Timing for cranioplasty to improve neurological outcome: A systematic review

INTRODUCTION: Cranioplasty is a surgical technique applied for the reconstruction of the skullcap removed during decompressive craniectomy (DC). Cranioplasty improves rehabilitation from a motor and cognitive perspective. However, it may increase the possibility of postoperative complications, such as seizures and infections. Timing of cranioplasty is therefore crucial even though literature is controversial. In this study, we compared motor and cognitive effects of early cranioplasty after DC and assess the optimal timing to perform it. METHODS: A literature research was conducted in PubMed, Web of Science, and Cochrane Library databases. We selected studies including at least one of the following test: Mini‐Mental State Examination, Rey Auditory Verbal Learning Test immediate and 30‐min delayed recall, Digit Span Test, Glasgow Coma Scale, Glasgow Outcome Scale, Coma Recovery Scale‐Revised, Level of Cognitive Functioning Scale, Functional Independence Measure, and Barthel Index. RESULTS: Six articles and two systematic reviews were included in the present study. Analysis of changes in pre‐ and postcranioplasty scores showed that an early procedure (within 90 days from decompressive craniectomy) is more effective in improving motor functions (standardized mean difference [SMD] = 0.51 [0.05; 0.97], p‐value = 0.03), whereas an early procedure did not significantly improve neither MMSE score (SMD = 0.06 [−0.49; 0.61], p‐value = 0.83) nor memory functions (SMD = −0.63 [−0.97; −0.28], p‐value < 0.001). No statistical significance emerged when we compared studies according to the timing from DC. CONCLUSIONS: It is believed that cranioplasty performed from 3 to 6 months after DC may significantly improve both motor and cognitive recovery.