Unrest, filmmaker Jennifer Brea’s debut feature about her seven years bedbound after a severe virus, traveled the world and connected her to a neurosurgeon who found that abnormalities—including severe brainstem compression—were underlying her symptoms. A series of neurosurgeries got her out of a wheelchair and led to a seemingly miraculous remission.

4mm picks up where Unrest left off, documenting the story of physicians, patients, and researchers on the frontlines of one of the greatest medical mysteries of our times. A sporadic infection, a pandemic, pregnancy, trauma – all seemingly unrelated events – strike a subset of the population with debilitating neurological symptoms. Many patients — an estimated 215 million around the world — spend years or decades disabled, homebound, or bedridden.

Jennifer documents the world of neurosurgeons, neurologists, immunologists, and internists who have been working with patients with ME, Long Covid, Ehlers-Danlos Syndrome, POTS, Lyme, MCAS and related conditions under the radar. What they all share in common is the ability to see patterns other physicians can’t — or won’t — see. Renegades in every sense, will their ideas break through to mainstream medicine or remain buried in history, as has happened so many times before?