RARE DISEASE
Trigeminal neuralgia
Trigeminal neuralgia
Trigeminal neuralgia
Drug discovery
7
drugs
With orphan designations
Overview
Trigeminal neuralgia (TN) is a chronic neuropathic disorder characterized by sudden, severe, unilateral facial pain described as electric shock-like or lancinating attacks. Episodes are typically triggered by innocuous stimuli (e.g., chewing, light touch) and classified as classic (vascular nerve compression), secondary (underlying pathology like multiple sclerosis), or idiopathic. Diagnosis is clinical after excluding dental causes, with MRI often used to identify neurovascular conflict or structural lesions [1][5][11]. Multidisciplinary management prioritizes rapid pain control and tailored interventions.
Population
Predominantly affects adults >50 years, with a female-to-male ratio of ~3:2 [1][9][16].
Incidence: 4.7–23.1/100,000 person-years, rising with age [9][17][19]. Lifetime prevalence ~0.3% [1][7].
Strongly associated with hypertension, multiple sclerosis (relative risk 20.0), and cerebrovascular anomalies [9][11][12].
Burden
Debilitating impact on quality of life: 30–50% develop depression/anxiety; 8% report suicidal ideation [9][12][18].
Frequent healthcare utilization due to misdiagnosis, medication side effects, or recurrent surgeries [9][18].
Remission periods shorten over time, with 30–50% recurrence post-surgery within 5–10 years [6][8][14].
Therapies
First-line: Carbamazepine or oxcarbazepine (50–90% efficacy) [1][5][6]. Second-line agents include lamotrigine, gabapentin, or baclofen [1][5][18].
Refractory cases: Microvascular decompression (MVD) for classic TN (62–89% long-term remission) [1][8][11]; stereotactic radiosurgery or percutaneous rhizotomy for high-risk patients [2][6][8].
Adjuncts: Botulinum toxin injections or neuromodulation for medication-resistant pain [3][5][18].
Categories: rare neurological diseases
Research Papers
3,862 drug discovery papers about Trigeminal neuralgia, with 3 first-in-class and 19 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
3,862 drug discovery papers about Trigeminal neuralgia, with 3 first-in-class and 19 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
2026-08-15 | Trigger zones in trigeminal neuralgia: clinical features, pathophysiological mechanisms, and therapeutic strategies.
Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by recurrent, unilateral, electric shock-like facial pain, with trigger zones representing one of its most distinctive clinical features. These localized hypersensitive regions can be reliably activated by innocuous mechanical stimuli such as light touch, speech, or chewing, and their distribution provides important guidance for localizing the affected trigeminal branch and directing treatment decisions. Current evidence suggests that trigger zone formation involves peripheral nerve hyperexcitability driven by upregulation of voltage-gated sodium channels, mechanical sensitization from adjacent facial and masticatory muscle activity, and central sensitization within the trigeminal brainstem complex. At the brainstem level, abnormal activation of wide dynamic range neurons results in the misinterpretation of innocuous tactile input as pain. Clinically, systemic sodium channel blockers remain the foundation of initial treatment, while trigger zone-targeted interventions including peripheral nerve blockade, botulinum toxin type A injections, and minimally invasive ablative techniques have emerged as important adjunctive approaches. The absence of standardized objective assessment criteria and insufficient comparative clinical evidence remain key limitations in the field. A more thorough understanding of trigger zone pathophysiology may ultimately support the development of precision-based, individualized management strategies for TN.
2026-08-11 | Botulinum toxin type A attenuates trigeminal neuralgia-like pain by suppressing CGRP release and modulating NaV1.7-associated signaling.
