Persistent posttraumatic headaches and functioning in veterans: Injury type can matter

Can Long-Term Outcomes of Posttraumatic Headache be Predicted?

PURPOSE OF REVIEW

Headache is one of the most common symptoms of traumatic brain injury, and it is more common in patients with mild, rather than moderate or severe, traumatic brain injury. Posttraumatic headache can be the most persistent symptom of traumatic brain injury. In this article, we review the current understanding of posttraumatic headache, summarize the current knowledge of its pathophysiology and treatment, and review the research regarding predictors of long-term outcomes.

RECENT FINDINGS

To date, posttraumatic headache has been treated based on the semiology of the primary headache disorder that it most resembles, but the pathophysiology is likely to be different, and the long-term prognosis differs as well. No models exist to predict long-term outcomes, and few studies have highlighted risk factors for the development of acute and persistent posttraumatic headaches. Further research is needed to elucidate the pathophysiology and identify specific treatments for posttraumatic headache to be able to predict long-term outcomes. In addition, the effect of managing comorbid traumatic brain injury symptoms on posttraumatic headache management should be further studied. Posttraumatic headache can be a persistent symptom of traumatic brain injury, especially mild traumatic brain injury. It has traditionally been treated based on the semiology of the primary headache disorder it most closely resembles, but further research is needed to elucidate the pathophysiology of posttraumatic headache and determine risk factors to better predict long-term outcomes.

Double Blast Wave Primary Effect on Synaptic, Glymphatic, Myelin, Neuronal and Neurovascular Markers

Explosive blasts are associated with neurological consequences as a result of blast waves impact on the brain. Yet, the neuropathologic and molecular consequences due to blast waves vs. blunt-TBI are not fully understood. An explosive-driven blast-generating system was used to reproduce blast wave exposure and examine pathological and molecular changes generated by primary wave effects of blast exposure. We assessed if pre- and post-synaptic (synaptophysin, PSD-95, spinophilin, GAP-43), neuronal (NF-L), glymphatic (LYVE1, podoplanin), myelin (MBP), neurovascular (AQP4, S100β, PDGF) and genomic (DNA polymerase-β, RNA polymerase II) markers could be altered across different brain regions of double blast vs. sham animals. Twelve male rats exposed to two consecutive blasts were compared to 12 control/sham rats. Western blot, ELISA, and immunofluorescence analyses were performed across the frontal cortex, hippocampus, cerebellum, and brainstem. The results showed altered levels of AQP4, S100β, DNA-polymerase-β, PDGF, synaptophysin and PSD-95 in double blast vs. sham animals in most of the examined regions. These data indicate that blast-generated changes are preferentially associated with neurovascular, glymphatic, and DNA repair markers, especially in the brainstem. Moreover, these changes were not accompanied by behavioral changes and corroborate the hypothesis for which an asymptomatic altered status is caused by repeated blast exposures.