Secondary Brain Injuries: What Happens Inside the Brain After a Severe TBI

Brain injuries cause a variety of symptoms and conditions that can profoundly affect an individual’s cognitive, motor, and neurological function. Some of the common conditions associated with severe TBI, include:

Conditions Associated with Severe TBI

Aphasia

Aphasia refers to a person’s ability to communicate effectively, comprehend language, or express thoughts verbally or in writing. Individuals with aphasia may have trouble speaking, understanding spoken or written language, finding words, or forming coherent sentences, leading to challenges in communication and social interaction.¹

Apraxia

Apraxia is a motor disorder characterized by difficulty in executing purposeful movements or coordinating voluntary actions despite having the muscle strength and function to perform those actions. People with apraxia may struggle to perform skilled movements or gestures, leading to challenges in activities of daily living, use tools, or perform tasks that require coordination.²

Seizures

Seizures are abnormal electrical activity in the brain that cause sudden, involuntary movements, altered consciousness, sensory disturbances, or behavioral changes. Seizures may vary in severity and presentation, impacting an individual’s alertness, motor control, sensation, cognition, and behavior, with potential implications for safety, daily functioning, and quality of life.³

Ataxia

Ataxia impairs coordination, balance, and muscle control, leading to unsteady gait, slurred speech, tremors, and difficulties in voluntary movements. Ataxia can affect an individual’s mobility, fine motor skills, hand-eye coordination, and posture. It can affect activities such as walking, writing or being able to perform precise movements.⁴

Brain Stem Injury

Brain Stem Injury involves damage to the lower part of the brain that controls basic life functions, such as breathing, heart rate, consciousness, and sleep-wake cycles. Brain stem injuries can result in profound neurological deficits, including coma, locked-in syndrome, respiratory difficulties, cranial nerve impairments, and alterations and vital functions critical for survival.⁵

Cerebral Infarct (Stroke)

Cerebral Infarct is a stroke, and it occurs when the blood flow to a specific part of the brain is blocked, leading to tissue damage, cellular death, and neurological deficits. Strokes can cause focal neurological impairments, such as weakness, numbness, speech difficulties, cognitive deficits, and sensory disturbances, depending on the location and extent of the stroke.⁶

Coma

Coma is a profound unconsciousness in which individuals are unresponsive to external stimuli, unable to wake, and lack awareness of their surroundings. Individuals in a coma show no purposeful responses, eye opening, or meaningful interactions, and require intensive medical management and monitoring of vital functions.⁷

Permanent Vegetative State

Permanent Vegetative State is a profound neurological injury characterized by no meaningful awareness or conscious responsiveness. People in a permanent vegetative state have reflexive behaviors, minimal voluntary movements, lack of higher brain functions, and require long-term care and support for basic needs.⁸

These secondary conditions often develop alongside primary diagnoses such as diffuse axonal injury or intracranial hematoma. For a full breakdown of these terms, see our guide to TBI medical terminology.