Design of an Artificial Neural Network for Diagnosis of Facial Pain Syndromes

The role of artificial intelligence in the management of trigeminal neuralgia

Trigeminal neuralgia (TN) is the most frequent facial pain. It is difficult to treat pharmacologically and a significant amount of patients can become drug-resistant requiring surgical intervention. From an etiologically point of view TN can be distinguished in a classic form, usually due to a neurovascular conflict, a secondary form (for example related to multiple sclerosis or a cerebello-pontine angle tumor) and an idiopathic form in which no anatomical cause is identifiable. Despite numerous efforts to treat TN, many patients experience recurrence after multiple operations. This fact reflects our incomplete understanding of TN pathogenesis. Artificial intelligence (AI) uses computer technology to develop systems for extension of human intelligence. In the last few years, it has been a widespread of AI in different areas of medicine to implement diagnostic accuracy, treatment selection and even drug production. The aim of this mini-review is to provide an up to date of the state-of-art of AI applications in TN diagnosis and management.

A systematic review of screening diagnostic tools for trigeminal neuralgia

Background and objective

Trigeminal neuralgia (TN) is a rare chronic neuropathic pain condition of sudden and severe pain, often described as an electric shock. Diagnosis is challenging for non-expert clinicians, particularly in primary care settings. We wanted to identify and assess the diagnostic accuracy of existing screening tools for TN and orofacial pain that could be used to support the diagnosis of TN in primary care.

Databases and data treatment

We searched key databases (MEDLINE, ASSIA, Embase, and Web of Knowledge and PsycINFO) supplemented by citation tracking from January 1988 to 2021. We used an adapted version of the Quality of Diagnostic Accuracy Studies (QUADAS-2) to assess the methodological quality of each study.

Results

Searches identified five studies, from the UK, USA and Canada; three validated self-report questionnaires; and two artificial neural networks. All screened for multiple orofacial pain diagnoses, including dentoalveolar pain, musculoskeletal pain (temporomandibular disorders) and neurological pain (trigeminal neuralgia, headache, atypical facial pain and postherpetic neuralgia). The overall quality assessment was low for one study.

Conclusions

Diagnosis of TN can be challenging for non-expert clinicians. Our review found few existing screening tools to diagnose TN, and none is currently suitable to be used in primary care settings. This evidence supports the need to adapt an existing tools or to create a new tool for this purpose. The development of an appropriate screening questionnaire could assist non-expert dental and medical clinicians to identify TN more effectively and empower them to manage or refer patients for treatment more effectively.

Intelligent systems for precision dental diagnosis and treatment planning – A review

Machines have changed the course of mankind. Simple machines were the basis of human civilization. Today with humongous technological development, machines are intelligent enough to carry out very complex nerve-racking tasks. The ability of a machine to learn from algorithms changed eventually into, the machine learning by itself, which constitutes artificial intelligence. Literature has plausible evidence for the use of intelligent systems in medical field. Artificial intelligence has been used in the multiple denominations of dentistry. These machines are used in the precision diagnosis, interpretation of medical images, accumulation of data, classification and compilation of records, determination of treatment and construction of a personalized treatment plan. Artificial intelligence can help in timely diagnosis of complex dental diseases which would ultimately aid in rapid commencement of treatment. Research helps us understand the effectiveness and challenges in the use of this technology. The apt use of intelligent systems could transform the entire medical system for the better.

An artificially intelligent (or algorithm-enhanced) electronic medical record in orofacial pain

This review examines how a highly structured data collection system could be used to create data-driven diagnostic classification algorithms. Some preliminary data using this process is provided. The data collection system described is applicable to any clinical domain where the diagnoses being explored are based predominately on clinical history (subjective) and physical examination (objective) information. The system has been piloted and refined using patient encounters collected in a clinic specializing in Orofacial Pain treatment. In summary, whether you believe a branching hybrid check-box based data collection system with built-in algorithms is needed, depends on your individual agenda. If you have no plans for data analysis or publishing about the various phenotypes discovered and you do not need pop-up suggestions for best diagnosis and treatment options, it is easier to use a semi-structured narrative note for your patient encounters. If, however, you want data-driven diagnostic and disease risk algorithms and pop-up best-treatment options, then you need a highly structured data collection system that is compatible with machine learning analysis. Automating the journey from data collection to diagnoses has the potential to improve standards of care by providing faster and reliable predictions.

