Towards Cross-Disorder Connectomics
Many different psychiatric and neurological disorders are associated with disturbances to brain connectivity. But how come that many different disorders are related to the same brain network, and vise versa, how come that the same system can display so many diverse types of disorders? From clinical and genetic studies we know that there can be large overlap in the symptomatology and genetic background of brain disorders. This argues for characteristic commonalities also in the disturbances in brain connectivity.
In a Nature Reviews Neuroscience perspective article, published this month, Martijn van den Heuvel (CTG, CNCR) and Olaf Sporns (Indiana University, Bloomington, USA) explore how commonalities and differences in patterns of brain connectivity disturbances may reveal important relations across brain disorders. They start by overviewing connectivity abnormalities as reported in a wide range of neurological and psychiatric disorders, but now discuss these findings in the context of ‘key principles of wiring’ of the human brain (Van den Heuvel and Sporns, Trends in Cognive Science, 2017): 1) the tendency of the (healthy) human brain to display a strong modular architecture (i.e. forming local subcommunities good for functional specialization) and 2) the property of brain regions to invest a lot of resources in features that bring topological integration (i.e. to form an infrastructure so information can be efficiently coupled across brain areas). They argue that these two key features of brain connectivity, important for healthy brain functioning, may also shape the spectrum of brain disorders and potentially relationships between disorders.
In their review article they suggest that many disease-related disturbances to human brain connectivity are directly related to these principle axes of healthy human brain organization. They outline how these shared changes in connectional network attributes point to potentially shared network mechanisms underpinning disorders. They describe a cross-disorder ‘connectome landscape of dysconnectivity’ along the principal dimensions of network organization that may place shared connectome alterations between brain disorders in a common framework. They conclude with underlining the importance of future studies to work on ‘cross-disorder’ neuroscience, to explore features that are shared and features that are unique to brain disorders, in search for better (neuroimaging) disease biomarkers.