"There is possibility of further brain damage. We will get to know tomorrow after a CT scan," Dr Nishant, a neurosurgeon at the hospital said.
The child's father Sherif and stepmother Aneesha have been charged with attempt to murder after investigations revealed they had tortured the little boy for years. They had brought him to the hospital claiming he had been hurt in a fall while taking his bath.
Relatives crowding the hospital corridors have not been allowed anywhere near the child. Adopted by the state, the boy is now solely under the care of the hospital staff and the Child Helpline, the body designated by Child Welfare Committee. The state government has said it would spare no expense in the child's treatment.
In the Kumali town where the boy lived, neighbours are stunned with the abuse that stayed hidden, although they had often heard the boy crying.
"I have seen the mother drag the child around, pinch him, I have heard the child cry many times in a day," a neighbor, Vasu, told NDTV.
"Neighbors told us the child was not allowed outside. And at home, he would be absolutely quiet when there were visitors," added Investigating Officer CI Binu Kumar.
The police say the boy's brother was sent to an orphanage because of frequent fights in the family, but the details are not immediately clear.
After such instances of child brutality in the state, Kerala Chief Minister Oommen Chandy has talked about a separate law and set up a panel to suggest guidelines for child safety.