How Can Neuropsychological Evidence Help Assess the Functional Impact of Brain Injury?

In a brain injury claim, identifying a cognitive difficulty is only part of the picture. For the individual concerned, and often for the litigation, the more important question is what that difficulty means in everyday life.

Problems with memory, attention, processing speed or executive functioning may affect employment, independence, relationships and the ability to manage complex daily tasks. In other cases, measurable cognitive weaknesses may have relatively little practical impact because the individual is able to compensate effectively.

A clinical neuropsychologist can help examine the relationship between cognitive findings and real-world functioning. This involves more than administering cognitive tests. Neuropsychological evidence brings together formal assessment, clinical history, information about pre-injury functioning and evidence about how the person now manages the demands of everyday life.

What is meant by functional impact?

In this context, functional impact refers to the practical consequences of cognitive difficulties. Two people can demonstrate apparently similar weaknesses on cognitive testing but experience very different consequences.

For one person, a mild difficulty with divided attention may have little noticeable effect on daily life. For someone whose occupation requires them to monitor several complex sources of information simultaneously, make rapid decisions and move repeatedly between competing tasks, the same difficulty may be much more significant.

Similarly, a memory weakness may be manageable where routines are predictable and effective compensatory strategies can be used, but considerably more disabling where somebody must retain large amounts of unfamiliar information throughout the day.

The significance of a cognitive finding therefore depends partly upon the demands placed upon that particular individual.

Why cognitive test scores are not the whole story

Standardised neuropsychological tests allow different aspects of cognitive functioning to be examined systematically.

Depending upon the questions arising in the case, assessment might consider:

• attention and concentration;

• processing speed;

• learning and memory;

• language;

• visuospatial functioning; and

• executive abilities such as planning, organisation, problem-solving and cognitive flexibility.

These findings are important, but a test score does not provide a direct measure of how well somebody will manage their job, household or wider life. Most neuropsychological tests are completed in a relatively quiet and structured environment. Instructions are clear. Tasks are presented individually. Distractions are limited. The person often knows precisely what they are being asked to do. Everyday life can be quite different.

At work, somebody may need to remember information while being interrupted, prioritise competing demands, plan several steps ahead, notice errors and maintain performance for many hours.

A person who performs reasonably well during a structured assessment may still have difficulties when those cognitive demands are combined. The clinical interpretation therefore involves considering test results alongside evidence of everyday functioning.

The importance of pre-injury functioning

Functional impact is usually concerned with change. It is therefore important to consider what the individual was capable of doing before the injury.

A person who previously managed a demanding professional role, complex finances, family responsibilities and a busy social life may notice the effects of a relatively subtle cognitive change much more readily than somebody whose previous activities placed different demands upon those abilities.

This is particularly relevant for individuals with a high level of pre-injury cognitive functioning.

Their performance after injury may remain within broadly average limits when compared with the population as a whole, while nevertheless representing a meaningful reduction from their own previous level.

The opposite can also occur. A cognitive weakness identified after an injury may reflect a longstanding difficulty rather than a new change.

Information about educational attainment, occupational history, previous independence and earlier cognitive or developmental difficulties can therefore provide important context.

Return to work after brain injury

Employment is one area in which the functional consequences of cognitive change may become particularly apparent. Returning to work involves much more than demonstrating that individual cognitive abilities remain intact.

A role may require somebody to:

• retain new information;

• switch rapidly between tasks;

• deal with interruptions;

• organise their workload independently;

• identify priorities;

• solve unfamiliar problems;

• work accurately under time pressure;

• communicate effectively;

• sustain concentration throughout the working day; and

• manage fatigue while maintaining performance.

The cognitive demands of jobs vary enormously. A difficulty that has little effect in one occupational setting may be highly significant in another.

It can therefore be useful to understand the actual requirements of the person's pre-injury role and what happened during any attempted return to work.

Some people return successfully but require reduced hours, altered responsibilities or additional strategies. Others can perform individual components of their previous job but struggle to manage the combined demands of the role over a full working week.

Neuropsychological evidence can help place those difficulties in the context of the cognitive findings.

Cognitive fatigue and stamina

One issue that can be difficult to capture in a conventional assessment is cognitive stamina.

Someone may be able to perform well for a limited period but find that sustained cognitive effort becomes increasingly difficult.

They may report needing more breaks, taking longer to complete tasks or being unable to maintain the same level of activity throughout the day. Fatigue itself can have many contributing factors, including neurological, psychological, physical and sleep-related influences.

A neuropsychological assessment does not reduce these issues to a single test result.

