ElectrodesCraniotomyElectrodes, ImplantedNeurosurgical ProceduresPneumocephalusIon-Selective ElectrodesFrontal BoneHematoma, Subdural, AcuteElectrochemistryTrephiningSubdural SpaceHead Injuries, PenetratingElectrochemical TechniquesBrain NeoplasmsDelayed Emergence from AnesthesiaHematoma, SubduralDura MaterIntracranial AneurysmMeningeal NeoplasmsSurgical Fixation DevicesSupratentorial NeoplasmsFrontal SinusMicroelectrodesStereotaxic TechniquesTemporal BoneMeningiomaOligonucleotide Array Sequence AnalysisArachnoid CystsMicrosurgeryTomography, X-Ray ComputedGlasgow Coma ScaleHematoma, Epidural, CranialMagnetic Resonance ImagingHematoma, Subdural, ChronicCerebrospinal Fluid RhinorrheaCranial Fossa, AnteriorFourth VentricleBiosensing TechniquesPotentiometryNeurosurgery