I'm curious as to what can cause stuttering all of the sudden?

Neurogenic stutter-: ing can be caused by a variety of injuries or diseases of the Central Nervous System. See http://www.stutteringhelp.org/neurogenic-stuttering. Psychogenic stuttering could follow an anxiety-provoking event, especially in a person with a prior history of speech/language disorders. Stuttering during " the age of dysfluency", 2-5 years, of sudden or gradual onset, may go away on its own within 6 mos.