What do you think is the cause of the patient's presentation?
Left extra-axial collection.
Extra-axial collection related to the previous left sided craniotomy is again demonstrated, with a fluid fluid level seen posteriorly on some images suggesting an acute on chronic subdural.
More worrying, here's a locule of what is thought to be is gas seen superiorly which was not evident on previous imaging and raises the possibility of this representing an evolving subdural empyema. Appearances are otherwise unchanged, or encephalomalacia involving the superior aspect of the left frontal lobe in keeping with the previous surgery.
No hydrocephalus. No midline shift. No infarct or intraparenchymal haemorrhage.