Is It Psychogenic Non-Epileptic Event, Sleep Related Rhythmical Movement Disorder or Hypermotor Seizure?

Distinguishing non-epileptic events from epileptic seizures remains a clinical challenge, particularly when occurring exclusively during sleep. Sleep-related rhythmical movement disorder (SRRMD) is a benign condition typically seen in early childhood, characterised by stereotyped, rhythmical repetitive movements involving large muscle groups, predominantly during Stage II of non-REM sleep. These movements can closely mimic features of sleep parasomnias, hypermotor seizures or psychogenic non-epileptic seizures (PNES), complicating the diagnostic approach. We present a case of an adolescent female with comorbid SRRMD and PNES and a clinical approach to distinguish between them.