Atypical facial pain

Some sources list some non-specific signs that may be associated with AFP/AO. These include increased temperature and tenderness of the mucosa in the affected area, which is otherwise normal in every regard. ==Causes==

Health care associated Sometimes dental treatment or surgical procedures in the mouth appear to precede the onset of AFP, or sometimes persons with AFP will blame clinicians for their pain. "Neuralgia-inducing cavitational osteonecrosis" Neuralgia-inducing cavitational osteonecrosis (NICO) is a controversial term, and it is questioned to exist by many. Osteonecrosis of the jaws refers to the death of bone marrow in the maxilla or the mandible due to inadequate blood supply. It is not necessarily a painful condition, typically there will be no pain at all unless bone necrotic bone becomes exposed to the mouth or through the facial skin, and even then this continues to be painless in some cases. When pain does occur, it is variable in severity, and may be neuralgiform or neuropathic in nature. The term NICO is used to describe pain caused by ischemic osteonecrosis of the jaws, where degenerative extracellular cystic spaces (cavitations inside the bone) are said to develop as a result of ischemia and infarctions in the bone marrow, possibly in relation to other factors such as a hereditary predisposition for thrombus formation within blood vessels, chronic low-grade dental infections and the use of vasoconstrictors in local anesthetics during dental procedures. This proposed phenomenon has been postulated to be the cause of pain in some patients with AFP or trigeminal neuralgia, but this is controversial. NICO is said to be significantly more common in females, and the lesions may or may not be visible on radiographs. When they are visible, the appearance is very variable. About 60% of the lesions appear as a "hot spot" on a technetium 99 bone scan. Proponents of NICO recommend decortication (surgical removal of a section of the cortical plate, originally described as a treatment for osteomyelitis of the jaws) and curettage of the necrotic bone from the cavitation, and in some reported cases, this has relieved the chronic pain. However, NICO appears to show a tendency to recur and develop elsewhere in the jaws. The American Association of Endodontists Research and Scientific Affairs Committee published a position statement on NICO in 1996, stating: Atypical trigeminal neuralgia Some suggest that AFP is an early form of trigeminal neuralgia. Psychologic Sometimes stressful life events appear to precede the onset of AFP, such as bereavement or illness in a family member. Hypochondriasis, especially cancerophobia, is also often cited as being involved. Most people with AFP are "normal" people who have been under extreme stress, however other persons with AFP have neuroses or personality disorders, and a small minority have psychoses. Some have been separated from their parents as children. Depression, anxiety and altered behavior are strongly correlated with AFP. It is argued whether this is a sole or contributing cause of AFP, or the emotional consequences of suffering with chronic, unrelieved pain. It has been suggested that over 50% of people with AFP have concomitant depression or hypochondria. Furthermore, about 80% of persons with psychogenic facial pain report other chronic pain conditions such as listed in the table. ==Diagnosis==

