A study published in the July 2006 issue of The Lancet Neurology suggests a relationship could exist between disorders during REM sleep and future neurodegenerative pathologies such as Parkinson’s, Lewy body dementia and mild cognitive impairment.
The possible association was discovered in a retrospective evaluation of patients by the Multidisciplinary Unit of Sleep Disorders at the Hospital Clinic de Barcelona.
Investigators discovered a high incidence (45%) of the disorders over the course of multi-year follow-up. Significantly, individuals diagnosed with neurodegenerative disorders were those who had been displaying a sleep behavior disorder for the longest period.
The article is based on a descriptive study conducted since 1991 in which 44 patients from the Hospital Clínic were assessed. Given the low incidence of this disorder, the sample of patients studied by this Catalan group is the highest until today. All these patients presented idiopathic REM sleep behaviour disorder. These patients, usually over 60 years, suffer from unpleasant dreams and express uneasiness by screaming, crying, kicking, punching and even falling from their beds.
According to the results of this study, 20 of these patients (45%), after being correctly diagnosed in the centre and followed up during five years, developed a neurodegenerative disease. This incidence is much higher than what is expected in the general population of the same age and gender. Therefore, scientists drew the conclusion that this disorder permits the early detection of neurodegenerative diseases such as Parkinson’s disease, Lewy body dementia, multiple system atrophy or mild cognitive impairment.
Furthermore, the fact that the twenty patients who developed a neurodegenerative disease were those who had suffered from REM sleep behaviour disorder for the longest time, suggests that this incidence could be superior in the future.
The importance of these results lie firstly in the future possibility of administrating neuroprotective drugs to patients with the REM sleep behaviour disorder who have still not developed a degenerative disease. Furthermore, the monitoring of these patients will permit an early administration of palliative drugs, which are already available. Toward this end, the Ministry of Health has awarded this group with a FIS award named “Prognostic markers of the development of a neurodegenerative disease in patients affected with REM sleep behavior disorder”.
Source: Hospital Clínic de Barcelona