It is difficult to identify children most likely to experience persistent neurological symptoms after suffering a concussion, though doing so would have important clinical applications.
A systematic literature review recently examined 15 studies that attempted to find predictive factors for persistent symptoms. The review, conducted by Roger Zemek, MD, of Children’s Hospital of Eastern Ontario and colleagues, found no consistent pattern in the results. The study authors wrote:
“Minimal, and at times contradictory evidence exists to associate clinically available factors with eventual development of persistent concussion symptoms in children.”
Due to this lack of a method to predict which children will recover rapidly and which will experience long-term symptoms, doctors must continue to recommend conservative management, followed by a gradual return to normal activity level, for all children with concussion. They suggest that a “multicenter prospective study” should be conducted to determine potential factors that could identify children at high risk of prolonged symptoms.
Zemek and colleagues found that existing studies on childhood concussion recovery were heterogeneous, making meta-analysis difficult. Of 561 published studies, all but 15 were thrown out of the systematic literature review for failing to provide data on all of the following clinical factors: age, medical history, comorbidities, pre-existing medication use, mechanism of injury, and initial presence and severity of symptoms. Zemek and colleagues also noted the large array of instruments used for measuring symptoms—in the 15 studies included in the review, ten different assessment tools were used.
Despite these issues, Zemek and colleagues suggest that some clues to potential predictors can be found. Two of the larger prospective studies concluded that “the risk for developing persistent concussion symptoms was increased in older children with a history of loss of consciousness and either headache or nausea/vomiting.” Several smaller studies also noted that initial dizziness could be predictive of prolonged recovery. The researchers concluded that no “clear conclusions” could be reached on factors potentially associated with safely resuming normal activities such as sports and school.
Despite these findings, scientists continue to search for a tool for predicting prognosis of pediatric brain injuries.
Zemek R, et al. Prognosticators of persistent symptoms following pediatric concussion: a systematic review. JAMA Pediatrics 2013; 10(1001): 216.