A recent study in the New England Journal of Medicine related mild traumatic brain injury (MTBI) with post-traumatic stress disorder [PTSD (1) weeks or months after the injury. The report found PTSD as a common accompaniment of MTBI, an unanticipated result of injury. Other symptoms were reported as primary complaints such as sleep disturbance, fatigue, somatic pain and headache (1). The study stated that about 8% of patients experienced dizziness or balance problems, but there were no reports of loss and/or distortion of smell or flavor perception. Apparently, these latter symptoms were not studied by the investigators.

Currently, an active search is being conducted to identify symptoms of MTBI weeks or months after the concussive event. It would be useful to add to this study information about the loss and/or distortion of smell and flavor after MTBI. Investigating these symptoms would help to further define the symptoms of MTBI.

It has been shown that loss of smell occurs in as many as 65% of patients who report MTBI (3). This indicates that it is a common symptom that many patients with MTBI experience. Ten percent of these patients may have had trivial brain injuries – such as hitting the head on a cupboard – and thus even minor brain injury can result in a severe loss or distortion of smell, even as severe as after major traumatic brain injury (3).

Based upon extensive past literature (3,4), vertigo has been found as the most common, longest lasting and frequent symptom following MTBI. Loss and distortion of smell and flavor perception are the next most common, frequent and persistent symptoms following MTBI (3,4). However, these findings do not appear to be prominent in the current report (1). The need for a clear operational definition of MTBI is evident (2).

This lack of interest in loss and distortion of smell and flavor after MTBI, which are common and sometimes disabling conditions, is disturbing. It should be a call to action to help the many soldiers who return from Iraq and are not able to either find help or even find a comforting ear to listen to their complaints about this problem much less to seek treatment for this condition.

I bring this call to action in this section in order to bring attention to this common, often disabling and neglected condition. This injury affects major regions of the brain, including prefrontal or temporal cortex, regions that play important roles in both mentation and every day living.

References

1. Hoge, C.W., McGurk, D., Thomas, J.L., et al. Mild traumatic brain injury in U.S. soldiers returning from Iraq. New Engl. J. Med. 2008; 358: 453-463.

2. Bryant, R.A. Disentangling mild traumatic brain injury and stress reaction. New Engl. J. Med. 2008; 358: 523-527.

3. Sumner, D. Post-traumatic anosmia. Brain. 1964; 87: 107-120.

4. Schechter, P., Henkin, R.I. Abnormalities of taste and smell after head trauma. J. Neurol. Neurosurg. Psychiatr. 1974; 37: 802-810.