2 . Glycerol rhizolysis : this technique uses a chemical called glycerol to interrupt the transmission of pain through the nerve .
3 . Balloon compression : a balloon is inserted alongside a particular nerve to compress it , resulting in injury . This injury prevents the pain transmission
4 . Gamma knife therapy : Despite its name , Gamma knife therapy does not involve a knife . It is a device that uses focused beams of cobalt radiation into a small space . When used for neuralgia , this therapy uses the beams of radiation therapy to a nerve . The radiation will kill or “ lesion ” the nerve thus , preventing pain transmission . This type of therapy was invented at the Karolinska Institute in Sweden in 1967 .
Glossopharyngeal Neuralgia ( GPN ) is a far less common cranial neuralgia than transcranial neuralgia but can be confused due to similar characteristics . Like TN , GPN consists of brief episodes of recurrent sharp pains . However , the location of GPN pain is in the distribution of the branches of the glossopharyngeal and vagus nerves ( cranial nerves IX and X ) as opposed to the trigeminal nerve . Patients describe a severe , stabbing , lancinating ( piercing ) pain that lasts a fraction of a second up to 2 minutes . The pain may be located in the ear , base of the tongue , tonsils , or beneath the angle of the jaw . Triggers of GPN pain include yawning , talking , coughing , swallowing , or touching the outside of the ear .
Occasionally , GPN and TN may coexist . The incidence of GPN is very rare and estimated to be 0.2 to 0.7 per 100,000 patients . GPN is rarely seen in children , and is most commonly found in females . The majority of patients with GPN are over the age of 50 .
Location of the glossopharyngeal nerve
The majority of cases of GPN are thought to be idiopathic ( no known cause ) as thorough imaging and physical examinations usually do not reveal any abnormalities . Secondary causes may be from compression of the glossopharyngeal nerve by blood vessels or tumors . The majority of secondary cases are believed due to an artery compressing the glossopharyngeal nerve as it exits the brain .
Considering the rarity of this disorder , a comprehensive evaluation should be undertaken . A high resolution MRI with thin views through the brainstem will help evaluate for tumors . Angiography of the spine will also identify any compression by a blood vessel .
First-line treatment is similar to that for TN , with medical management with anti-seizure drugs such as carbamazepine , oxcarbazepine , gabapentin , pregabalin , and phenytoin . Surgical options such as microvascular decompression have been successful with long-term pain-free outcomes in upwards of 80 % of patients with a low rate of complications such as dysphagia ( difficulty swallowing ) or hoarseness .
Nervus Intermedius Neuralgia ( NIN ) also known as geniculate neuralgia is an extremely rare condition affecting an estimated 0.03 per 100,000 people per year . It is usually seen in patients 50 years and older , and women appear to be affected more than men . The pain is a brief , sudden bout of pain felt deep inside the ear , lasting seconds to minutes . During the attack , the patient may complain of a bitter taste in their mouth . The nervus intermedius is a small branch of the facial nerve ( cranial nerve VII ) that supplies the inner ear , middle ear , mastoid cells , Eustachian tube , and part of the pinna of the ear . Contrast-enhanced imaging ( MRA ) should be utilized to identify dilation of a vessel or any abnormal vessels . Treatment regimens include carbamazepine and other anti-seizure drugs that are used to treat TN .
COMPARISON OF LOCATIONS OF Trigeminal Neuralgia ( TN ), Glossopharyngeal Neuralgia ( GN ), and ervus Intermedius Neural ia NIN
TN
GPN
NIN
Along the branches of cranial nerve V , V2 and V3 : cheek bone and lower face
Along cranial nerve IX and X : inner ear , base of tongue , tonsils , or along angle of the jaw
Along the branch of cranial nerve VII , the nervus intermedius : deep inside the inner ear
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