Final answer:
Symptomatic trigeminal neuralgia is primarily caused by vascular compression on the trigeminal nerve, although infections by the herpes zoster virus and HSV-1 can also contribute to the condition.
Step-by-step explanation:
Symptomatic trigeminal neuralgia is primarily caused by vascular compression on the trigeminal nerve. This condition occurs when a blood vessel is pressing on the nerve, leading to the characteristic severe facial pain associated with trigeminal neuralgia.
Other factors that can contribute to symptomatic trigeminal neuralgia include infection by the herpes zoster virus, which can cause the development of painful lesions on the face or trunk, and infection by HSV-1 (herpes simplex virus type 1), which can lead to cold sores or fever blisters.
In summary, vascular compression, herpes zoster virus infection, and HSV-1 infection can all cause symptomatic trigeminal neuralgia.