Highly concentrated solutions are disclosed along with methods of inhibiting and/or ameliorating functional neurological disorders of the brain. The method may include administering directly to a brain of a subject a medicament multiple times over a time period of at least two days. The medicament may include a half-life of less than 2 hour in the cerebrospinal fluid. The method may include inhibiting and/or ameliorating a functional neurological disorder of the brain using the medicant.