Is preoperative brain midline shift a determinant factor for neurological improvement after cranioplasty?

In patients with traumatic brain injury, the degree of brain midline shift is related to prognosis. In this study, we evaluated the impact of the presence of a preoperative brain midline shift on the Glasgow Coma Scale (GCS) scores and muscle power (MP) improvement after cranioplasty. Methods: In this 6-year retrospective cohort study, we compared cranioplasty patients from Taiwan with and without a preoperative brain midline shift. We assigned the patients to the following two groups: the midline shift group and the nonmidline shift group. The GCS score and MP contralateral to the lesion site were recorded and analyzed both prior to and 1 year after the operation. Results: We enrolled 56 cranioplasty patients (35 patients with a midline shift and 21 without a midline shift) and analyzed their complete clinical characteristics. There were significant improvements in the GCS (p=0.0078), arm MP (p=0.0056), and leg MP (p=0.0006) scores after cranioplasty. There was also a significant improvement in the GCS score in the brain midline shift group (0.4±0.149 in the brain midline shift group vs. 0.05±0.48 in the nonmidline shift group, p=0.03). Conclusion: For patients who underwent craniectomy, an improvement in neurological function 1 year after cranioplasty was observed. The patients with brain midline shift showed more improvement in consciousness after cranioplasty than those without a brain midline shift. The presence of a preoperative brain midline shift may be an isolated determinant for the prediction of the outcome after cranioplasty.