Trigeminal neuralgia (TN) is a disabling facial pain disorder, and current treatments remain insufficient for a substantial proportion of patients. Botulinum toxin type A (BoNT/A) has shown therapeutic benefit in TN, but its peripheral analgesic mechanisms remain incompletely understood. We aimed to determine whether BoNT/A alleviates TN-like pain by modulating the calcitonin gene-related peptide (CGRP)-extracellular signal-regulated kinase (ERK)-NaV1.7 pathway in trigeminal ganglion neurons. TN-like pain was induced in mice by chronic constriction injury of the infraorbital nerve (CCI-ION). On postoperative day 14, BoNT/A (10 U) or saline was injected intradermally into the whisker pad. Evoked and spontaneous pain-like behaviors were assessed using von Frey testing, the Ugo Basile facial pain test, and spontaneous scratching recordings; anxiety-like behavior was evaluated using the elevated plus maze. Myelin pathology was examined by Luxol fast blue staining and transmission electron microscopy. CGRP, NaV1.7/NaV1.8, and ERK/MAPK signaling were examined in trigeminal ganglion neurons using immunofluorescence, Western blotting, RT-qPCR, ELISA, calcium-influx assays, and whole-cell patch-clamp recordings. Olcegepant and PD98059 were used to interrogate CGRP receptor- and ERK-dependent mechanisms. BoNT/A significantly attenuated CCI-ION-induced mechanical allodynia, increasing the facial withdrawal threshold from 0.11 to 1.29 g, and reducing spontaneous pain-like behaviors. BoNT/A also improved anxiety-like behavioral measures in CCI-ION mice. Histological and ultrastructural analyses shown partial amelioration of myelin pathology, accompanied by increased myelin basic protein expression and a lower g-ratio. Mechanistically, BoNT/A reduced CGRP-associated activity in TRPV1-positive trigeminal ganglion neurons, accompanied by lower serum CGRP levels and attenuated capsaicin-evoked calcium influx. These changes were associated with a preferential reduction in NaV1.7 membrane localization, without a comparable reduction in NaV1.8, and with a marked decrease in sodium current density, with peak sodium current reduced by 78.6%. Pharmacological inhibition of CGRP receptors or ERK phosphorylation reproduced the effects of BoNT/A on NaV1.7 membrane localization. These findings suggest that BoNT/A alleviates CCI-ION-induced TN-like pain, at least in part, by suppressing CGRP-dependent ERK activation and subsequent NaV1.7 membrane recruitment in trigeminal ganglion neurons. The CGRP-ERK-NaV1.7 pathway may represent a peripheral mechanism of BoNT/A-mediated analgesia and a potential target for neuropathic facial pain. Not applicable.
2026-08-11 | Manual and automated capture of analgesic-responsive facial pain behaviors of unrestrained mice in a trigeminal neuralgia model.
Trigeminal neuralgia (TN), a devastating neuropathic pain condition, profoundly affects human well-being. Despite an initial response to carbamazepine (CBZ), many patients become refractory to pharmacotherapy and subsequent invasive procedures. Although preclinical trigeminal neuropathic pain models following extracranial chronic constriction injury (CCI) of the trigeminal nerve have been developed, the injury-induced facial hypersensitivity is rarely CBZ-responsive, questioning the models' relevance to TN. In recent reports, CBZ-responsive facial pain can be induced by intracranial CCI that better mimics the compression observed in classical TN. Nevertheless, behavioral assessment of persistent pain in these models often requires a restrained setting that could trigger unpredictable behaviors that are not necessarily pain associated. Here, we focused on spontaneous and evoked measures of pain in unrestrained mice after a CBZ-sensitive intracranial CCI, namely the FRICT-ION model. To measure these behaviors long-term, we developed a high-frame rate videography analysis that reliably captures increased chronic spontaneous asymmetric grooming and mechanically evoked facial rubbing, ipsilateral to the injury. Notably, this altered behavioral phenotype was significantly reversed by a nonsedating dose of CBZ. Using DeepLabCut tracking, we also found that the speed of head movement after facial mechanical stimulation is a significant CBZ-sensitive behavioral correlate of TN allodynia. Importantly, these behavioral measures accurately recapitulated the clinical outcomes-both success and failure-of a cohort of specific nonopioid analgesics that have previously been tested in the clinical management of TN. Together, these measures should greatly facilitate the research development of innovative TN therapies.
2026-08-07 | Pearls & Oy-sters: Bilateral Neuropathic Facial Pain With Autonomic Features and Neurovascular Contact.
Trigeminal neuralgia (TN) is an uncommon disorder, with an annual prevalence of 0.03%-0.3% in North America. It is typically unilateral, most commonly involving the V2 and V3 distributions and may be accompanied by mild autonomic features. We report a 35-year-old woman who developed severe right more than left-sided facial pain in the V1 and V2 divisions (upper and midface), occurring up to 100 times daily after repetitive use of cosmetic products. Following a viral upper respiratory infection, the pain progressed to bilateral symmetric V1 and V2 involvement and was associated with new bilateral autonomic symptoms, including facial swelling, tearing, and nasal congestion. As recommended in all TN cases, MRI of the head was performed to assess for secondary causes, such as multiple sclerosis, cerebellopontine angle tumors, systemic lupus erythematosus, and neurosarcoidosis. Imaging revealed neurovascular contact between the superior cerebellar artery and the bilateral trigeminal nerves, without evidence of demyelination or nerve signal abnormality. Because the nerves appeared intact, this finding was felt unlikely to explain the symptoms, but rather, to be incidental. The patient experienced significant pain relief with carbamazepine and additional improvement in autonomic symptoms with a trial of indomethacin after a postinfectious pain flare, suggesting possible overlap with trigeminal autonomic cephalalgias (TACs). This case illustrates the diagnostic challenges of an uncommon facial pain presentation, characterized by progression to mirror-symmetric bilateral V1 and V2 involvement and autonomic features. Given the overlap between TN and other facial pain syndromes, including TACs, a multifaceted treatment approach may be necessary.
