Louisiana, La. Op. Att’y Gen. 963 (1942) provides:
"In answer to your second question, the only method by which persons can change their names in this State is that authorized by the act above quoted and we do not recognize the common law right to take and use any name desired unless and until the formalities prescribed by our acts of the Legislature have been fully complied with."

Common Law Name changes invalid according to The Right to Control One’s Name, Kushner UCLA law review:
In the 1940s an attorney general opinion in Louisiana asserted that the state did not recognize a common law right to change one’s name. See La. Op. Att’y Gen. 963 (1942). Louisiana law is derived from the French civil law tradition, rather than the British common law tradition; this likely accounts for the difference between Louisiana’s approach to abrogation and that of other states.