What is post-concussive syndrome (PCS)?

From the Guidelines

Post concussion syndrome (PCS) is a complex condition characterized by persistent symptoms beyond the expected recovery period, typically lasting more than 4 weeks after a head injury, and is defined by a combination of physical, cognitive, and emotional or behavioral symptoms. According to the study published in JAMA Network Open in 2021 1, the symptoms of PCS can include headache, dizziness, blurred vision, sleep disturbance, neck pain, fatigue, slowed thinking, difficulties with attention, concentration, memory, or executive functions, and changed emotional responsivity.

Key Characteristics of PCS

• The condition is estimated to affect up to 34% to 44% of patients with concussion or mild traumatic brain injury (mTBI) at 3 to 6 months after injury, and between 5% and 20% experience symptoms at 12 months after injury 1.
• The true incidence of mTBI is estimated to be around 600 per 100 000 inhabitants per year, with the yearly incidence in Denmark being 457 per 100 000 inhabitants 1.
• PCS is likely the result of temporary neurometabolic disruptions, inflammation, and altered neurotransmitter function rather than structural brain damage, which explains why conventional imaging often appears normal despite persistent symptoms.

Treatment and Management

• Active management and treatment of PPCS is recommended, both through individual disciplines targeting specific problems and through interdisciplinary rehabilitation 1.
• Treatment is primarily symptom-based, with rest and gradual return to activities being fundamental.
• For headaches, acetaminophen (500-1000mg every 6 hours as needed) is preferred over NSAIDs due to bleeding risk.
• Sleep disturbances may be addressed with melatonin (3-5mg before bedtime) or short-term use of medications like trazodone (25-50mg at bedtime).
• Physical therapy can help with balance and vestibular issues, while cognitive rehabilitation may benefit those with persistent cognitive problems.
• Patients should avoid alcohol, maintain good sleep hygiene, and gradually increase physical and mental activities without triggering symptoms.

Prognosis

• Most cases of PCS resolve within 3 months, but some patients experience symptoms for a year or longer.
• The condition can have a significant impact on a patient's quality of life, and early intervention and treatment are crucial to improve outcomes.

From the Research

Definition and Characteristics of Post Concussion Syndrome

• Post concussion syndrome (PCS) is a complex and heterogeneous condition characterized by a set of signs and symptoms in somatic, cognitive, and emotional domains 2.
• The syndrome is comprised of symptoms such as headaches, dizziness, cognitive difficulties, somatosensory issues, and a variety of other symptoms with varying durations 3.
• The most commonly reported post concussion symptoms are headache, dizziness, decreased concentration, memory problems, irritability, fatigue, visual disturbances, sensitivity to noise, judgment problems, depression, and anxiety 4.

Diagnosis and Treatment of Post Concussion Syndrome

• Clinical management of PCS may require a multidisciplinary approach, including a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators 5.
• Treatment for PCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies 5.
• A guided prescription of aerobic exercise is beneficial for early- and late-phase disorders after concussion 2.
• Successful treatment requires thoughtful differential diagnosis, including consideration of comorbid and premorbid conditions and other possible contributing factors 2.

Risk Factors and Prognosis of Post Concussion Syndrome

• Risk factors for development of a late-phase disorder include a high early symptom burden, a history of multiple concussions, psychiatric conditions, longer duration of unconsciousness or amnesia, and younger age 2.
• The clinical consequences of concussion may be best conceptualized as two multidimensional disorders: early-phase posttraumatic disorder and late-phase posttraumatic disorder 2.
• While symptoms of concussion resolve in most individuals over days to weeks, a minority of individuals experience symptoms persisting months to years 2.