Is trigeminal neuralgia a symptom of multiple sclerosis?

Possibly. Trigeminal neuralgia in a younger adult may be caused by multiple sclerosis. However, there must be more than just trigeminal neuralgia to define definite ms. History of other suspicious symptoms, abnormalities on neuro exam other than just trigeminal neuralgia and supplemental diagnostic studies will better define the suspicion for ms.
YES. Trigeminal neuralgia can indeed be a complication of MS lesions within the brain stem afflicting the trigeminal nerve, or its connections.