Psychological Aspects And Mental Health In Trigeminal Neuralgia

Introduction

Trigeminal neuralgia (TN) is a type of craniofacial neuropathic pain that has been suggested to be one of the most excruciating types of pain. TN involves sudden, brief, and severe facial pain attacks in one or more of the trigeminal nerve (V) branches, often described as stabbing, burning, or reminiscent of an electric shock. TN strongly reduces the life quality of individuals suffering from it not only because of the arising pain attacks but also due to other TN-associated consequences, including anxiety, depression, sleep disorders, social withdrawal, and cognitive impairment.¹ This article further explores the effects of TN on mental health and other psychological aspects.

Trigeminal neuralgia (TN) – Overview 

The trigeminal nerve (V)

The trigeminal nerve (V), primarily involved in TN, is the fifth and largest of all the cranial nerves. It is part of the trigeminal sensory system that conveys the received sensory information from the craniofacial region.¹ This nerve takes part in the sensory innervation of the face as well as the stimulation of the mastication muscles. It has three main branches which all supply different territories:²

• Ophthalmic (V1) – sensory branch, supplies the superior third of the face and skull
• Maxillary (V2) – sensory branch, supplies the midfacial region
• Mandibular (V3) – sensory and motor branch, supplies the lower third of the face 

As mentioned before, a dysfunction of this nerve can lead to painful conditions, including TN.² In around 60% of TN cases, only one branch of the trigeminal nerve (maxillary or mandibular) is involved while both branches are involved in around 35% of cases. The involvement of the ophthalmic branch is rare.¹

TN causes, classification and epidemiology

The exact underlying mechanisms of TN are not yet fully understood. Some of the stimuli that can trigger TN pain attacks can include the following:¹

• Teeth brushing 
• Touching one’s face 
• Activation of facial/masticatory muscles while speaking or eating 

Naturally, it can become difficult for TN sufferers to fully participate in their daily lives, with some even starting to avoid activities such as eating or socialising in an attempt to prevent triggering a new pain episode. This can further result in reduced life quality and mental health issues.¹

Based on its aetiology, TN can be classified into:¹

• Classic – caused by neurovascular compression (NVC) occurring in the trigeminal root entry zone
  • NVC commonly leads to nerve fibre demyelination, which can then begin to fire ectopically  
• Secondary – could be caused by an underlying disease (e.g. artery malformations/tumours)
  • Multiple sclerosis (MS) patients show a high prevalence of TN
• Idiopathic – unknown causes

It has been estimated that on an annual basis, TN affects 4-13 people per 100,000. TN most commonly develops after the age of 50, with a possibility of developing this disease in the second/third decades of life. Given that having MS is a known risk factor for TN development, seeing TN present in a young person should raise suspicions of a potential MS case. Women are also thought to be affected by TN more frequently than men.³

TN-associated psychological impact

Mental health disorders 

TN is one of the most painful conditions that has even been called a “suicide disease”. It causes a major reduction in the patient’s quality of life while psychiatric disorders – including anxiety and depression – have been suggested to be highly prevalent in TN patients.^4,5 TN sufferers have also reported sleep disturbances due to frequent awakenings from the pain attacks.⁶

Some relevant scientific findings are summarised below:

• A study evaluating the relationship between the severity of TN-associated chronic orofacial pain and anxiety found that TN patients exhibited significantly higher anxiety than healthy controls and there were no significant differences in anxiety levels between those assigned male at birth (AMAB) and those assigned female at birth (AFAB) in either of the groups⁵
• A retrospective cohort study, comparing patients without vs. with newly diagnosed TN, reported significantly higher incidences of newly diagnosed depressive, anxiety, and sleep disorders, the risk for which was increased not only within the first year but also >1 year after a TN diagnosis⁶
• Another study, assessing TN patients who underwent microvascular decompression (MVD) surgical procedure, concluded that 64.8% of the patients suffered from depression and 18.8% from anxiety⁴
  • Further analysis suggested that factors including high pain intensity, being AFAB,  and ineffective medicine treatment were linked to depression, with the first two also being associated with anxiety⁴
  • MVD was concluded to not only help with pain relief but also improve depression and anxiety symptoms⁴

A few explanations linking the increased risk for new-onset anxiety and depressive disorders to TN have been suggested:⁶

• TN could lead to a serotonin and norepinephrine decrease, both of which are also linked to anxiety and depressive disorders
• The potential involvement of glutamatergic systems in TN pathophysiology may also increase the risk for these disorders

It is also important to remember that the consequences arising from the experience of living with this condition are severe – TN patients describe their experience as being one of fear and uncertainty. The sufferers often live with the fear of pain and have their daily functioning disrupted.⁷

