Two inexpensive electronic circuits for analog display of multichannel EEG signals.

Two electronic circuits useful for high-resolution EEG recording systems are described. The first is an analog display driver that formats large numbers of EEG signals for display in a variety of modes on a standard CRT display. The second is an analog demultiplexer circuit that reconstitutes large numbers of analog EEG signals from multiplexed D/A outputs. Each provides a readily expandable, high-resolution EEG display that can easily provide real-time or faster performance and that is much less expensive than computer-based digital display systems with comparable capabilities.

Somatic evoked potential evaluation of cerebral status in Reye syndrome.

Median nerve somatic evoked potentials (SEPs) were serially recorded in 12 Reye syndrome patients from shortly after admission to discharge. Recovery was clinically satisfactory in nine, unsatisfactory in two, and one died. All SEP components were absent or markedly depressed in initial recordings. Early progressive recovery of primary cortical components was associated with patient survival; lack of it was associated with death. Progressive recovery of SEP components later than 100 msec was associated with satisfactory clinical recovery; failure of recovery of these components was associated with residual neuropsychological deficit. Evaluation of late component recovery required comparison with age-dependent SEP configurations in normal children which differ from adults. We conclude that serial SEP recording is of significant value and superior to the EEG in early prognosis for survival, prognosis for clinically satisfactory or unsatisfactory recovery, and general evaluation of neurologic status in Reye syndrome.