Effects of the N-Methyl-D-Aspartate Receptor Antagonist Dextromethorphan on Temporal Summation of Pain are Similar in Fibromyalgia Patients and Normal Control Subjects

Results of this study demonstrate that FM patients show abnormal WUSP during thermal and mechanical stimulation compared with NC. Because oral doses of the NMDA receptor antagonist DEX attenuated thermal and mechanical WUSP similarly in FM patients and NC, other mechanisms than WUSP need to be considered for the widespread pain of FM patients. These mechanisms might include tonic nociceptive input from peripheral tissues and/or enhanced descending facilitation.