What Is Post-Concussion Syndrome?

Post-concussion syndrome (PCS) describes a collection of physical, emotional, cognitive (thinking-related), and behavioral symptoms that persist for several weeks to months after sustaining a mild traumatic brain injury (concussion).

Symptoms of PCS are highly variable and can negatively affect how a person feels and functions in their everyday life. The diagnosis of PCS is often tricky and should be made by an experienced healthcare professional.

Once diagnosed, treatment is focused on managing symptoms. This is done through various interventions like early education, rest, cognitive behavioral therapy, and/or taking one or more medications.

Post-Concussion Syndrome Symptoms

Symptoms associated with a concussion usually develop immediately or within hours to days after a brain injury. In most cases, these symptoms ease within a couple of weeks.

For those with PCS, however, concussion-related symptoms may persist for months, or even a year or more. While not an exhaustive list, symptoms associated with PCS include the following.

Headaches

The headache of PCS typically resembles that of a tension-type headache, migraine, or some combination, and develops in over 60% of patients with a mild head injury.

Factors that may increase the risk for developing a headache after a concussion include:

• A previous history of headache
• A less severe injury
• Female sex
• Presence of other psychiatric disorders

Dizziness

Patients with PCS may report dizziness, lightheadedness, or vertigo. Some patients also exhibit symptoms of vestibular migraine.

Anxiety, depression, or post-traumatic stress disorder (which are also symptoms of PCS) may also contribute to a patient’s dizziness.

Sleep Disturbances

Sleep disturbances associated with post-concussion syndrome include:

• Insomnia, including problems falling asleep and waking up too early in the morning
• Excessive daytime sleepiness
• Increased sleep need
• Circadian sleep-wake rhythm disorders
• Abnormal behaviors/movements like dream reenactment, sleep talking, sleep-related enuresis (involuntary urination), and sleep-related bruxism (teeth grinding)
• Sleep apnea

Cognitive and Emotional Changes

Impaired memory and concentration are seen in PCS and are most likely to occur right after the brain injury. Patients may also report fatigue, feeling groggy or foggy, and have trouble thinking clearly or paying attention.

Personality changes, irritability, intolerance to stress, emotional blunting (apathy, emotional numbness), disinhibition (not suppressing inappropriate or unwanted behavior), or mood swings may also occur.

Other

A variety of other somatic (physical) symptoms have been reported with PCS including blurry vision or double vision, restlessness, increased susceptibility to alcohol, light and noise sensitivity, tinnitus (ringing in the ears), nausea, and neck pain.

Causes

Concussions usually follow a direct blow to the head, like from a fall, assault, or sports impact injury (e.g., football, hockey, soccer, lacrosse).

Concussions can also occur from rapid acceleration-deceleration movements of the head, such as from a blast-related injury or whiplash injury (e.g., motor vehicle accident).

It’s not clear why some people develop PCS after a concussion and others do not. Experts suspect the answer likely stems from a combination of physical and psychological factors.

Physical Factors

Some of the abnormal brain processes that result from a concussion and potentially contribute to PCS development include:

• Inflammation within the brain
• Injury to nerve fibers
• Changes in brain glucose metabolism
• Decreased cerebral blood flow
• Rapid release of neurotransmitters throughout the brain

Psychological Factors

Psychological factors before, during, and after a brain injury may also contribute to PCS manifestation, duration, and/or severity.

As an example, research suggests that those with PCS are more likely to have various psychiatric ailments like depression, anxiety, and PTSD than people with head injuries who did not develop persistent PCS.

Being female and experiencing amnesia or a loss of consciousness from your brain injury may also make you more likely to have a higher number of PCS symptoms.

Finally, factors like malingering and/or poor effort on cognitive testing have been proposed as possible explanations for why a person’s PCS symptoms may be inconsistent with the severity of their brain injury.

Diagnosis

Post-concussive syndrome is a clinical diagnosis. This means that there is no single blood or imaging test that can definitively say whether a patient has the condition.

Instead, to make the diagnosis, doctors rely on a patient’s medical history and criteria set forth in various professional society publications like the International Statistical Classification of Diseases and Related Health Problems (ICD-10) or the Diagnostic and Statistical Manual of Mental Disorders (DSM).

For example, using the ICD-10’s criteria, a patient may be diagnosed with PCS if they have a history of a traumatic brain injury and exhibit at least three of the following eight symptoms:

• Headache
• Dizziness
• Fatigue
• Irritability
• Insomnia
• Concentration difficulty
• Memory difficulty
• Intolerance of stress, emotion, or alcohol

During the diagnostic process, your doctor may order one or more imaging tests like brain magnetic resonance imaging (MRI) or an advanced MRI technique called diffusion tensor (DT) imaging. These tests can help rule out alternative diagnoses (e.g., tumor or stroke) and/or detect more serious brain pathologies (e.g., brain bleed).

Treatment

The treatment of PCS focuses on managing a patient’s symptoms.

PCS therapies that your doctor may suggest and tailor to your individual care include:

• Reassurance: Early education about the symptoms and providing support, comfort, and assurance that your symptoms will resolve
• Cognitive rest: Limiting activities that require a high brain metabolic demand like attending crowded events or social gatherings where there is a lot of visual/hearing stimuli
• Physical rest: Avoiding activities that put you at risk for a repeated concussion or that worsen your current symptoms
• Cognitive behavioral therapy (CBT): Therapy to help reduce stress and manage symptoms like anxiety, depression, and insomnia
• Vestibular rehabilitation: Exercises to help manage dizziness, vertigo, and imbalance
• Medications: Drugs that target a specific symptom like selective serotonin reuptake inhibitors (SSRIs) for depression/anxiety or melatonin for sleep disturbances
• Graded exercise program: Introducing aerobic exercise training in stages to help improve cerebral blood flow after a concussion

Prognosis

Most patients with PCS recover by three months—although, for some, the symptoms may persist for a year or longer (called persistent PCS). There is a lack of high-quality studies that might help predict who is more likely to take longer to recover.

If you have any physical factors or life circumstances that may negatively impact your ability to heal from PCS, please reach out to your healthcare team. You may need extra strategies or assistance (e.g., guidance from a social worker) to ensure that you don’t get behind in your recovery process.

Summary

Post-concussion syndrome can develop after recovery from a concussion and last for weeks, months, or years after the initial injury. Symptoms may be physical (headache, dizziness, sleep problems), cognitive (difficulty with memory or concentration), or behavioral (irritability, intolerance). They are highly variable and affect daily life.

Treatment is focused on managing the symptoms through education, psychological therapy, or medications.

A Word From Verywell

If you or a loved one is suffering from post-concussion syndrome, remain patient and hopeful as your brain heals. Recovery from PCS is a gradual, stepwise process—symptoms may ebb and flow, and you can still have bad days, even when you are feeling and functioning like yourself again.

During this trying time, reach out to loved ones, compassionate friends, or a support group for comfort, guidance, and/or assistance. Remember to be gentle to yourself and listen to your intuition. Rest when needed, take steps to reduce stress in your life, and stick to your treatment plan, which may require frequent tweaks along the way.