Biomedical subjects

S Wilhelms

Publications and source records attributed to S Wilhelms.

3 recordsLinked to original sources

PubMed1992

Brain death: practicability of evoked potentials.

Multimodally evoked potentials were registered in 85 patients who fulfilled the criteria for brain death. While somatosensory and visual evoked potentials have been found to be of limited value for the diagnosis of brain death, the stepwise abolition of brain stem auditory evoked potentials (BAEP) confirmed brain death in 26 out of 85 patients, i.e. 31%. Registration of the abolition of BAEP is concluded to be a safe and acceptable confirmatory test. It is, however, more feasible for institutions, in which BAEP are analysed routinely. In spite of all efforts sequential BAEP could not be used for the diagnosis of brain death in the majority of cases either because of absence of reproducible responses at the initial registration or because the patient was already apnoic at the time of the initial BAEP. Assuming that bilateral preservation of wave I has the same significance as the stepwise abolition of BAEP, since it also proves the integrity of the peripheral receptor, BAEP are relevant for the declaration of brain death in approximately 30% of patients.

Brain Death↗

PubMed1991

Pyramidal tract lesions in comatose patients.

In 197 comatose patients transcranial magnetic evoked potentials were registered to investigate the integrity of the pyramidal tract. Findings were compared to somatosensory, visual and auditory evoked potentials. Preservation, abnormalities and absence of evoked potentials were related to survival and non-survival. Transcranial magnetic and somatosensory evoked potentials proved to be of high prognostic value. While the accuracy of prediction of a fatal outcome based on transcranial magnetic evoked potentials was close to 90%, the prediction of survival was less dependable. Transcranial magnetic evoked potentials are concluded to be a valuable adjunct to the neurophysiological assessment of the comatose patient.

Adolescent↗

PubMedDate not supplied

Pyramidal tract function during onset of brain death.

In 51 patients with primary brain lesions, who fulfilled the criteria of brain death, sequential recording of transcranial magnetic evoked potentials (TMEPs) and somatosensory evoked potentials (SEPs) were performed. In all comatose patients with apnoeic cranial nerve areflexia the TMEP could not be elicited, while the response after cervical magnetic stimulation was always preserved. Similarly, no cortical SEPs were preserved in apnoeic cranial nerve areflexia; however, the cervical somatosensory response was preserved in 44%. In deteriorating patients with coma grade III TMEPs were preserved in 3 instances, while cortical SEPs were already absent. Current brain death criteria, however, were not challenged, as TMEPs were absent in all 51 patients, at the latest when apnoea was noted.

Adolescent↗