Dr. Richardson initially presents with severe nausea and vomiting attributed to bad sushi, keeping him bedridden. This drives the central plot as his absence as the only neurosurgeon threatens to shut down the ER and ICU. The team must diagnose and treat him urgently to keep the hospital operational.
Also known as: Pufferfish poisoning
The true diagnosis - Richardson consumed toad roe (eggs) at a seafood festival, causing nausea, delirium, and bizarre behavior including stripping. This is the actual condition requiring treatment with a fast-acting antidote to restore his mental function so he can return to work as a neurosurgeon.
Also known as: Huntington's disease
Thirteen's Huntington's disease is referenced as she discusses joining a clinical trial in Rome involving fetal neural transplantation. This is part of her ongoing character arc with the degenerative condition, though it's revealed at episode's end that she lied about the trial.