Differential Diagnosis of Complex Nocturnal Behaviors

Purpose of Review Complex nocturnal movements and behaviors are the manifestation of numerous disorders encountered in clinical practice, which are challenging to diagnose due to overlapping clinical manifestations and limitations of the clinical history. We review the three most common causes of complex nocturnal behaviors, disorders of arousal (DOAs) from non-rapid eye movement (NREM) sleep, REM sleep behavior disorder (RBD), and sleep hypermotor epilepsy (SHE), and their overlapping manifestations that can stump clinicians. Recent Findings Correlation of semiology with electrical signals (electro-clinical correlation) is key to the diagnosis. Emerging science is demonstrating a shared pathophysiology of SHE and DOAs and RBD as a precursor of neurodegenerative disorders, underscoring the importance of diagnostic accuracy in the sleep and EEG laboratory. Summary The evaluation of complex nocturnal movements and behaviors requires a detailed clinical history taken from the patient and observers, video recordings, and in most cases, EEG/PSG confirmation.