Trigeminal input, pupil size and cognitive performance: from oral to brain matter.

Trigeminal input, pupil size and cognitive performance: from oral to brain matter. Brain Res. 2020 Nov 04;:147194 Authors: Paola Tramonti Fantozzi M, De Cicco V, Argento S, De Cicco D, Barresi M, Cataldo E, Bruschini L, d'Ascanio P, Faraguna U, Manzoni D Abstract It has been observed that, in patients affected by temporomandibular disorders (TMDs) and edentulism, a left-right asymmetry in electromyographic (EMG) activity of masseter muscles during clenching and in pupil size at rest (anisocoria) is present. Both are greatly reduced by an orthotic-prosthetic correction. In parallel, the correction significantly improves cognitive performance. These effects are possibly due to the recovery of a cortical balance, via Locus Coeruleus (LC) modulation, whose activity is powerfully affected by the sensorimotor trigeminal input. The role of this functional axis was further investigated in subjects without overt occlusal or dental problems. In these individuals, the EMG asymmetry was significantly correlated to anisocoria at rest, with the dental arches open or in contact. Also in normal subjects, both the EMG and the pupil asymmetry during clenching could be significantly reduced by an orthotic (bite) correction. Closing the arches without bite increased anisocoria and reduced performance in the Spinnler-Tognoni matrices test, as well as the mydriasis induced by a haptic task. When the bite was interposed, anisocoria was reduced, while both ...
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research