Favourable long-term recovery after decompressive craniectomy: the Northern Finland experience with a predominantly adolescent patient cohort.

PURPOSE: Decompressive craniectomy (DC) is an effective treatment of intracranial hypertension. Correspondingly, the procedure is increasingly utilised worldwide. The number of patients rendered vegetative following surgery has been a concern-a matter especially important in children, due to long anticipated lifetime. Here, we report the long-term outcomes of all paediatric DC patients from an 11-year period in a tertiary-level centre that geographically serves half of Finland. METHODS: We identified all patients younger than 18 years who underwent DC in the Oulu University Hospital between the years 2009 and 2019. Outcomes and clinicoradiological variables were extracted from the patient records. RESULTS: Mean yearly prevalence of brain injury requiring DC was 1.34/100 000 children-twenty-four patients underwent DC during the study period and 21 (88%) survived. The median age of the patients was 16.0 years, and the median preoperative GCS was 5.0 (IQR 5.0). Fifteen patients (63%) had made a good recovery (Extended Glasgow Outcome Scale ≥ 7). Of the surviving patients, two (9.5%) had not returned to school. After traumatic brain injury (n = 20), the Rotterdam CT score (mean 3.0, range 1 to 5) was not associated with mortality, poor recovery or inability to continue school (p = 0.13, p = 0.41, p = 0.43, respectively). Absent basal cisterns were associated with mortality (p = 0.005), but not with poor recovery if the patient survived DC (p = 0.81). Hydrocephalus was associated with poor recovery and inability to continue school (p = 0.01 and p = 0.03, respectively). CONCLUSION: Most of our patients made a favourable recovery and were able to continue school. No late mortality was observed. Thus, even in clinically and radiologically severely brain-injured children, decompressive craniectomy appears to yield favourable outcomes.

Analysis of human brain tissue derived from DBS surgery.

BACKGROUND: Transcriptomic and proteomic profiling of human brain tissue is hindered by the availability of fresh samples from living patients. Postmortem samples usually represent the advanced disease stage of the patient. Furthermore, the postmortem interval can affect the transcriptomic and proteomic profiles. Therefore, fresh brain tissue samples from living patients represent a valuable resource of metabolically intact tissue. Implantation of deep brain stimulation (DBS) electrodes into the human brain is a neurosurgical treatment for, e.g., movement disorders. Here, we describe an improved approach to collecting brain tissues from surgical instruments used in implantation of DBS device for transcriptomics and proteomics analyses. METHODS: Samples were extracted from guide tubes and recording electrodes used in routine DBS implantation procedure to treat patients with Parkinson's disease, genetic dystonia and tremor. RNA sequencing was performed in tissues extracted from the recording microelectrodes and liquid chromatography-mass spectrometry (LC-MS) performed in tissues from guide tubes. To assess the performance of the current approach, the obtained datasets were compared with previously published datasets representing brain tissues. RESULTS: Altogether, 32,034 RNA transcripts representing the unique Ensembl gene identifiers were detected from eight samples representing both hemispheres of four patients. By using  LC-MS, we identified 734 unique proteins from 31 samples collected from 14 patients. The datasets are available in the BioStudies database (accession number S-BSST667). Our results indicate that surgical instruments used in DBS installation retain brain material sufficient for protein and gene expression studies. Comparison with previously published datasets obtained with similar approach proved the robustness and reproducibility of the protocol. CONCLUSIONS: The instruments used during routine DBS surgery are a useful source for obtaining fresh brain tissues from living patients. This approach overcomes the issues that arise from using postmortem tissues, such as the effect of postmortem interval on transcriptomic and proteomic landscape of the brain, and can be used for studying molecular aspects of DBS-treatable diseases.