A brainstem inflammatory lesion causing REM sleep behavior disorder and sleepwalking (parasomnia overlap disorder)

(A) Axial T1-weighted brain MRI of the patient between neurological episodes showing hyperintensities in the pontine tegmentum. (B) Axial T2 FLAIR-weighted brain MRI showing hypointensities in the pontine tegmentum. (C) Superior axial section of the brainstem reproduced with permission from [15], at the same level as the MRI images of the patient, when the path of the 3rd and 4th cranial nerves is horizontal. No 20: medial longitudinal fasciculus; No 21: superior cerebellar peduncle; No 22: IVth ventricle; No 23: coeruleus nucleus, No 24: mesencephalic nucleus of trigeminal nerve; No 25: tentorum of cerebellum.

Night-time hypnogram of the patient with parasomnia overlap disorder, showing two awakenings during slow-wave sleep. The x-axis displays the time, the y-axis displays the sleep–wake stages, with REM, Rapid eye movement sleep; W, wakefulness.

An example of an 1 min-period of REM sleep without atonia in the patient, with enhanced tonic chin muscle tone during REM sleep. The montage includes, from top to bottom, EEG (Fp1-A2 , C3-A2, C3-01), right and left electrooculograms, chin electromyogram, left and right tibialis anterior electromyogram, pulse, thoracic and abdominal breathing efforts, airflow and EKG.