• Migraine • Dental diseases • Neoplasia • Infection AFP and AO can be difficult to diagnose, Excluding an organic cause for the pain is the most important part of the diagnosis. Odontogenic pain should especially be ruled out, since this accounts for over 95% of cases of orofacial pain. There is considerable symptom overlap between atypical facial pain and temporomandibular joint dysfunction. However, there is a degree of overlap between the features of these diagnoses, e.g. between AFP and TMD and burning mouth syndrome. Atypical odontalgia is similar in nature to AFP, but the latter term generally is used where the pain is confined to the teeth or gums, and AFP when the pain involves other parts of the face. Atypical odontalgia There are no globally accepted definitions of AO, but some suggested definitions are listed below: • "continuous pain in the teeth or in a tooth socket after extraction in the absence of any identifiable dental cause," (International headache society, description included as a side note of "persistent idiopathic facial pain" in the ICHD-2, i.e. with no separate diagnosis for atypical odontalgia). • "Severe throbbing pain in the tooth without major pathology" (IASP definition in the "Classification of Chronic Pain", listing AO as "tooth pain not associated with lesions"). • "pain and hypersensitive teeth in the absence of detectable pathology". Originally, AFP was intended to describe a group of individuals whose response to neurosurgical procedures was not typical. Another cited reason for discontinuing use of the term AFP is that some cases appear to follow surgeries or injuries involving the face, teeth and gums, possibly suggesting infectious or traumatic etiologies. Despite the controversy surrounding the use of the term, it has a long history, and it is still in common use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments. Classic trigeminal neuralgia refers to sudden, shooting pain in the face, which is usually short lived and brought on by accidental stimulation of trigger points on the face, as may occur when washing. Trigeminal neuralgia has been described as one of the most painful conditions possible. Trigeminal neuralgia and AFP are traditionally considered separate, since AFP typically involves constant, often burning pain and trigeminal neuralgia classically shows paroxysmal, shooting pain, but in reality there is some overlap in their features. This last category (TN7) was termed atypical facial pain, although many cases that would otherwise be traditionally labelled as AFP would fall into other groups in this classification, especially into the second group. In a publication of the Trigeminal Neuralgia Association (TNA), the following was said about this new classification and AFP: As a result, some sources list terms such as "atypical trigeminal neuralgia", "trigeminal neuropathic pain" and "atypical facial neuralgia" as synonyms of AFP. ICHD-2 Diagnostic criteria The ICHD-2 lists diagnostic criteria for "persistent idiopathic facial pain" (the term that replaces AFP in this classification): ::A. Pain in the face, present daily and persisting for all or most of the day, fulfilling criteria B and C, ::B. Pain is confined at onset to a limited area on one side of the face, and is deep and poorly localized, ::C. Pain is not associated with sensory loss or other physical signs, ::D. Investigations including x-ray of face and jaws do not demonstrate any relevant abnormality. There are presently no accepted medical tests which consistently discriminate between facial pain syndromes or differentiate Atypical Facial Pain from other syndromes. However, a normal Radiograph, CT, and MRI may help to exclude other pathology such as arterio-veinous malformation, tumor, temporomandibular joint disorder, or MS. ==Management==

Psychosocial interventions Psychosocial interventions for AFP include cognitive behavioral therapy and biofeedback. A systematic review reported that there was weak evidence to support the use of these treatments to improve long-term outcomes in chronic orofacial pain, however these results were based primarily upon temporomandibular joint dysfunction and burning mouth syndrome rather than ATP and AO. Psychosocial interventions assume 2 models of chronic facial pain, namely "inactivity" and "over activity". The former is where people with pain become conditioned to avoid physical activity as a result of exacerbating their pain. These negative thoughts and behaviors in fact prolong and intensify their symptoms. Some psychosocial interventions work on this fear-avoidance behaviour to improve functioning and thereby alleviate symptoms. The over activity model involves factors such as anxiety, depression or anger acting to increase pain by triggering autonomic, visceral and skeletal activity. Medication • Analgesics • Antidepressants • Centrally acting muscle relaxants • Anticonvulsants Surgical Some have suggested that surgery is not an appropriate for treatment for AFP, however the frequent failure medical treatment to relieve pain has occasionally lead surgeons to attempt surgical treatments. Surgery may give a temporary remission from pain, but rarely is there a long term cure achieved via these measures. Sometimes the pain may be increased or simply migrate to an adjacent area following a surgical procedure. Descriptions of procedures such as removal of a portion of the affected branch of the trigeminal nerve, or direct injections of a caustic substance (e.g. phenol, glycerol, alcohol) into the nerve have been reported. Proponents of the so-called "Neuralgia inducing cavitational necrosis" suggest surgical exploration of the bone marrow surrounding the intra-bony course of the affected nerve to discover diseased marrow. ==Prognosis==

Research suggests that people with AFP are not helped greatly by health care professionals.