A review published in the journal Nature and Science of Sleep explores the links between sleep disturbance and neurodegeneration in diseases such as Huntington’s disease (HD). The authors state that sleep difficulties might not only be a symptom of the underlying neurodegeneration but also a contributing factor driving the disease.
The review, “Chronic sleep disturbance and neural injury: links to neurodegenerative disease,“ was a combined effort by Northwestern University Feinberg School of Medicine researcher Sabra M. Abbott and Aleksandar Videnovic from Harvard Medical School.
Up to 90 percent of HD patients suffer from sleep disturbance, including difficulty initiating and maintaining sleep, reduced sleep efficiency and less total sleep time. Studies have shown that as the disease progresses, circadian rhythm disturbances become progressively worse. Research indicates that in the case of HD, hypnotic drugs can improve sleep-wake patterns and, as a consequence, cognition.
The review notes that there is increasing evidence that sleep disturbances observed in patients with HD and other neurodegenerative diseases have a neuroanatomical basis. Reduced numbers of neurons in the suprachiasmatic nucleus – a brain region that is considered the circadian pacemaker in mammals – are linked to the amplitude of sleep-wake activity.
Sleep disturbance is also associated with altered secretion of melatonin, an antioxidant that protects cells from oxidative stress. Researchers have found that in addition to mirroring sleep disturbance, reduced melatonin signaling may actually speed up the progression of disease. And, melatonin can block the assembly and toxicity of α-synuclein – a protein which aggregates in the brains of Parkinson’s disease patients and might also contribute to HD.
Read more on the studies findings in the full article at huntingtonsdiseasenews.com