Trigeminal Neuralgia, also known as TN or tic douloureux, is a rare neurological condition characterised by sudden onset of severe pain on one side of the lower face and jaw. The pain is often referred to as an “electric shock” like pain and although the exact mechanism is unknown, the pain is thought to be due to the irritation of the trigeminal nerve which is responsible for sensation in the face. It is considered by many patients to be ‘the worlds worst pain’ which is why it is important to gain better understanding of the little known condition.
History
Trigeminal Neuralgia was first described as early as AD 81 by ancient Greek Physicians such as Galen and Arataeus. However, the first official description was documented in 1773 by the British physician John Fothergill who described it as "a painful affection of the face". The first accurate explanation for the condition wasn't conjectured at until 1932 by Walter Dandy, and was confirmed in 1967 by Peter Janetta.
Suffering from Trigeminal Neuralgia
The two main types of Trigeminal Neuralgia
Primary TN is due to compression of the nerve from contact between a healthy artery or vein and the trigeminal nerve at the base of the brain. This puts pressure on the nerve and causes the nerve to fire inappropriately, and this nerve activity is detected by the brain as pain. This is described as Paroxysmal Trigeminal Neuralgia; sharp infrequent pain.
Secondary TN is caused by pressure on the nerve from a tumour, cyst, facial injury or a medical condition that damages the outer coating of the nerve. This is rarer but often causes duller more continuous aches and is described as Atypical Trigeminal Neuralgia.
Symptoms
The pain usually appears suddenly and is only felt on one side of the face. It is often described as a sharp, burning or electric shock like pain and can affect the jaw, teeth, cheek and sometimes the eyes and forehead. You may even experience pain at night when sleeping. Each attack lasts up to 30 seconds. The number of attacks that occur can vary between individuals; some may have one attack a day whereas others can have hundreds.
Triggers
Any contact with the face can potentially trigger an attack of Trigeminal Neuralgia, individuals with TN tend to identify common provoking factors over time. These include:
Confusion in diagnosis
The diagnosis is mainly based on a bedside clinical assessment by a GP as there is no specific test to confirm or refute a diagnosis of TN. They will ask about the severity, longevity and location of the pain attacks to exclude causes of facial pain like dental ache. Imaging such as an MRI is sometimes done to determine whether there is a structural change causing the TN as well as helping to rule out more complex causes such as inflammation of the sinuses or nerve damage from MS. Your GP may refer you to a specialist such as a Neurologist, a pain specialist or a Neurosurgeon if medications do not control your symptoms.
The commonly understood symptoms of shooting pains or electrical jolts are common but not exclusive, with many reporting continuous or slow dull aches. Zakrzewska (2001) stated patients should be encouraged to tell their own story to grow the collection of experience of this varied condition. Studies (Wu, 2023) show ease of misdiagnosis without comprehensive verbal clinical assessment, with Trigeminal Neuralgia sometimes misdiagnosed as Glossopharyngeal Neuralgia or CRPS. Anyone suffering, or believe they may be, should recognise the variety of pain symptoms and should be communicative with their doctors.
Treatments
Medication
Painkillers are ineffective against TN, so anticonvulsants designed for treating epilepsy are used, as they help block pain signals between the nerve and the brain. Carbamazepine is used as the initial preventative medication and is the only medicine licensed for use in the UK.
Other non-licensed medications – those less extensively tested by clinical trials – can be used as an add-on or replacement if a specialist deems it necessary. These include Gabapentin and Oxcarbazepine. If these are not effective, the individual becomes unresponsive to the medication or develops intolerable side effects, several types of surgery are an option.
Surgery
Microvascular Decompression: a procedure where an artery or vein that is compressing the trigeminal nerve is relocated or removed. This is a major surgery involving opening the skull, the NHS states it is the closest to a cure with longer lasting relief rates, however it is dangerous with “serious complications including death” in 1 in a 1000 cases.
Gamma knife surgery: a procedure where radiation is applied to the root of your trigeminal nerve, damaging the nerve. It usually provides short term relief from several months to several years.
Radiofrequency or Percutaneuous Rhizotomy: a minimally invasive procedure where nerve fibres involved in causing pain are destroyed. This can be done by cutting the nerve fibres using a surgical instrument or burning them (chemical or electrical). It provides similar short term relief but is less invasive.
SPCR's Involvement
At St Pancras Clinical Research we are carrying out phase II and III trials to test new medications for Trigeminal Neuralgia. This research will help us understand whether the new medications can reduce the frequency and/or severity of the pain episodes, reduce the need for other medications or surgery and increase function of daily living.
If you get in touch with us about taking part in research, one of our experienced team will have a confidential phone chat to discuss the study and your suitability based on medical history, diagnosis and current medications. If suitable and you would like to go ahead, we would then invite you for a Patient Information Visit to meet the clinic team, discuss the study in more detail and have the opportunity to ask any questions and raise any concerns you might have.
For more information on this process, you can read our Patient Journey article, our FAQ’s, or our Introduction to Clinical Trials article.