This disorder is characterized by episodes of severe facial pain along the trigeminal nerve divisions. The trigeminal nerve is a paired cranial nerve that has three major branches: the ophthalmic nerve (V), the maxillary nerve (V), and the mandibular nerve (V). One, two, or all three branches of the nerve may be affected. Trigeminal neuralgia most commonly involves the middle branch (the maxillary nerve or V) and lower branch (mandibular nerve or V) of the trigeminal nerve.

An individual attack usually lasts from a few seconds to several minutes or hours, but these can repeat for hours with very short intervals between attacks. In other instances, only 4-10 attacks are experienced daily. The episodes of intense pain may occur paroxysmally. To describe the pain sensation, people often describe a trigger area on the face so sensitive that touching or even air currents can trigger an episode; however, in many people, 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. The 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, 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 but extremely rare for both to be affected at the same time. 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 people. Pain may migrate to other branches over time but in some people remains very stable.

Rapid spreading of the pain, bilateral involvement or simultaneous participation with other major nerve trunks (such as Painful Tic Convulsif 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 tumors.

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 people 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.

However, not all people 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 ), 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 are 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 care pathways 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 anesthesia 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 person.

Trigeminal neuralgia (TN or TGN) is a chronic pain disorder that affects the trigeminal nerve. There are two main types: typical and atypical trigeminal neuralgia. The typical form results in episodes of severe, sudden, shock-like pain in one side of the face that lasts for seconds to a few minutes. Groups of these episodes can occur over a few hours. The atypical form results in a constant burning pain that is less severe. Episodes may be triggered by any touch to the face. Both forms may occur in the same person. It is one of the most painful conditions and can result in depression.

The exact cause is unclear but believed to involve loss of the myelin around the trigeminal nerve. This may occur due to compression from a blood vessel as the nerve exits the brain stem, multiple sclerosis, stroke, or trauma. Less common causes include a tumor or arteriovenous malformation. It is a type of nerve pain. Diagnosis is typically based on the symptoms after ruling out other possible causes such as postherpetic neuralgia.

Treatment includes medication or surgery. The anticonvulsant carbamazepine or oxcarbazepine is the usual initial treatment and is effective in about 80% of people. Other options include lamotrigine, baclofen, gabapentin, and pimozide. Amitriptyline may help with the pain but opioids are not usually effective in the typical form. In those who do not improve or become resistant to other measures, a number of types of surgery may be tried.

It is estimated that 1 in 8,000 people develop trigeminal neuralgia a year. It usually begins in people over 50 years old, but can occur at any age. Women are more commonly affected than men. The condition was first described in detail in 1773 by John Fothergill.

Symptoms:

- With resolution of the herpes zoster eruption, pain that continues for three months or more is defined as postherpetic neuralgia.

- Pain is variable, from discomfort to very severe, and may be described as burning, stabbing, or gnawing.

Signs:

- Area of previous herpes zoster may show evidence of cutaneous scarring.

- Sensation may be altered over the areas involved, in the form of either hypersensitivity or decreased sensation.

- In rare cases, the patient might also experience muscle weakness, tremor, or paralysis if the nerves involved also control muscle movement.

ATN pain can be described as heavy, aching, stabbing, and burning. Some sufferers have a constant migraine-like headache. Others may experience intense pain in one or in all three trigeminal nerve branches, affecting teeth, ears, sinuses, cheeks, forehead, upper and lower jaws, behind the eyes, and scalp. In addition, those with ATN may also experience the shocks or stabs found in type 1 TN.

Many TN and ATN patients have pain that is "triggered" by light touch on shifting trigger zones. ATN pain tends to worsen with talking, smiling, chewing, or in response to sensations such as a cool breeze. The pain from ATN is often continuous, and periods of remission are rare. Both TN and ATN can be bilateral, though the character of pain is usually different on the two sides at any one time.

Geniculate ganglionitis or geniculate neuralgia (GN), also called nervus intermedius neuralgia, Ramsay Hunt syndrome, or Hunt's neuralgia, is a rare disorder characterized by severe paroxysmal neuralgic pain deep in the ear, that may spread to the ear canal, outer ear, mastoid or eye regions. GN may also occur in combination with trigeminal or glossopharyngeal neuralgia.

The pain of GN is sharp, shooting or burning and can last for hours. Painful attacks can be triggered by cold, noise, swallowing or touch, but triggers are usually unique to the sufferer. Other related symptoms that may be experienced include increased salivation, bitter taste, tinnitus and vertigo.

