title: Neuroanatomical correlates of childhood apraxia of speech: A connectomic approach.
abstract: Childhood apraxia of speech (CAS) is a paediatric speech sound disorder in which precision and consistency of speech movements are impaired. Most children with idiopathic CAS have normal structural brain MRI. We hypothesize that children with CAS have altered structural connectivity in speech/language networks compared to controls and that these altered connections are related to functional speech/language measures. Whole brain probabilistic tractography, using constrained spherical deconvolution, was performed for connectome generation in 17 children with CAS and 10 age-matched controls. Fractional anisotropy (FA) was used as a measure of connectivity and the connections with altered FA between CAS and controls were identified. Further, the relationship between altered FA and speech/language scores was determined. Three intra-hemispheric/interhemispheric subnetworks showed reduction of FA in CAS compared to controls, including left inferior (opercular part) and superior (dorsolateral, medial and orbital part) frontal gyrus, left superior and middle temporal gyrus and left post-central gyrus (subnetwork 1); right supplementary motor area, left middle and inferior (orbital part) frontal gyrus, left precuneus and cuneus, right superior occipital gyrus and right cerebellum (subnetwork 2); right angular gyrus, right superior temporal gyrus and right inferior occipital gyrus (subnetwork 3). Reduced FA of some connections correlated with diadochokinesis, oromotor skills, expressive grammar and poor lexical production in CAS. These findings provide evidence of structural connectivity anomalies in children with CAS across specific brain regions involved in speech/language function. We propose altered connectivity as a possible epiphenomenon of complex pathogenic mechanisms in CAS which need further investigation.
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Fiori
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy; Department of Clinical and Experimental Medicine, University of Pisa, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Guzzetta
authors.affiliation: CSIRO, Commonwealth Scientific and Industrial Research Organization, Centre for Computational Informatics, Brisbane, Australia.
authors.forename: Jhimli
authors.initials: J
authors.lastname: Mitra
authors.affiliation: Department of Computing, Imperial College London, London, United Kingdom.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Pannek
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Pasquariello
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Cipriani
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Tosetti
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy; Department of Clinical and Experimental Medicine, University of Pisa, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cioni
authors.affiliation: CSIRO, Commonwealth Scientific and Industrial Research Organization, Centre for Computational Informatics, Brisbane, Australia.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Rose
authors.affiliation: Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Chilosi
mesh_terms: D001072:Apraxias / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002675:Child, Preschool; D063132:Connectome / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006801:Humans; D007805:Language Development Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013064:Speech Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Childhood apraxia of speech; Connectivity; Diadochokinesis; Diffusion magnetic resonance; Fractional anisotropy