| 2854 Dysfunction of the Jaw-movement-related Mirror Neuron System in Patients with Temporomandibular Disorders | ||
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T. ISHIKAWA1, Y. SHIBUKAWA1, M. SHINTANI1, Z. ZHANG2, T. JIANG2, M. SHIMONO1, K. TAKAHASHI1, T. KUMAI3, M. KATO4, T. SUZUKI1, and Y. NAKAMURA5, 1 Tokyo Dental College, Chiba, Japan, 2 Peking University, Beijing, China, 3 Matsumoto Dental University, Shiojiri, Japan, 4 Keio University, Tokyo, Japan, 5 Teikyo Heisei University, Ichihara, Japan Objectives: A group of neurons in the monkey premotor cortex discharge when the monkey is performing a given action as well as when it is observing the experimenter performing a similar action (mirror neuron system; action execution/observation matching system). Several brain imaging studies indicate that the system exists also in humans. The present study aimed to determine the spatial and temporal activation patterns of the human mirror neuron system during observation of jaw movements. We compared cortical areas activated during observation of jaw movements between healthy normal human subjects and patients with temporomandibular disorders (TMD). Methods: Whole-scalp neuromagnetic responses were recorded from 6 healthy volunteers (mean age: 33.3 years) and 6 patients with TMD (mean age: 37.1 years) using a 306-channel whole-head SQUID neuromagnetometer. The subjects were asked to carefully observe, on videotape, bilaterally symmetrical jaw-opening movements performed by another individual. Results: In the healthy control subjects, the occipitotemporal region near the inferior temporal sulcus (MT/V5 human homologue), inferior parietal cortex (IPC) and jaw-movement-related area of the primary motor cortex (M1mx) was activated sequentially with left hemisphere dominance during observation of jaw movements. In patients with TMD, although a sequential activation of the MT/V5 and IPC was found during same observation task as normal subjects, activation of the primary motor cortex was lacking. Conclusions: These findings suggest that M1mx is included in the jaw movement-related mirror neuron system in human, and the dysfunction of the jaw movement-related mirror neuron system is one of the important factors in initiating and/or maintaining the symptoms of TMD. (Supported by Grants (HRC 3A04, 12 and 13) for High-Tech Research Center Projects from the MEXT in Japan) | ||
| Seq #285 - TMD - Pathophysiology, Psychophysiology and Treatment 11:00 AM-12:15 PM, Saturday, 28 June 2003 Svenska Massan Exhibition Hall B | ||
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