Instead, the expert can consider the pattern of cognitive findings, the person's history, clinical evidence and information about functioning over longer periods.

This can be particularly relevant where the individual has returned to some activities but cannot sustain their previous workload.

Memory difficulties in everyday life

Memory is one of the most commonly reported concerns following brain injury.

Formal testing can help establish whether there is evidence of difficulty with learning or retaining information, but the practical consequences vary considerably.

In everyday life, memory problems might affect:

• remembering appointments;

• retaining information from conversations;

• learning new procedures;

• remembering instructions;

• keeping track of tasks;

• managing medication;

• recalling information needed at work; or

• remembering what has already been completed.

People also vary in their ability to compensate.

Diaries, electronic reminders, written routines and other external aids can substantially reduce the practical effect of some memory difficulties. The relevant question is therefore not simply whether memory performance is reduced, but how any weakness interacts with the demands of the person's life and the strategies available to them.

Executive functioning and complex everyday tasks

Executive functions include abilities involved in planning, organising, monitoring behaviour, solving problems and adapting when circumstances change.

Difficulties in these areas can sometimes be less immediately obvious than a marked memory impairment.

An individual may communicate fluently, perform familiar activities and appear relatively unaffected during a brief interaction, while experiencing problems when required to organise complex or unfamiliar tasks independently.

Possible consequences can include:

• difficulty prioritising;

• becoming overwhelmed by competing demands;

• poor organisation;

• problems completing multi-stage tasks;

• difficulty adapting when a plan changes;

• reduced awareness of errors; or

• needing greater structure or prompting from other people.

These are also areas where information about real-world functioning can be particularly valuable.

Formal assessment may identify cognitive weaknesses, but evidence about how somebody manages complex activities helps establish their practical significance.

Independence does not necessarily mean an absence of difficulty

Functional outcome is not always adequately described by asking whether somebody is independent. A person may continue to live independently, drive, work or manage their own affairs while having to invest considerably more time and effort than they did previously. They may rely heavily upon routines, technology or assistance from family members.

Alternatively, somebody may appear independent because another person has gradually taken responsibility for particular tasks. Understanding how an activity is achieved can therefore sometimes be as important as establishing whether it is achieved at all. This is particularly relevant when assessing subtle cognitive changes.

The question may not be whether an individual remains capable of performing an activity in some form, but whether there has been a meaningful alteration in the way they function.

The role of collateral information

The person's own account is an important part of a neuropsychological assessment, but other sources of information can sometimes provide additional context.

Depending upon the case, this might include information from:

• a spouse or other family member;

• an employer;

• a case manager;

• occupational therapy;

• rehabilitation professionals;

• treating clinicians; or

• contemporaneous records.

This does not mean that collateral accounts are automatically more reliable than the individual's own report. Different people observe functioning in different situations and may have different perspectives.

The neuropsychologist considers those sources alongside one another and alongside the objective assessment findings. Where several independent sources describe a similar change in functioning, that may be clinically informative. Where accounts differ, understanding the reason for the discrepancy can also be useful.

Functional difficulties can have more than one cause

Cognitive functioning after brain injury does not exist separately from the rest of the person's health.

Pain, fatigue, sleep disturbance, medication, depression, anxiety and post-traumatic stress symptoms can all affect everyday cognitive efficiency. Someone may also have physical limitations that make previously straightforward activities more demanding.

The functional difficulties seen after an injury may therefore reflect several interacting factors.

The role of the neuropsychologist is not necessarily to assign every difficulty to a single cause. Instead, neuropsychological assessment can help identify the cognitive component of the presentation and consider it within the wider clinical context.

This is particularly important in complex cases, where neurological, psychological and physical factors may all contribute to the individual's overall level of functioning.

Functional impact after mild traumatic brain injury

Questions about everyday functioning can be particularly important where cognitive symptoms persist following mild traumatic brain injury.

The reported difficulties may be relatively subtle: reduced concentration, forgetfulness, slower information processing, difficulty multitasking or reduced mental stamina.

These symptoms can nevertheless be important where the person's previous activities were cognitively demanding.

Neuropsychological assessment can help determine whether there is objective evidence of cognitive difficulty and consider the findings alongside the person's wider clinical presentation and everyday functioning.

It can also help distinguish between demonstrating a cognitive weakness and determining the practical significance of that weakness.

Functional impact in clinical negligence cases

Similar questions can arise in clinical negligence claims.

Where an alleged neurological injury has occurred following delayed treatment, surgery, stroke, hypoxic injury or another medical event, the medical evidence may address the nature and mechanism of the injury. The neuropsychological evidence can contribute to understanding its cognitive consequences.

