Holistic Health Articles and Research Related to Herbal Medicines, Foods and Phytochemicals : Trigeminal neuralgia

Monday 2 December 2013

Trigeminal neuralgia - Diagnosis and Misdiagnosis

Trigeminal neuralgia is defined as a condition of episodes of intense facial pain as a result of the affect of trigeminal nerve, containing 3 branches. The first (upper) branch includes the eye, eyebrow, and forehead. The second (middle) branch corresponds to the upper lip, upper teeth, upper gum, cheek, lower eyelid, and side of the nose. The third (lower) branch involves the lower lip, lower teeth, lower gum, and one side of the tongue. It also includes a narrow area that extends from the lower jaw in front of the ear to the side of the head(1). The pain is nearly always unilateral, and it may occur repeatedly throughout the day(2).
Diagnosis and Misdiagnosis
A. Misdiagnosis
1. Acute dental pain
Pre-trigeminal and atypical neuralgias are amongst the possible differential diagnoses of acute dental pain. * In a patient with nonodontogenic pain, simultaneous dental pain in the same area could be overlooked. * Dentists should consider a nonodontogenic origin as a possible explanation for burning, lancinating or atypical pain. In such cases, an appropriate medical specialist should be consulted, according to Dr. Sanner F.(12)

2. Paroxysmal orofacial pains
Paroxysmal orofacial pains can cause diagnostic problems, especially when different clinical pictures occur simultaneously. Pain due to pulpitis, for example, may show the same characteristics as pain due to trigeminal neuralgia would. Moreover, the trigger point of trigeminal neuralgia can either be located in a healthy tooth or in the temporomandibular joint. Neuralgic pain is distinguished into trigeminal neuralgia, glossopharyngeal neuralgia, Horton's neuralgia, cluster headache and paroxysmal hemicrania, according to Dr. de Bont LG. at the Universitair Medisch Centrum, Groningen(13).

3. Trigeminal neuralgia and other facial pain
Attacks of facial pain are often triggered by cutaneous stimuli to the face or the oral cavity, which may be such minor activities as talking, chewing, brushing the teeth, or even wind blowing on the face. As a result, facial hygiene as well as a good diet may be neglected. Although 1% of the patients may eventually develop the disorder bilaterally, pain does not cross the midline during any single episode. The clinical course is characterized by exacerbations and remissions, but as the disorder progresses, remissions become shorter and exacerbations more severe. If the trigeminal neuralgia may be considered as a nerve irritation, like the glossopharyngeal neuralgia and the nasociliary neuralgia, nerve lesion may elicit neurogenic or neuropathic pain, characterized by chronic burning pain; post-zoster pain, iatrogenic and posttraumatic pain illustrate this condition. Cluster headache (Horton neuralgia), Sluder's neuralgia and auriculotemporal neuralgia may be related to a dysfunction of the autonomous nervous system(14).

4. Leprosy
There is a report of healthy without any overt features suggestive of infection patient who had migrated to Australia from India 24 years previously, but a review of the literature revealed that the trigeminal nerve is frequently involved in leprosy, usually associated with sensory loss rather than neuropathic pain(15).

5 Etc.

B. Diagnosis
The diagnosis is typically determined clinically, although imaging studies or referral for specialized testing may be necessary to rule out other diseases. Accurate and prompt diagnosis is important because the pain of trigeminal neuralgia can be severe(16).
According to International Headache Society diagnostic criteria for trigeminal neuralgia, Trigeminal neuralgia is diagnosed depending to
Classical

Paroxysmal attacks of pain lasting from a fraction of a second to 2 min, affecting one or more divisions of the trigeminal nerve, and fulfilling criteria B and C
Pain has at least one of the following characteristics:
1. Intense, sharp, superficial, or stabbing
2. Precipitated from trigger zones or by trigger factors
Attacks are sterotyped in the individual patient
There is no clinically evident neurologic deficit
Not attributed to another disorder

Symptomatic

Paroxysmal attacks of pain lasting from a fraction of a second to 2 min, with or without persistence of aching between paroxysms, affecting one or more divisions of the trigeminal nerve, and fulfilling criteria B and C
Pain has at least one of the following characteristics:
1. Intense, sharp, superficial, or stabbing
2. Precipitated from trigger zones or by trigger factors
Attacks are sterotyped in the individual patient
A causative lesion, other than vascular compression, has been demonstrated by special investigations and/or posterior fossa exploration(17)

MRI is particularly useful in planning the management of those conditions where surgical or medical intervention can result in improvement or resolution of symptoms and to exclude the symptomatic TN due to multiple sclerosis and tumors.