Introduction

If you’re an avid player of contact sports, have ever been in a road accident, or suffered from a particularly nasty fall, you might have been diagnosed with a concussion. A common injury, concussions arise from a head injury that causes the brain to rapidly shake back and forth inside the skull, causing a temporary disruption of brain function. Despite the rather frightening description, they’re usually nothing to worry about; most cases resolve on their own after a few days or weeks without causing any long-term damage to the brain. As such, a concussion is also known as a mild or minor head injury and is referred to medically as a mild traumatic brain injury (mTBI). For the person experiencing the aftermath of a concussion, however, the symptoms can feel anything but mild - particularly when they persist.^{1, 2} 

Post-concussion or post-concussive syndrome (PCS) describes the persistence of interrelated symptoms following a mild head injury, which can occur for a few weeks or months until full recovery. PCS may also develop after a sub-concussive head impact or more moderate to severe TBIs.³ 

The symptoms of PCS are usually the same as those experienced after a concussion and may involve physical, emotional, behavioural and cognitive changes like those listed below.^{2, 3} 

The severity, combination, and duration of symptoms vary from person to person. Understandably, the wide-ranging effects can be a major source of distress. This is especially true for its impact on cognition, which determines how we learn, understand, and communicate. Cognitive symptoms of PCS can therefore play a significant role in our interactions with the world around us, which might make navigating your recovery journey with optimism difficult.⁴ 

Whether you’re on the pathway to recovery after a concussion or just want to know how to support someone close to you, read on to familiarise yourself with the cognitive effects of PCS, learn when to seek support, and better understand how to aid the healing process so that you can get back to feeling like yourself as soon as possible.

Understanding the aftermath of a concussion 

Around 10-15% of concussions go on to be diagnosed as PCS - though researchers have reason to believe that this is an underestimation due to underdiagnosis and inconsistencies in how the condition is defined. Regardless, if the majority (90%) of mild head injuries heal over a short period, what makes these cases different?^{2, 3}

Although the exact underlying causes are unclear, certain factors may increase the risk of developing PCS, including:^{2, 5}

• A history of mental health conditions (e.g. depression, anxiety, bipolar disorder) 
• Other brain-related conditions (e.g. ADHD, learning difficulties)
• A history of chronic pain syndromes
• Being assigned female at birth (though this may be due to differences in the likelihood of seeking medical help)
• Being older
• Having sustained a previous head injury
• Presenting with complications to the head injury, such as bleeding inside the brain or skull (e.g. subarachnoid haemorrhage or subdural haematoma), a displacement of the brain from its centre (midline shift), or a skull fracture

Diagnosis 

To diagnose a concussion following a head injury, your doctor will likely:³ 

• Ask you about your experience of the symptoms
• Assess your level of consciousness (via the Glasgow Coma Scale)
• Issue a brain scan, e.g. a CT scan of the head, to check for any physical complications (like those mentioned above)

Notably, you don’t have to lose consciousness to experience a concussion. In fact, the severity of the injury doesn’t appear to be associated with the development of PCS, so it’s important to seek prompt medical support if you sustain a head injury that leaves you feeling confused or disoriented - even if you don’t feel it was serious.^{6, 3} 

If your symptoms persist, your doctor may then reassess your condition, for example, via a more detailed MRI scan, physical assessment, and an interview. Depending on the outcomes of these tests, you might be diagnosed with PCS. You’ll likely then be booked in for follow-up visits to track your symptoms and receive treatment and management recommendations accordingly.³ 

Recovery timeline 

Each person’s experience of PCS is unique. In most cases, however, the symptoms are at their worst one to two weeks post-injury, followed by an improvement or even resolution after one month. Most people will improve or recover within three months, provided there were no initial complications associated with the injury.² 

This 3-month recovery expectation applies even to those who have more severe symptoms at the time of diagnosis. Although rare, symptoms (in particular emotional symptoms) may linger for three to six months, or even up to a year or more for some people. These cases may be diagnosed as persistent PCS.² 

REMEMBER: Though rare, serious complications can develop in the days or even weeks following a concussion. As such, it’s important to closely monitor your condition and get in touch with your GP if your symptoms are severe or you’re not seeing any improvement 2 weeks post-injury. If you notice any new concerning symptoms or a sudden worsening of existing symptoms, immediately contact emergency services.

The science behind the cognitive symptoms

How concussions affect cognition 

Though brain scans of mild head injuries show no visible signs of the concussion (if they’re without complications), many of the symptoms of PCS are brought about by damage to the part of our nervous system responsible for controlling automatic functions such as heart rate, blood pressure and blood flow to the brain (the autonomic nervous system). Disruptions to these particular functions - in particular those causing less blood flow to the brain - explain the aforementioned symptoms such as headaches, dizziness, and becoming more easily fatigued, as well as cognitive effects like poorer concentration, attention, memory, and ‘brain fog’.^{2, 3}

Certain brain scans (like SPECT, PET, and MRI) show that in some parts of the brain - particularly areas involved in emotion and decision-making - there's less blood flow, lower energy use, and less activity after a concussion, indicating these areas aren't working as well as they should.^{2, 3}