GN is rare, and only limited data is available regarding the incidence, prevalence, and risk factors associated with this condition. Middle-aged adults, however, seem to be predominantly affected, women more than men.

GN may be caused by compression of somatic sensory branch of cranial nerve VII which goes through the nervus intermedius. In sufferers of GN, signals sent along these nerves are altered and interpreted by the geniculate ganglion (a structure in the brain) as GN pain. GN may also develop following herpes zoster oticus (Ramsay Hunt syndrome), where cold sores occur on the ear drum or ear. This may also be associated with facial paresis (weakness), tinnitus, vertigo and deafness. Disorders of lacrimation, salivation and/or taste sometimes accompany the pain. There is a common association with herpes zoster.

Atypical trigeminal neuralgia (ATN), or type 2 trigeminal neuralgia, is a form of trigeminal neuralgia, a disorder of the fifth cranial nerve. This form of nerve pain is difficult to diagnose, as it is rare and the symptoms overlap with several other disorders. The symptoms can occur in addition to having migraine headache, or can be mistaken for migraine alone, or dental problems such as temporomandibular joint disorder or musculoskeletal issues. ATN can have a wide range of symptoms and the pain can fluctuate in intensity from mild aching to a crushing or burning sensation, and also to the extreme pain experienced with the more common trigeminal neuralgia.

Postherpetic neuralgia is a nerve pain due to damage caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin, and follows an outbreak of herpes zoster (commonly known as shingles) in that same dermatomic area. The neuralgia typically begins when the herpes zoster vesicles have crusted over and begun to heal, but can begin in the absence of herpes zoster—a condition called "zoster sine herpete" (see Herpes zoster).

The symptoms and signs include acute facial nerve paralysis, pain in the ear, taste loss in the front two-thirds of the tongue, dry mouth and eyes, and an erythematous vesicular rash in the ear canal, the tongue, and/or hard palate.

Since the vestibulocochlear nerve is in proximity to the geniculate ganglion, it may also be affected, and patients may also suffer from tinnitus, hearing loss, and vertigo. Involvement of the trigeminal nerve can cause numbness of the face.

Diagnostic criteria:

A. Pain paroxysms of intermittent occurrence, lasting for seconds or minutes, in the depth of the ear

B. Presence of a trigger area in the posterior wall of the auditory canal

C. Not attributed to another disorder

90% of all headaches are primary headaches. Primary headaches usually first start when people are between 20 and 40 years old . The most common types of primary headaches are migraines and tension-type headaches. They have different characteristics. Migraines typically present with pulsing head pain, nausea, photophobia (sensitivity to light) and phonophobia (sensitivity to sound). Tension-type headaches usually present with non-pulsing "bandlike" pressure on both sides of the head, not accompanied by other symptoms. Other very rare types of primary headaches include:

- cluster headaches: short episodes (15–180 minutes) of severe pain, usually around one eye, with autonomic symptoms (tearing, red eye, nasal congestion) which occur at the same time every day. Cluster headaches can be treated with triptans and prevented with prednisone, ergotamine or lithium.

- trigeminal neuralgia or occipital neuralgia: shooting face pain

- hemicrania continua: continuous unilateral pain with episodes of severe pain. Hemicrania continua can be relieved by the medication indomethacin.

- primary stabbing headache: recurrent episodes of stabbing "ice pick pain" or "jabs and jolts" for 1 second to several minutes without autonomic symptoms (tearing, red eye, nasal congestion). These headaches can be treated with indomethacin.

- primary cough headache: starts suddenly and lasts for several minutes after coughing, sneezing or straining (anything that may increase pressure in the head). Serious causes (see secondary headaches red flag section) must be ruled out before a diagnosis of "benign" primary cough headache can be made.

- primary exertional headache: throbbing, pulsatile pain which starts during or after exercising, lasting for 5 minutes to 24 hours. The mechanism behind these headaches is unclear, possibly due to straining causing veins in the head to dilate, causing pain. These headaches can be prevented by not exercising too strenuously and can be treated with medications such as indomethacin.

- primary sex headache: dull, bilateral headache that starts during sexual activity and becomes much worse during orgasm. These headaches are thought to be due to lower pressure in the head during sex. It is important to realize that headaches that begin during orgasm may be due to a subarachnoid hemorrhage, so serious causes must be ruled out first. These headaches are treated by advising the person to stop sex if they develop a headache. Medications such as propranolol and diltiazem can also be helpful.

- hypnic headache: moderate-severe headache that starts a few hours after falling asleep and lasts 15–30 minutes. The headache may recur several times during night. Hypnic headaches are usually in older women. They may be treated with lithium.

