Propriospinal myoclonus: diagnostic value of polymyography and video polysomnography

Clinical and video polysomnography findings in our patient were consistent with those described for PSM in the current literature. Moreover, a comprehensive assessment of clinical and neurophysiological tests, such as electroencephalogram, electroneurography-electromyogram, somatosensory evoked potentials, motor evoked potentials, and magnetic resonance imaging was helpful to rule out spinal cord or brain injuries. In the current case, PSM was detected up to stage 2 of the non-rapid eye movement sleep; furthermore, it also appeared even at rapid eye movement sleep. This report presents a case of jerks caused by activation of an initial muscle and subsequent spread to involved muscles through a defined pattern (rostral and caudal from the initial segment), which persisted during sleep. Only few studies have documented the persistence of jerks with these characteristics during sleep.

https://jcsm.aasm.org/doi/full/10.5664/jcsm.10486