Brain-wave Test Challenges Vegetative-State Diagnosis
By Morgen E. Peck
First Published August 2008
Tests using an EEG have shown unexpected cortical
functioning in vegetative patients
PHOTO: Peter Arnold/Alamy
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6 August 2008— Eluana Englaro has been lying
motionless in a hospital bed in Italy for 16 years. In
1992, Englaro survived a serious car crash that left her
brain damaged, completely unresponsive, and unable to
eat, drink, or breathe on her own. She is now in a class
of patients diagnosed as “persistently vegetative.” Her
father, convinced that Eluana would have opposed the
medical intervention she received, has fought in court
for the past nine years for the right to remove her
feeding tubes and turn off her respirator. In early
July, he finally won, but Italian state prosecutors have
60 days to appeal.
End-of-life decisions in nonresponsive patients like
Englaro and American Terri Schiavo pose a deep challenge
to the science of consciousness. When these types of
cases go to trial, courts spend much of their time
hearing opinions on whether the patient is truly in a
vegetative state and whether he or she has any chance of
improving. The controversy surrounding these disputes is
due in part to the primitive methods we rely on when
assessing consciousness. But some scientists are working
on technical ways to measure consciousness in patients
with brain injuries.
Niels Birbaumer, a neurobiologist at the University
of Tübingen, in Germany, used EEG recordings to study
the brain activity of patients diagnosed as vegetative
and found unexpected levels of cortical activity. He
presented his work this month at the Euroscience Open
Forum, in Barcelona, and discussed the medical implications.
In one of the studies, Birbaumer and his colleagues
looked for patterns in the brain’s electrical activity
as patients listened to sentences being read aloud. The
experimenters attached 10 to 20 electrodes to the scalps
of 98 patients who had suffered severe brain damage. The
group was composed of both completely vegetative
patients and others that still retained control of their
gaze or other simple physical abilities. In the
experiment, patients listened to a series of seven-word
sentences. Half the time the sentences were semantically
logical. The other half of the sentences ended with a
nonsensical word. An example might be “I baked a cake in
the banjo.”