OVERVIEW

What is a concussion?

A concussion is a temporary, widespread neurological dysfunction caused by head trauma, without any evidence of structural brain damage, often accompanied by amnesia regarding the circumstances of the injury.
In simpler terms, it refers to a brain injury that results in brief symptoms like unconsciousness, slowed reactions, and often an inability to recall the incident—commonly described as "being dazed." However, CT or MRI scans show no structural damage such as brain contusions or hemorrhages.

What is post-concussion syndrome?

In layman's terms, it refers to a condition where the brain suffers trauma without direct exposure of brain tissue to the external environment, followed by persistent symptoms such as headaches, dizziness, sensitivity to light and sound, fatigue, difficulty concentrating, poor memory, sleep disturbances, anxiety, and irritability. However, neurological examinations like CT or MRI scans reveal no clear abnormalities such as brain hemorrhages, contusions, or subarachnoid bleeding.

What else is post-concussion syndrome called?

Due to the lack of definitive diagnostic criteria, it is often interchangeably referred to as post-traumatic sequelae, traumatic neurosis, or similar terms.

Are post-concussion syndrome and post-concussive syndrome the same condition?

Post-concussion syndrome was originally named based on the ICD-10 coding system (with the code T90.554). Later, with the introduction of updated national diagnostic codes, the term was replaced by post-concussive syndrome (F07.200). Essentially, it's the same condition but with a new name.

How common is post-concussion syndrome?

In the United States, its incidence is approximately 0.5%, with a rising trend in recent years.

What are the types of post-concussion syndrome?

Currently, there is no definitive classification for post-concussion syndrome.

SYMPTOMS

What are the common manifestations of post-concussion syndrome?

• Physical symptoms: Headache, nausea, vomiting, tinnitus, dizziness, blurred vision, double vision, photopsia (a sensation of seeing flashes of light), balance disorders (unsteady walking, difficulty maintaining balance with eyes closed), sensitivity to light and sound (intolerable brightness or volume that others find normal);

• Psychological symptoms: Reduced physical or mental energy, fatigue, excessive sleepiness, difficulty falling asleep, irritability, depression, anxiety, etc.;

• Cognitive symptoms: Slowed reaction times, confusion, difficulty concentrating, memory decline, etc.

Some of these symptoms typically appear immediately after the injury. Balance impairment is more likely within 24 hours, while slowed reactions, reduced learning ability, and memory decline often emerge within 48 hours.
If the impact occurs near the back of the head, brainstem symptoms may occur, such as confusion, unconsciousness (usually lasting less than 30 minutes), accompanied by sweating, pale complexion, shallow breathing, low blood pressure, and slowed heart rate.

CAUSES

Does a head injury always cause a concussion?

Not every head injury necessarily causes a concussion, as the cerebrospinal fluid surrounding the brain provides some cushioning against external forces.

How are post-concussion syndromes caused?

Post-concussion syndromes are mostly caused by external forces, such as trauma or injuries, with traffic accidents being the most common cause, followed by intense competitive sports, violence, etc.
Although the cerebrospinal fluid around the brain offers some protection against external forces, when these forces exceed the cushioning limit, they can damage normal brain tissue cells. Some may directly cause nerve cell apoptosis, while others may alter cell metabolism and cerebral blood flow, leading to increased excitability and excitotoxicity, resulting in the death of additional neurons.

Who is most likely to experience post-concussion syndromes?

Post-concussion syndromes are primarily caused by trauma, with traffic accident injuries being the leading cause. They are also commonly seen in competitive athletes, soldiers, victims of violent abuse, and epilepsy patients.

DIAGNOSIS

How to Determine if Someone Has Post-Concussion Syndrome?

• First, the patient must be diagnosed with a concussion;

• Second, symptoms such as dizziness, headaches, sensitivity to light or sound (i.e., overreacting to or being unable to tolerate normal levels of light or sound, or fearing even mild stimuli), fatigue, difficulty concentrating, perceived memory problems, sleep disturbances, anxiety, irritability (easily flying into a rage over minor issues), and in some cases, dizziness, must be present;

• Finally, these symptoms must appear immediately after the injury or within three months at the latest, and persist for more than 35 days.

What Tests Are Needed for Post-Concussion Syndrome?

The diagnosis of post-concussion syndrome is one of exclusion. Therefore, tests such as CT or MRI scans, and in some cases, a lumbar puncture for CSF analysis or brain ultrasound and EEG may be required to thoroughly rule out organic diseases before considering this diagnosis.

What Should Be Noted When Getting a CT Scan for Post-Concussion Syndrome?

• Due to radiation exposure, frequent and unnecessary CT scans are not recommended. Pregnant women should not undergo this test.

• CT scans include plain scans, contrast-enhanced scans (intravenous injection of organic iodine to highlight certain abnormalities), and angiographic scans (scanning after organ or tissue contrast administration). Therefore, those allergic to iodine or contrast agents cannot undergo enhanced or angiographic scans.

• For gastrointestinal contrast scans, fasting for 4–6 hours beforehand is usually required. Patients prone to hypoglycemia should carry candy or drinks to prevent low blood sugar.

• To avoid artifacts that may distort images and interfere with diagnosis, remove all metal objects from the area being scanned. For head scans, avoid hairpins or earrings; for abdominal scans, avoid belts or corsets.

Which Conditions Can Be Confused with Post-Concussion Syndrome? How to Differentiate Them?

Since post-concussion syndrome is primarily diagnosed based on subjective symptoms, it is often confused with post-traumatic stress disorder (PTSD). PTSD is a clinical syndrome caused by experiencing or witnessing life-threatening or traumatic events, leading to feelings of fear or helplessness. Symptoms include difficulty concentrating, sleep disturbances, explosive anger, irritability, hypervigilance, and exaggerated startle response. Experienced doctors can differentiate the two based on the cause of injury (direct physical trauma vs. significant psychological trauma) and post-injury manifestations.

