September 22, 2023

Takeaways highlights

  1. Postconcussion syndrome and functional overlay often coexist, presenting unique challenges in diagnosis and treatment.
  2. Functional overlay in postconcussion syndrome isn’t just psychological or “all in the patient’s head,” nor is it entirely explained by a neurological condition.
  3. Comprehensive neurological and psychiatric assessment is crucial to diagnose functional overlay in postconcussion syndrome.
  4. Managing such patients often requires a multidisciplinary approach, incorporating the expertise of neurologists, psychiatrists, psychologists, and physiotherapists.
  5. Further research is needed to better understand the mechanisms underlying the overlap of postconcussion syndrome and functional overlay, with the aim to improve diagnostic strategies and treatment interventions.
  6. Addressing the stigma associated with functional disorders, including in the context of postconcussion syndrome, is crucial for improving patient care and outcomes.


Traumatic brain injury (TBI), particularly concussions, often leads to a diverse array of symptoms that persist long after the initial injury, a condition referred to as postconcussion syndrome (PCS). These symptoms range from headaches and dizziness to cognitive deficits and mood disturbances. However, it’s not uncommon for a significant proportion of patients with PCS to exhibit additional symptoms that don’t align entirely with the expected pathology of a concussion. This phenomenon, referred to as functional overlay, adds a layer of complexity to the clinical picture of PCS.

Functional overlay is the coexistence of symptoms originating from a recognized organic disease (in this case, PCS) and additional symptoms that can’t be fully accounted for by the organic disease itself. These functional symptoms are real and distressing to patients, although they are not caused by structural damage to the body. Instead, they are thought to arise from disruptions in the normal functioning of the nervous system and are influenced by a variety of psychological and social factors.

The interaction between PCS and functional overlay brings into sharp focus the intricate interplay between neurology and psychiatry. Understanding this relationship is crucial for the accurate diagnosis and effective management of patients navigating the challenging journey of recovery post concussion. The following sections of this article will delve deeper into this complex clinical landscape, aiming to provide valuable insights into the intricate and often elusive world of PCS and functional overlay.

Understanding Postconcussion Syndrome

Postconcussion syndrome (PCS) is a complex disorder with an array of symptoms that may persist for weeks, months, or even a year or more after a concussion. A concussion, also known as a mild traumatic brain injury, typically results from a blow to the head or a violent shaking of the head and body. Despite the term “mild,” the impact on the individual can be quite severe and life-altering, particularly when PCS develops.

Symptoms of PCS can be quite diverse, ranging from physical manifestations like headaches and dizziness to cognitive impairments such as difficulty with concentration and memory. Emotional and behavioral changes, including irritability, depressive symptoms, and anxiety, are also common. Disturbed sleep, fatigue, noise and light sensitivity, and balance problems may also occur.

The onset of PCS symptoms usually occurs soon after the injury, but in some cases, they may not be noticed until days or even weeks later, when the individual attempts to return to regular activities. The variable and delayed onset of symptoms, along with the broad range of manifestations, often makes the diagnosis of PCS a challenge.

In many cases, symptoms of PCS are self-limiting and most individuals recover with time. However, in some cases, symptoms may persist, leading to significant disability and reduction in quality of life. This is particularly true when PCS is complicated by a functional overlay, a concept we explore further in the next sections.

Functional Overlay in Postconcussion Syndrome

‘Functional overlay’ is a term used to describe a situation where an individual’s symptoms cannot be fully explained by an underlying organic or neurological condition. In other words, while there may be a real and identifiable neurological issue present – such as the effects of a concussion – the severity, duration, or range of the individual’s symptoms seem to go beyond what would typically be expected from that condition alone.

In the context of postconcussion syndrome (PCS), functional overlay often refers to additional symptoms or deficits that cannot be solely attributed to the concussion itself. These might include physical symptoms like excessive fatigue, pain, visual disturbances, or balance issues, as well as cognitive, emotional, or behavioral changes, such as memory problems, difficulty concentrating, irritability, anxiety, or depression.

The concept of functional overlay acknowledges the intricate interaction between physical health and mental well-being. It recognizes that our psychological state can significantly impact our experience of physical symptoms and vice versa. This interplay is particularly relevant in conditions like PCS, where the event that caused the concussion may have also been traumatic or stressful, potentially contributing to emotional distress or psychological conditions.

