Head Injury – Introduction and clinical features

• Introduction
• Disabling effects
• Mild disability
• Moderate to severe disability
• Prolonged coma and vegetative state

Introduction

It is estimated that in the UK each year, approximately 1 million people attend the Accident and Emergency Department following a head injury. Over 50% of people are less than 30 years old. They occur more often in males than females. About 25% are admitted. Of the 25% that are admitted, 85% will have sustained a mild head injury, 10% a moderate head injury and 5% a severe head injury. The majority of injuries result from road traffic accidents and a smaller proportion are due to domestic or industrial accidents, sporting incidents or violence.

This guidance only deals with the neuro-psychiatric and psychological aspects of brain injury.

Although the severity of brain injury is the most important predictor of outcome, there are many other determining factors, such as age. With the same degree of brain damage, old people recover tend to recover less well than young people.

Disabling Effects

The disabling effects of head injury are varied. The nature and severity of the problems and their various permutations not only depend on the nature of the injury but also on the personality of the person prior to the head injury.

Although severe physical disability following head injury is quite uncommon, focal neurological deficits can cause physical impairment of varying severity. This can result in a plethora of potential physical problems that include communication problems, swallowing difficulties, continence problems weakness or loss of coordination of the limbs.

Mild disability

The varying symptoms reported include headache, dizziness, fatigue, reduced speed of thought, poor concentration, poor memory, irritability, depression and anxiety.

Most people with mild brain injury return home within a few days and the symptoms subside over days to weeks. Cognitive deficits resolve within 3 months in the majority of people.

A very small minority have some cognitive deficit for several years after the injury. Most of the non-specific physical symptoms like headache and fatigue are assumed to result from the chronic effort required to overcome and cope with the persisting cognitive deficits.

Though apparently normal, it may be difficult for these people to hold down jobs or maintain relationships. Ignorance about the cognitive deficits and the problems arising from them leads to feelings of frustration, guilt and anxiety.

It must be emphasised, however, that these long-term residual cognitive deficits are minor and present in only a small minority of people after minor brain injury. The majority of people return to pre-injury levels of function within a period of 3 months.

Moderate to severe disability

In these people, there are persistent residual cognitive and behavioural problems leading to significant functional impairment. The resulting functional impairment varies in severity from moderate to severe according to the severity of the deficits.

Commonly reported long-term deficits include:

• Attention deficit
• Reduced concentration
• Learning and memory problems
• Impaired planning and problem solving
• Concrete thinking (inability to deal with abstract concepts)
• Lack of initiative
• Inflexibility
• Dissociation between thought and action
• Impulsivity
• Irritability and temper outbursts
• Physical aggression
• Communication problems
• Socially inappropriate behaviour and dis-inhibition
• Self-centred behaviour and egocentricity
• Changes in affect (flat affect, inappropriate emotions and mood)
• Lack of insight

Potential disabling effects of the above may include:

• Poor attention and memory may affect the ability to cope with tasks and with pressure. A previously active person may become inactive and sit for hours doing nothing. There may be a tendency to forget the risks and hazards of daily life.
• Poor concentration may lead to an inability to pursue previously enjoyed leisure activities.
• Short attention span may result in the need for lots of prompting and may affect the ability to read.
• The ability to learn and retain new skills may be affected. There may be impairment in problem solving and planning. There may be impairment of the ability to perform complex tasks that require strategic thinking, planning and error checking.
• Adapting to new and unfamiliar situations may be difficult. Abstract thinking may be impaired resulting in the inability to generalise from a single example. The ability to understand humour and indirect language may be lost.
• There may be a tendency to rely on rigid routines. Anxiety and irritability on change of routine may be a feature.
• There may be a failure to control, regulate and monitor thoughts and behaviour.
• Lack of initiative may lead to self-neglect and avoidance of routine tasks.
• Fatigue may cause the person to feel overwhelmed by multiple tasks and individual tasks may be left incomplete.
• Behavioural problems and temper outbursts may lead to interpersonal problems and an inability to interact with people. They may also have a tendency to physical aggression. Frustration may also cause irritability and a resultant preference to be left alone. This together with communication difficulties may result in social isolation.

Prolonged coma and vegetative state

A few people remain in prolonged coma (for more than two weeks) or in a persistent vegetative state. The prognosis for these people is poor but some long-term improvements are possible.

In one study about half of those people who were unaware at one month subsequently regained awareness and of those, about three quarters eventually returned home, albeit with severe residual disabilities. Only about 10% of those who recovered consciousness returned to gainful employment.

Click on the links for details of:

• Lifestyle issues – Head Injury
• Classification of brain injury severity
• The Glasgow coma score
• Other methods of assessing brain injury
• CAPE test & scoring system

Amended July 2012