The signs and symptoms of a traumatic brain injury (TBI) can be subtle. Symptoms of a TBI may not appear until days or weeks following the injury or may even be missed as people may look fine even though they may act or feel differently.
If any of the following symptoms appear suddenly or worsen over time following a TBI, especially within the first 24 hours after the injury, people should see a medical professional on an emergency basis.
Common Signs and Symptoms of a TBI
People should seek immediate medical attention if they experience any of the following symptoms:
- loss of or change in consciousness anywhere from a few seconds to a few hours
- decreased level of consciousness, i.e., hard to awaken
- convulsions or seizures
- unequal dilation in the pupils of the eyes or double vision
- clear fluids draining from the nose or ears
- nausea and vomiting
- new neurologic deficit, i.e., slurred speech; weakness of arms, legs, or face; loss of balance
Other common symptoms that should be monitored include:
- Light-headedness, dizziness, vertigo, or loss of balance or coordination
- Sensory problems:
- blurred vision, seeing stars, or eyes that tire easily
- ringing in ears
- bad taste in mouth
- loss of sense of smell or taste
- Sensitivity to lights, sounds, or distractions;
- Mood changes or swings. agitation (feeling sad or angry for no reason), combativeness, or other unuaual behavior
- Feelings of depression or anxiety
- Fatigue or drowsiness; a lack of energy or motivation
- Changes in sleep patterns (sleeping a lot more or having a difficult time falling or staying awake), inability to wake up from sleep
- Problems remembering, concentrating, or making decisions
- Slowness in thinking, speaking, acting, or reading
Headache, dizziness, confusion, and fatigue tend to start immediately after an injury, but resolve over time. Emotional symptoms such as frustration and irritability tend to develop later on during the recovery period. Many of the signs and symptoms can be easily missed as people may appear healthy even though they act or feel different. Many of the symptoms overlap with other conditions, such as depression or sleep disorders.
In some cases, repeated blows to the head can cause chronic traumatic encephalopathy (CTE) – a progressive neurological disorder associated with a variety of symptoms, including cognition and communication problems, motor disorders, problems with impulse control and depression, confusion, and irritability. CTE occurs in those with extraordinary exposure to multiple blows to the head and as a delayed consequence after many years. Studies of retired boxers have shown that repeated blows to the head can cause a number of issues, including memory problems, tremors, and lack of coordination and dementia. Recent studies have demonstrated rare cases of CTE in other sports with repetitive mild head impacts (e.g., soccer, wrestling, football, and rugby). A single, severe TBI also may lead to a disorder called post-traumatic dementia (PTD), which may be progressive and share some features with CTE. Studies assessing patterns among large populations of people with TBI indicate that moderate or severe TBI in early or mid-life may be associated with increased risk of dementia later in life.2
Children: TBI Signs and Symptoms
Children with a brain injury can have the same symptoms as adults, but it is often harder for them to let others know how they feel. Call your child's doctor if they have had a blow to the head and you notice any of these symptoms:
- Changes in eating or nurseing habits
- Persistent crying, irritability, or crankiness; inability to be consoled
- Changes in ability to pay attention; lack of interest in a favorite toy or activity
- Changes in the way the child plays
- Changes in sleep patterns
- Loss of skill, such as toilet training
- Loss of balance or unsteady walking
- Tiredness or listlessness
- Changes in performance at school
Effects on Consciousness
A TBI can cause problems with arousal, consciousness, awareness, alertness, and responsiveness. Generally, there are four abnormal states that can result from a severe TBI:
- Brain death
The lack of measurable brain function and activity after an extended period of time is called brain death and may be confirmed by studies that show no blood flow to the brain.
A person in a coma is totally unconscious, unaware, and unable to respond to external stimuli such as pain or light. Coma generally lasts a few days or weeks after which an individual may regain consciousness, die, or move into a vegetative state.
- Vegetative state
A result of widespread damage to the brain, people in a vegetative state are unconscious and unaware of their surroundings. However, they can have periods of unresponsive alertness and may groan, move, or show reflex responses. If this state lasts longer than a few weeks it is referred to as a persistent vegetative state.
- Minimally conscious state
People with severely altered consciousness who still display some evidence of self-awareness or awareness of one's environment (such as following simple commands, yes/no responses).2