Yes, a TBI can cause loss of taste and smell. This can be a part of
concussion. If this is so, there is a chance of
recovery once the effects of concussion wear off, which may take a few years at times. Also the loss of smell could be due to injury to the nose causing a blockage inside the nose. Hence an ENT consultation is a must to rule this out.
The other possibility is injury to nerves or the center in the brain. Generally the taste goes away because of loss of smell.