The Connection Between Vascular Health and Cognition

As suppliers of critical oxygen and nutrients to the brain, blood vessels can have a profound impact on cognitive health. When there’s an issue with a blood vessel—whether it be blocked, narrowed, or ruptured—brain cells can’t receive the oxygen and nutrients they need, causing them to die off. Cognitive functions can suffer as a result, in a phenomenon known as vascular dementia.

Understanding vascular dementia

According to the Mayo Clinic, vascular dementia is “a general term describing problems with reasoning, planning, judgment, memory and other thought processes caused by brain damage from impaired blood flow to your brain.” Any damage to arteries—from brain hemorrhaging to narrowed blood vessels—can lead to the development of vascular dementia overtime, but it can also onset suddenly after a stroke or major surgery.

Vascular dementia’s symptoms span from incontinence and mood changes to slowed and disorganized thinking. While vascular dementia is seemingly similar to Alzheimer’s disease, the two are distinct, with vascular dementia being more commonly linked to difficulties in thinking and problem-solving opposed to memory loss.

That said, Alzheimer’s and vascular dementia often coexist. The same cardiovascular diseases that cause vascular dementia—obesity, high cholesterol, high blood pressure, and diabetes—are thought to increase the likelihood of developing Alzheimer’s disease. Other risk factors for vascular dementia are smoking, atrial fibrillation, and atherosclerosis.

Interventions for post-stroke cognitive impairment

Strokes frequently lead to the development of vascular dementia and cognitive impairment. Research indicates that approximately 30% of patients develop dementia within the first year of having a stroke, and over 40% develop post-stroke cognitive impairment (PSCI), making stroke the second most common cause of both dementia and cognitive impairment.

Due to the high frequency of cognitive impairment after stroke, it’s important to properly screen patients after one occurs. When cognitive impairment is identified early on, occupational therapists and neuropsychologists can work with patients to manage the effects they’re experiencing.

Cognitive remediation, also known as cognitive rehabilitation, is one approach for helping patients with cognitive impairments recover. By targeting memory, processing speed, and attention, cognitive remediation interventions can help patients use the areas of their brain that are working well in order to compensate for new challenges and improve problem areas. While cognitive remediation varies depending on the needs of the individual, possible interventions include:

• Mnemonic strategies like acronyms, rhymes, and acrostics to remember important information
• Virtual reality programs to improve short-term and sustained memory, as well as selected and divided attention, such as Saebo VR, BrightBrainer, and Reh@City
• Task analysis and breakdown to make daily tasks easier
• Memory aids like agendas, calendars, labels, and reminders

With proper interventions and early screening, stroke patients can improve executive functions and overall cognition, and hopefully lower their risk for developing dementia over the long-term.

Screening stroke patients with MoCA  

MoCA is a cognitive screening tool in both paper and digital formats that can quickly and accurately test patients for mild cognitive impairment (MCI), including impairment that onsets after stroke. The test is available in over 100 languages and dialects, and comes in a variety of versions to meet the needs of specific patient populations.

The following peer reviewed studies have demonstrated MoCA’s sensitivity for detecting cognitive impairment in stroke survivors:

• “From the studies we reviewed, the use of MoCA as a brief cognitive tool in both the acute/subacute and chronic poststroke periods seems overall feasible.” Researchers reviewed studies concerning MoCA use with stroke patients, and found that the test reliably predicts PSCI for both the acute (2 weeks after the event) and chronic (12-24 weeks after the event) post-stroke periods.¹
• “All three of the Montreal cognitive assessment visuoexecutive sub-tests detected more abnormalities than the mini-mental state examination pentagon copying and thus contributed to the over 10-fold superiority of Montreal cognitive assessment…” Interested in whether MoCA or the mini-mental state examination (MMSE) is better at detecting visuoexecutive dysfunction in transient ischemic attack (TIA) and stroke patients, researchers compared the tests and found MoCA to be more successful than MMSE in detecting abnormalities.²
• “This approach could facilitate clinical care pathways and patient selection for research.” This study sought to establish an approach for identifying moderate to severe CI in patients, and ultimately found that grouping patients into three categories—high-, intermediate-, and low-risk—with MoCA could help with clinical care and research.³
• “Early cognitive testing by MoCA predicts long-term cognitive outcome, functional outcome, and mortality after stroke. Our results support routine use of the MoCA in stroke patients.” Researchers set out to determine whether MoCA could predict long-term CI, functional outcome, and mortality when given to patients within the first week of a stroke, and found the test to be successful in doing so.⁴

Given the high prevalence of stroke around the world, screening for PSCI can help dramatically improve the daily lives of countless stroke survivors. Learn more about MoCA and other adapted testing content to screen for cognitive impairment caused by a wide range of conditions.

References:

1 Chiti, G. & Pantoni, L. Use of Montreal cognitive assessment in patients with stroke. Stroke 45, 3135–3140. https://doi.org/10.1161/STROKEAHA.114.004590 (2014).

2 Mai LM, Sposato LA, Rothwell PM, Hachinski V, Pendlebury ST. A comparison between the MoCA and the MMSE visuoexecutive sub-tests in detecting abnormalities in TIA/stroke patients. International Journal of Stroke. 2016;11(4):420-424. doi:10.1177/1747493016632238

3 Swartz, Richard H., et al. “Validating a Pragmatic Approach to Cognitive Screening in Stroke Prevention Clinics Using the Montreal Cognitive Assessment.” Stroke (2016): STROKEAHA-115.

4 Zietemann V, Georgakis MK, Dondaine T, Müller C, Mendyk AM, Kopczak A, Hénon H, Bombois S, Wollenweber FA, Bordet R, