Sprained ankle three weeks ago, can walk with brace, most bruising gone, but very painful persistent pins and needles on top of foot. cause? solution?

Nerve injury: There is a cutaneous (skin) nerve on top of the foot that could have been stretched or is irritated because of swelling or from the brace. Elevate, massage, ace wrap, maybe some benefit to physical therapy.

Ice it on the top: Where it hurts....You may have a neuropraxia, kind of like a whiplash of the nerves....

Have it evaluated.: An excessive amount of swelling or nerve injury could cause a numbness pins and needles sensation. Have it evaluated by a professional and get the appropriate treatment.