0957 “To Be, Or Not To Be? Case Series Of Patients With Discrepancy Between Clinical Vs. Psg Criteria For Diagnosis Of Rem Behavior Disorder (RBD).”

Abstract

The ICSD 3 lists the presence of REM without atonia (RWA) on PSG, as an essential criterion for the diagnosis of RBD. However, the scoring criteria for RWA are not clearly defined in the AASM scoring manual (2012). We describe three patients with clinical diagnosis of RBD, who did not fulfill the PSG criteria for RWA. They reported improvement on treatment with melatonin. These three males, aged 68, 73 and 73 years, complained of >1 year history of witnessed semi-purposeful behaviors in sleep, that correlated with their dream content. One patient had a history of Parkinson’s Disease (PD) with worsening episodes, despite being on dopaminergic therapy. All three patients underwent PSG with Multiple Muscle Montage (MMM) which includes upper extremities EMG, in our lab. All 3 patients PSG’s revealed excessive transient muscle activity in some epochs of REM sleep as defined by AASM manual, but these epochs did not add up to >50% of the total REM epochs, and hence did not meet the PSG criteria for RWA in our lab. Of these, 2 patients had neither OSA nor PD. In 1 of the 2 PSG’s, dream enactment behavior (DEB) was noted. The PD patient had mild OSA and underwent a CPAP study with MMM, which revealed DEB but also did not meet the criteria for RWA. The AASM definition of RWA is deficient in specifying: 1) the percentage of total REM epochs that should show excessive twitching 2) the minimal duration of REM sleep required for application of this definition 3) whether the definition is applicable if the patient has comorbid OSA or is on dopaminergic medications 4) whether the montage for assessment of RWA should include upper extremities EMG. These deficiencies may lead to underestimation of RBD in some labs, and reduced inter-scorer reliability between labs. Hence, further clarification of the definition is needed before RWA is deemed as an essential criterion for the diagnosis of RBD. Support (If Any)