The Prognostic Value of Somatosensory Evoked Potentials in Traumatic Primary and Secondary Brain Stem Lesions

Abstract

To estimate the prognostic value of somatosensory evoked potentials elicited via stimulation of the median nerve (M-SSEP) in cases of primary and secondary brainstem lesions 126 patients with traumatic brainstem lesions (GCS < or = 6) were investigated on admission to our hospital. Various parameters of the patients' M-SSEP were compared with the corresponding data of 40 healthy persons. Latency and amplitude of the cervical (N14) and cortical (N20) derived potentials and the central conduction time (CCT) were taken into account. Changes or a loss of the N20 signal and of the CCT were related to clinical outcome for up to two years. All patients had a normal N14 bilaterally. Most patients with a primary brainstem lesion (n = 25) showed symmetrical N20 changes bilaterally. However, the majority of patients with a secondary brainstem lesion (n = 62) showed asymmetric N20 changes in M-SSEP which became more symmetrical in cases with marked progressive brainstem compression. Irrespective of a primary or secondary traumatic brainstem lesion, marked changes of N20 represented an unfavourable clinical prognosis. A loss of N20 was closely correlated with a very poor outcome (GOS 1-2) if the N20 potential had not recovered within 48 hours. The recovery of this potential, however, was not necessarily correlated to a recovery of the brain function.

Brainstem Associated Somatosensory Evoked Potentials and Response to Vagus Nerve Stimulation: An Investigation of the Vagus Afferent Network

“…Previous studies have shown that changes in SSEP amplitude, latency, and/or absence or presence of certain SSEP components can be indicative of aberrant CNS connectivity (18,19). For example, patients with unilateral cerebrovascular lesions have abnormal, high-amplitude SSEPs over the non-affected hemisphere (20).…”

Rehabilitation forecast markers: complex assessment of damaged brain using electroencephalogram (EEG) and somatosensory evoked potentials (SSEP)

“…Отсутствие коркового ответа или снижение амплитуды коркового ответа всегда связано с неблагоприятным исходом у пациентов. Следовательно, кортикальный ответ является самым надёжным прогностическим показателем для пациентов с травмой [14,15].…”