Understanding and identifying functional overlay in PCS is crucial because it may significantly impact the patient’s recovery and treatment approach. The presence of a functional overlay often calls for a more holistic, multi-disciplinary approach to care that addresses not just the physical, but also the psychological aspects of the patient’s health. In the next section, we will discuss this further, looking specifically at the implications for treatment and management.

Link Between Postconcussion Syndrome and Functional Overlay

The relationship between postconcussion syndrome (PCS) and functional overlay is complex and multifactorial. Various factors may contribute to the development of functional symptoms after a concussion. Some of these include the individual’s psychological vulnerability, their response to stress, a history of previous functional disorders, and other personal or environmental factors.

Psychological vulnerability can significantly influence how an individual perceives and copes with symptoms after a concussion. For example, individuals with a tendency toward anxiety or hypervigilance may be more prone to noticing and misinterpreting normal physiological sensations or minor post-concussion symptoms, leading to heightened distress and potentially exacerbating these symptoms.

Stress also plays a crucial role in PCS and functional overlay. The event causing the concussion is often stressful or traumatic, which can lead to heightened physiological arousal, increased perception of symptoms, and a greater risk of developing both PCS and functional symptoms. Moreover, the stress associated with coping with PCS, such as disruptions to work, education, or social activities, may also contribute to the development or exacerbation of functional symptoms.

Another key factor is the history of functional disorders. Individuals who have previously experienced functional disorders may be more likely to develop functional symptoms after a concussion. This may be due to an increased vulnerability to the physiological effects of stress or a heightened awareness of physical sensations.

Finally, other personal and environmental factors may contribute to the development of functional overlay in PCS. These could include personal beliefs and expectations about health and illness, the responses of healthcare providers, family members, or colleagues to the individual’s symptoms, or access to appropriate care and support.

Given the multitude of potential factors involved, it is important to remember that the development of functional overlay in PCS is usually not due to any single factor, but rather a combination of several interacting factors. Understanding these factors can help in identifying individuals at risk and providing appropriate management. In the following section, we will discuss the implications of functional overlay in PCS for treatment and management.

Diagnostic Challenges in Postconcussion Syndrome with Functional Overlay

Diagnosing functional overlay in postconcussion syndrome can be a challenging task. The symptoms of postconcussion syndrome, such as headaches, dizziness, and cognitive difficulties, can be non-specific and may also be seen in various other neurological and psychological conditions. This makes it essential to conduct a thorough and careful neurological and psychiatric assessment.

The first step in the diagnostic process is to ensure that the symptoms are not entirely accounted for by another medical condition. This can be particularly difficult in the context of postconcussion syndrome, as some of the symptoms may be due to the concussion itself or other associated injuries. Therefore, it requires a careful examination of the patient’s medical history, a thorough physical and neurological examination, and appropriate investigations to rule out other potential causes of the symptoms.

Psychiatric assessment is equally important in these cases. Pre-existing psychiatric conditions, such as depression or anxiety disorders, can exacerbate or mimic the symptoms of postconcussion syndrome and can also contribute to the development of functional symptoms. Therefore, identifying and addressing these conditions is crucial.

Additionally, assessing for the presence of functional symptoms can be challenging. Functional symptoms are not just “all in the patient’s head,” but neither are they entirely explained by a neurological condition. This can make them difficult to identify and may require the use of specific examination techniques or tests to demonstrate their functional nature.

Moreover, the diagnosis of functional overlay requires a positive identification of functional symptoms, rather than simply ruling out other causes. This means that the clinician needs to demonstrate features that are typical of functional symptoms and inconsistent with a purely neurological cause. This often requires a good understanding of both neurological and psychiatric conditions, and the ability to communicate effectively with the patient about their symptoms.

Given these challenges, it is often beneficial to involve a multidisciplinary team in the assessment and management of these patients, including neurologists, psychiatrists, psychologists, and physiotherapists. This allows for a comprehensive assessment and ensures that all aspects of the patient’s condition are appropriately managed.

Management Strategies for Postconcussion Syndrome with Functional Overlay

The management of patients with postconcussion syndrome and functional overlay can be complex and often requires a multifaceted approach. The main goal of treatment is to reduce symptoms, improve function, and enhance the quality of life for the patient.

Treatment for postconcussion syndrome typically includes symptomatic management for headaches, dizziness, and cognitive difficulties. This might involve medication, physiotherapy for balance issues, or cognitive rehabilitation for problems with memory or concentration.

