A concussion is a form of mild traumatic brain injury (mild traumatic brain injury – mTBI) that can result from a direct blow to the head or from sudden acceleration and deceleration of the body, causing forces to be transmitted to the brain. A concussion usually causes a temporary disturbance of brain function and may affect concentration, memory, balance, sleep, mood, and overall daily functioning. Loss of consciousness is not necessary for a concussion to occur. Many patients remain fully conscious after the injury but experience headache, dizziness, confusion, or other symptoms.

Symptoms of Concussion

The symptoms of concussion vary from patient to patient. They may appear immediately after the injury or become more noticeable during the following hours or days.

Physical Symptoms

These may include:

• headache
• dizziness or vertigo
• nausea or vomiting
• unsteadiness or balance problems
• sensitivity to light
• sensitivity to sound
• blurred vision
• fatigue or reduced energy
• a sensation of pressure or heaviness in the head

Concentration, Thinking and Memory

Temporary cognitive difficulties may occur after a concussion, including:

• difficulty concentrating
• reduced attention
• difficulty remembering recent events
• slower processing of information
• reduced mental clarity
• difficulty solving problems
• difficulty making decisions

Some patients describe needing more time to think, read, or complete tasks that they previously performed easily.

Sleep Disturbances after Concussion

A concussion can significantly affect sleep.

Symptoms may include:

• difficulty falling asleep
• frequent awakenings
• daytime sleepiness
• an increased need for sleep
• reduced sleep duration
• feeling tired even after adequate sleep

Sleep quality is an important factor during the recovery process.

Mood and Behavioral Changes after Concussion

Changes in mood and behavior may also occur following a head injury.

These may include:

• irritability
• nervousness
• anxiety
• increased emotional sensitivity
• mood changes
• reduced tolerance to stress
• feelings of sadness or frustration

These symptoms may form part of the overall clinical presentation of concussion and should be assessed together with the neurological and physical symptoms.

Loss of Consciousness and Concussion

A common misconception is that a patient must lose consciousness in order to have sustained a concussion. In fact, a concussion can occur without loss of consciousness. Following the injury, the patient may experience temporary confusion, disorientation, difficulty recalling events immediately before or after the injury, dizziness, or reduced mental clarity. The presence or absence of loss of consciousness is only one of the factors considered during the neurological assessment.

Diagnosis of Concussion

The diagnosis of concussion is primarily clinical and is based on:

• the mechanism of injury
• symptoms that developed following the injury
• neurological examination
• assessment of memory and concentration
• assessment of balance and coordination
• the presence or absence of other neurological signs

Monitoring how symptoms develop during the hours and days following the injury is also particularly important.

CT and MRI after Concussion

A concussion primarily involves a functional disturbance of the brain, and therefore a Computed Tomography (CT) scan or conventional Magnetic Resonance Imaging (MRI) may be normal. A brain CT scan is not used to “confirm” a simple concussion. It is performed when the clinical presentation indicates a need to exclude more serious traumatic injuries, such as intracranial hemorrhage or a skull fracture. Brain MRI may be considered in selected cases, particularly when symptoms persist, the clinical presentation is atypical, or another brain injury is suspected. The need for brain imaging is determined individually following medical assessment.

Signs Requiring Immediate Medical Assessment after a Head Injury

Following a head injury, certain symptoms may indicate a more serious brain injury and require immediate emergency medical assessment.

These may include:

• a headache that significantly worsens
• repeated vomiting
• increasing drowsiness or difficulty waking
• worsening confusion or disorientation
• seizures
• weakness or numbness in a limb
• speech disturbance
• significant problems with walking or coordination
• unequal pupil size
• loss of consciousness or deterioration in the level of consciousness
• unusual or marked changes in behavior

The development of these symptoms should not automatically be attributed to a simple concussion.

Treatment and Management of Concussion

The management of concussion depends on the severity of symptoms, the patient’s age, daily activities, and individual needs. During the first few days after the injury, a short period of relative physical and cognitive rest is generally recommended. This does not necessarily mean complete inactivity, prolonged bed rest, or avoiding all activities until every symptom has disappeared. Instead, following the initial period of relative rest, a gradual return to light daily activities is encouraged, provided that these activities do not cause a significant or prolonged worsening of symptoms.

Return to Work, School and Daily Activities

The return to normal daily activities should be gradual and individualized.

Depending on the symptoms, temporary adjustments may include:

• taking more frequent breaks
• reducing working or studying hours
• limiting demanding cognitive activities
• adjusting screen use if it worsens symptoms
• avoiding activities that carry a risk of another head injury
• gradually increasing physical activity

Light aerobic activity may be gradually introduced when tolerated. A full return to sports or activities involving a risk of collision or falling requires greater caution and should follow an appropriate return-to-activity protocol.

Medication after Concussion

There is no specific medication that “cures” a concussion. In some cases, symptomatic treatment may be used for problems such as headache, nausea, sleep disturbances, or other persistent symptoms. Treatment should be individualized, taking into consideration the time elapsed since the injury, the patient’s symptoms, and their overall medical history.

Persistent Symptoms after Concussion

In most patients, symptoms gradually improve. In some cases, however, they may persist for a longer period of time.

Persistent symptoms may include:

• headache
• dizziness
• balance problems
• fatigue
• difficulty concentrating
• memory problems
• sensitivity to light or sound
• sleep disturbances
• anxiety or mood changes

When symptoms persist, reassessment is important in order to identify factors contributing to their persistence and to develop a more targeted treatment plan. Depending on the clinical presentation, management may include vestibular rehabilitation, headache treatment, assessment of sleep disturbances, cognitive support, or other specialized interventions.

Repeated Concussions

Avoiding a second head injury before full recovery is particularly important. Repeated head injuries, particularly in athletes or individuals who are regularly exposed to impacts to the head, may be associated with an increased risk of long-term neurological problems. Chronic traumatic encephalopathy (CTE) has primarily been associated with long-term exposure to repetitive head impacts and traumatic brain injuries. However, it should not be considered an inevitable consequence of one or a few isolated concussions.

Prognosis after Concussion

The prognosis following an uncomplicated concussion is generally very good. Most patients experience a gradual improvement in symptoms and return to their usual daily activities. Recovery time varies between individuals and may be influenced by the severity of the initial symptoms, previous concussions, migraine, sleep problems, and other individual factors.

Neurological Follow-Up after Concussion

Neurological reassessment is particularly important when symptoms are severe, worsen, persist for a prolonged period, or interfere with the patient’s return to work, school, or normal daily activities. Early diagnosis and appropriate management of concussion, combined with a gradual return to activity and appropriate follow-up, can contribute to a safe and effective recovery following a head injury.