Machine Learning and Intelligent Diagnostics in Dental and Orofacial Pain Management: A Systematic Review

Purpose

The study explored the clinical influence, effectiveness, limitations, and human comparison outcomes of machine learning in diagnosing (1) dental diseases, (2) periodontal diseases, (3) trauma and neuralgias, (4) cysts and tumors, (5) glandular disorders, and (6) bone and temporomandibular joint as possible causes of dental and orofacial pain.

Method

Scopus, PubMed, and Web of Science (all databases) were searched by 2 reviewers until 29^th October 2020. Articles were screened and narratively synthesized according to PRISMA-DTA guidelines based on predefined eligibility criteria. Articles that made direct reference test comparisons to human clinicians were evaluated using the MI-CLAIM checklist. The risk of bias was assessed by JBI-DTA critical appraisal, and certainty of the evidence was evaluated using the GRADE approach. Information regarding the quantification method of dental pain and disease, the conditional characteristics of both training and test data cohort in the machine learning, diagnostic outcomes, and diagnostic test comparisons with clinicians, where applicable, were extracted.

Results

34 eligible articles were found for data synthesis, of which 8 articles made direct reference comparisons to human clinicians. 7 papers scored over 13 (out of the evaluated 15 points) in the MI-CLAIM approach with all papers scoring 5+ (out of 7) in JBI-DTA appraisals. GRADE approach revealed serious risks of bias and inconsistencies with most studies containing more positive cases than their true prevalence in order to facilitate machine learning. Patient-perceived symptoms and clinical history were generally found to be less reliable than radiographs or histology for training accurate machine learning models. A low agreement level between clinicians training the models was suggested to have a negative impact on the prediction accuracy. Reference comparisons found nonspecialized clinicians with less than 3 years of experience to be disadvantaged against trained models.

Conclusion

Machine learning in dental and orofacial healthcare has shown respectable results in diagnosing diseases with symptomatic pain and with improved future iterations and can be used as a diagnostic aid in the clinics. The current review did not internally analyze the machine learning models and their respective algorithms, nor consider the confounding variables and factors responsible for shaping the orofacial disorders responsible for eliciting pain.

Altered brain network centrality in patients with trigeminal neuralgia: a resting-state fMRI study

Background

Neuroimaging studies revealed that trigeminal neuralgia was related to alternations in brain anatomical function and regional function. However, the functional characteristics of network organization in the whole brain is unknown.

Purpose

The aim of the present study was to analyze potential functional network brain-activity changes and their relationships with clinical features in patients with trigeminal neuralgia via the voxel-wise degree centrality method.

Material and Methods

This study involved a total of 28 trigeminal neuralgia patients (12 men, 16 women) and 28 healthy controls matched in sex, age, and education. Spontaneous brain activity was evaluated by degree centrality. Correlation analysis was used to examine the correlations between behavioral performance and average degree centrality values in several brain regions.

Results

Compared with healthy controls, trigeminal neuralgia patients had significantly higher degree centrality values in the right lingual gyrus, right postcentral gyrus, left paracentral lobule, and bilateral inferior cerebellum. Receiver operative characteristic curve analysis of each brain region confirmed excellent accuracy of the areas under the curve. There was a positive correlation between the mean degree centrality value of the right postcentral gyrus and VAS score (r = 0.885, P < 0.001).

Conclusions

Trigeminal neuralgia causes abnormal brain network activity in multiple brain regions, which may be related to underlying disease mechanisms.