2026-08-04 | Initial Experience With Stereotactic Radiosurgery for Refractory Trigeminal Neuralgia Using the OXRAY System.
We report our experience with frameless stereotactic radiosurgery (SRS) using a novel O-ring type linear accelerator (LINAC), the OXRAY system, for refractory trigeminal neuralgia (TN). Three elderly TN patients resistant to pharmacological therapy were included. The head was immobilized with a double-shell mask, and the target was contoured to encompass the entire diameter of the trigeminal nerve at the trigeminal impression. The treatment plan was designed to deliver a maximum dose of 90 Gy in a single fraction using 6 MV flattening filter-free (FFF), volumetric-modulated arc therapy (VMAT). During treatment, image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) was performed a total of five times between each arc. Case 1 was a 74-year-old woman with atypical TN of the left mandibular nerve (V3) and severe numbness, who had undergone three prior microvascular decompressions. SRS was performed with a total irradiation time of 2,492 seconds. Her pain and numbness decreased four months after SRS. At the 16-month follow-up, the Barrow Neurological Institute (BNI) pain score had improved from IV to IIIa, and the facial numbness score had improved from IV to II. The carbamazepine (CBZ) dose was reduced from 500 mg to 100 mg/day. Case 2 was a 95-year-old woman with typical right maxillary nerve (V2) TN. SRS was performed with a total irradiation time of 1,356 seconds. Her pain resolved within a week after SRS, and CBZ was tapered and discontinued over a two-month period. At the 10-month follow-up, the BNI pain score remained at I (improved from IV) without CBZ. Case 3 was an 85-year-old woman with typical right V2 and V3 TN. SRS was performed with a total irradiation time of 1,637 seconds. Her pain resolved the day after SRS, and CBZ was tapered and discontinued over a one-month period. At the five-month follow-up, the BNI pain score remained at I (improved from IV) without CBZ. In all cases, the positional displacement on CBCT was within 1 mm or 1°, and no correction was necessary. No adverse events related to SRS were observed. Frameless FFF-VMAT SRS using the OXRAY system with repeated IGRT demonstrated favorable initial pain relief. This approach may represent a feasible and effective treatment option for elderly patients with refractory TN. Long-term follow-up is necessary to evaluate the incidence of adverse events and recurrence. In the future, the addition of a continuous intrafraction motion monitoring function is expected to reduce radiation exposure, further improve accuracy, and shorten treatment time.
2026-08-15 | Trigger zones in trigeminal neuralgia: clinical features, pathophysiological mechanisms, and therapeutic strategies.
Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by recurrent, unilateral, electric shock-like facial pain, with trigger zones representing one of its most distinctive clinical features. These localized hypersensitive regions can be reliably activated by innocuous mechanical stimuli such as light touch, speech, or chewing, and their distribution provides important guidance for localizing the affected trigeminal branch and directing treatment decisions. Current evidence suggests that trigger zone formation involves peripheral nerve hyperexcitability driven by upregulation of voltage-gated sodium channels, mechanical sensitization from adjacent facial and masticatory muscle activity, and central sensitization within the trigeminal brainstem complex. At the brainstem level, abnormal activation of wide dynamic range neurons results in the misinterpretation of innocuous tactile input as pain. Clinically, systemic sodium channel blockers remain the foundation of initial treatment, while trigger zone-targeted interventions including peripheral nerve blockade, botulinum toxin type A injections, and minimally invasive ablative techniques have emerged as important adjunctive approaches. The absence of standardized objective assessment criteria and insufficient comparative clinical evidence remain key limitations in the field. A more thorough understanding of trigger zone pathophysiology may ultimately support the development of precision-based, individualized management strategies for TN.
2026-08-11 | Botulinum toxin type A attenuates trigeminal neuralgia-like pain by suppressing CGRP release and modulating NaV1.7-associated signaling.
