Mapping topography and network of brain injury in patients with disorders of consciousness: A text mining analysis of the literature

There is growing interest in the topography of brain regions associated with disorders of consciousness. This has caused increased research output, yielding many publications investigating the topic with varying methodologies. The objective of this study was to ascertain the topographical regions of the brain most frequently associated with disorders of consciousness. We performed a cross-sectional text mining analysis of disorders of consciousness studies. A text mining algorithm built in the Python programming language searched documents for anatomical brain terminology. We reviewed PubMed studies up to 9th July 2021 for the search query "Disorders of Consciousness." The frequency of brain regions mentioned in these articles was recorded, ranked, then built into a graphical network. Subgroup analysis was performed by evaluating the impact on our results if analyses were based on abstracts, full-texts, or topic modelled groups (non-negative matric factorization was used to create subgroups of each collection based on their key topics). Brain terms were ranked by their frequency and concordance was measured between subgroups. Graphical analysis was performed to explore relationships between anatomical regions mentioned. The PageRank algorithm (used by Google to list search results in order of relevance) was used to determine global importance of the regions. The PubMed search yielded 14,945 abstracts and 2178 full-texts. The topic-modelled subgroups contained 2440 abstracts and 367 full-texts. Text Mining across all document groups concordantly ranked the thalamus the highest (Savage score = 14.191). Graphical analysis had 4 clusters: cluster 1 had 20 members with the insular cortex [PageRank =0.167] as the most important member; cluster 2 had 29 members with the amygdala [PageRank =0.0199] being most important; cluster 3 had 10 members with the thalamus [PageRank = 0. 0205] being most important; cluster 4 had 19 members with the cingulate cortex [PageRank = 0. 0.020] being the most important. The cingulate cortex and thalamus are strongly associated with disorders of consciousness, likely due to the roles they play in maintaining awareness and involvement in the Default Mode Network respectively. Other areas of the brain like the cuneus, amygdala and hippocampus should be further investigated.