Alternative cerebral generators and circuitry pathways in alpha coma revealed by independent component analysis.
OBJECTIVE
This study investigates the generators of alpha coma activity and the probable cerebral pathways involved in alpha coma patients.


METHODS
This study uses independent component analysis (ICA) and dipole fitting algorithm to locate the cerebral generators in alpha coma and normal alpha rhythms.


RESULTS
Distinct distributions of the source generators for alpha activity were noted in alpha coma. They were localized to the anterior neocortical and subcortical regions, which includes caudate nucleus, midbrain and hypothalamus. In addition, the two patients who survive long term have five independent components identified vs. the other five patients who demised only had one or two independent components.


CONCLUSIONS
The findings showed that alpha activity could be generated using alternative generators and pathways. This is probably due to the disinhibition of the normally inhibited pathways in coma. The presence of less independent components is probably a marker of less preserved brain tissue and predicts worse outcome.


CONCLUSIONS
This is the first known human study using the ICA method to localize the cerebral generators in alpha coma. It might provide a new dimension of interpreting clinical EEGs in patients with alpha coma. It also might have significant application in predicting the clinical outcomes.
Abusleme
Isaac E
IE
Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
Chen
James W Y
JW