How Viruses Reshape the Brain: Imaging Neuroinflammation and Cancer Pathways with Claudia Kirsch

Episode notes

When COVID-19 began flooding hospitals, neuroradiologists started seeing something alarming. Dr. Claudia Kirsch recalls reading cases involving venous infarcts, massive inflammation, and devastating brain injury. Patients were experiencing hemorrhages and large infarctions linked to the virus. It was a wake-up cal, one that drove her to investigate how SARS-CoV-2 was affecting the brain at a structural and biological level. One of the earliest mysteries? Smell loss. Patients were losing their sense of smell without sinus inflammation. The virus requires ACE2 receptors to enter cells, yet those receptors are limited in the olfactory bulb. So how was it reaching the brain? Emerging hypotheses point toward alternative pathways, including vascular spread and lesser-known neural structures such as the nervus terminalis, tiny unmyelinated fibers that connect the olfactory region to the hypothalamus and are associated with nitric oxide signaling, immune response, and blood supply regulation. These discoveries extend beyond COVID. The episode also explores how viruses influence inflammation more broadly including their role in cancer biology and immune modulation.