Permanent incapacity of President or Vice-President
Section 144(2) · 1999 Constitution (2004 edition)
What Constitution says
(2) Where the medical panel certifies in the report that in its opinion the President or Vice- President is suffering from such infirmity of body or mind as renders him permanently incapable of discharging the functions of his office, a notice thereof signed by the President of the Senate and the Speaker of the House of Representatives shall be published in the Official Gazette of the Government of the Federation.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 72–73. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections