E. Vicenzini 1, P. Pulitano 1, R. Cicchetti 2, P. Papov 2, G. Spadetta 3, M. Rocco 3, V. Di Piero 1, G. L. Lenzi 1, O. Mecarelli 1
1 Department of Neurology and Psychiatry,
2 Neonatal Intensive Care Unit,
3 Transplant Coordinator, Intensive Care Unit. Sapienza, University of Rome – Rome, Italy
Objective: Transcranial Doppler is sensitive technique for the diagnosis of cerebral circulatory arrest in brain death, when specific patterns such as reverberant flow and short systolic spikes are observed in intracranial arteries. These patterns are related to the occurrence of brain swelling in the inextensible skull, resulting in transformation from a normal “low-resistance” into a “high-resistance” brain parenchyma. In infants, the non-ossified fontanelles initially compensates for intracranial hypertension. We describe TCD patterns in infants with brain death, different from adults, with the hemodynamic modifications induced by anterior fontanelle compression.
Methods: Transcranial Doppler was performed in infants with brain death admitted to the neonatal intensive care unit. Results: Transcranial Doppler showed a large peak, atypical “reverberant” flow, with a high peak systolic velocity and a consistent retrograde component, away from the brain. The observation of this pattern may be misleading for the final diagnosis. Compression on the anterior fontanelle induced, at first, a reduction of the systolic flow with the subsequent appearance of the adult characteristic short systolic spikes. Upon compression removal, a brief increase of the systolic flow was observed, before the prompt reappearance of the reverberant flow.
Conclusion: Transcranial Doppler for brain death diagnosis should be done cautiously in infants with the non-ossified skull because non-typical patterns could be observed. Reverberant flow in intracranial arteries, even if with a large and long duration peak and with a high peak systolic velocity, may be indicative of cerebral circulatory arrest in these cases. Large fontantelle compression for few seconds may reproduce the classical TCD patterns of brain death observed in adults, supporting the diagnosis of cerebral circulatory arrest in infants with brain death.
Key words: brain death, infants, transcranial Doppler.