Marjolein Verly

Altered functional connectivity of the language network in ASD: Role of classical language areas and cerebellum

The development of language, social interaction and communicative skills is remarkably different in the child with autism spectrum disorder (ASD). Atypical brain connectivity has frequently been reported in this patient population. However, the neural correlates underlying their disrupted language development and functioning are still poorly understood. Using resting state fMRI, we investigated the functional connectivity properties of the language network in a group of ASD patients with clear comorbid language impairment (ASD-LI; N = 19) and compared them to the language related connectivity properties of 23 age-matched typically developing children. A verb generation task was used to determine language components commonly active in both groups. Eight joint language components were identified and subsequently used as seeds in a resting state analysis. Interestingly, both the interregional and the seed-based whole brain connectivity analysis showed preserved connectivity between the classical intrahemispheric language centers, Wernickes and Brocas areas. In contrast however, a marked loss of functional connectivity was found between the right cerebellar region and the supratentorial regulatory language areas. Also, the connectivity between the interhemispheric Broca regions and modulatory control dorsolateral prefrontal region was found to be decreased. This disruption of normal modulatory control and automation function by the cerebellum may underlie the abnormal language function in children with ASD-LI.

Structural and functional underconnectivity as a negative predictor for language in autism.

The development of language, social interaction, and communicative skills are remarkably different in the child with autism spectrum disorder (ASD). Atypical brain connectivity has frequently been reported in this patient population. However, the interplay between their brain connectivity and language performance remains largely understudied. Using diffusion tensor imaging tractography and resting‐state fMRI, the authors explored the structural and functional connectivity of the language network and its relation to the language profile in a group of healthy control subjects (N = 25) and a group of children with ASD (N = 17). The authors hypothesized that in children with ASD, a neural connectivity deficit of the language network can be related to the observed abnormal language function. They found an absence of the right‐hemispheric arcuate fascicle (AF) in 28% (7/25) of the healthy control children and in 59% (10/17) of the children with ASD. In contrast to healthy control children, the absence of the right‐hemispheric AF in children with autism was related to a lower language performance as indicated by a lower verbal IQ, lower scores on the Peabody Picture Vocabulary Test, and lower language scores on the Dutch version of the Clinical Evaluation of Language Fundamentals (CELF‐4NL). In addition, through iterative fMRI data analyses, the language impairment of children with ASD could be linked to a marked loss of intrahemispheric functional connectivity between inferior frontal and superior temporal regions, known as the cortical language network. Both structural and functional underconnectivity patterns coincide and are related to an abnormal language function in children with ASD. Hum Brain Mapp 35:3602–3615, 2014.

Evaluation of the language profile in children with rolandic epilepsy and developmental dysphasia: Evidence for distinct strengths and weaknesses

ABSTRACT Although benign, rolandic epilepsy (RE) or benign childhood epilepsy with centro‐temporal spikes is often associated with language impairment. Recently, fronto‐rolandic EEG abnormalities have been described in children with developmental dysphasia (DD), suggesting an interaction between language impairment and interictal epileptiform discharges. To investigate if a behavioral‐linguistic continuum between RE and DD exists, a clinical prospective study was carried out to evaluate the language profile of 15 children with RE and 22 children with DD. Language skills were assessed using an extensive, standardized test battery. Language was found to be impaired in both study groups, however RE and DD were associated with distinct language impairment profiles. Children with RE had difficulties with sentence comprehension, semantic verbal fluency and auditory short‐term memory, which are unrelated to age of epilepsy onset and laterality of epileptic focus. In children with DD, sentence comprehension and verbal fluency were among their relative strengths, whereas sentence and lexical production constituted relative weaknesses.