It looks like the drug company was interested in seeing the effects of etanercept on Alzheimer's. A study was just completed, but the results have not been published:
http://www.clinicaltrials.gov/ct2/show/NCT01068353
In the study that was reported in the Sun-Sentinel, only 12 out of 629 patients had TBI. Motor impairment and spasticity in the TBI patients were improved; there was no indication that cognition was improved. I do not have access to the full paper, but you can read the abstract here:
http://www.ncbi.nlm.nih.gov/pubmed/23100196
I would love to read the full paper.