Rapid eye movement (REM) sleep typically inhibits seizures and epileptiform activity in persons with epilepsy. In animal models, REM sleep without atonia has been shown to facilitate seizures and epileptiform activity. We sought to rigorously examine muscle tone in the REM sleep of persons with epilepsy for the first time using a novel quantitative electroencephalographic (QEEG) technique. QEEG software (Persyst, USA) analyzed continuously recorded EEG in the University of Manitoba Epilepsy Monitoring Unit (EMU) over a 12-month period to quantify muscle artifact intensity during REM sleep. Additional electrooculogram and muscle electrodes were included for REM sleep identification. QEEG represented muscle artifact as green bars of varying intensity. The maximal degree of greenness (M) was calculated as RGB values in order to represent the overall muscle tone of a REM sleep epoch. 790 REM sleep epochs were identified from 94 patients (mean age 37.6 years, 66% female). 58 patients were on medications capable of affecting muscle tone. Of patients not on these medications, 30 were epileptic (n = 272 epochs) and 6 were nonepileptic controls (n = 56 epochs). While half of epileptic patients were male, all nonepileptic patients were female. Age and gender were not significantly correlated with M. M was significantly lower in epileptic patients (M = 5.05 vs. 8.68, p < 0.001). As additional controls, M was also calculated for patients outside the 12-month period: a nonepileptic patient with REM sleep behavior disorder (M = 13.95), and another epileptic patient during a generalized tonic-clonic seizure (M = 128). This study shows for the first time that QEEG can be used to detect and quantify muscle tone in persons with epilepsy. We found that REM sleep muscle tone was significantly lower in epileptic patients than nonepileptic controls. Given the association of REM sleep without muscle atonia and seizure facilitation in animal models, this phenomenon may be a homeostatic protective mechanism against seizures in persons with epilepsy.