Hello Worried Parent-
I might keep an open mind about the possibility of trauma- at least for a while. You know the fight happened. Do you remember your nephew being sick prior to this? In my experience, the doctors I have gone to really do not have much of a clue as far as how non-traumatic brachial plexus injuries get started. Maybe your doctors do not think a simple fight with another child is indication of enough trauma to cause this, and they may be right. But, still be open to it. I have been going to various doctors about my non-trauma caused BPN for close to 8 years now, and no one mentioned a possibility of the cause being viral until just recently.
In my opinion, the viral cause is just a “guess.” They do not think your nephew’s fight was enough to cause the condition, so they click off to the next possible cause. They know I did not have trauma to cause my condition, so the virus is the next thing down the list. Oh, you do not remember being sick either? Maybe then you were born with this. That would be extremely rare, so it is probably not the case for you. Do you have any family history of the same condition in blood relatives? No? Well, it was probably a virus. Getting to the cause of non-trauma induced BPN is a mystery to me, and most doctors I have run into.
In my case, I have been attacked twice. I would think that might rule out a virus in my case, and put it more to the genetic version of the condition, but you never know. The first time, I lost use of my thumb and first two fingers of my right hand. It was totally out of the blue. I had had pretty bad arm pain, and could barely lift it. That got better, and I thought I was in the clear. Then one day I realized I could not pick up a pencil. The doctors at that time had no clue it was BPN related. I kept telling them it started in my shoulder and traveled to my hand. They were not interested in how it started.
After 2 years or so, I got back use of my fingers. After around 5 years, I got some movement back in my thumb. The strength to my thumb is still lacking, and overall my arm strength was reduced from prior levels. Looking back now, I see this as a symptom of BPN. At the time, the doctors thought my arm was weak because I was not using it enough. They were wrong.
Two years ago, I got another attack of arm pain. This time it was much more severe than the first time. It took a number of days before I could move my right arm again. The weird thing is that after that, I felt OK. I got back strength initially, even though my shoulder blade was winging and shoulder was not really stable. But after a few months, my strength started to fall off again. And it fell off in both arms even though my attack was to my right. And again, the doctors think my weakness is from lack of use. I admit I am not lifting much with my right arm-hand combination. But I am exercising, and I strength is not returning on either side.
One thing that my last doctor advised and ordered was that I finally get an MRI of my neck, since I still have some neck pain on the right with head aches at times on my left side near my neck. It is that left sided headache that I think may be the reason I am weak on that side too. Once I get the results, I will know for sure. I have only been waiting 6 weeks for the report
Overall, recovery is slow. And it may not be complete to prior levels. But, your nephew is young. He should have a good chance of beating this- ar at least adapting to any permanant loss.
Richard