Abstract
Background: There is a growing body of evidence that under-performance in neuropsychological assessments is common in cases of claims for compensation, and disproportionately so among the less severely head injured. There is also evidence that neuropsychologists are not good at detecting such under-performance using standard instruments, and other sources of clinically relevant information can be overlooked. Even when assessment is correctly broad-based, evidence of the diagnostic validity of extraneous information is lacking, and further, many authors suggest a reluctance of clinicians to diagnose malingering. It is now clear that all assessments of cognitive functioning in compensation claims should include specialised procedures for the detection of underperformance, and, since such procedures tend to be of low sensitivity, several methods of detection should be employed in any assessment. Specialised procedures are few, and based on even fewer principles, which it is assumed are not known to the naive malingerer. In the current information revolution, this assumption can only become less tenable. It is therefore important to develop new techniques and enhance the sensitivity of existing ones. Furthermore, many existing tests, though widely recommended, have little normative or validating data. The Present Study was designed to provide some guiding data from local populations for a battery of tests of under-performance, and to test the diagnostic validity of a new and relatively untested dimension of an existing test: response latency in a computerised forced-choice recognition test. Methodology: Four groups will be formed, with in excess of 20 participants in each: 1. Patients with minor head injuries (MHI) complaining of post-concussional symptoms (PCS). 2. Uninjured participants (“Normals”) 3. Patients with severe head injuries and documented cognitive impairment (“Disabled”). 4. Uninjured participants encouraged to simulate the effects of head injury on the tests (Simulators) Groups will be compared using one-way analyses of variance for each score dimension of the test battery (maximum 6 comparisons) using the Bonferroni correction for multiple comparisons. Participants will be tested on a battery of tests, including a measure of response latency in one of the tests, and it is hypothesised that the simulators will perform worse on the tests than all other groups, while those with PCS will not differ from normals on the tests, and will not score lower than the Disabled group. Approval has been obtained from the Local Research Ethics Committee of the Mid-Sussex NHS Trust. Participants will be recruited from staff at the Princess Royal Hospital, Haywards Heath, patients recorded with head injury at the A&E department at the Princess Royal, patients given neuropsychological assessments at Hurstwood Park Neurological Centre, and attenders of Headway Hurstwood Park day centre, Newick.