Old headaches are usually primary headaches and are not dangerous. They are most often caused by migraines or tension headaches. Migraines are often unilateral, pulsing headaches accompanied by nausea or vomiting. There may be an aura (visual symptoms, numbness or tingling) 30–60 minutes before the headache, warning the person of a headache. Migraines may also not have auras. Tension type headaches usually have bilateral "bandlike" pressure on both sides of the head usually without nausea or vomiting. However, some symptoms from both headache groups may overlap. It is important to distinguish between the two because the treatments are different.

The mnemonic 'POUND' helps distinguish between migraines and tension type headaches. POUND stands for Pulsatile quality, 4–72 hOurs in length, Unilateral location, Nausea or vomiting, Disabling intensity. One review article found that if 4–5 of the POUND characteristics are present, migraine is 24 times as likely a diagnosis than tension type headache (likelihood ratio 24). If 3 characteristics of POUND are present, migraine is 3 times more likely a diagnosis than tension type headache (likelihood ratio 3). If only 2 POUND characteristics are present, tension type headaches are 60% more likely (likelihood ratio 0.41). Another study found the following factors independently each increase the chance of migraine over tension type headache: nausea, photophobia, phonophobia, exacerbation by physical activity, unilateral, throbbing quality, chocolate as headache trigger, cheese as headache trigger.

Cluster headaches are relatively rare (1–3 in 10,000 people) and are more common in men than women. They present with sudden onset explosive pain around one eye and are accompanied by autonomic symptoms (tearing, runny nose and red eye).

Temporomandibular jaw pain (chronic pain in the jaw joint), and cervicogenic headache (headache caused by pain in muscles of the neck) are also possible diagnoses.

For chronic, unexplained headaches, keeping a headache diary can be useful for tracking symptoms and identifying triggers, such as association with menstrual cycle, exercise and food. While mobile electronic diaries for smartphones are becoming increasingly common, a recent review found most are developed with a lack of evidence base and scientific expertise.

Ramsay Hunt syndrome type 2, also known as herpes zoster oticus, is a disorder that is caused by the reactivation of varicella zoster virus in the geniculate ganglion, a nerve cell bundle of the facial nerve.

Ramsay Hunt syndrome type 2 typically presents with inability to move many facial muscles, pain in the ear, taste loss on the front of the tongue, dry eyes and mouth, and a vesicular rash..

The pain occurs only on one side of the head (unilateral), around the eye (orbital), particularly above the eye (supraorbital), in the temple (temporal), or in any combination.

The pain of CH attack is remarkably greater than in other headache conditions, including severe migraine. The pain is typically described as burning, stabbing, boring or squeezing, and may be located near or behind the eye. As a result of the pain, those with cluster headaches may experience suicidal thoughts during an attack (giving the alternative name "suicide headache" or "suicidal headache"). It is reported as one of the most painful conditions.

Atypical facial pain (AFP) is a type of chronic facial pain which does not fulfill any other diagnosis. There is no consensus as to a globally accepted definition, and there is even controversy as to whether the term should be continued to be used. Both the International Headache Society (IHS) and the International Association for the Study of Pain (IASP) have adopted the term persistent idiopathic facial pain (PIFP) to replace AFP. In the 2nd Edition of the International Classification of Headache Disorders (ICHD-2), PIFP is defined as "persistent facial pain that does not have the characteristics of the cranial neuralgias [...] and is not attributed to another disorder." However, the term AFP continues to be used by the World Health Organization's 10th revision of the International Statistical Classification of Diseases and Related Health Problems and remains in general use by clinicians to refer to chronic facial pain that does not meet any diagnostic criteria and does not respond to most treatments.

The main features of AFP are: no objective signs, negative results with all investigations/ tests, no obvious explanation for the cause of the pain, and a poor response to attempted treatments. AFP has been described variably as a medically unexplained symptom, a diagnosis of exclusion, a psychogenic cause of pain (e.g. a manifestation of somatoform disorder), and as a neuropathy. AFP is usually burning and continuous in nature, and may last for many years. Depression and anxiety are often associated with AFP, which are either described as a contributing cause of the pain, or the emotional consequences of suffering with unrelieved, chronic pain. For unknown reasons, AFP is significantly more common in middle aged or elderly people, and in females.

