[The impact of early cranioplasty on cerebral blood flow and its correlation with neurological and cognitive outcome. Prospective multi-centre study on 24 patients].

INTRODUCTION: Cranioplasty after decompressive craniectomy in patients suffering from severe head injury often leads to a functional improvement although, to date, the pathophysiology of this phenomenon remains unclear. A few hypotheses have been proposed. The impact of cranioplasty on cerebral perfusion could be one explanation. We have evaluated the impact of cranioplasty on the functional status of patients undergoing decompressive craniectomy for severe head injury with its influence on cerebral perfusion.

MATERIALS AND METHODS: Twenty-four patients undergoing craniectomy for severe head injury were included in this multi-centric and prospective study. All of them had a cranioplasty within 12 weeks following decompressive craniectomy. A clinical and radiological evaluation was performed prior to and after cranioplasty. Neurological and cognitive evaluation was performed with the Glasgow Outcome Score (GOS), the Frontal Assessment Battery (FAB) and the Mini Mental State Examination (MMSE). Radiological evaluation was performed by perfusion CT scan and transcranial Doppler.

RESULTS: A statistically significant neurological and cognitive improvement was observed in 92% of patients at 6 months follow-up (F-U). Brain perfusion was improved at 6 weeks F-U, predominantly in the affected hemisphere. Systolic and diastolic blood velocity flow were improved in both middle cerebral arteries.

CONCLUSION: Cranioplasty after decompressive craniectomy for patients suffering from severe head injury probably improves the functional outcome of these patients, thanks to a global improvement of cerebral perfusion.