Increased Risk of Stroke in Patients of Concussion: A Nationwide Cohort Study

Abstract

Long-term morbidities can develop after traumatic brain injury (TBI). Some studies have suggested that the risk of stroke is higher after TBI, but the association between concussion and stroke remains unclear. Using a national cohort, the authors analyzed the incidence of both hemorrhagic and ischemic strokes in patients with previous concussion. A representative cohort of approximately one million people was followed up for four years. Patients with new-onset concussion were identified (n = 13,652) as the concussion group. Subsequently, the incidence rates of later stroke events in the concussion group were compared to a sex-, age- and propensity score–matched comparison group (n = 13,652). The overall incidence rate of stroke in the concussion group was higher than that of the comparison group (9.63 versus 6.52 per 1000 person-years, p < 0.001). Significantly higher stroke risk was observed in the concussion group than in the comparison group (crude hazard ratio 1.48, p < 0.001; adjusted HR 1.65, p < 0.001). In the concussion group, the cumulative incidence rates of both ischemic stroke and hemorrhagic stroke were higher than those of the comparison group (8.9% vs. 5.8% and 2.7% vs. 1.6%, respectively, both p < 0.001). Concussion is an independent risk factor for both ischemic and hemorrhagic strokes. Prevention and monitoring strategies of stroke are therefore suggested for patients who have experienced concussion.

Time Course of Hemostatic Disruptions After Traumatic Brain Injury: A Systematic Review of the Literature

“…There is controversy regarding the exact nature of hemostatic disruption after TBI, and evidence exists to support the presence of both a hyper-and hypocoagulable state [2]. While the initial head injury often leads to impaired clot formation and exacerbation of hemorrhagic lesions [2,[7][8][9], TBI is also independently associated with an increased risk of venous thromboembolism [10][11][12][13] and ischemic stroke [14][15][16][17][18]. Most likely, there is a progression from early increased bleeding risk to a later prothrombotic state.…”

Does Complement-Mediated Hemostatic Disturbance Occur in Traumatic Brain Injury? A Literature Review and Observational Study Protocol

“…With regards to TBI, there are no studies that have assessed if complement plays a role in the hemostatic disturbance that is seen following injury. Based on the data provided in this review, one might instinctively suggest that any such interaction would result in increased thrombosis, and could thus explain the prothrombotic sate that is seen days to weeks following TBI [53][54][55][56][57]. However, it should be noted that the initial bleeding tendency that is seen following TBI is also believed to be due to unregulated thrombosis, culminating in a consumptive coagulopathy that leads to the exacerbation of hemorrhagic lesions [2].…”

“…Currently, there is controversy within the literature regarding the exact nature of hemostatic perturbations after TBI, and evidence exists for the presence of both a hypercoagulable and hypocoagulable state [2]. For example, while the initial head injury often leads to increased bleeding tendency and the exacerbation of hemorrhagic lesions [2,[46][47][48], TBI is also independently associated with an increased risk for venous thromboembolism [49][50][51][52] and ischemic stroke [53][54][55][56][57]. Autopsy studies have also revealed that micro-thrombosis is present in the majority patients who have died from head trauma [58].…”

A Bayesian Approach to Competing Risks Model with Masked Causes of Failure and Incomplete Failure Times

“…In this paper, we investigated the case where the data is masked and the failure time is partly interval-censored (PIC) using the Bayesian approach. We employed the Cox proportional hazards model, which is used extensively but mostly for public health studies; see, for example, Han et al [16] and Liu et al [17]. e rest of the paper is organized as follows.…”