Factors Predicting Successful Outcomes for Percutaneous Radiofrequency Thermocoagulation in Patients With Idiopathic Trigeminal Neuralgia: Implications for Surgical Decision Making

OBJECTIVES

In this study we aimed to identify specific factors predicting successful outcomes after percutaneous radiofrequency thermocoagulation (RFT) for idiopathic trigeminal neuralgia (ITN) and risk factors that were associated with inferior outcomes.

METHODS

We retrospectively reviewed our cohort of 1,624 patients who underwent RFT for trigeminal neuralgia between January 2000 and December 2017. Demographic and clinical data including age, gender, disease duration, affected side, baseline pain score, pain distribution, history of previous surgical intervention, and pain characteristics were collected and evaluated for their association with outcome using univariate and multivariate logistic regression analysis.

RESULTS

78.1% of patients experienced a successful outcome of RFT for ITN as predefined criteria. Pain characteristics and history of surgical treatment were significant predictors associated with successful outcomes in regression analysis. Multivariate analysis identified provoked episodic pain at diagnosis (odds ratio [OR] = 23.629, 95% confidence interval [CI]: 16.316 to 34.219, P = 0.010), mixed pain (OR = 8.394, 95% CI: 5.951 to 11.840, P = 0.011), and no history of surgical treatment (OR = 2.189, 95% CI: 1.411 to 3.396, P = 0.019) as independent predictors for successful RFT outcome.

CONCLUSION

Presence of provoked episodic pain and mixed pain were significantly associated with successful outcome of RFT for ITN. Moreover, patients with ITN who underwent RFT for the first time were more likely to benefit from successful outcome. These findings should be considered when managing ITN with RFT to improve the likelihood of a successful outcome.

A Clinical Study on Comparative Evaluation of the Effectiveness of Carbamazepine and Combination of Carbamazepine with Baclofen or Capsaicin in the Management of Trigeminal Neuralgia

Background:

Trigeminal neuralgia (TN) is characterized by recurrent attacks of lancinating pain in the trigeminal nerve distribution. Various medicinal and surgical procedures have been utilized for the treatment of TN. Over the time, several drugs other than carbamazepine have been used but none of them have shown satisfying results.

Objective:

The objective of the study is to evaluate the effectiveness of carbamazepine and combination of carbamazepine with baclofen or capsaicin in the management of TN.

Materials and Methods:

A total of 45 patients diagnosed with TN were randomly divided into three groups. The patients were prescribed carbamazepine in Group 1, carbamazepine and baclofen in Group 2, and carbamazepine and capsaicin in Group 3. All the patients were followed on the 7^th day, 15^th day, and 1-month period to evaluate the response to the drugs. Data were subjected to statistics.

Results:

The results are composed of a total of 45 patients (15 in each group). The mean visual analogue scale scores were calculated for each group at day 0, 7^th day, 15^th day, and 30 days, and it was found that there was statistically significant reduction of pain (P < 0.001) in all the three groups at different intervals. At day 7, comparative percentage reduction of pain in both groups was not statistically significant. At 15-days and 30 days, percentage change in pain reduction in Group 1 was 42.3% and 48.0% respectively and in Group 2 it was found to be 60.3% and 83.4%, respectively. The reduction in pain percentage was found to be statistically significant. Similarly, Group 1 was compared to Group 3, significant reduction of pain was found for carbamazepine-capsaicin combination at 30-day interval but the comparative reduction of pain at 7^th day and 15^th day was not statistically significant.

Conclusion:

Carbamazepine in combination with baclofen is more efficient and effective in reducing pain in TN patients, followed by carbamazepine-capsaicin combination compared to carbamazepine alone.

