thoughts won't change.

大脑不受影响你的思想依然在