1047 Caught on Camera: Interpretation of Polysomnogram

Abstract

As home sleep apnea testing becomes more popular, in laboratory attended polysomnograms (PSG) are done less frequently. However a PSG provides valuable information using multiple channels and diagnostic tools. We present a case where comprehensive review of a PSG highlights the importance of the multifaceted aspects of a PSG in making an accurate diagnosis. Our case is a 24 year-old lady with chronic insomnia and daytime sleepiness with an Epworth Sleepiness Scope of 13 out of 24. She suffered from anxiety, depression, post-traumatic stress disorder, and asthma. She also had symptoms suggestive of restless leg syndrome. Physical exam was unremarkable and overnight oximetry showed some heart rate variability with possibility of minimal to mild sleep disordered breathing. Due to concern for undiagnosed sleep disordered breathing and periodic leg movements with restless leg symptoms, patient underwent diagnostic PSG. While the PSG did not show evidence of sleep apnea-hypopnea syndrome, there were periods with increased tibial electromyography (EMG) tone at regular intervals with simultaneous abnormal signals in the abdominal plethysmography band, suggestive of periodic limb movements. Video correlation reveals these abnormal findings were related to leg crossing. Abnormal EMG tone was absent when legs were uncrossed. This case highlights the importance of the comprehensive review of an in-lab PSG. PSG is an invaluable tool to pick up artifacts, which would have otherwise been missed and resulted in false diagnosis and treatment of periodic limb movement.