Pain. Part 7: Trigeminal Neuralgia

Trigeminal neuralgia (TN) is also known as 'tic douloureux' (in French, 'painful twitch'). It is a rare chronic facial pain syndrome, characterized by severe, brief, stabbing, 'electric shock-like 'recurrent pain attacks felt in one or more divisions of trigeminal nerve innervation areas. So intense is the elicited pain that TN has a significant effect on a sufferer's quality of life, rendering many patients unable to consider a future with the ongoing threat of recurrent pain. The aim of this article is to discuss the diagnosis and management of this disabling facial pain condition. CPD/Clinical Relevance: As general medical practitioners may struggle differentiating TN from toothache, primary care dentists have an important role in excluding odontogenic cause of pain, diagnosing TN and referring patients to a facial pain clinic for further investigations and multidisciplinary team management.

Artificial neural networks in neurosurgery

Artificial neural networks (ANNs) effectively analyze non-linear data sets. The aimed was A review of the relevant published articles that focused on the application of ANNs as a tool for assisting clinical decision-making in neurosurgery. A literature review of all full publications in English biomedical journals (1993-2013) was undertaken. The strategy included a combination of key words 'artificial neural networks', 'prognostic', 'brain', 'tumor tracking', 'head', 'tumor', 'spine', 'classification' and 'back pain' in the title and abstract of the manuscripts using the PubMed search engine. The major findings are summarized, with a focus on the application of ANNs for diagnostic and prognostic purposes. Finally, the future of ANNs in neurosurgery is explored. A total of 1093 citations were identified and screened. In all, 57 citations were found to be relevant. Of these, 50 articles were eligible for inclusion in this review. The synthesis of the data showed several applications of ANN in neurosurgery, including: (1) diagnosis and assessment of disease progression in low back pain, brain tumours and primary epilepsy; (2) enhancing clinically relevant information extraction from radiographic images, intracranial pressure processing, low back pain and real-time tumour tracking; (3) outcome prediction in epilepsy, brain metastases, lumbar spinal stenosis, lumbar disc herniation, childhood hydrocephalus, trauma mortality, and the occurrence of symptomatic cerebral vasospasm in patients with aneurysmal subarachnoid haemorrhage; (4) the use in the biomechanical assessments of spinal disease. ANNs can be effectively employed for diagnosis, prognosis and outcome prediction in neurosurgery.

Orofacial pain: a guide for the headache physician

Orofacial pain represents a significant burden in terms of morbidity and health service utilization. It includes very common disorders such as toothache and temporomandibular disorders, as well as rare orofacial pain syndromes. Many orofacial pain conditions have overlapping presentations, and diagnostic uncertainty is frequently encountered in clinical practice. This review provides a clinically orientated overview of common and uncommon orofacial pain presentations and diagnoses, with an emphasis on conditions that may be unfamiliar to the headache physician. A holistic approach to orofacial pain management is important, and the social, cultural, psychological and cognitive context of each patient needs to be considered in the process of diagnostic formulation, as well as in the development of a pain management plan according to the biopsychosocial model. Recognition of psychological comorbidities will assist in diagnosis and management planning.

Differential diagnosis of facial pain and guidelines for management

The diagnosis and management of facial pain below the eye can be very different dependant on whether the patient visits a dentist or medical practitioner. A structure for accurate diagnosis is proposed beginning with a very careful history. The commonest acute causes of pain are dental and these are well managed by dentists. Chronic facial pain can be unilateral or bilateral and continuous or episodic. The commonest non-dental pains are temporomandibular disorders (TMDs), especially musculoskeletal involving the muscles of mastication either unilaterally or bilaterally; they may be associated with other chronic pains. A very wide range of treatments are used but early diagnosis, reassurance and some simple physiotherapy is often effective in those with good coping strategies. Dentists will often make splints to wear at night. Neuropathic pain is usually unilateral and of the episodic type; the most easily recognized is trigeminal neuralgia. This severe electric shock like pain, provoked by light touch, responds best to carbamazepine, and neurosurgery in poorly controlled patients. Trauma, either major or because of dental procedures, results in neuropathic pain and these are then managed as for any other neuropathic pain. Red flags include giant cell arteritis which much be distinguished from temporomandibular disorders (TMD), especially in >50 yr olds, and cancer which can present as a progressive neuropathic pain. Burning mouth syndrome is rarely recognized as a neuropathic pain as it occurs principally in peri-menopausal women and is thought to be psychological. Chronic facial pain patients are best managed by a multidisciplinary team.

