Cerebral cortical dysfunction in patients with temporomandibular disorders in association with jaw movement observation

Abstract

Temporomandibular disorders (TMD) represent a group of chronic painful conditions in the masticatory musculature and temporomandibular joint. To examine possible changes in cortical machinery in TMD patients, we compared neuromagnetic signals evoked by cortical neurons between healthy subjects and TMD patients while they were carefully observing the video frames of jaw-opening movements performed by another person. During the movement observation task in the healthy subjects, we found cortical activation in t he following sequence with left hemisphere dominance: 1) the occipitotemporal region near the inferior temporal sulcus (human homologue of MT/V5 in monkeys), 2) the inferior parietal cortex (IPC), and 3) the anterior part of the inferior-lateral precentral gyrus (PrCG). In the TMD patients, however, we found deficit or marked attenuation of the neuromagnetic responses in the PrCG and IPC, while the activity of the MT/V5 showed no differences from that in the healthy subjects. In addition, we could not find any differences in cortical magnetic responses between healthy subjects and TMD patients when they were observing palm-opening movements, indicating that cortical dysfunction associated with jaw-movement observation is specific phenomena in the patients of TMD. Thus the present study provides new neuropathological evidence that TMD patients exhibit dysfunction of recognition mechanisms in cerebral cortex during motor observation, and suggests that disturbance of cortical functions

Time‐dependent hemispheric shift of the cortical control of volitional swallowing

“…This is supported by an MEG brain imaging study finding a left hemispheric specialization of mirror neurons regarding movements of the temporomandibular joint. Healthy subjects showed left lateralized activation in the inferior parietal cortex, the anterior part of the inferior-lateral precentral gyrus and the occipitotemporal region during movement observation of symmetrical jaw-opening [Shibukawa et al, 2007]. The same group found no hemispheric specialization in jaw movement preparation [Shibukawa et al, 2004].…”

Magnetoencephalography Study of Right Parietal Lobe Dysfunction of the Evoked Mirror Neuron System in Antipsychotic-Free Schizophrenia

“…Previous studies have suggested that passive viewing of BM (particularly of goal-directed hand action and of mouth movement [23]) alone could activate various brain regions [24]–[26] that are thought to have a role in the human MNS. In agreement with these earlier studies, four to eight ECDs were estimated in both hemispheres.…”

Cortical Representation Area of Human Dental Pulp

“…Equivalent current dipoles were determined by least-squares search, based on signals from 20-30 channels over the response area. Only dipoles attaining a more than 90% goodness-of-fit were accepted for further analysis, where the entire time period and all channels were taken into account in computations of the parameters of a time-varying dipole model (Shibukawa et al, , 2006. In this model, the strength of the dipoles was allowed to change as a function of time.…”