Dr. Hamrah et al. report interesting results of neuronal changes on both symptomatic and asymptomatic sides in other unilateral pain syndromes.
We agree that our findings of sensory abnormalities in both sides of the face and in the hand, an area located outside the trigeminal innervation, in a unilateral facial pain syndrome, may be caused not only by central mechanisms but also by peripheral mechanisms, as discussed in our paper.
It is unlikely that our findings can be explained by the co-occurrence of polyneuropathy in our patients in addition to trigeminal neuralgia. Thus, there were no clinical signs of polyneuropathy in our patients, and there is no evidence of increased prevalence of polyneuropathy in patients with trigeminal neuralgia.
We hope that this will stimulate further research in these highly debilitating pain disorders.