Neuropsychological differentiation of subnormal arithmetic abilities in children

For the neuropsychological diagnosis of a Specific disorder of arithmetic s kills the standard is defined worldwide by the diagnostic guidelines of the two major classification systems of psychiatric disorders, the ICD-10 and the DSM-IV, both of which use the discrepancy criterion as the key feature of the diagnosis. It becomes clear that following such guidelines can only mean an extensive diagnostic assessment of patients with subnormal arithmet ic abilities, including the social and previous medical history followed by the exclusion of a present disorder or disability, often necessitating lab oratory, neuroimaging and neurophysiological tests. In the neuropsychologic al diagnosis of a Specific disorder of arithmetical skills we found a stepw ise approach including previously obtained test results to be most practica l and economical. The assessment instruments such as intelligence tests, ne uropsychological test batteries, academic achievement tests, specific neuro psychological tests, test batteries for arithmetic abilities or error analy sis are discussed. An overview of case studies in the literature is given; however, the overwhelming majority of case reports on patients with arithme tic disabilities are casuistics of adult patients with an acquired loss of arithmetic abilities. The importance of a differentiated neuropsychological diagnosis is demonstrated by four of our own cases: of borderline deficien t intelligence, a combined disorder of academic skills, congenital brain dy sfunction, and a specific disorder of arithmetic skills. Especially the new quality in assessing arithmetic abilities with the NUCALC battery is demon strated; diagnostic and therapeutic consequences are discussed.