Severe Head Injury: a Comparison of EEG and Somatosensory Evoked
J. Moulton, Jennifer I.M. Brown and Stefan J. Konasiewicz
We report on our experience with long-term monitoring of
the EEG power spectrum and somatosensory evoked potentials (SSEPs)
in 103 patients with severe closed head injury (Glasgow Coma
Scale &endash; GCS ² 8). Patients were monitored for an average
of 5 days post injury and monitoring was terminated when they
died, regained consciousness or their intracranial physiologic
parameters (primarily intracranial pressure &endash; ICP) were
stable for 2-3 days. Patients were treated according to a standard
protocol that included mechanical ventilation, sedation, and
neuromuscular blockade. At 7 of 9 twelve hour time intervals
post injury, SSEPs were significantly (p < .05) different
between outcome groups using the Glasgow Outcome Score collapsed
to 3 categories. The percent slow (delta) activity in the EEG
was not significantly different between outcome groups at any
time point, post injury. The total power in the EEG power spectrum
differed only at the last time epoch post injury (108 hr.).
Based on the superior prognostic capabilities of the SSEP, we
routinely base critical management decisions on SSEP values.
We have not been able to rely on EEG parameters for these same
decisions due to the lack of clear distinction between good
and poor prognosis groups based on common EEG parameters.
J. Neurol. Sci. 1998; 25: S7 - S11