Neurodegeneration in Narcolepsy-Associated Rapid Eye Movement Sleep Behavior Disorder

Secondary RBD: Not just neurodegeneration

Rapid eye movement sleep behavior disorder is a parasomnia characterized by excessive muscle activity during rapid eye movement sleep (rapid eye movement sleep without atonia), along with dream enactment behavior. Isolated rapid eye movement sleep behavior disorder tends to occur in older males and is of concern due to the known link to Parkinson's disease and other synucleinopathies. When rapid eye movement sleep behavior disorder occurs in association with other neurological or general medical conditions, or resulting from the use of various substances, it is called secondary rapid eye movement sleep behavior disorder; the most common cause is neurodegenerative illness, specifically the synucleinopathies. Here, the focus will be on the subset of secondary rapid eye movement sleep behavior disorder in which there is no neurodegenerative disease.

[Speech and behavioral contaminations as non-epileptic automatic behavior in Parkinson's disease]

Parkinson's disease is characterized by a variety of motor and non-motor symptoms. More than two hundred years have passed since its description, but we still discover its new manifestations. Abnormal behaviors include impulse control disorders, dopamine dysregulation syndrome, psychotic disorders and others. However, two new phenomena have been recently described in patients with PD. It can manifest in the form of doing inappropriate actions which patient doesn't recognize, or pronouncing/writing unsuitable words and phrases. Patients can't remember such episodes, but find «signs» of their unconscious activity or hear about it from attestors. This article represents a review of literature on unrelated communication interlude and automatic behavior in Parkinson's disease and discusses its possible reasons.