Chapter 17 Clinical neuropsychology in rehabilitation

Introduction

The field of clinical psychology that is concerned with neurological disorders has now become known as clinical neuropsychology. Although in the UK there is no formal definition of a clinical neuropsychologist, developments are currently under way which will result in the establishment of professional qualifications in neuropsychology. In practice, clinical neuropsychologists are clinical psychologists registered with the UK Health Professions Council, with specialist experience and expertise in the field of neuropsychology, and often title themselves ‘neuropsychologists’.

Whilst clinical neuropsychology is only now emerging as an independent area of professional psychology, it has a history as long as that of modern scientific psychology. From the end of the last century, psychologists have investigated the behavioural effects of lesions to the brain, not only for the light this study could shed on the operation of normal brain processes but also from a genuine desire to alleviate the distress and disability resulting from neurological injury and disease.

Clinical neuropsychology was given an inevitable stimulus by the two world wars of the twentieth century, the study of missile wounds proving a fertile ground for the association of specific psychological deficits with defined regions of the brain. This research carried significant implications for a debate, inherited from nineteenth-century neurology which occupied at least the first half of the twentieth century, about the nature of the representation of psychological functions in the brain. Put rather crudely, the opposite poles of the debate argued either for the highly localized and specific representation of functions, or for a mass action view whereby psychological functions are distributed across the entire cerebral cortex. This debate has never been finally resolved, but the position that most clinical neuropsychologists now adopt is one of relative localization: that many functions are localized to regions of the cortex but cannot be more finely localized. This is often qualified by a tertiary model of cortical function in that the primary cortex, subserving sensation and discrete motor control, is quite highly localized; the secondary cortex, subserving perception and the control of movements, is rather less localized; and the tertiary or association cortex, supporting all higher-level functions, is much less clearly localized. However, current developments in connectionist theory, which point to radical models for neuropsychological processes, are starting to modify these views. For a fuller discussion, see Beaumont (1996, 2008) and for illustrations see Code et al. (1996, 2001).

Only within the last three decades has rehabilitation become an active focus of interest for clinical neuropsychology. Before that time clinicians saw their role as primarily one of assessment, either in the context of diagnosis or of vocational adjustment. The widespread introduction of modern neuroimaging greatly diminished the contribution of neuropsychology to diagnosis and as a result the embarrassing period of neglect of rehabilitation, both in terms of research and of practical interventions, came to an end. Rehabilitation is now the central focus of neuropsychology and assessment is understood, quite properly, as only a significant stage in the planning of rehabilitation and management.

Approaches in clinical neuropsychology

Clinical psychological management involves detailed assessment, which is discussed prior to reviewing interventions.

Neuropsychological assessment

Neuropsychological assessment should be understood as the essential precursor to the planning and implementation of rehabilitation. It is not an end in itself, but is designed to provide a description in psychological terms of the client’s current state with respect to the clinical problems being addressed. Such a description should provide an insight into the processes which are no longer functioning normally in that individual, and so provide the rationale upon which the intervention is based. Subsequent reassessments allow progress to be monitored and interventions to be adjusted, according to the client’s current state. Rehabilitation should never proceed without an adequate assessment having been undertaken.

There are historically three traditions in clinical neuropsychology. The first, most eloquently expressed in the work of Luria (see Christensen, 1974), is based upon behavioural neurology, although it is a much more sophisticated extension of it. The approach is based upon the presentation of simple tasks, selected in a coherent way from a wide variety of tests available, which any normal individual can be expected successfully to complete without difficulty. Any failure on the task is a pathological sign and the pattern of these signs, in skilled hands, allows a psychological description to be built up.

The second tradition, associated with work in North America, is a psychometric battery-based approach, most notably expressed in the Halstead–Reitan and Luria Nebraska Neuropsychological Test Batteries (any apparent theoretical link with the approach of Luria is quite illusory). In this approach a standard, and often large, battery of tests is administered to all clients and the resulting descriptions arise out of a psychometric analysis of the pattern of test scores.

The third approach, the normative individual-centred approach, has been dominant in Europe, particularly in the UK, but is now the leading international methodology. It relies upon the use of specific tests, associated wherever possible with adequate normative standardization, which are selected to investigate hypotheses about the client’s deficits; testing these hypotheses permits the psychological description to be built up. Whilst requiring a high level of expertise, this neuropsychological detective work can be more efficient and provide a finer degree of analysis, when applied intelligently. In practice, many neuropsychologists employ a mixture of these approaches, although the normative individual-centred approach is generally becoming more dominant.