The traditional teaching was that concussions resolve within weeks. Large prospective studies have revised that picture.
TRACK-TBI, an NIH-funded study that enrolled patients at 11 Level I trauma centers across the United States, followed mild TBI patients for a year after injury. At 12 months, 53 percent of mild TBI patients reported injury-related functional limitations []. These were patients whose injuries were classified as mild at presentation.
The CDC's Report to Congress on traumatic brain injury documents the same reality at the population level: for a meaningful share of people, TBI is not an event but the beginning of a long-term condition affecting cognition, mood, sleep, and daily function [].
Persistent symptoms cluster in recognizable domains: headaches and fatigue, dizziness and balance problems, sensitivity to light and noise, slowed thinking, memory and concentration difficulty, irritability, anxiety, disturbed sleep [, ]. Patients often describe the cognitive and emotional symptoms as the most disruptive and the least visible to others.
Two cautions keep this honest. First, the 53 percent figure comes from patients treated at Level I trauma centers, a group with more significant injuries on average than every person who bumps their head. Second, persistent symptoms in an individual do not by themselves establish structural brain injury, which is why evaluation combines history, examination, imaging, and laboratory findings [].
What the numbers rule out is the dismissal. When a majority of trauma-center mild TBI patients report functional limitations a year later [], lasting symptoms after a real injury are not rare, not surprising, and not evidence that the patient is imagining them.