Trigeminal neuralgia (TN) is a disabling facial pain disorder, and current treatments remain insufficient for a substantial proportion of patients. Botulinum toxin type A (BoNT/A) has shown therapeutic benefit in TN, but its peripheral analgesic mechanisms remain incompletely understood. We aimed to determine whether BoNT/A alleviates TN-like pain by modulating the calcitonin gene-related peptide (CGRP)-extracellular signal-regulated kinase (ERK)-NaV1.7 pathway in trigeminal ganglion neurons. TN-like pain was induced in mice by chronic constriction injury of the infraorbital nerve (CCI-ION). On postoperative day 14, BoNT/A (10 U) or saline was injected intradermally into the whisker pad. Evoked and spontaneous pain-like behaviors were assessed using von Frey testing, the Ugo Basile facial pain test, and spontaneous scratching recordings; anxiety-like behavior was evaluated using the elevated plus maze. Myelin pathology was examined by Luxol fast blue staining and transmission electron microscopy. CGRP, NaV1.7/NaV1.8, and ERK/MAPK signaling were examined in trigeminal ganglion neurons using immunofluorescence, Western blotting, RT-qPCR, ELISA, calcium-influx assays, and whole-cell patch-clamp recordings. Olcegepant and PD98059 were used to interrogate CGRP receptor- and ERK-dependent mechanisms. BoNT/A significantly attenuated CCI-ION-induced mechanical allodynia, increasing the facial withdrawal threshold from 0.11 to 1.29 g, and reducing spontaneous pain-like behaviors. BoNT/A also improved anxiety-like behavioral measures in CCI-ION mice. Histological and ultrastructural analyses shown partial amelioration of myelin pathology, accompanied by increased myelin basic protein expression and a lower g-ratio. Mechanistically, BoNT/A reduced CGRP-associated activity in TRPV1-positive trigeminal ganglion neurons, accompanied by lower serum CGRP levels and attenuated capsaicin-evoked calcium influx. These changes were associated with a preferential reduction in NaV1.7 membrane localization, without a comparable reduction in NaV1.8, and with a marked decrease in sodium current density, with peak sodium current reduced by 78.6%. Pharmacological inhibition of CGRP receptors or ERK phosphorylation reproduced the effects of BoNT/A on NaV1.7 membrane localization. These findings suggest that BoNT/A alleviates CCI-ION-induced TN-like pain, at least in part, by suppressing CGRP-dependent ERK activation and subsequent NaV1.7 membrane recruitment in trigeminal ganglion neurons. The CGRP-ERK-NaV1.7 pathway may represent a peripheral mechanism of BoNT/A-mediated analgesia and a potential target for neuropathic facial pain. Not applicable.
2026-08-11 | Manual and automated capture of analgesic-responsive facial pain behaviors of unrestrained mice in a trigeminal neuralgia model.
Trigeminal neuralgia (TN), a devastating neuropathic pain condition, profoundly affects human well-being. Despite an initial response to carbamazepine (CBZ), many patients become refractory to pharmacotherapy and subsequent invasive procedures. Although preclinical trigeminal neuropathic pain models following extracranial chronic constriction injury (CCI) of the trigeminal nerve have been developed, the injury-induced facial hypersensitivity is rarely CBZ-responsive, questioning the models' relevance to TN. In recent reports, CBZ-responsive facial pain can be induced by intracranial CCI that better mimics the compression observed in classical TN. Nevertheless, behavioral assessment of persistent pain in these models often requires a restrained setting that could trigger unpredictable behaviors that are not necessarily pain associated. Here, we focused on spontaneous and evoked measures of pain in unrestrained mice after a CBZ-sensitive intracranial CCI, namely the FRICT-ION model. To measure these behaviors long-term, we developed a high-frame rate videography analysis that reliably captures increased chronic spontaneous asymmetric grooming and mechanically evoked facial rubbing, ipsilateral to the injury. Notably, this altered behavioral phenotype was significantly reversed by a nonsedating dose of CBZ. Using DeepLabCut tracking, we also found that the speed of head movement after facial mechanical stimulation is a significant CBZ-sensitive behavioral correlate of TN allodynia. Importantly, these behavioral measures accurately recapitulated the clinical outcomes-both success and failure-of a cohort of specific nonopioid analgesics that have previously been tested in the clinical management of TN. Together, these measures should greatly facilitate the research development of innovative TN therapies.
2026-08-07 | Pearls & Oy-sters: Bilateral Neuropathic Facial Pain With Autonomic Features and Neurovascular Contact.
