[Alpha coma: clinical, electroencephalographic and aetiological correlation in childhood].

INTRODUCTION

Alpha coma is defined as the appearance, in an unconscious patient, of EEG activity in the alpha frequency band (8-13Hz).

OBJECTIVE

To determine, in our setting, the incidence, aetiology, clinical significance and course of alpha coma in paediatric patients and review the literature.

PATIENTS AND METHODS

We did a retrospective study of the patients admitted to a paediatric intensive care unit who had alpha activity recorded whilst in coma.

RESULTS

Only two patients, aged 5 and 12 years, were found. Both had complex congenital cardiopathy and cardio-respiratory arrest one and twelve days postoperatively, respectively. Several EEGs were done whilst they were in coma. Barbiturate coma was not used. Both had clinical mid-brain involvement during alpha recording. The pattern was bilateral, arreactive and preceded by a theta pattern, appeared two days after the arrest, was maintained for two and three days in the two cases and was followed by delta pattern. The second case finally showed a 'burst-suppression'. The CAT was normal. The patients died 4 and 11 days after the appearance of alpha coma.

CONCLUSIONS

Alpha coma is rare in childhood. Both the aetiology and the bad prognosis are similar to that of adults. Alpha coma is a transient EEG pattern occurring during the evolution of coma. We consider it to be due probably to mid-brain involvement.