Prevalence of trigeminal neuralgia in Al-Quseir city (Red sea Governorate), Egypt

BACKGROUND

Trigeminal neuralgia or tic douloureux is sometimes described as the most excruciating pain known to humanity.

OBJECTIVES

To estimate the prevalence of trigeminal neuralgia among the population of Al-Quseir city.

METHODS

This study forms a part of door to door survey of major neurological disorders in Al-Quseir city, Red sea governorate, Egypt. The total population (33,285 persons) were screened through door to door (every door) by three specialists of Neurology and fifteen female social workers. Then, positive cases were subjected to clinical and neurological examination by other three staff members of neurology. Cases were identified as suffering from trigeminal neuralgia according to the diagnostic criteria of the International headache society (IHS).

RESULTS

We identified 4 female patients out of 13,541 persons (aged 30 years and more) suffering from trigeminal neuralgia with age specific prevalence rate of 29.5/100,000. Co-morbid depression and hypertension were observed among the affected persons.

Multi-dimensionality of chronic pain of the oral cavity and face

Orofacial pain in its broadest definition can affect up to 7% of the population. Its diagnosis and initial management falls between dentists and doctors and in the secondary care sector among pain physicians, headache neurologists and oral physicians. Chronic facial pain is a long term condition and like all other chronic pain is associated with numerous co-morbidities and treatment outcomes are often related to the presenting co-morbidities such as depression, anxiety, catastrophising and presence of other chronic pain which must be addressed as part of management . The majority of orofacial pain is continuous so a history of episodic pain narrows down the differentials. There are specific oral conditions that rarely present extra orally such as atypical odontalgia and burning mouth syndrome whereas others will present in both areas. Musculoskeletal pain related to the muscles of mastication is very common and may also be associated with disc problems. Trigeminal neuralgia and the rarer glossopharyngeal neuralgia are specific diagnosis with defined care pathways. Other trigeminal neuropathic pain which can be associated with neuropathy is caused most frequently by trauma but secondary causes such as malignancy, infection and auto-immune causes need to be considered. Management is along the lines of other neuropathic pain using accepted pharmacotherapy with psychological support. If no other diagnostic criteria are fulfilled than a diagnosis of chronic or persistent idiopathic facial pain is made and often a combination of antidepressants and cognitive behaviour therapy is effective. Facial pain patients should be managed by a multidisciplinary team.

Can treatment success with 5% lidocaine medicated plaster be predicted in cancer pain with neuropathic components or trigeminal neuropathic pain?

An expert group of 40 pain specialists from 16 countries performed a first assessment of the value of predictors for treatment success with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain. Results were based on the retrospective analysis of 68 case reports (sent in by participants in the 4 weeks prior to the conference) and the practical experience of the experts. Lidocaine plaster treatment was mostly successful for surgery or chemotherapy-related cancer pain with neuropathic components. A dose reduction of systemic pain treatment was observed in at least 50% of all cancer pain patients using the plaster as adjunct treatment; the presence of allodynia, hyperalgesia or pain quality provided a potential but not definitively clear indication of treatment success. In trigeminal neuropathic pain, continuous pain, severe allodynia, hyperalgesia, or postherpetic neuralgia or trauma as the cause of orofacial neuropathic pain were perceived as potential predictors of treatment success with lidocaine plaster. In conclusion, these findings provide a first assessment of the likelihood of treatment benefits with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain and support conducting large, well-designed multicenter studies.

