Case ReportsVerbal Adynamia and Conceptualization in Partial Rhombencephalosynapsis and Corpus Callosum DysgenesisBarker, Megan S. PhD*,†; Knight, Jacquelyn L. DPsyc*; Dean, Ryan J. PhD‡; Mandelstam, Simone MD§,∥,¶; Richards, Linda J. PhD‡,#; Robinson, Gail A. PhD*,‡ Author Information *Neuropsychology Research Unit, School of Psychology, The University of Queensland, St Lucia, Brisbane, Australia †Taub Institute, Columbia University Medical Center, New York, New York ‡Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, Australia §Department of Radiology, University of Melbourne, Royal Children’s Hospital, Parkville, Victoria, Australia ∥Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia ¶Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia #School of Biomedical Sciences, The University of Queensland, St. Lucia, Brisbane, Australia Portions of this work were presented at the International Research Consortium for the Corpus Callosum and Cerebral Connectivity (www.irc5.org) Symposium, June 2018, Costa Mesa, California. Supported in part by an Australian Government Research Training Program Scholarship to M.S.B., an Australian National Health and Medical Research Council (NHMRC) Principal Research Fellowship to L.J.R., and the Australian NHMRC Boosting Dementia Research Leadership Fellowship Scheme to G.A.R. R.J.D. was supported by Brain Injured Childrens After-Care Recovery Endeavours Inc. The authors declare no conflicts of interest. Correspondence: Gail A. Robinson, PhD, School of Psychology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia (email: [email protected]) Cognitive and Behavioral Neurology: March 2021 - Volume 34 - Issue 1 - p 38-52 doi: 10.1097/WNN.0000000000000261 Buy SDC Metrics Abstract Verbal adynamia is characterized by markedly reduced spontaneous speech that is not attributable to a core language deficit such as impaired naming, reading, repetition, or comprehension. In some cases, verbal adynamia is severe enough to be considered dynamic aphasia. We report the case of a 40-year-old, left-handed, male native English speaker who presented with partial rhombencephalosynapsis, corpus callosum dysgenesis, and a language profile that is consistent with verbal adynamia, or subclinical dynamic aphasia, possibly underpinned by difficulties selecting and generating ideas for expression. This case is only the second investigation of dynamic aphasia in an individual with a congenital brain malformation. It is also the first detailed neuropsychological report of an adult with partial rhombencephalosynapsis and corpus callosum dysgenesis, and the only known case of superior intellectual abilities in this context. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.