TREATMENT

Which department should I visit for post-concussion syndrome?

You can seek diagnosis and treatment at the trauma surgery, neurosurgery, neurology, or emergency department.

Can post-concussion syndrome be cured?

Most concussion patients recover to their pre-injury level after treatment.

How is post-concussion syndrome treated?

First, early measures should be taken after brain injury to prevent cerebral ischemia and hypoxia caused by cerebrovascular spasms, improve cerebral blood circulation, and maintain relatively stable cerebral blood flow, which can reduce the incidence of post-concussion syndrome. After the injury, patients should rest, receive pain relief, sedation, and, if necessary, psychological therapy.
For this condition, treatment mainly focuses on symptomatic and supportive care (treating specific symptoms as they arise, such as pain relief for headaches or antiemetics for nausea) and neurotrophic therapy.

Does post-concussion syndrome require hospitalization?

Hospitalization is strongly recommended if the following symptoms occur after trauma:

• Persistent severe headache;
• Vomiting, especially frequent vomiting;
• Seizures;
• Loss of consciousness lasting more than 5 minutes;
• Persistent post-traumatic amnesia;
• Glasgow Coma Scale score below 15 or continuously decreasing within 2 hours after injury;
• Possible skull fracture;
• Pre-existing coagulation or bleeding disorders;
• Persistent abnormalities in alertness or cognitive function;
• Age over 65.

In such cases, a head CT or MRI should be performed. If the CT shows abnormalities, immediate hospitalization is required. If the results are normal, the patient may be observed in the hospital for 1–2 days. If symptoms improve without persistent memory, alertness, cognitive, or behavioral issues, and if the patient lives nearby or has continuous care, home observation may be considered.

Does post-concussion syndrome require follow-up? How?

Hospitalized patients should have their first follow-up visit at the relevant specialty department (usually neurology) 1–3 months after discharge. The follow-up plan and tests depend on the hospitalization condition. For example, if a brain CT showed abnormalities during hospitalization, a repeat CT is needed. If electrolyte imbalances were present, fasting blood tests for biochemical and electrolyte levels should be performed early in the morning.

DIET & LIFESTYLE

Why do patients with post-concussion syndrome have high energy demands? How to address it?

After a brain injury, the body enters a hypermetabolic state, meaning energy consumption and demand increase. This typically peaks within 3–5 days post-injury and begins to subside after 7 days, but the elevated metabolic rate can persist for up to 3 weeks. Therefore, active and rational nutritional supplementation is essential. The form of energy supplementation depends on the patient's condition—for example, if the patient is comatose or has swallowing difficulties, early parenteral nutrition (intravenous infusion of fat emulsions, amino acids, glucose, etc.) should be administered under medical supervision until the patient recovers enough to eat normally.

What dietary precautions should patients with post-concussion syndrome take?

The diet should follow a diversified principle: early-stage intake should consist of low-residue, high-fiber liquids with moderate protein supplementation. Avoid spicy or irritating foods.

How to care for patients with post-concussion syndrome?

• Early-stage care mainly involves mobilizing the patient's joints and muscles to prevent joint stiffness and muscle atrophy. Massage, kneading, and other techniques should be applied to paralyzed limbs to prevent atrophy.

• Passive joint exercises: Generally, exercises should proceed from the healthy side to the affected side, from top to bottom, from distal to proximal, and with gradually increasing range of motion.

• Active bed exercises: Interlock hands with the affected thumb on top, palms facing each other, or use the healthy hand to assist the weak hand in raising overhead. Perform frequent squatting and standing exercises for the lower limbs.

• Position changes and balance training: Include rolling over, moving the torso up/down/left/right, transitioning from lying to sitting, etc.

• Standing balance and gait training: Progress from standing to stepping, then walking—initially with support from both hands, then one hand, then crutches, and finally unassisted walking and stair climbing.

• Speech training: Start with simple syllables and gradually increase complexity.

• Self-care ability training: Encourage the patient to perform daily activities independently and engage in preferred tasks to foster initiative.

• Psychological care: Many patients worry excessively about their condition, and severe symptoms may lead to loss of confidence. Encouragement and companionship from loved ones are crucial.

• Care for cognitive impairment: Patients with severe brain injuries may suffer from cognitive and perceptual deficits. Provide multisensory stimulation (auditory, tactile, etc.), share past experiences, show old photos, or play familiar music to aid memory and cognitive recovery.

Can patients with post-concussion syndrome fly, engage in strenuous exercise, or travel to high-altitude areas?

Currently, there is no research on the effects of low air pressure on brain injury patients. However, studies on hyperbaric oxygen therapy for brain injury patients confirm that hemoglobin's oxygen-carrying capacity is limited. Air pressure affects dissolved oxygen levels in the body, influencing oxygen partial pressure. High pressure can also raise blood pressure and slow heart rate. Therefore, in the early stages of brain injury—when vital signs (blood pressure, heart rate) are unstable or brain cells are in a post-traumatic edema phase and highly sensitive to hypoxia—it is advisable to avoid flying, strenuous activities, or high-altitude travel until the condition stabilizes.

PREVENTION

Can Post-Concussion Syndrome Be Prevented? How to Prevent It?

Post-concussion syndrome is a chronic traumatic encephalopathy. Since it primarily manifests as neurodegenerative decline, the focus should be on early prevention, prompt detection, and timely intervention to slow disease progression.
Providing sufficient nutritional support, adequate rest, neuroprotective treatments, and psychological interventions with family care in the early stages of the condition can, to some extent, help prevent the onset of post-concussion syndrome.