When it comes to managing the functional overlay, a biopsychosocial model is typically adopted. This model recognises that biological, psychological, and social factors all play a role in the development and persistence of functional symptoms. Therefore, treatment often involves a combination of physical rehabilitation, psychological therapy, and social support.

Physical rehabilitation focuses on improving functional ability through physical and occupational therapy. The specific techniques used will depend on the nature of the functional symptoms. For example, in the case of functional motor symptoms, physiotherapy might focus on retraining movement patterns and improving physical fitness.

Cognitive behavioural therapy (CBT) is a type of psychological therapy that has been found to be effective in the treatment of functional neurological symptoms. CBT can help patients to understand and change the thoughts, feelings, and behaviours that may contribute to their symptoms.

Social support is also crucial. Living with postconcussion syndrome and functional overlay can be challenging and can often lead to feelings of isolation or frustration. Support from family, friends, and support groups can help to alleviate these feelings and provide practical assistance.

Involvement of a multidisciplinary team, including neurologists, psychiatrists, psychologists, and physiotherapists, can be beneficial in ensuring a comprehensive approach to treatment. Each professional can bring their own unique expertise to the management plan, ensuring that all aspects of the patient’s condition are addressed.

Finally, it’s important to remember that each patient’s journey with postconcussion syndrome and functional overlay is unique. Therefore, management strategies should be individualised to meet each patient’s specific needs and circumstances. The aim should always be to empower the patient, supporting them in their recovery and helping them to regain control over their symptoms and their life.

Clinical Case Study: Unraveling the Complexity of Postconcussion Syndrome with Functional Overlay

Let’s consider the case of Mr. A, a 38-year-old man who was involved in a significant motor vehicle accident where he sustained a mild traumatic brain injury. He was initially managed in the emergency department and discharged after a brief observation period.

A few weeks after the accident, Mr. A started experiencing persistent headaches, dizziness, and difficulties with concentration and memory – classic symptoms of postconcussion syndrome. However, alongside these symptoms, he also developed a pronounced limp on his right leg, which was inconsistent with his initial injuries and the subsequent medical investigations.

The limp was characterised by a sudden onset without a precipitating event and varied in severity and frequency. Interestingly, the limp was absent during an unnoticed examination, suggesting a functional component to the presentation.

Given the co-occurrence of postconcussion syndrome and an unusual gait pattern, a potential functional overlay was considered. The diagnostic process involved a thorough neurological examination, psychiatric assessment, and targeted investigations to rule out any other potential causes.

Mr. A was managed by a multidisciplinary team comprising a neurologist, psychiatrist, psychologist, and physiotherapist. His treatment plan included medication for postconcussion symptoms, physical therapy for his limp, and cognitive-behavioral therapy to address the functional overlay and associated psychological stressors. Social support was also mobilised, including family counselling and connecting him to a local support group.

Over time, with appropriate and focused intervention, Mr. A’s symptoms improved significantly. His headaches and dizziness became less frequent, his concentration improved, and his limp resolved completely. His case serves as a reminder of the importance of considering a functional overlay when managing patients with postconcussion syndrome. It also highlights the need for a comprehensive and multidisciplinary approach to management to achieve the best possible outcome.

Conclusion: Deciphering the Complexity of Postconcussion Syndrome with Functional Overlay

In conclusion, managing patients with postconcussion syndrome, where there is a suspected or confirmed functional overlay, presents unique challenges and complexities. The interplay of neurological and psychological factors in these cases necessitates a multidisciplinary approach that brings together expertise from various medical specialties. It underscores the importance of comprehensive clinical evaluations, patient-centered communication, and individualized treatment plans.

While we continue to gain insights into the mechanisms of postconcussion syndrome and functional disorders, there is still much we do not understand about the overlap between these conditions. The development of functional symptoms in the aftermath of a concussion is likely multifactorial, involving a complex interplay of biological, psychological, and social factors. Understanding these factors in greater depth will be crucial for improving our diagnostic strategies and therapeutic interventions.

Furthermore, the stigma associated with functional disorders, including in the context of postconcussion syndrome, is a significant barrier to care that needs to be addressed. There is a need for greater awareness and understanding of these conditions among healthcare professionals and the wider public.

As we continue to delve deeper into the complexities of postconcussion syndrome with functional overlay, it is our hope that further research will help shed more light on this intriguing overlap, leading to better outcomes for our patients. This article underscores the significance of this topic in the realm of neurology and emphasises our continued commitment to enhancing patient care and improving quality of life for those living with postconcussion syndrome and functional overlay.

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