The El Salvadoran fisherman who survived 13 months drifting in the Pacific will undergo additional medical tests and stay in hospital until at least Monday.
Doctors who have seen Jose Salvador Alvarenga since he returned to El Salvador on Tuesday say he is in remarkable physical shape but needs psychological attention following his ordeal.
They say a neurosurgeon will examine the results of an MRI brain scan performed on Friday.
A psychiatrist Angel Fredi Sermeno says the fisherman was now terrified of the sea, and he was suffering from post-traumatic stress disorder and mental exhaustion that often made him cry.
