title: Burning mouth syndrome as a trigeminal small fibre neuropathy: Increased heat and capsaicin receptor TRPV1 in nerve fibres correlates with pain score.
abstract: Burning mouth syndrome (BMS) is often an idiopathic chronic and intractable pain condition, affecting 1.5-5.5% of middle-aged and elderly women. We have studied the heat and capsaicin receptor TRPV1, and its regulator nerve growth factor (NGF), in BMS. Patients with BMS (n=10) and controls (n=10) were assessed for baseline and post-topical capsaicin pain scores, and their tongue biopsies immunostained for TRPV1, NGF, and structural nerve markers neurofilament and peripherin. Nerve fibres penetrating the epithelium were less abundant in BMS (p<0.0001), indicating a small fibre neuropathy. TRPV1-positive fibres were overall significantly increased in BMS (p=0.0011), as were NGF fibres (p<0.0001) and basal epithelial cell NGF staining (p<0.0147). There was a significant correlation between the baseline pain score and TRPV1 (p=0.0143) and NGF fibres (p=0.0252). A significant correlation was observed between baseline and post-capsaicin pain (p=0.0006). Selective TRPV1 and NGF blockers may provide a new therapy for BMS.
authors.affiliation: Clinical and Diagnostic Oral Sciences, St Bartholomew's and Royal London School of Medicine and Dentistry, Queen Mary College, University of London, and Peripheral Neuropathy Unit, Hammersmith Hospital, London, UK.
authors.forename: Z
authors.initials: Z
authors.lastname: Yilmaz
authors.forename: T
authors.initials: T
authors.lastname: Renton
authors.forename: Y
authors.initials: Y
authors.lastname: Yiangou
authors.forename: J
authors.initials: J
authors.lastname: Zakrzewska
authors.forename: I P
authors.initials: IP
authors.lastname: Chessell
authors.forename: C
authors.initials: C
authors.lastname: Bountra
authors.forename: P
authors.initials: P
authors.lastname: Anand
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002054:Burning Mouth Syndrome / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D062559:NAV1.8 Voltage-Gated Sodium Channel; D009412:Nerve Fibers / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000378:metabolism; D016900:Neurofilament Proteins / Q000378:metabolism; D010147:Pain Measurement / Q000379:methods; D015222:Sodium Channels / Q000378:metabolism; D050916:TRPV Cation Channels / Q000378:metabolism*; D014059:Tongue / Q000473:pathology; D020433:Trigeminal Nerve Diseases / Q000150:complications* / Q000473:pathology
chemical_list: D062559:NAV1.8 Voltage-Gated Sodium Channel; D016900:Neurofilament Proteins; C568317:SCN10A protein, human; D015222:Sodium Channels; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D020932:Nerve Growth Factor