Poster #: 25
Topic: Clinical applications (incl. consciousness)
Wednesday, Sep 9, 2015
Residual cognitive functions in PVS patients by means of MMN paradigm using emotional content. Neural generators of remaining brain activity
1Neurophysiology, Neurology and Neurosurgery Institute, La Habana, Cuba
2Cuban Neuroscience Center, Cuba
3Psychology, University of Jyväskylä, Jyväskylä, Finland
4Neurology and Neurosurgery Institute, Cuba
5Cuban Endocrinology Institute, Cuba
6“Hermanos Ameijeiras” Hospital, Cuba
Background: Cognitive Event Related Potentials are more frequently obtained with more ecologic stimuli or having an emotional content. However, its functional mechanisms and neural basis remain unknown.
Objective: To determine and localize sources of residual electrical cognitive activities in Persistent Vegetative State (PVS) patients, by using an auditory stimulation paradigm including Subject Own Name (SON).
Methods: A Mismatch Negativity (MMN) component using SON was reconstructed in 10 patients in PVS. The auditory paradigm was validated in 20 healthy volunteers matched by age and gender, using 32 EEG channels montage. MMN Grand Average was computed and electrical sources were estimated by means of the Bayesian Model Averaging (BMA) approach in all groups. BAEPs were recorded for hearing assessment and clinical variables were evaluated for the PVS group.
Results: The MMN component was observed in 4 PVS patients showing right lateralization. MMN major sources were localized in fronto-temporal and fronto-central cortical areas in healthy subjects. For patients, these sources were localized in residual functional cortical areas although PVS patients showed structures similar to the controls in response to emotional stimuli (recreated by SON).
Conclusions: Regardless of VS duration, in some patients residual cognitive markers of central auditory processing of their own name appear. These results suggest recovery of consciousness, with its consequent practical and ethical implications. MMN is a helpful tool in identifying the ability to recover from VS and a valid measurement of clinical improvement.