Arithmetic performance of children with cerebral palsy: The influence of cognitive and motor factors Maaike van Rooijen a, *, Ludo Verhoeven a , Dirk-Wouter Smits b,c , Marjolijn Ketelaar b,c , Jules G. Becher d,e , Bert Steenbergen a a Radboud University Nijmegen, Behavioural Science Institute, PO Box 9104, 6500 HE Nijmegen, The Netherlands b Rudolf Magnus Institute of Neuroscience and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and Rehabilitation Center De Hoogstraat, PO Box 85500, 3508 GA Utrecht, The Netherlands c NetChild, Network for Childhood Disability Research in the Netherlands, Utrecht, The Netherlands d Department of Rehabilitation Medicine, VU University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands e EMGO Institute for Health and Care Research, VU University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands 1. Introduction Cerebral palsy (CP) is characterized by an atypical development of movement and posture which is the result of non- progressive disturbances in the developing brain. Next to compromised motor control, CP is often accompanied by additional problems related to sensation, perception, behavior, communication and cognition (Rosenbaum et al., 2007). Although the motor performance and the deviations therein have been described in some detail, knowledge about the cognitive skills and scholastic performance in CP is limited (Straub & Obrzut, 2009). This is remarkable given the high prevalence of learning problems related to arithmetic (26%) and reading (19%) in children with hemiplegic CP (Frampton, Yude, & Goodman, 1998). Numbers and arithmetic are an important aspect of our society. People are confronted with numerical information in everyday activities, such as looking up a page in a book or paying for groceries (Butterworth, 2005). The study of the Research in Developmental Disabilities 33 (2012) 530–537 ARTICLE INFO Article history: Received 3 October 2011 Received in revised form 25 October 2011 Accepted 25 October 2011 Available online Keywords: Cerebral palsy Arithmetic Motor skills Cognition ABSTRACT Children diagnosed with cerebral palsy (CP) often show difficulties in arithmetic compared to their typically developing peers. The present study explores whether cognitive and motor variables are related to arithmetic performance of a large group of primary school children with CP. More specifically, the relative influence of non-verbal intelligence, working memory, word decoding capacities, gross- and fine motor skills on arithmetic performance is examined using structural equation modeling. One-hundred sixteen primary school children with a formal diagnosis of CP participated (76 males, M = 7; 3 years, SD = 3 months). In agreement with previous studies our results showed that the cognitive and motor predictors were all positively correlated to each other. Furthermore, in the cognitive model, non-verbal intelligence and word decoding were related to arithmetic in primary school. Our combined model (that included both motor and cognitive variables) showed that word decoding and fine motor skills were the strongest predictors of arithmetic performance. To conclude, this study was the first to show the influence of word decoding and fine motor skills on arithmetic performance of children with CP. ß 2011 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +31 0 24 3615812; fax: +31 0 24 3616211. E-mail addresses: M.vanRooijen@pwo.ru.nl (M. van Rooijen), L.Verhoeven@pwo.ru.nl (L. Verhoeven), D.Smits@dehoogstraat.nl (D.-W. Smits), M.Ketelaar@dehoogstraat.nl (M. Ketelaar), JG.Becher@vumc.nl (J.G. Becher), B.Steenbergen@pwo.ru.nl (B. Steenbergen). Contents lists available at SciVerse ScienceDirect Research in Developmental Disabilities 0891-4222/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ridd.2011.10.020