Trigeminal neuralgia (TN) is an uncommon disorder, with an annual prevalence of 0.03%-0.3% in North America. It is typically unilateral, most commonly involving the V2 and V3 distributions and may be accompanied by mild autonomic features. We report a 35-year-old woman who developed severe right more than left-sided facial pain in the V1 and V2 divisions (upper and midface), occurring up to 100 times daily after repetitive use of cosmetic products. Following a viral upper respiratory infection, the pain progressed to bilateral symmetric V1 and V2 involvement and was associated with new bilateral autonomic symptoms, including facial swelling, tearing, and nasal congestion. As recommended in all TN cases, MRI of the head was performed to assess for secondary causes, such as multiple sclerosis, cerebellopontine angle tumors, systemic lupus erythematosus, and neurosarcoidosis. Imaging revealed neurovascular contact between the superior cerebellar artery and the bilateral trigeminal nerves, without evidence of demyelination or nerve signal abnormality. Because the nerves appeared intact, this finding was felt unlikely to explain the symptoms, but rather, to be incidental. The patient experienced significant pain relief with carbamazepine and additional improvement in autonomic symptoms with a trial of indomethacin after a postinfectious pain flare, suggesting possible overlap with trigeminal autonomic cephalalgias (TACs). This case illustrates the diagnostic challenges of an uncommon facial pain presentation, characterized by progression to mirror-symmetric bilateral V1 and V2 involvement and autonomic features. Given the overlap between TN and other facial pain syndromes, including TACs, a multifaceted treatment approach may be necessary.
2026-08-04 | Initial Experience With Stereotactic Radiosurgery for Refractory Trigeminal Neuralgia Using the OXRAY System.
We report our experience with frameless stereotactic radiosurgery (SRS) using a novel O-ring type linear accelerator (LINAC), the OXRAY system, for refractory trigeminal neuralgia (TN). Three elderly TN patients resistant to pharmacological therapy were included. The head was immobilized with a double-shell mask, and the target was contoured to encompass the entire diameter of the trigeminal nerve at the trigeminal impression. The treatment plan was designed to deliver a maximum dose of 90 Gy in a single fraction using 6 MV flattening filter-free (FFF), volumetric-modulated arc therapy (VMAT). During treatment, image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) was performed a total of five times between each arc. Case 1 was a 74-year-old woman with atypical TN of the left mandibular nerve (V3) and severe numbness, who had undergone three prior microvascular decompressions. SRS was performed with a total irradiation time of 2,492 seconds. Her pain and numbness decreased four months after SRS. At the 16-month follow-up, the Barrow Neurological Institute (BNI) pain score had improved from IV to IIIa, and the facial numbness score had improved from IV to II. The carbamazepine (CBZ) dose was reduced from 500 mg to 100 mg/day. Case 2 was a 95-year-old woman with typical right maxillary nerve (V2) TN. SRS was performed with a total irradiation time of 1,356 seconds. Her pain resolved within a week after SRS, and CBZ was tapered and discontinued over a two-month period. At the 10-month follow-up, the BNI pain score remained at I (improved from IV) without CBZ. Case 3 was an 85-year-old woman with typical right V2 and V3 TN. SRS was performed with a total irradiation time of 1,637 seconds. Her pain resolved the day after SRS, and CBZ was tapered and discontinued over a one-month period. At the five-month follow-up, the BNI pain score remained at I (improved from IV) without CBZ. In all cases, the positional displacement on CBCT was within 1 mm or 1°, and no correction was necessary. No adverse events related to SRS were observed. Frameless FFF-VMAT SRS using the OXRAY system with repeated IGRT demonstrated favorable initial pain relief. This approach may represent a feasible and effective treatment option for elderly patients with refractory TN. Long-term follow-up is necessary to evaluate the incidence of adverse events and recurrence. In the future, the addition of a continuous intrafraction motion monitoring function is expected to reduce radiation exposure, further improve accuracy, and shorten treatment time.
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Drug Discovery Landscape
7 orphan drug designations for Trigeminal neuralgia.
7 orphan drug designations for Trigeminal neuralgia.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
trimeprazine tartrate | small molecules | FDA | 2026-05-22 | — | Undaunted Bio, Inc. |
A potent negative allosteric modulator (NAM) of human alpha5-GABAA receptor | small molecules | FDA | 2024-01-31 | — | Shanghai SIMR Biotechnology Co., Ltd. |
carbon dioxide | small molecules | FDA | 2015-12-17 | — | Capnia, Inc. |
vixotrigine | small molecules | FDA | 2013-07-24 | — | Biogen, Inc. |
dehydrated alcohol | small molecules | FDA | 2012-03-16 | — | Luitpold Pharmaceuticals, Inc. |
L-baclofen | small molecules | FDA | 1998-01-06 | — | Osmotica Pharmaceutical Corp. |
L-baclofen | small molecules | FDA | 1990-07-13 | — | Fromm, Gerhard M.D. |
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