Atypical odontalgia (AO) is very similar in many respects to AFP, with some sources treating them as the same entity, and others describing the former as a sub-type of AFP. Generally, the term AO may be used where the pain is confined to the teeth or gums, and AFP when the pain involves other parts of the face. As with AFP, there is a similar lack of standardization of terms and no consensus regarding a globally accepted definition surrounding AO. Generally definitions of AO state that it is pain with no demonstrable cause which is perceived to be coming from a tooth or multiple teeth, and is not relieved by standard treatments to alleviate dental pain.

Depending upon the exact presentation of atypical facial pain and atypical odontalgia, it could be considered as craniofacial pain or orofacial pain. It has been suggested that, in truth, AFP and AO are umbrella terms for a heterogenous group of misdiagnosed or not yet fully understood conditions, and they are unlikely to each represent a single, discrete condition.

Cluster headaches are recurring bouts of excruciating unilateral headache attacks of extreme intensity. The duration of a typical CH attack ranges from about 15 to 180 minutes. Most untreated attacks (about 75%) last less than 60 minutes.

The onset of an attack is rapid and most often without preliminary signs that are characteristic in migraine. Preliminary sensations of pain in the general area of attack, referred to as "shadows", may signal an imminent CH, or these symptoms may linger after an attack has passed, or even between attacks. Though CH is strictly unilateral, there are some documented cases of "side-shift" between cluster periods, or, extremely rarely, simultaneous (within the same cluster period) bilateral cluster headaches.

In addition to persistent daily headache of HC, which is usually mild to moderate (and frequently severe), HC can present other symptoms. These additional symptoms of HC can be divided into three main categories:

1. Autonomic symptoms:

- conjunctival injection

- tearing

- rhinorrhea

- nasal stuffiness

- eyelid edema

- forehead sweating

2. Stabbing headaches:

- Short, "jabbing" headaches superimposed over the persistent daily headache.

- Usually lasting less than one minute.

3. Migrainous features:

- throbbing pain

- nausea and/or vomiting

- phonophobia

- photophobia

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.

Patient often reports symptoms of paresthesia, pain, and throbbing. Physical examination may be normal, but hypoesthesia, hyperesthesia, and allodynia may be found.

The features of atypical facial pain can be considered according to the Socrates pain assessment method (see table).

The following diagnostic criteria are given for hemicrania continua:

1. Headache for more than 3 months fulfilling other 3 criteria:

2. All of the following characteristics:

- Unilateral pain without side-shift

- Daily and continuous, without pain-free periods

- Moderate intensity, but with exacerbations of severe pain

3. At least one of the following autonomic features occurs during exacerbations and ipsilateral to the side of pain:

- Conjunctival injection and/or lacrimation

- Nasal congestion and/or rhinorrhea

- Ptosis and/or miosis

4. Complete response to therapeutic doses of indomethacin, although cases of hemicrania continua that do not resolve with indomethacin treatment have been documented.

A variant on hemicrania continua has also been described, in which the attacks may shift sides, although meeting the above criteria in all other respects.

Main features differentiating CPH from cluster headaches (migrainous neuralgia, above) are the higher frequency and shorter duration of attacks, higher incidence in women, and the response to treatment with indomethacin. CPH is not associated with cranial nerve palsies.

A tumor compressing the facial nerve anywhere along its complex pathway can result in facial paralysis. Common culprits are facial neuromas, congenital cholesteatomas, hemangiomas, acoustic neuromas, parotid gland neoplasms, or metastases of other tumours.

Often, since facial neoplasms have such an intimate relationship with the facial nerve, removing tumors in this region becomes perplexing as the physician is unsure how to manage the tumor without causing even more palsy. Typically, benign tumors should be removed in a fashion that preserves the facial nerve, while malignant tumors should always be resected along with large areas of tissue around them, including the facial nerve. While this will inevitably lead to heightened paralysis, safe removal of a malignant neoplasm is worth the often treatable palsy that follows. In the best case scenario, paralysis can be corrected with techniques including hypoglossal-facial nerve anastomosis, end-to-end nerve repair, cross facial nerve grafting, or muscle transfer/transposition techniques, such as the gracilis free muscle transfer.

Patients with facial nerve paralysis resulting from tumours usually present with a progressive, twitching paralysis, other neurological signs, or a recurrent Bell's palsy-type presentation.

The latter should always be suspicious, as Bell's palsy should not recur. A chronically discharging ear must be treated as a cholesteatoma until proven otherwise; hence, there must be immediate surgical exploration. Computed tomography (CT) or magnetic resonance (MR) imaging should be used to identify the location of the tumour, and it should be managed accordingly.

Other neoplastic causes include leptomeningeal carcinomatosis.

