title: Effects of intra-articular ketamine on pain and somatosensory function in temporomandibular joint arthralgia patients.
abstract: Recent studies have hypothesized that peripheral glutamate receptors could be implicated in deep craniofacial pain conditions. In this study 18 temporomandibular joint (TMJ) arthralgia patients received intra-articular injections of the N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine, or normal saline to study in a cross-over, double-blinded, placebo-controlled manner the effect on TMJ pain and somatosensory function. Spontaneous pain and pain on jaw function was scored by patients on 0-10 cm visual analogue scale (VAS) for up to 24h. Quantitative sensory tests (QST): tactile, pin-prick, pressure pain threshold and pressure pain tolerance were used for assessment of somatosensory function at baseline and up to 15 min after injections. There were no significant effects of intra-articular ketamine over time on spontaneous VAS pain measures (ANOVA: P=0.532), pain on jaw opening (ANOVA: P=0.384), or any of the somatosensory measures (ANOVA: P>0.188). The poor effect of ketamine could be due to involvement of non-NMDA receptors in the pain mechanism and/or ongoing pain and central sensitization independent of peripheral nociceptive input. In conclusion, there appears to be no rationale to use intra-articular ketamine injections in TMJ arthralgia patients, and peripheral NMDA receptors may play a minor role in the pathophysiology of this disorder.
authors.affiliation: Department of Clinical Oral Physiology, School of Dentistry, University of Aarhus, Vennelyst Boulevard 9, DK-8000 Aarhus, Denmark Department of Neurology, Aarhus University Hospital, Denmark Department of Oral Maxillofacial Surgery, Aarhus University Hospital, Aarhus, Denmark Center for Sensory Motor Interaction, Aalborg University, Denmark.
authors.forename: Emad E
authors.initials: EE
authors.lastname: Ayesh
authors.forename: Troels S
authors.initials: TS
authors.lastname: Jensen
authors.forename: Peter
authors.initials: P
authors.lastname: Svensson
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D000700:Analgesics / Q000008:administration & dosage; D018771:Arthralgia / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D009619:Nociceptors / Q000187:drug effects / Q000378:metabolism; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010919:Placebos; D011434:Proprioception / Q000187:drug effects / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects* / Q000378:metabolism; D013704:Temporomandibular Joint / Q000187:drug effects* / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D017211:Treatment Failure; D014276:Trigeminal Nerve / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000700:Analgesics; D018691:Excitatory Amino Acid Antagonists; D010919:Placebos; D016194:Receptors, N-Methyl-D-Aspartate; D007649:Ketamine