Concussions can also cause chemical changes within the brain resulting in cell damage, which may contribute to symptoms post-injury. Whether these changes are involved in the continuation of symptoms, however, is not yet known. More research is needed to better define both the processes of injury and recovery that might influence the development and persistence of PCS.^{6, 7} 

‘Psychogenic’ factors 

‘Psychogenic pain’ is a now outdated but still popularly used term for the pain resulting from, or worsened by, psychological, emotional or behavioural factors. In addition to the above, PCS symptoms such as headaches, dizziness, sleep issues and cognitive effects are also thought to stem from, or be intensified by, associated mental health conditions such as depression, anxiety, and PTSD.^{2, 3}

In fact, persistent cognitive symptoms are thought to be mainly related to psychological factors. Supporting this theory, the previously mentioned changes observed in brain scans can also be found in these mental health conditions, and their recommended treatments (e.g. antidepressants) can improve PCS symptoms.^{2, 3}

Living with PCS 

Treatment 

As symptoms vary among people with PCS and often get better on their own for most, there’s no set treatment or cure for the condition. Managing your symptoms effectively is the main way to help you along your recovery journey.⁴

Lifestyle factors such as fatigue and stress can worsen cognitive symptoms. They also tend to be both more common and intense during this period due to the impact of PCS on life circumstances such as finances and relationships. It’s therefore even more important to be mindful of both your physical and mental wellbeing while you recover.⁴

The most effective approach to PCS management is one that:⁸

• Begins early
• Involves regular check-ins with your doctor
• Individually addresses the symptoms that are having the largest impact on your wellbeing
• Involves multiple forms of treatment in a way that works best for you e.g. a combination of recommended medications, positive physical lifestyle changes and cognitive therapies (e.g. cognitive rehabilitation) 

For cognitive symptoms, management largely involves focusing on self-care by, for example:⁹

• Getting enough good-quality sleep
• Managing stress
• Limiting alcohol as much as possible (a head injury can reduce your alcohol tolerance) 
• Being patient with yourself rather than trying to do too much too soon, both physically and mentally 
• Avoid activities that might put you at risk of another head injury for at least three weeks or until you’ve received medical clearance - especially if you play sports. (Second-impact syndrome can be very serious and repeated head injuries may put you at a higher risk of neurodegenerative diseases in later life)¹⁰

You may also be referred to a specialist for more support (see the ‘Further help’ section below).

Your healthcare provider might issue advice similar to this in the form of informational guidelines which can include strategies to address specific symptoms - much like those included below for the management of cognitive effects.⁹

Strategies for managing cognitive symptoms 

As you will have gathered, the good news is that even in cases where your symptoms last longer, they’ll still eventually resolve on their own. The even better news? There are ways in which you can support your brain as it works hard to heal itself while minimising the impact of these symptoms on your life.

Memory issues

• Use planners or digital reminders for important dates e.g. appointments
• Write yourself reminders on sticky notes placed in locations that you pass during your daily routine
• Keep a dedicated notebook for jotting down to-do lists
• Use kitchen timers as cues for cooking or other timed activities
• Designate specific spots for frequently used items to avoid misplacing them
• Set up screen-time reminder notifications on your phone to prevent cognitive overload and possible sleep disruption from overuse
• Simplify new information into smaller, manageable parts for better recall 
• Prioritise getting a good night's rest to help you function optimally

Difficulties with attention, concentration and problem-solving

• Begin tasks when your focus is strongest and take breaks as needed - remember to pay attention to your symptoms and pace yourself accordingly 
• To minimise distractions, try to eliminate background noise and seek quiet spaces for more complex tasks
• Focus on one task at a time and break large tasks into smaller, more manageable steps
• Be sure to take plenty of rest if you’re too tired to focus; alertness is key for concentration

Problems with planning and organisation

• Try to maintain a regular daily routine
• Gradually return to work or any form of sports training - if you’re able to, start part-time or at a lower intensity and try to take on less demanding tasks, to begin with; try not to push yourself too hard as taking on physical or mental strain prematurely can have a negative effect on recovery ⁴
• Simplify meal prep by using step-by-step recipes and cooking with others if possible
• Create to-do lists and set achievable daily goals, understanding that not every goal has to be met that day if you’re not feeling well enough 

Further help

If you’re struggling with your symptoms despite implementing management strategies, it’s well worth speaking to your doctor who may be able to refer you to a specialist e.g. a neurologist, neuropsychologist or neuropsychiatrist for more support. Alternatively, private services are available via the British Psychological Society website, where you can find a directory of chartered neuropsychologists.

For family and caregivers 

If you’re a family member, friend or caregiver to someone who’s experiencing PCS, fostering a supportive environment is crucial; your patience and understanding can make a considerable difference as they adjust to, and recover from, the many unexpected changes that PCS might bring.

Summary

The symptoms of, and recovery from, PCS can look different for everyone. As such, it’s best managed by an approach that addresses your specific symptoms from multiple angles. To lessen the impact of the condition’s cognitive effects such as problems with memory, concentration, and organisation, it can help to make changes in your lifestyle that benefit both your physical and mental health. Seeking support from your doctor (and potentially specialists), as well as those close to you can help you on your journey back to health. Remember that the process isn’t always linear; while there may be small setbacks along the way, remaining patient with yourself will give your body and mind the best chance of prompt recovery.