A woman regained full consciousness on Christmas Eve after 16 years in a coma-like state.

Patricia White Bull, 42, slipped into a catatonic state while giving birth to her fourth child at a hospital in Albuquerque, New Mexico, US.

Since then she has been unable to speak, swallow or move much.

But on Christmas Eve she suddenly snapped back into consciousness, telling staff who were trying to fix her nursing home bed: "Don't do that."

Doctors cannot explain why Ms White Bull suddenly regained consciousness.

Ms White Bull's condition was caused by a blood clot that lodged in her lung and caused her to stop breathing while her son Mark Junior was being delivered by Caesarean section.

She was resuscitated but suffered brain damage from lack of oxygen.

Family developments

Since she regained full consciousness, Ms White Bull has been speaking her children's names and catching up on family developments.

Her speech is clear but limited. Her hands, which had been clenched tightly for 16 years, have loosened and she has been able to take a few shaky steps.

Ms White Bull's children have been raised by their father on the Standing Rock Sioux Reservation in South Dakota.

For three years after Ms White Bull slipped into a catatonic state, her husband kept the children in Albuquerque.

But after doctors told him that his partner would stay in a coma for the rest of her life he moved his children to the reservation so they could be raised with the help of his family.