Symptoms and Causes of Traumatic Brain Injury

Traumatic brain injury (TBI) encompasses a spectrum of neurological disturbances resulting from external mechanical force applied to the head or body, leading to temporary or permanent disruption of normal brain function. Clinical manifestations vary widely depending on injury severity, location, and mechanism—ranging from mild concussion with transient confusion and headache to severe TBI characterized by prolonged unconsciousness, seizures, focal neurological deficits, or coma.

Common symptoms include persistent headache, dizziness, nausea, fatigue, impaired concentration, memory lapses, sleep disturbances, emotional lability, and sensitivity to light or sound. In moderate to severe cases, patients may exhibit slurred speech, limb weakness, loss of coordination, visual changes, or altered mental status—including agitation, disorientation, or diminished responsiveness. Delayed complications such as post-traumatic epilepsy, cognitive decline, or neuropsychiatric disorders—including depression, anxiety, and impulsivity—may emerge weeks to months after the initial event.

The primary causes of TBI reflect diverse mechanisms of injury: falls—especially among older adults and young children—are the most frequent etiology globally. Motor vehicle collisions—including car, motorcycle, bicycle, and pedestrian accidents—constitute another major cause, often associated with higher rates of moderate-to-severe injury. Other contributors include sports-related impacts, blast injuries in military settings, physical assault, and non-accidental trauma such as abusive head trauma in infants.

Pathophysiologically, TBI involves both primary injury—the immediate structural damage from impact—and secondary injury processes—including cerebral edema, intracranial hemorrhage, ischemia, excitotoxicity, and neuroinflammation—that evolve over hours to days and significantly influence clinical outcomes. Early recognition, prompt neuroimaging (typically non-contrast CT for acute evaluation), and multidisciplinary management—including neurocritical care, rehabilitation, and long-term neuropsychological support—are essential to optimizing recovery and minimizing disability.