Central somatosensory conduction time and short latency somatosensory evoked potentials in post-traumatic coma

How reliable is the predictive value of SEP (somatosensory evoked potentials) patterns in severe brain damage with special regard to the bilateral loss of cortical responses?

“…Additionally, our findings agree with the observations of others [3,6,9,11,15,16] that the initial BLCR pattern in adult patients most often means a fatal outcome (GOS 1, 14 of our 15 adult patients developed brain death) or, rarely, the unfavorable outcome of a permanent vegetative state (GOS 2: in our study n = 1, case 1).…”

“…Our findings of a highly significant correlation of initial SEP scores with later outcome (measured by the GOS) correspond well with the results of earlier studies [1][2][3][4][5][6][7][8][9], demonstrating the predictive value of median nerve SEP recording in the early phase of posttraumatic coma for both a favorable and an unfavorable prognosis, even during treatment with sedatives and muscle relaxants. As the severity of evoked potential abnormalities (SEP score according to Anderson et al [1], CNC, am- plitude ratio N20/N13) increased in our study, favorable outcomes decreased.…”

“…Under these conditions, somatosensory evoked potentials (SEP) after median nerve stimulation correlated best with later prognosis and neurological deficit [1][2][3][4][5][6][7][8][9], comparable to other neurophysiological, neuroradiological, or clinical features [10]. The following SEP criteria have been suggested to define the extent of cortical and brainstem dysfunction: (a) (NC) central nerve conduction time (between lower brainstem and cerebral cortex) [4,6]; (b) amplitude ratio cortical N20/cervical N13 [1,11]; (c) complex SEP scoring, integrating the criteria above particularly with the presence or loss of the primary cortical response N20/P25 [1,6]. In the literature, primary bilateral loss of cortical responses (BLCR) is regarded as one of the best prognostic indicators, predicting that most of the patients will die or the outcome will be a persistent vegetative state at best [11].…”

Predictive value of somatosensory evoked potentials for awakening from coma*

“…Data were not sufficient to analyze normal vs. abnormal responses. Tables 2 and 3 present Glasgow outcome scale results according to normal and abnormal SEP results, summarizing data from eight articles for HIE adults (4,24,26,27,29,33,45,46) and eight articles for TBI adults and adolescents (24,26,28,30,31,42,47,48). Those with normal cortical responses had better outcomes than those with abnormal responses for both HIE (chi-square ϭ 57.6, p Ͻ .001) and TBI (chi-square ϭ 64.4, p Ͻ .001).…”

Neurophysiological Monitoring in the Intensive Care Unit

“…These studies assess brainstem function but not cerebral cortex function, however, and have been more predictive of survival than of the quality of life. SEP abnormalities have correlated with an unfavorable prognosis in coma [24]. Studies performed shortly after head trauma documented the predictive accuracy of central conduction (P/N13 to N19) [25].…”