The most common symptom of post-concussive syndrome (PCS) is post-traumatic headache (PTH) accompanied by photophobia. Post-traumatic headache is currently categorized as a secondary headache disorder with a clinical phenotype described by its main features and resembling one of the primary headache disorders: tension, migraine, migraine-like cluster. Although PTH is often treated with medication used for primary headache disorders, the underlying mechanism for PTH has yet to be elucidated. The goal of this narrative literature review is to determine the current level of knowledge of these PTHs and photophobia in mild traumatic brain injury (mTBI) in order to guide further research and attempt to discover the underlying mechanism to both symptoms. The ultimate purpose is to better understand the pathophysiology of these symptoms in order to provide better and more targeted care to afflicted patients. A review of the literature was conducted using the databases CINAHL, EMBASE, PubMed. All papers were screened for sections on pathophysiology of PTH or photophobia in mTBI patients. Our paper summarizes current hypotheses. Although the exact pathophysiology of PTH and photophobia in mTBI remains to be determined, we highlight several interesting findings and avenues for future research, including central and peripheral explanations for PTH, neuroinflammation, cortical spreading depolarization and the role of glutamate excitotoxicity. We discuss the possible neuroanatomical pathways for photophobia and hypothesize a possible common pathophysiological basis between PTH and photophobia.

To compare the acute clinical profile of patients with uncomplicated vs complicated mild TBI (MTBI), socio-demographic and medical history variables were gathered for 176 patients diagnosed with MTBI and with (complicated, N = 45) or without (uncomplicated, N = 131) positive findings on cerebral imaging. Neurological examination, neuropsychological assessment and self-evaluation of post-concussive symptoms were done at 2 weeks post trauma. Patients with complicated MTBI were more likely to show auditory and vestibular system dysfunction. Surprisingly, the uncomplicated group reported more severe post-concussive symptoms than patients with positive CT scans. The groups showed no other difference in neurological, psychological, or cognitive outcome. A complete neurological examination should be done acutely in patients with MTBI to determine more specific follow-up required.

Objective: To determine if health outcomes and demographics differ according to helmet status between persons with cycling-related traumatic brain injuries (TBI). Methods: This is a retrospective study of 128 patients admitted to the Montreal General Hospital following a TBI that occurred while cycling from 2007-2011. Information was collected from the Quebec trauma registry and the coroner's office in cases of death from cycling accidents. The independent variables collected were socio-demographic, helmet status, clinical and neurological patient information. The dependent variables evaluated were length of stay (LOS), extended Glasgow outcome scale (GOS-E), injury severity scale (ISS), discharge destination and death. Results: 25% of cyclists wore a helmet. The helmet group was older, more likely to be university educated, married and retired. Unemployment, longer intensive care unit (ICU) stay, severe intracranial bleeding and neurosurgical interventions were more common in the no helmet group. There was no significant association between the severity of the TBI, ISS scores, GOS-E or death and helmet wearing. The median age of the subjects who died was higher than those who survived. Conclusion: Cyclists without helmets were younger, less educated, single and unemployed. They had more severe TBIs on imaging, longer LOS in ICU and more neurosurgical interventions. Elderly cyclists admitted to the hospital appear to be at higher risk of dying in the event of a TBI. Les variables indépendantes recueillies étaient les données sociodémographiques, le port du casque, l'information clinique et neurologique. Les variables indépendantes étaient la durée du séjour hospitalier, le score à l'échelle de devenir de Glasgow étendue (GOS-E), le score à l'ISS (injury severity scale), la destination au moment du congé hospitalier et le décès. Résultats: Vingt-cinq pour cent des cyclistes portaient un casque. Le groupe de patients qui portaient un casque était plus âgé, plus susceptible d'avoir un niveau de scolarité universitaire, d'être marié et d'être à la retraite. Le chômage, un séjour prolongé à l'unité de soins intensifs (USI), un saignement intracrânien plus sévère et un traitement neurochirurgical étaient plus fréquemment présents dans le groupe de cyclistes qui ne portaient pas de casque. Il n'y avait pas d'association significative entre la sévérité du TC, les scores ISS, GOS-E ou le décès et le port du casque. L'âge médian des sujets qui sont décédés était plus élevé que celui des survivants. Conclusion: Les cyclistes qui ne portaient pas de casque étaient plus jeunes, moins instruits, plus fréquemment célibataires et sans emploi. Ils avaient un TC plus sévère à l'imagerie, ils ont été hospitalisés à l'USI plus longtemps et ils ont subi plus d'interventions neurochirurgicales. Le risque de décès était plus élevé chez cyclistes plus âgés qui ont été hospitalisés suite à un TC.