Facial nerve paralysis is characterised by unilateral facial weakness, with other symptoms including loss of taste, , and decreased salivation and tear secretion. Other signs may be linked to the cause of the paralysis, such as s in the ear, which may occur if the facial palsy is due to shingles. Symptoms may develop over several hours. Acute facial pain radiating from the ear may precede the onset of other symptoms.

The facial nerve is the seventh of 12 cranial nerves. This cranial nerve controls the muscles in the face. Facial nerve palsy is more abundant in older adults than in children and is said to affect 15-40 out of 100,000 people per year. This disease comes in many forms which include congenital, infectious, traumatic, neoplastic, or idiopathic. The most common cause of this cranial nerve damage is Bell's palsy (idiopathic facial palsy) which is a paralysis of the facial nerve. Although Bell's palsy is more prominent in adults it seems to be found in those younger than 20 or older than 60 years of age. Bell's Palsy is thought to occur by an infection of the herpes virus which may cause demyelination and has been found in patients with facial nerve palsy. Symptoms include flattening of the forehead, sagging of the eyebrow, and difficulty closing the eye and the mouth on the side of the face that is affected. The inability to close the mouth causes problems in feeding and speech. It also causes lack of taste, acrimation, and sialorrhea.

The use of steroids can help in the treatment of Bell's Palsy. If in the early stages, steroids can increase the likelihood of a full recovery. This treatment is used mainly in adults. The use of steroids in children has not been proven to work because they seem to recover completely with or without them. Children also tend to have better recovery rates than older adults. Recovery rate also depends on the cause of the facial nerve palsy (e.g. infections, perinatal injury, congenital dysplastic). If the palsy is more severe patients should seek steroids or surgical procedures. Facial nerve palsy may be the indication of a severe condition and when diagnosed a full clinical history and examination are recommended.

Although rare, facial nerve palsy has also been found in patients with HIV seroconversion. Symptoms found include headaches (bitemporal or occipital), the inability to close the eyes or mouth, and may cause the reduction of taste. Few cases of bilateral facial nerve palsy have been reported and is said to only effect 1 in every 5 million per year.

Cranial nerve disease is an impaired functioning of one of the twelve cranial nerves. Although it could theoretically be considered a mononeuropathy, it is not considered as such under MeSH.

It is possible for a disorder of more than one cranial nerve to occur at the same time, if a trauma occurs at a location where many cranial nerves run together, such as the jugular fossa. A brainstem lesion could also cause impaired functioning of multiple cranial nerves, but this condition would likely also be accompanied by distal motor impairment.

A neurological examination can test the functioning of individual cranial nerves, and detect specific impairments.

Ear pain can be caused by disease in the external or middle ear(because of infection), or inner ear, but the three are indistinguishable in terms of the pain experienced.

External ear pain may be:

- Mechanical: trauma, foreign bodies such as hairs, insects or cotton buds.

- Infective (otitis externa): "Staphylococcus", "Pseudomonas", "Candida", herpes zoster, or viral Myringitis. (See Otitis externa)

Middle ear pain may be:

- Mechanical: barotrauma (often iatrogenic), Eustachian tube obstruction leading to acute otitis media.

- Inflammatory / infective: acute otitis media, mastoiditis.

A cold-stimulus headache, also known as brain freeze, ice-cream headache, trigeminal headache or its given scientific name sphenopalatine ganglioneuralgia (meaning "pain of the "sphenopalatine ganglion""), is a form of brief pain or headache commonly associated with consumption (particularly quick consumption) of cold beverages or foods such as ice cream and ice pops. It is caused by having something cold touch the roof of the mouth, and is believed to result from a nerve response causing rapid constriction and swelling of blood vessels or a "referring" of pain from the roof of the mouth to the head. The rate of intake for cold foods has been studied as a contributing factor. An cold-stimulus headache is distinct from dentin hypersensitivity, a type of pain that can occur under similar circumstances.

Cats and other animals have been observed experiencing a similar reaction when presented with a similar stimulus.

The term "ice-cream headache" has been in use since at least January 31, 1937, contained in a journal entry by Rebecca Timbres published in the 1939 book "We Didn't Ask Utopia: A Quaker Family in Soviet Russia".

Ear pain, also known as otalgia , is pain in the ear. Primary ear pain is pain that originates inside the ear. Referred ear pain is pain that originates from outside the ear.

Ear pain is not always associated with ear disease. It may be caused by several other conditions, such as impacted teeth, sinus disease, inflamed tonsils, infections in the nose and pharynx, throat cancer, and occasionally as a sensory aura that precedes a migraine.