Bilateral Perisylvian Syndrome (BPS) often presents with epilepsy and significant behavioral impairments that can include mental retardation, dysarthria, delayed speech development, and delayed fine motor development (Graff-Radford et al., 1986 and Kuzniecky et al., 1993). While a small subset of BPS cases have been described as having relatively isolated language delays (Leventer et al., 2010), BPS is not expected in children with dyslexia. As part of a Medical University of South Carolina, IRB approved multi-site study involving retrospective and de-identified dyslexia data, we unexpectedly identified a 14.05 year old male with evidence of BPS whose father had been diagnosed with dyslexia and dysgraphia. This child had been recruited for a neuroimaging study on dyslexia from a school specializing in educating children with dyslexia. The T1-weighted MRI scan from this child demonstrated a highly unusual perisylvian sulcal/gyral patterning that is a defining feature of BPS (Fig. 1). BPS cases exhibit bilateral dysgenesis of the Sylvian fissure and surrounding gyri, which appears to occur because of a limited or absent arcuate fasciculus (Kilinc, Ekinci, Demirkol, & Agan, 2015). This BPS case also had a relatively enlarged atrium of the lateral ventricle that is consistent with the BPS anatomical presentation and reduction of parietal white matter (Graff-Radford et al., 1986, Kilinc et al., 2015 and Toldo et al., 2011).
- bilateral perisylvian syndrome
- reading disability
- Sylvian fissure