Chick head trauma caused leg paralysis? Help!

[hglick]

I have a three and a half week old chick that escaped its pen and was mingling with the mother and chicks of another batch (5 weeks old). I found the chick sitting/lying, and with a head wound - presumably from the mother of the older chicks. After just rescuing a fully scalped chick two weeks ago, the head wound seems minor. It was on the top, back of its head, and another little wound at the beak. The main wound was a little bloody, but didn't appear to go through all the tissue or skull. Yet, when I picked the chick up, the left side of it's body seemed paralyzed. After a day of care, it appears to be moving it's left wing fine (perhaps I just overlooked it initially), but the left leg is still completely paralyzed. The leg is limp (no tense muscles). I examined it for broken bones and could not locate anything obvious. As far as tendon or ligament injuries, I can't tell. Moving the leg manually produces the appropriate reflexes in the foot, but it is so limp and floppy it is possible that there is damage. I tested the chick for pain stimulus with a needle on its left foot and leg - no response at all. Given, it didn't respond well on seemingly healthy parts of its body. Other than the leg, the chick is breathing a little heavily, but is alert, eating/drinking on its own, and moves itself around a little with the one functioning leg and its wings. The paralysis appears to be neurological (my best guess), but other parts of the left side of it's body seem to function. There is no obvious injury of the spinal column closer to where the leg joint articulates with the body. Is it possible that a head trauma could have caused such an isolated injury? How much mobility could one expect it to recover? Can chickens get by with one leg?

To all you knowledgeable people out there, what is your interpretation of this, has anyone else had a very similar scenario, and will/might it heal? This was a completely healthy, pastured bird prior to the trauma. Zero sign of illness or disease. Thanks to all who respond.