This may involve considering whether there has been a change in cognitive functioning, how substantial any change is and what it means for employment, independence and everyday life.

The precise contribution will depend upon the issues in the individual case and the questions falling within the neuropsychologist's expertise.

Neuropsychology and rehabilitation

Understanding functional impact can also help identify areas in which rehabilitation or compensatory strategies may be useful.

For some people, the objective is restoration of impaired cognitive abilities.

For others, the emphasis may be upon learning ways to work around continuing difficulties.

Strategies might include greater use of external memory aids, changes to routines, environmental modifications, pacing or approaches designed to reduce the cognitive demands of particular activities.

The appropriateness of any recommendation depends upon the individual findings and may involve professionals from several disciplines.

Occupational therapists, speech and language therapists, rehabilitation physicians, psychologists, case managers and vocational rehabilitation specialists may all contribute to different aspects of the person's recovery and functioning.

Neuropsychological evidence is therefore often one component of a wider rehabilitation picture rather than a substitute for the expertise of those other professionals.

How does neuropsychology differ from an occupational assessment?

There can be some overlap in the questions considered by clinical neuropsychologists and other rehabilitation professionals, but the disciplines bring different expertise. The clinical neuropsychologist's particular focus is the relationship between brain function, cognition, behaviour and emotion.

Formal cognitive assessment can help identify the nature and pattern of cognitive strengths and weaknesses and place reported functional problems within that context. An occupational therapist may examine activities and functional performance in greater detail, including how somebody manages tasks within their actual environment.

In some cases, the two forms of evidence are particularly complementary.

Neuropsychology may help explain why a particular activity is difficult, while occupational evidence may demonstrate how that difficulty manifests itself in practice.

Prognosis and changing functional demands

Functional outcome is not necessarily static.

Cognitive recovery may occur over time, particularly during the earlier stages following neurological injury. Rehabilitation, adaptation and compensatory strategies can also improve day-to-day functioning even where some cognitive weakness remains. At the same time, changes in circumstances may expose difficulties that were previously less apparent.

A person may initially function well within a highly supported environment but encounter greater difficulty when they return to employment or resume more complex responsibilities.

Prognosis therefore involves more than predicting whether a cognitive test score will improve.

The expert may need to consider the likely course of the cognitive difficulties, the person's capacity to compensate and the demands they are likely to face in the future.

Functional impact and capacity are different questions

Cognitive difficulties can sometimes raise questions about capacity, but functional impairment should not be confused with a lack of capacity. Someone may require help with complex tasks while remaining able to make the relevant decisions for themselves.

Conversely, particular cognitive difficulties may have implications for a specific decision even where the person functions independently in many other areas.

Capacity is decision-specific and requires separate consideration.

Where litigation capacity or another particular capacity is in issue, that should therefore be considered as a distinct question rather than inferred simply from the person's level of everyday functioning.

Our article on capacity to conduct litigation considers this issue in more detail

The expert's role remains independent

In civil litigation, the clinical neuropsychologist's role is to provide an objective opinion on matters falling within their expertise.

CPR Part 35 provides that an expert's overriding duty is to help the court, and Practice Direction 35 requires expert evidence to be independent and uninfluenced by the pressures of litigation. That applies equally when considering functional impact.

The assessment may provide evidence that reported difficulties are consistent with identified cognitive impairment and have substantial practical consequences.

It may also indicate that the extent of functional difficulty is not fully explained by the cognitive findings, or that several different factors are contributing.

Sometimes the available evidence does not permit a precise conclusion.

A balanced neuropsychological opinion should reflect those possibilities rather than beginning with an assumption about the extent of disability.

Looking beyond the test scores

The purpose of a medico-legal neuropsychological assessment is not simply to produce a table of cognitive test results. The more useful question is what those findings mean for the individual.

A difficulty with memory, attention or executive functioning can have very different consequences depending upon previous ability, occupational demands, support, compensatory strategies and the wider clinical picture.

By combining formal cognitive assessment with information about the person's history and everyday functioning, neuropsychological evidence can help clarify whether an identified cognitive change has meaningful consequences and how those consequences are likely to affect work, independence and daily life.

That can provide an important part of the wider expert evidence in a brain injury claim.

Dr Vikk Hunkin provides independent clinical neuropsychology expert-witness assessments for solicitors acting for claimants and defendants in personal injury and clinical negligence proceedings across England and Wales.

For further information about direct instructions and areas of expertise, see our clinical neuropsychology expert-witness services for solicitors.