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Trigeminal neuralgia (TN, or TGN), also known as prosopalgia, tic doloureux, or Fothergill's disease is a neuropathic disorder characterized by episodes of intense pain in the face. It has been described as among the most painful conditions known. The pain originates from a variety of different locations on the face and may be felt in front of the ear, eye, lips, nose, scalp, forehead, cheeks, mouth, or jaw and side of the face. The pain of TN is from the trigeminal nerve. The trigeminal nerve is a paired cranial nerve that has three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). One, two, or all three branches of the nerve may be affected. 1–6% of cases occur on both sides of the face but extremely rare for both to be affected at the same time.〔http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC4258705〕 Trigeminal neuralgia most commonly involves the middle branch (the maxillary nerve or V2) and lower branch (mandibular nerve or V3) of the trigeminal nerve.〔(Trigeminal neuralgia and hemifacial spasm ) by UF&Shands – The University of Florida Health System. Retrieved Mars 2012〕 There are a variety of treatment options, both surgical and medical, for trigeminal neuralgia.〔Satta Sarmah (2008). "Nerve disorder's pain so bad it's called the 'suicide disease'". ''Medill Reports Chicago''. http://news.medill.northwestern.edu/chicago/news.aspx?id=79817〕 Carbamazepine is considered the first line treatment. It is estimated that 1 in 15,000 or 20,000 people have TN, although the actual figure may be significantly higher due to misdiagnosis. In most cases, TN symptoms begin appearing over the age of 50, although there have been cases with people being as young as three years of age. It is more common in females than males.〔(【引用サイトリンク】first=R )〕 Trigeminal neuralgia was first described by physician John Fothergill and treated surgically by John Murray Carnochan, both of whom were graduates of the University of Edinburgh Medical School. ==Signs and symptoms== This disorder is characterized by episodes of intense facial pain. Each individual attack of pain lasts from a few seconds to several minutes or hours, but these can repeat for hours with very short intervals between each attack. In other instances only 4-10 attacks are experienced daily. The episodes of intense pain may occur paroxysmally. To describe the pain sensation, patients often describe a trigger area on the face so sensitive that touching or even air currents can trigger an episode; however, in many patients the pain is generated spontaneously without any apparent stimulation. It affects lifestyle as it can be triggered by common activities such as eating, talking, shaving and brushing teeth. Wind, chewing and talking can aggravate the condition in many patients. The attacks are said by those affected to feel like stabbing electric shocks, burning, exploding, sharp, pressing, crushing, exploding or shooting pain that becomes intractable. The pain also tends to occur in cycles with remissions lasting months or even years. 1-6% of cases occur on both sides of the face. This normally indicates problems with both trigeminal nerves, since one serves strictly the left side of the face and the other serves the right side. Pain attacks are known to worsen in frequency or severity over time, in some patients. Pain may migrate to other branches over time but in some patients remains very stable. Rapid spreading of the pain, bilateral involvement or simultaneous participation with other major nerve trunks (such as Tic Convulsive of nerves V & VII or occurrence of symptoms in the V and IX nerves) may suggest a systemic cause. Systemic causes could include multiple sclerosis or expanding cranial tumours. The severity of the pain makes it difficult to wash the face, shave, and perform good oral hygiene. The pain has a significant impact on activities of daily living especially as patients live in fear of when they are going to get their next attack of pain and how severe it will be. It can lead to severe depression and anxiety.〔http://www.ncbi.nlm.nih.gov/pubmed/24171179〕 However, not all patients will have the symptoms described above and there are variants of TN. One of which is atypical trigeminal neuralgia ("trigeminal neuralgia, type 2" or trigeminal neuralgia with concomitant pain ),〔(【引用サイトリンク】title=Neurological surgery: facial pain )〕 based on a recent classification of facial pain. In these instances there is also a more prolonged lower severity background pain that can be present for over 50% of the time and is described more as a burning or prickling, rather than a shock. Trigeminal neuropathic pain is similar to TN2 but can have the electric pulses associated with classic TN. The pain is usually constant and can also give off a tingling, numbness sensation. This pain is due to unintentional damage to one or more of the trigeminal nerves from trauma, oral surgery, dentistry work, etc. It is difficult to treat but sufferers are usually given the same anticonvulsant and tricyclics antidepressant medicines as with the other types of neuralgias. Surgical options are DREZ (dorsal root entry zone) lesion and MCS or Motor Cortex Stimulation. TN needs to be distinguished from other forms of unilateral pain which is related to damage to the trigeminal nerve by trauma to the face or dental treatments. This is often termed painful trigeminal neuropathy or post traumatic neuropathy as some sensory changes can be noted e.g. decrease in pain sensation or temperature. This is important as different carepathways are used. Trigeminal pain can also occur after an attack of herpes zoster and post herpetic neuralgia has the same manifestations as in other parts of the body. Trigeminal deafferentation pain (TDP) also termed anaesthesia dolorosa is from intentional damage to a trigeminal nerve following attempts to surgically fix a nerve problem. this pain is usually constant with a burning sensation and numbness. TDP is very difficult to treat as further surgeries are usually ineffective and possibly detrimental to the patient. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Trigeminal neuralgia」の詳細全文を読む スポンサード リンク
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