The relation of electrodermal response measures to outcome from early
post-traumatic vegetative state (VS) was investigated in 15 brain-inju
red and five control subjects. Brain-injured subjects were in acute VS
or persistent VS (PVS), or had recovered from acute VS (RVS). Signifi
cant group differences were found on all electrodermal response measur
es, primarily due to the greater amplitude, number and consistency of
responses in control subjects. Group differences in electrodermal habi
tuation and orientation to auditory tones reflected the absence of ori
entation in most RVS subjects and the absence of both habituation and
orientation PVS subjects. The groups differed in their response to mat
ching fades and names. All of the control subjects, two of five RVS su
bjects and none of five acute subjects produced significant responses.
Surprisingly, two PVS subjects also produced significant responses. F
or acute subjects a positive outcome at 6 months post-trauma was assoc
iated with early electrodermal startle amplitude and baseline lability
. These results indicate that electrodermal responsiveness is generall
y reduced following acute VS, even in subjects with a relatively good
recovery. Greater electrodermal activity in early VS may be associated
with better potential for recovery.