Trigeminal neuralgia provocation Patients with trigeminal neuralgia often describe a specific trigger stimulus, such as provocation by touching the face or cheek, provocation by talking, swallowing, and many patients report that exposure of the face to cold can also trigger the pain. Cutaneous triggers are often triggered by non-injurious stimuli and are often confined to the anterior region. The area of trigger is often ipsilateral to the pain, but can be caused by the same or different trigeminal nerve branches. Trigger areas outside of the trigeminal innervation territory are rare and are often found in the skin of the upper cervical segment. Patients with trigger points on the scalp often refuse to wash or comb their hair, shaving is not possible for patients with trigger points on the upper lip or face, and oral hygiene is not possible for patients with trigger points on the teeth or gums. When swallowing or chewing excites pain, it may affect the patient’s ability to eat and drink, and in severe cases, malnutrition or dehydration may occur. Distribution of trigeminal neuralgia pain The vast majority of patients with trigeminal neuralgia have pain that is confined to the cortical area innervated by the trigeminal nerve. A small percentage of pain occurs in the trigeminal innervation area and the innervation areas of the middle nerve (VIII), the glossopharyngeal nerve (IX) and the vagus nerve (X) at the same time. The most common site of pain is the area innervated by the second and third branches of the trigeminal nerve, and the least common is the area jointly innervated by the first and third branches. The buccal region is the most frequent site of trigeminal neuralgia. The pain syndrome can occur in any part of the face and forehead, and all combinations of pain sites have been reported. The course of trigeminal neuralgia Trigeminal neuralgia is an intermittent attack, with many cases reporting an interval of months or even years between attacks. Recurrences are almost always in the same area of the face, but the pain tends to be more widespread. The interictal period is usually progressively shorter while the severity and frequency of attacks increase. Some patients experience no relief once the disease is present. Patients often complain of small, non-invasive stabbing pains in the painful area during episodes of severe pain. Physiological and psychological stress significantly increases the level of pain in patients with trigeminal neuralgia, but there is no evidence that stress is the cause of the disorder. Diagnosis and differential diagnosis of trigeminal neuralgia Trigeminal neuralgia must be distinguished from other facial pain. The criteria that have been discussed are sufficient to form a diagnosis, but there is no supporting diagnosis available to determine the presence of trigeminal neuralgia. It is therefore necessary to distinguish trigeminal neuralgia from similar pain syndromes caused by other cranial nerves, which can be identified by detailed history taking and physical examination to determine the precise trigger point and pain site. It is also important to distinguish the condition from atypical facial pain that occurs unilaterally. Atypical facial pain occurs most often in young women, is characterized by a persistent burning pain rather than a discharge-like pain, and is not triggered, often outside the innervated territory of the trigeminal nerve. Facial myalgia involving the masticatory muscles and TMJ pain can be difficult to distinguish from each other, but should not be confused with trigeminal neuralgia. Pain in this group of syndromes occurs primarily in the posterior face and presents as aching, burning, and spasmodic pain associated with the use of the jaw and its muscles, with tension in the associated muscles on palpation and radiation to the headboard and neck. Cluster headache and other triple and autonomic nerve-related pains are usually intermittent burning, cutting, or throbbing pains with definite episodes and autonomic symptoms such as lacrimation, runny eyes, facial sweating, and redness. Onset is clustered or random, with a variety of presentations. Localized pathological changes in the sinuses, jaws, teeth, pharynx, or skull base can cause severe pain. This facial pain is often constant and described as aching, throbbing, or burning, but rarely discharge-like pain. The pain is not triggered by a non-injurious stimulus away from the painful area, and if a nerve branch is involved, a sensory deficit is produced. Physical examination and appropriate ancillary diagnoses usually suggest the presence of a focal lesion.