Concussion, mild brain injury and trauma

This book focuses on patients who have sustained a concussion and, therefore, possibly transient mild injuries to the brain.

“Concussion” describes the immediate temporary symptoms that may occur following the impact of a force that causes the head and the brain inside to shake rapidly and intensively. Depending on the severity of the force, an external trauma to the structures of the head, neck or shoulders is likely. Hippocrates described concussion in 2400AD and medically it was first defined by a Persian doctor as an abnormal physiological state rather than a brain injury. The terms “mild brain injury” and “concussion” seem to be used interchangeably because many of the symptoms overlap.

The core clusters of the post-concussion syndrome are:

• • physical: headache, vertigo and dizziness, malaise and fatigue, sensitivity to light and noise, sleep problems;
• • emotional: trauma, stress, irritability, emotional lability, anxiety, PTSD, depression, anger;
• • cognitive: concentration and memory problems, reduced mental processing ability;
• • other: tinnitus, lower tolerance of alcohol, preoccupation with the injury including irrational fear of brain damage, secondary illness behaviours including avoidance.

The symptoms may develop within a two-week period following the event and are normally expected to resolve within three to six months. This affects about 30-80% of people, but a substantial proportion of cases develop difficulties that can even last years.

Some symptoms, such as cognitive disturbances, may resolve early on, whereas others, such as headaches or vertigo, may persist beyond the onset event. The number of repeated concussions (e.g., in contact sports) is an important factor that influences the severity and timeline of these problems.

Pre-injury and comorbid genetic, psychological and psychiatric presentations - especially depression, anxiety and PTSD, poor motivation and inappropriate coping strategies - play a most significant role in the maintenance of the condition. Further risk factors include illness behaviours, alcohol or substance misuse and the pursuit of compensation claims. Such added vulnerabilities and complexities affect the resilience or hardiness of individuals facing and recovering from such symptoms.

Prolonged post-concussion symptoms may therefore have multiple aetiologies. The spectrum spans from the purely organic to the purely psychological over the course of time following the trauma event (Figure 1.1). As outlined throughout this book, the clinician must be aware of predispositions, onset and setting factors as well as secondary and reinforcing variables.

More severe cases of concussion can lead to mechanical injury or deformation of the neural tissue caused by the rotation or deceleration forces acting on the head and neck. Diffuse axonal injury, associated with the tearing, stretching, compressing or shearing of axons, and the swelling of brain tissue are common organic changes in concussion. Metabolic and molecular neurophysiological changes ultimately contribute to the physiological vulnerability generated by this condition. It is, thus, not surprising that people

Figure l.l Evolving multifaceted post-concussion syndrome.

with enduring concussion symptoms experience information-processing difficulties, which are essentially caused by disturbances of neurotransmitter flow, the processing of chemical messages and their conversion into electrical potentials. The traumatised person may become aware of these abnormalities in the form of cognitive under-performance, particularly in the areas of attention, short-term memory, mental speed and flexibility. Even though such neurocognitive problems may be sub-clinical on testing, they can heighten emotional problems nevertheless. At this point, the syndrome goes “full circle,” as hypervigilance and hyperarousal exacerbate the organic strain as well as subjective and psychogenic sensitivity. It may not be surprising, therefore, that headaches can be a consequence as well as a trigger within this whole conundrum.

Headaches are the key symptom of concussion. Persistent posttraumatic headaches are also associated with a multifaceted expression of experiences that were perceived to have developed after a traumatic onset.

The term “mild brain trauma” has emerged in clinical practice to aid the paradigm shift from the concept of an organic brain lesion that requires medical interventions towards an understanding of its biopsychosocial nature requiring proactive life-management. The term “mild brain trauma” is used throughout this book in favour of “mild brain injury” in order to emphasise the complex and multifaceted nature of the condition. Furthermore, the use of trauma crucially highlights the significance of experiences, which may have deeply shattered the identity of an individual, either pre- and/or post-injury. Whilst the scientific literature about mild traumatic brain injury and concussion underpins this work, the focus on brain trauma here emphasises the psychological and holistic reformulation that informs the therapeutic approach introduced in this book.