A link may exist between vascular dementia and excessive sleeping. Sleep disturbances, particularly excessive daytime sleeping, may predict the later development of vascular dementia.

A 2010 study of males in the United Kingdom came to this conclusion, noting that severe sleepiness in the daytime strongly predicted vascular dementia but not nonvascular dementia.

Excessive sleeping can occur in different types of dementia for various reasons. The condition may directly alter a person’s sleep patterns, causing sleep issues at night and napping during the day. Coexisting conditions, such as depression or side effects of medication, could also be explanations.

This article discusses vascular dementia and excessive sleeping, including the causes, the stage in which it occurs, and treatment.

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Excessive sleeping can occur in people with vascular dementia.

Vascular dementia develops when disrupted blood flow to the brain affects thinking, memory, and behavior. The condition can change sleep patterns, which may result in excessive sleepiness.

Excessive sleeping may also develop before vascular dementia. The above 2010 study looking at males living in Wales, United Kingdom, found that this symptom strongly predicted the development of the condition across 10 years.

This does not mean that every person who is frequently tired will inevitably have dementia. The relationship was strongest for those who reported severe daytime sleepiness, which was 30% of participants at the start of the study. By the end of the study, 7.6% of the 1,225 surviving participants had signs of dementia.

A further 14.3% of participants had signs of cognitive impairment without dementia, or mild cognitive impairment (MCI). MCI is not debilitating and does not always worsen, unlike dementia. Around 10–20% of those with MCI over the age of 65 progress to having dementia within 1 year.

However, the 2010 study also did not include females, which could affect the results, as biological differences between sexes may influence a person’s risk for dementia.

There are several reasons why people with vascular dementia could sleep a lot, such as:

  • The condition itself: Dementia causes changes in the brain that can directly affect sleep, mood, and other functions.
  • Depression: Depression is common in those with vascular brain conditions and can also cause persistent fatigue and changes in sleep.
  • Medications: Many medications can cause fatigue or sleepiness as a side effect, including antihistamines such as diphenhydramine (Benadryl), antidepressants, lithium and antipsychotics, and certain Parkinson’s disease drugs, such as levodopa (Inbrija).
  • Brain aging: A 2016 study found that excessive daytime sleepiness in people without dementia had links to increased rates of cortical thinning. This may indicate accelerated brain aging.

The charity Alzheimer’s Society notes that generally, doctors group cases of dementia of any type into early, middle, and late stages. It notes that sleep disturbances are a potential symptom of middle and late stage dementia.

However, excessive sleepiness may occur at any stage of vascular dementia. It may begin before dementia signs develop or not until later. People with vascular can also experience short periods of improvement, making the staging difficult.

People therefore cannot determine the stage of a person’s dementia according to their sleepiness alone. A doctor may be able to assess the progression of their condition.

There are no specific drugs that treat excessive sleeping in vascular dementia specifically. However, there are several strategies people can try:

  • Routine changes: If daytime sleepiness occurs due to disturbances or insomnia at night, people can try strategies to improve nighttime sleep, such as avoiding caffeine, having a relaxing nighttime routine, and making the bedroom quiet and comfortable. This may reduce daytime napping.
  • Daytime activity: Increasing daytime activity and light exposure may help regulate a person’s sleep. If they spend a lot of time indoors, trying to do more activities outside could be beneficial.
  • Melatonin: If routine changes do not work, a 2017 review notes that melatonin may help. Low doses of mirtazapine, which is a type of antidepressant, can also be a sleep aid.
  • Medications: Low doses of mirtazapine, which is a type of antidepressant, can be a sleep aid. For people whose daytime sleepiness and dementia cooccur with Parkinson’s disease, modafinil (Provigil) may improve the drowsiness.
  • Medication changes: If sleepiness is a side effect of medication, people can speak with a doctor about changing the dosage or medication.

Vascular dementia can deteriorate more quickly than other types of dementia. According to the Alzheimer’s Association, people live for around 3 years after developing dementia following a stroke, on average.

However, various factors can affect the speed of deterioration, so there is no way to know how rapidly an individual’s condition will progress.

If a person with dementia does suddenly get worse, it could signify an underlying problem. For example, they may have had another stroke, or the underlying condition that caused their vascular dementia may have worsened.

Infections can also exacerbate dementia symptoms, causing delirium, which can appear similar to the hallucinations or delusions that occur in later stage dementia.

As a result, anyone caring for someone with dementia who has suddenly begun showing more severe symptoms should seek medical advice.

Anyone experiencing excessive sleepiness in the daytime can speak with a doctor for advice. They may run tests to check for underlying causes.

In those who already have vascular dementia, a doctor can also advise on ways to manage this symptom and may be able to prescribe medications. In some cases, simple interventions may make a difference.

Older research findings suggest an association between vascular dementia and excessive sleeping. This symptom may have links to a higher risk of developing the condition later on. It can also be a symptom of current dementia.

Vascular dementia itself, sleep difficulties, medications, depression, and other factors could all lead to excessive sleepiness. There are ways of managing it, but what helps may depend on the cause. People can try changes in routine, more physical activity during the daytime, and treatments such as melatonin.

Anyone who is suddenly a lot sleepier than usual or has rapidly deteriorating dementia symptoms may require medical care.