Life in fear 

Living with the fear of TN pain episodes has been reported to drive various avoidance behaviours that have to do with the patient’s face – for instance, preventing the sufferers from partaking in personal care activities which had been experienced as pain stimuli. Eating has been suggested as a significant issue that could drive the patients to avoid chewing or result in disordered consumption of food and drinks, further increasing the risk of nutrient deficiency. Dietary restrictions, relying on liquidised food, and using alcohol to help cope with the pain have all been reported as arising behaviours. Additionally, eating while in pain has been concluded to be anxiety-provoking and further have an effect on social interactions.⁷

Social withdrawal

TN patients have also been noted to exhibit feelings of isolation and social withdrawal; the rising pain as well as the fear of pain commonly drove them to decide to withdraw. Despite the support coming from families and relatives, the severity of TN pain has still been reported to cause isolation and difficulties in terms of social interactions, even with the patients’ families. The unpredictable nature of this condition and the experienced pain can therefore lead to adjustment difficulties for all parties involved.⁷

Cognitive consequences

TN patients have also been suggested to have a significantly elevated risk of central neurodegeneration (where the cells in the central nervous system (CNS) stop working or die) which can be further linked to memory loss and cognitive impairment. TN is considered to be a neuropathic pain and, based on epidemiological data, at least 50% of patients with neuropathic pain report cognitive issues.⁸ 

A study investigating rats using a TN neuropathic pain model concluded that TN rats had obvious cognitive impairment as well as central nervous degeneration, further linking it to a reduction of docosahexaenoic acid (DHA). These findings are important as they aid in explaining the pathogenesis of TN-associated central neurodegeneration but also present DHA as a potential target to protect TN patients from CNS damage as TN rat cognitive impairment was shown to improve after central DHA level restoration.⁸ 

Regardless of whether TN is an independent risk factor for developing cognitive issues or not, these impairments have been reported to influence factors such as personal relationships, daily functioning, therapy adherence, ability to participate in various leisure/work activities, and overall patient quality of life.⁶

TN management

TN can be managed in a number of ways, and are discussed below. However, treatment plans can only be determined by your healthcare provider after relevant diagnostic tests are carried out. Consult with your doctor in order to gain proper medical advice on how to manage TN.

Pharmacological therapy 

Antiepileptic drugs, while traditionally used to treat epilepsy, are considered to be the mainstay of TN management.⁹ Carbamazepine and oxcarbazepine have been suggested to be the first-line pain management treatment option, however, the associated arising adverse effects can influence the patients’ willingness to continue this treatment. Oxcarbazepine has been reported to cause relatively fewer adverse effects compared to carbamazepine.¹⁰ 

Surgical options

Surgical interventions are generally considered for TN patients who exhibit debilitating pain which is refractory to pharmacological treatment (not responding to treatment that involves the use of drugs/medication) using at least 3 drugs, including carbamazepine. The recommended surgical procedures, with proven efficacy for medical refractory TN, include:¹¹

• Microvascular decompression
• Gamma knife (stereotactic radiosurgery)
• Percutaneous procedures on the Gasserian ganglion

The surgery can be either destructive or non-destructive – the sensory function of the trigeminal nerve is intentionally destroyed during the former while the latter decompresses the nerve and preserves its function.¹¹

Psychological management 

Neuropathic pain is common, however, the treatments are not always effective. Therefore, in cases where pharmacological and surgical treatment options are not successful, chronic pain sufferers could benefit from receiving psychologically-based rehabilitation aimed at improving their quality of life.¹² A study that investigated the effects of a customised cognitive behavioural therapy (CBT) group intervention on adult TN patients reported:¹³ 

• Increased confidence to manage daily tasks while experiencing TN symptoms 
• Decrease in pain-associated negative beliefs 
• Increased engagement in meaningful activity

Summary 

• TN is a type of craniofacial pain that causes sudden and excruciating facial pain attacks and involves one or more of the trigeminal nerve branches
• Certain stimuli can trigger TN pain attacks, including face touching, teeth brushing, or eating, making it difficult for the patients to fully participate in their lives as they try to avoid triggering a new pain episode
• Living with TN can seriously negatively impact the quality of life as it can be potentially linked to exhibiting the following:
  • Psychiatric disorders such as anxiety and depression
  • Sleep disturbances
  • Disordered food and drink consumption
  • Feelings of isolation and social withdrawal
  • Negative cognitive consequences that may further influence personal relationships, work/leisure activities, therapy adherence, and daily functioning
• Alongside the pharmacological and surgical treatment approaches, neuropathic pain sufferers may benefit from psychological rehabilitation approaches to improve their quality of life such as CBT