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minh \u0111\u00f4 via Unsplash<\/p>\n
Poor sleep has been linked to an increased dementia risk<\/a>, though we don\u2019t yet know exactly how one affects the other.<\/p>\n But roughly 90% of people with the sleep condition known as isolated REM sleep behaviour disorder (iRBD) go on to develop Parkinson\u2019s or Lewy body dementia, according to a study published in\u00a0Neurology<\/a>.<\/p>\n The leader of the research team,\u00a0Professor\u00a0Shady Rahayel, said iRBD<\/a> is \u201cnot just restless sleep \u2013 it\u2019s a neurological warning sign\u201d.<\/p>\n But what is iRBD, and what does the new study show?<\/p>\n What is REM sleep behaviour disorder?<\/p>\n This is a condition where you physically or verbally act out in your sleep.<\/p>\n Its symptoms include thrashing around, shouting, and \u201csudden, often violent arm and leg movements during REM sleep\u201d. It is also known as<\/a> \u201cdream-enacting behaviour\u201d.<\/p>\n You might accidentally hit your partner in your sleep, swear while you\u2019re dreaming, or fall out of bed. Per the Cleveland Clinic<\/a>, about 80% of those with the condition get injured from the actions in their sleep.<\/p>\n Usually, our brain prevents our limbs<\/a> from moving during our dream cycle. With REM sleep behaviour disorders, though, this doesn\u2019t work.<\/p>\n According to\u00a0the Mayo Clinic<\/a>, it can come on gradually and get worse over time.<\/p>\n But the type most heavily linked to Lewy body dementia and Parkinson\u2019s is isolated, or idiopathic, REM sleep disorder<\/a>.<\/p>\n This issue, which affects about 2% of the population<\/a>\u00a0and \u201ccommonly presents in males >50 years\u201d, comes with no other obvious neurological conditions \u2013 hence why this particular type is described as \u201cisolated\u201d.<\/p>\n Speak to your doctor if you or your partner notice that you\u2019re \u201cacting out\u201d your dreams, especially if you\u2019re injuring yourself or others.<\/p>\n The findings could lead to dementia being spotted sooner in patients<\/p>\n Using MRI scans, the researchers found those with iRBD who saw changes to the amount of free water in the part of their brains responsible for thought and reasoning were eight times more likely to have a type of dementia with Lewy bodies.<\/p>\n \u201cWhat\u2019s fascinating is that this marker picks up very early changes \u2013 even before symptoms emerge,\u201d the study\u2019s lead author, Celine Haddad, said<\/a>.<\/p>\n And people with iRDB who also had a lower DTI-ALPS index (a MRI-based measuring technique focusing on fluid) in the left hemisphere of the brain were 2.4 times more likely to develop Parkinson\u2019s in the coming years.<\/p>\n This is hopeful news, because the earlier these conditions are spotted, the better it is for scientists and patients, who can access timely treatment and potentially help slow the rate of disease.<\/a><\/p>\n