Trigeminal Neuralgia: The Suicide Disease
Dr. Peter Codd, a former university lecturer from Wales, had been suffering from one of the most painful diseases known to man called trigeminal neuralgia (TN) for the past two decades.1 The rare disease had completely taken over his life, but doctors were able to mostly alleviate his pain via surgery involving anaesthetics and pads to reduce pressure.1 Dr. Codd’s story proves that TN is a curable disease and researchers should focus their efforts on treating the cause of the disease rather than its symptoms.
Pathology and Etiology
“The trigeminal nerve, the fifth cranial nerve, is the root of the disease.”
TN is an extremely painful and chronic disease that involves light triggers causing severe episodes of facial pain.2 The pain is so severe that the disease is known as the “suicide disease”.1 The trigeminal nerve, the fifth cranial nerve, is the root of the disease.2 This nerve is responsible for generating facial sensations and motor input to the muscles involved in chewing and gives rise to three distinct branches.2 The trigeminal nerve, just like any other nerve, is surrounded by a myelin sheath, which is a substance that increases the efficiency of neurotransmission.2 Damage to the myelin sheath is possible and can have devastating results like TN.2
TN is a rare disease with an incidence of 4 to 13 per 100,000 people, with a higher proportion of elderly patients afflicted.2 Most cases of the disease are caused by compression of the trigeminal nerve, usually near its roots.2 The compression is mostly caused by pressure from a blood vessel, but can have other origins like a tumour or a cyst.2 There is thought to be a specific region of the trigeminal nerve near its root where the the type of cell that myelinates the nerve switches to another type.3 This area, known as the “transition zone”, is particularly sensitive and vulnerable to demyelination, which is thought to be the mechanism by which TN arises.3 Pressure to this transition zone causes demyelination which in turn results in hyperactive axons, leading to unwanted facial sensory stimulation.3 Other causes of TN include structural lesions and multiple sclerosis (MS), an autoimmune disorder that attacks the myelin sheath of nerves.2
Not much research exists regarding the genetics of the disease, but one study found case reports of TN having familial patterns. While they found inheritance patterns, familial TN (FTN) is very rare and more research must be done into it.4
Symptoms
“TN is clinically defined as intense, electric-like stabbing pain across the face depending on the branch or branches of the trigeminal nerve affected.”
TN is classified into two categories: classic TN, mainly caused by vascular compression of the nerve, and painful trigeminal neuropathy due to other causes like structural lesions or multiple sclerosis, an autoimmune disorder that targets the myelin sheath of nerves.2 Most cases of TN have similar characteristics.2 TN is clinically defined as intense, electric-like stabbing pain across the face depending on the branch or branches of the trigeminal nerve affected.2 The pain is described to be severe and episodes can last several seconds.2 Some patients have a refractory period in which more attacks do not occur. Muscle spasms can follow TN attacks.2
TN is caused by the lightest of triggers, which is why the disease is so painful.
2 Lightly touching regions innervated by the nerve can trigger attacks; these triggers include chewing, talking, brushing one’s teeth and smiling. 2 These triggers exhibit how TN can control and dominate a patient’s life. 2 Patients can experience attacks for weeks and months followed by a brief respite depending on the intensity of the disease. 2
Diagnosis
Diagnosis of the disease firstly involves examining the symptoms of the disease and matching them with the clinical characteristics of TN.2 Then, using The International Classification of Headache Disorders criteria which involves factors such as having three unilateral attacks of facial pain, attacks occurring in the distribution of the trigeminal nerve and electric-like pain, a patient can be diagnosed.2 Magnetic resonance angiography (MRA), which examines blood vessels, can identify the site of compression whereas Magnetic resonance imaging (MRI) can be used to locate tumours responsible for TN.2
Medication is often the first treatment option doctors prescribe.3 This includes sodium channel blockers, like carbamazepine and oxcarbazepine, which reduce the frequency of nerve impulses from the trigeminal nerve and thus reduce the pain elicited.3 However, side effects like nausea and dizziness can arise from these drugs.3 A novel method involves careful alcohol injections into peripheral nerves.5 This is an option for those patients who do not respond well to medication, and these injections have been noted to cause pain relief for patients.5 Complications include burning sensations around the injection site and sensory loss.5 Additionally, the alcohol injections were toxic and had to be administered very carefully.5
Pain Management
“Certain veins, the superior petrosal vein, can and need to be sacrificed in order to treat TN, but this sacrifice should only occur when absolutely necessary.”
The methods described previously aim to reduce the effect of the symptoms of TN. While there is no treatment available for permanent pain relief, some options have more promise than others.5 Microvascular decompression surgery is a treatment option that attempts to target the root cause of TN.6 This surgery involves two types of veins in the brain, bridging veins and veins of the brainstem.6 These veins can be dissected to alleviate pressure from the trigeminal nerve, but severe complications exist.6 Certain veins, the superior petrosal vein, can and need to be sacrificed in order to treat TN, but this sacrifice should only occur when absolutely necessary.6 A cushion can be inserted to further decrease pressure on the trigeminal nerve.6 This method was used in the case of Dr. Codd. However, this method is quite invasive and still must be improved to reduce the complications involved; more research must be done.6
In conclusion, TN is a life-altering disease with no known permanent cure. However, research into microvascular decompression surgery is the most promising method and scientists should focus their efforts in that regard.
Zain Daudi
Works Cited
- “‘Suicide Disease’ Man Is Pain-Free after 20 Years of Suffering.” BBC News, 6 July 2013, www.bbc.com/news/uk-wales-23181650.
- Kes VB. Accommodation to Diagnosis of Trigeminal Neuralgia. Acta Clinica Croatica. 2017:157-161. doi:10.20471/acc.2017.56.01.21
- Maarbjberg, S, et al. “Trigeminal Neuralgia, Diagnosis and Treatment.” SpringerReference, doi:10.1007/springerreference_124634.
- Cervera-Martinez, Claudia, et al. “Surgical Management of Familial Trigeminal Neuralgia With Different Inheritance Patterns: A Case Report.” Frontiers in Neurology, vol. 9, 2018, p. 316, www.ncbi.nlm.nih.gov/pubmed/29867726, 10.3389/fneur.2018.00316.
- Tiwari, Arunesh Kumar, et al. “Repeated Peripheral Alcohol Injection Is an Effective Treatment of Trigeminal Neuralgia in Non-Drug Compliance Patients.” National Journal of Maxillofacial Surgery, vol. 10, no. 1, 2019, pp. 56–58, www.ncbi.nlm.nih.gov/pubmed/31205389, 10.4103/njms.NJMS_62_18.
- Toda, Hiroki, et al. “Bridging Veins and Veins of the Brainstem in Microvascular Decompression Surgery for Trigeminal Neuralgia and Hemifacial Spasm.” Neurosurgical Focus, vol. 45, no. 1, July 2018, p. E2, 10.3171/2018.4.focus18122.
Cite This Article:
Daudi Z., Huicochea-Munoz M., Kord D., Rashid S., Chan G. Trigeminal Neuralgia: The Suicide Disease. Illustrated by C. Qian. Rare Disease Review. October 2020.
DOI:10.13140/RG.2.2.20757.96488
