A relationship between bruxism and orofacial-dystonia A trigeminal electrophysiological approach in a case report of pineal cavernomaReport as inadecuate

A relationship between bruxism and orofacial-dystonia A trigeminal electrophysiological approach in a case report of pineal cavernoma - Download this document for free, or read online. Document in PDF available to download.

Behavioral and Brain Functions

, 9:41

First Online: 28 October 2013Received: 19 April 2013Accepted: 17 October 2013


BackgroundIn some clinical cases, bruxism may be correlated to central nervous system hyperexcitability, suggesting that bruxism may represent a subclinical form of dystonia. To examine this hypothesis, we performed an electrophysiological evaluation of the excitability of the trigeminal nervous system in a patient affected by pineal cavernoma with pain symptoms in the orofacial region and pronounced bruxism.

MethodsElectrophysiological studies included bilateral electrical transcranial stimulation of the trigeminal roots, analysis of the jaw jerk reflex, recovery cycle of masseter inhibitory reflex, and a magnetic resonance imaging study of the brain.

ResultsThe neuromuscular responses of the left- and right-side bilateral trigeminal motor potentials showed a high degree of symmetry in latency 1.92 ms and 1.96 ms, respectively and amplitude 11 mV and 11.4 mV, respectively, whereas the jaw jerk reflex amplitude of the right and left masseters was 5.1 mV and 8.9 mV, respectively. The test stimulus for the recovery cycle of masseter inhibitory reflex evoked both silent periods at an interstimulus interval of 150 ms. The duration of the second silent period evoked by the test stimulus was 61 ms and 54 ms on the right and left masseters, respectively, which was greater than that evoked by the conditioning stimulus 39 ms and 35 ms, respectively.

ConclusionsWe found evidence of activation and peripheral sensitization of the nociceptive fibers, the primary and secondary nociceptive neurons in the central nervous system, and the endogenous pain control systems including both the inhibitory and facilitatory processes, in the tested subject. These data suggest that bruxism and central orofacial pain can coexist, but are two independent symptoms, which may explain why numerous experimental and clinical studies fail to reach unequivocal conclusions.

KeywordsBruxism Orofacial pain Temporomandibular disorders Dystonia Oro facial dystonia Trigeminal electrophysiology Bilateral Root-MEPs AbbreviationsbR-MEPsbilateral root-notor evoked potentials

JJrJaw jerk reflex

rcMIRrecovery cycle of masseter inhibitory reflex

SP2Silent period 2

S2Test stimulus

S1Conditioning stimulus

OFDOrofacial dystonia

OPorofacial pain

TMDsTempomandibular disorders

IAInterposed activity

NVmtTrigeminal motor nucleus

PeriVPeritrigeminal area

PCRtParvocellular reticular formation

EPSPsExcitatory postsynaptic potentials

IPSPsInhibitory postsynaptic potentials


Electronic supplementary materialThe online version of this article doi:10.1186-1744-9081-9-41 contains supplementary material, which is available to authorized users.

Gianfranco Sau, Flavio Frisardi, Carlo Leornadis, Aurea Lumbau, Paolo Enrico, Donatella Sirca, Enrico Maria Staderini contributed equally to this work.

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Author: Gianni Frisardi - Cesare Iani - Gianfranco Sau - Flavio Frisardi - Carlo Leornadis - Aurea Lumbau - Paolo Enrico - Donatell

Source: https://link.springer.com/

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