Development of a test battery (NPM-X) for neuropsychological and neuromotor examination of children with developmental disabilities or mental retardation. A theoretical and clinical study.

Biological and behavioural diagnosis often do not provide information on functional competence. This is, however, of utmost importance in planning services as well as in research on treatment effects for children with developmental disorders. For school-aged children neuropsychological assessment has proved its value in this respect. For children of chronological age (CA) below 5-7 with specific developmental disabilities, and for children with severe mental retardation there has been a lack of applicable test batteries. This thesis presents a new test battery for neuropsychological and neuromotor examination, NPM-X, for these two groups of children. The first part of the thesis reviews available medical and psychological tests and assessment procedures with respect to applicability and relevance for neuropsychological assessment to children with mental retardation and mental age (MA) below 7. The second part describes the theoretical background and the content of the new test battery. The methodology for testing these children, who due to their age and/or their developmental disabilities often co-operate poorly, is described. Scoring categories, specifically developed to enable a detailed and differentiated description of the child, are presented. Because of the instability of the behavioural function in early age as well as in cases of severe disability, the scoring system records both the child's optimal functional capacity and inconsistencies in behaviour. For the purpose of planning treatment and training according to the child's resources as well as dysfunctions, two different functional profiles are provided. In the normative functional profile the child's functional level is compared to normal expectations for the child's CA, and in the ideographic functional profile the child's function in each area is compared to the child's average functional level. In the third part of the thesis the reliability results are presented and discussed. A pair of trained M.D.s, or psychology or special education Ph.D.s examined 110 children in a blind design. The study showed satisfactory interrater and test-retest reliability. In the fourth part current validation theory is reviewed before content and construct validity for the test battery is discussed. A concurrent criterion validation study is presented as well. Assessments available in the psychological and psychiatric records (PPR) of 35 children with CA below 7 were compared to test results obtained with NPM-X. The comparison showed high agreement in areas of function assessed both by PPR and NPM-X. In addition, NPM-X provided more information about the child's functional capacity, of relevance for the diagnostic appraisal as well as for the treatment of the child. It is concluded that a reliable and valid test battery for neuropsychological and neuromotor developmental assessment has showed its applicability and clinical utility for children with specific developmental disabilities and CA < 7 and for children with general developmental disabilities up to CA 12-13 but with MA < 7.