Giron Gp

Is the auditory brain-stem response (ABR) effective in the assessment of post-traumatic coma?

The aim of the present study is to evaluate the capacity of ABRs to detect the limit between reversible dysfunction and irreversible damage to the brain-stem after severe head injuries. ABRs were recorded in 40 severely head-injured patients, strictly selected on the basis of clinical and CT scan findings and the absence of otologic disease. The interpeak latency of waves V-I (IPL V-I) was calculated and compared to that recorded in 19 healthy control subjects. The distribution curve for IPL V-I in surviving patients was analysed. The overall mortality was 47.5%; all the patients showing an IPL V-I greater than 4.48 msec died or remained vegetative, while all but 2 of the patients with IPL V-I less than 4.48 msec survived. The IPL V-I was significantly different from normal value in surviving patients, showing a brain-stem dysfunction in reversible post-traumatic coma. The 95% confidence limits for the mean IPL V-I in the surviving population were 4.08 and 4.24 msec. Our results confirm the high prognostic accuracy of ABR (P less than 0.001) and suggest the hypothesis that 95% of survivors have an IPL V-I ranging between 3.82 and 4.50 msec.

Early outcome prediction in severe head injury: comparison between children and adults

The prognostic value in 49 children and 56 adults of the following parameters recorded on admission was analyzed: oculocephalic and light reflexes, posturing, Glasgow Coma Scale (GCS), the need for ventilatory support, and the presence of associated injuries. All patients had been in coma for at least 6 h. The presence of intracranial hematoma and the duration of coma were recorded and the relative risk of poor outcome calculated. There was poor outcome in 51% of the children and 61% of the adults. Oculocephalic and light reflexes, posturing, GCS, need for ventilatory support, and duration of coma were significantly related to the outcome in children. Only oculocephalic and light reflexes, and posturing were significantly related to the outcome in adults. Some parameters appeared to have different prognostic value in children and in adults: the simultaneous evaluation of oculocephalic reflex and need for ventilation was the best prognostic guide in children, the light reflex was the best prognostic indicator in adults.

Short latency evoked potentials: new criteria for brain death?

The aim of this study was to evaluate whether the auditory brain stem responses (ABR) and short latency somatosensory potentials (SEP) from median nerve stimulation are effective tools in the confirmation of brain death. Thirty six brain dead patients were submitted to ABR and 24 to SEP in the same session. All waves of the ABR were absent in 28 (77.8 per cent) patients, while only wave I was present in the others (22.2 per cent). In SEP recordings the components later than P13 were absent in 17 (70.8 per cent) of cases; in the remaining seven patients (29.2 per cent) a N13/P13 dissociation (namely, retention of the cervical N13 and absence of the far-field P13) was found. The results suggest that SEP and ABR are reliable tools in the diagnosis of brain death and should be included in the criteria: they enable the functional status of two pathways in the brainstem to be checked, which cannot be explored by the clinical examination.

Sensorimotor central conduction time in comatose patients

Motor evoked potentials (MEPs) following magnetic stimulation were recorded in 22 patients comatose as a result of head injury (13 cases), stroke (7 cases) or anoxia (2 cases). Somatosensory evoked potentials (SEPs) from median nerve were recorded as well in 19 cases in the same session. Thirteen patients died or remained vegetative (59.1%), 3 were severely disabled (13.6%) and 6 showed a good recovery (27.3%). MEPs were significantly related to the outcome; they appeared to be a more accurate prognostic indicator than the Glasgow Coma Scale (GCS). However, 1 out of 6 patients with bilaterally absent MEPs (16.7%) showed a good recovery. SEPs were significantly related to the outcome as well, but the combined use of SEP and MEP improved the outcome prediction, decreasing the rate of false negatives. Two patients had normal sensorimotor function, 13 a combined sensorimotor dysfunction, while 4 had a pure motor dysfunction. Our results suggest that SEPs and MEPs may improve the assessment of sensorimotor dysfunction in comatose patients. A significant relationship between MEPs and outcome appears to exist, but the assessment of MEP reliability requires further study.

Head injuries and their early management. An account of one year's experience

SummaryWe report 298 patients admitted to the Neurosurgical unit of the University of Padua during one calendar year. We divided the patients into two groups. “in coma” and “not in coma”, and analyze their data records. The time between injury and admission to a neurosurgical centre is important for therapy as well as for transport.The necessity of an “Admission Chart” is emphasized.

Admission chart as a protocol for reception and first management of head injuries

SummaryIn order to gather fundamental information about the reanimative, diagnostic, and therapeutic measures concerning head-injured patients, we propose the introduction of an “Admission Chart”.This Chart ought to accompany patients from the first contact with Accident-Emergency Medical Staff to arrival at a specialized Centre.