Treatment options in trigeminal neuralgia

The incidence of trigeminal neuralgia (TN) is 4.3 per 100,000 persons per year, with a slightly higher incidence for women (5.9/100,000) compared with men (3.4/100,000). There is a lack of certainty regarding the aetiology and pathophysiology of TN. The treatment of TN can be very challenging despite the numerous options patients and physicians can choose from. This multitude of treatment options poses the question as to which treatment fits which patient best. The preferred medical treatment for TN consists of anticonvulsant drugs, muscle relaxants and neuroleptic agents. Large-scale placebo-controlled clinical trials are scarce. For patients refractory to medical therapy, Gasserian ganglion percutaneous techniques, gamma knife surgery and microvascular decompression are the most promising invasive treatment options.

Diagnosis and management of trigeminal neuropathic pains

SUMMARY Trigeminal neuropathic pains have presented diagnostic and therapeutic challenges to providers. In addition, knowledge of pathophysiology, current classification systems, taxonomy and phenotyping of these conditions are incomplete. While trigeminal neuralgia is the most identifiable and studied, other conditions are being recognized and require distinct management approaches. Furthermore, other facial pain conditions such as atypical odontalgia and burning mouth syndrome are now considered to have neuropathic elements in their etiology. This article reviews current knowledge on the pathophysiology, diagnosis and management of neuropathic pain conditions involving the trigeminal nerve, to include: trigeminal neuralgia, trigeminal neuropathic pain (with traumatically induced neuralgia and atypical odontalgia) and burning mouth syndrome. Treatment modalities are reviewed based on current and best available evidence. Trigeminal neuralgia is managed with anticonvulsant drugs as the first line, with surgical options providing variable results. Trigeminal neuropathic pain is managed medically based on the guidelines for other neuropathic pain conditions. Burning mouth syndrome is also treated with a number of neuropathic medications, both topical and systemic. In all these conditions, patients need to be thoroughly educated about their condition, involved in its management, and be provided with supportive and adjunctive treatment resources.

Trigeminal Neuralgia - A Debilitating Facial Pain

Trigeminal neuralgia (TN) is characterised by sudden usually unilateral severe, brief, stabbing, recurrent episodes of pain in the distribution of one or more branches of the trigeminal nerve.Diagnosis is largely based on clinical history due to the current lack of objective investigations.MRI can identify those patients who have TN secondary to an underlying pathology such as multiple sclerosis.The first line medical management remains carbamazepine, with oxcarbazepine being the second choice medication.Both percutaneous techniques targeting the Gasserian ganglion and microvascular decompression can be considered effective in the management of TN. Microvascular decompression is considered to provide on average, the longest pain free period post surgery.There are a number of TN associations and support groups which provide a valued service to patients and clinicians.Due to a dearth of high quality studies in many aspects of the condition, TN requires further research to be conducted.

Medical management of trigeminal neuropathic pains

IMPORTANCE OF THE FIELD

Although trigeminal neuralgia has traditionally been considered the prime neuralgic condition in the face region, other forms of neuropathic pain are now being more frequently recognized and require recognition and a different management approach.

AREAS COVERED IN THIS REVIEW

This review principally covers medical management of trigeminal neuralgia; but also included is glossopharyngeal neuralgia, trigeminal neuropathic pain (atypical odontalgia) and burning mouth syndrome. Systematic reviews and guidelines will be discussed.

WHAT THE READER WILL GAIN

An update will be provided of drug therapy for these relatively rare facial pains.

TAKE HOME MESSAGE

Trigeminal neuralgia continues to be best managed using anticonvulsant drugs, the primary ones being carbamazepine and oxcarbazepine; baclofen may be helpful and, of the newly emerging drugs, pregabalin has potential. Glossopharyngeal neuralgia remains managed in the same way as trigeminal neuralgia. Trigeminal neuropathic pain is probably best managed according to guidelines used for the management of neuropathic pain, which include the use of tricyclic antidepressants, gabapentin, pregabalin, duloxetine, venalafaxine and topical lidocaine. Burning mouth syndrome is a neuropathic pain managed initially with topical clonazepam and then with other neuropathic drugs. Patients need to be involved in their management.