Hello and welcome to the NeuroTalk Support Groups.

Here is the link to the forum that Dave has mentioned in his post.

Traumatic Brain Injury & Post Concussion Syndrome Forum

Also, a lot of people are very sensitive to even small changes in their medications and yes, sometimes lowering a dose will cause physical symptoms. Depression can also have physical symptoms as can Anxiety. The majority of people will heal from a concussion quickly but there are many who will not and those symptoms associated with Post Concussion Syndrome can be much longer lasting.

I hope he is feeling better fast. Please do have him see the doctor if these problems persist.

take care.