Post-traumatic headache: facts and doubts

The International Classification of Headache Disorders does not separate the moderate from severe/very severe traumatic brain injury (TBI), since they are all defined by Glasgow coma scale (GCS) < 13. The distinction between the severe and very severe TBI (GCS < 8) should be made upon coma duration that in the latter may be longer than 15 days up to months in the case of vegetative state. Post-traumatic amnesia duration may double the coma duration itself. Therefore, the 3-month parameter proposed to define the occurrence or resolution of post-traumatic headache (PTH) appears inadequate. Following TBI, neuropathic pain, central pain, thalamic pain, combined pain are all possible and they call for proper pharmacological approaches. One more reason for having difficulties in obtaining information about headache in the early phase after regaining consciousness is the presence of concomitant medications that may affect pain perception. Post-traumatic stress disorder (PTSD) develops days or weeks after stress and tends to improve or disappear within 3 months after exposure; interestingly, this spontaneous timing resembles that of PTH. In our experience the number of TBI patients with PTH at 1-year follow-up is lower in those with longer coma duration and more severe TBI. Cognitive functioning evaluated after at least 12 months from TBI, showed mild or no impairment in these patients with severe TBI and PTH, whereas they have psychopathological changes, namely anxiety and depression. The majority of patients with PTH after severe/very severe TBI had skull fractures or dural lacerations and paroxystic EEG abnormalities. The combination of psychological changes (depression and anxiety) and organic features (skull fractures, dural lacerations, epileptic EEG abnormalities) in PTH may be inversely correlated with the severity of TBI, with prevalence of psychological disturbances in mild TBI and of organic lesions in severe TBI. On the other hand, only in severe TBI patients with good cognitive recovery the influence of the psychopathological disorders may play a role. In fact, the affective pain perception is probably related to the integrity of cognitive functions as in mild TBI and in severe TBI with good cognitive outcome.