How does urinary tract infection cause delirium?

Answer 1

The real answer is we don't know. That being said, there is a lot of speculation that the inflammatory response causes a release of inflammatory mediators such as cytokines which cause a dissociation in neurotransmitters, presumably affecting the hippocampus.

Fluid and electrolyte abnormalities are frequently encountered as contributing factors in elderly delirium. Dehydration coupled with electrolye and/or glucose imbalance (and inflammatory markers that change blood flow and composition) may be at the heart of the process underlying delirium caused by UTIs. This process remains poorly understood.