Speech and oral motor profile after childhood hemispherectomy Frédérique Liégeois a,b, * , Angela T. Morgan a,b,1 , Lorna H. Stewart c , J. Helen Cross d , Adam P. Vogel e , Faraneh Vargha-Khadem a a Developmental Cognitive Neuroscience Unit, UCL Institute of Child Health, London, UK b Harrison Research Centre, The Children’s Trust, Tadworth, UK c UCL Research Department of Clinical, Educational, and Health Psychology, London, UK d Neurosciences Unit, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK e Centre for Neuroscience, University of Melbourne, Australia article info Article history: Accepted 8 December 2009 Available online 21 January 2010 Keywords: Hemispherectomy Speech Dysarthria Plasticity abstract Hemispherectomy (disconnection or removal of an entire cerebral hemisphere) is a rare surgical proce- dure used for the relief of drug-resistant epilepsy in children. After hemispherectomy, contralateral hemi- plegia persists whereas gross expressive and receptive language functions can be remarkably spared. Motor speech deficits have rarely been examined systematically, thus limiting the accuracy of postoper- ative prognosis. We describe the speech profiles of hemispherectomized participants characterizing their intelligibility, articulation, phonological speech errors, dysarthric features, and execution and sequencing of orofacial speech and non-speech movements. Thirteen participants who had undergone hemispherec- tomy (six left, seven right; nine with congenital, four with acquired hemiplegia; operated between four months and 13 years) were investigated. Results showed that all participants were intelligible but showed a mild dysarthric profile characterized by neuromuscular asymmetry and reduced quality and coordination of movements, features that are characteristic of adult-onset unilateral upper motor neuron dysarthria, flaccid-ataxic variant. In addition, one left and four right hemispherectomy cases presented with impaired production of speech and non-speech sequences. No participant showed evidence of ver- bal or oral dyspraxia. It is concluded that mild dysarthria is persistent after left or right hemispherectomy, irrespective of age at onset of hemiplegia. These results indicate incomplete functional re-organization for the control of fine speech motor movements throughout childhood, and provide no evidence of hemi- spheric differences. Ó 2010 Elsevier Inc. All rights reserved. 1. Introduction The smooth execution of finely controlled speech articulation is a uniquely human skill that requires precise and fast coordination of over 100 muscles (Ackermann & Riecker, 2004). Although motor speech deficits have been reported in a range of adult clinical pop- ulations with focal neuropathology, including strokes and degener- ative diseases (see Kent, Duffy, Slama, Kent, and Clift (2001) for a review), similar studies in children are rare. The paucity of such re- ports limits our knowledge about the potential for re-organization of neural systems controlling motor speech, and therefore our abil- ity to predict outcome after lesions affecting those systems during development. One extreme example of unilateral lesion is seen in children who have undergone hemispherectomy, that is, complete removal or disconnection of an entire cerebral hemisphere. Although a remarkable sparing of language after childhood hemi- spherectomy has been reported in numerous studies (e.g. Basser, 1962; Curtiss & de Bode, 1999; Gott, 1973; Liégeois, Cross, Polkey, Harkness, & Vargha-Khadem, 2008b; Mariotti, Iuvone, Torrioli, & Silveri, 1998; Ogden, 1988) the motor speech profile of this patient group has rarely been described. The present study attempts to ad- dress this issue. Behavioral and direct cortical stimulation studies in humans with focal pathology indicate that vocalization involves a wide net- work of cortical and subcortical regions, namely the supplemen- tary motor area (SMA), the anterior cingulate, the premotor and primary motor cortices (face and trunk area) and Broca’s area, the putamen, substantia nigra, ventrolateral thalamus and cerebel- lum (see Jurgens (2002) for a comprehensive review). Neuroimag- ing studies on speech production have confirmed these findings and indicate a predominant left-lateralized system involving two 0093-934X/$ - see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.bandl.2009.12.004 * Corresponding author. Address: Developmental Cognitive Neuroscience Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK. Fax: +44 (0)20 7905 2616. E-mail address: F.Liegeois@ich.ucl.ac.uk (F. Liégeois). 1 Present address: Language & Literacy Unit, Murdoch Childrens Research Institute, Parkville, Australia. Brain & Language 114 (2010) 126–134 Contents lists available at ScienceDirect Brain & Language journal homepage: www.elsevier.com/locate/b&l