Understanding brain damage in vegetative state patients

Cortico-cortical and subcortico-cortical fibre pathways, as reconstructed in the healthy volunteers group. The colour scale (yellow-red) represents the percentage of participants for which each tract was successfully reconstructed.

Dr Davinia Fernández-Espejo, Lecturer in the School, has published a paper that provides new insight into the neural bases of the vegetative state and related disorders such as the minimally conscious state.

These disorders are amongst the least understood conditions in modern medicine because there is no particular type of brain damage that is known to cause them. This lack of knowledge leads to an alarmingly high level of misdiagnosis.

Davinia Fernández-EspejoIn this study, published in Neuroimage: Clinical, the researchers used a technique called diffusion tensor imaging tractography to investigate patients suffering from varying degrees of brain injury. This technique allows investigators to virtually reconstruct the pathways that connect different parts of the brain in the patients, while detecting subtle differences in their brain damage. Specifically, the authors were able to show that vegetative state patients have damage in specific fibers connecting a group of cortical brain regions known as the default mode network and a group of subcortical brain regions known as the anterior forebrain. Interestingly, the damage in those connections was more severe in patients in a vegetative state than those who were at least minimally conscious. This suggests that the damage in the identified fibers could be used as a potential diagnostic biomarker.

Reference

Nicholas D. Lanta, Laura E. Gonzalez-Laraa, Adrian M. Owena, Davinia Fernández-Espejo, ‘Relationship between the anterior forebrain mesocircuit and the default mode network in the structural bases of disorders of consciousness and the default mode network in the structural bases of disorders of consciousness’, NeuroImage: Clinical 11/2015; 10. DOI: 10.1016/j.nicl.2015.11.004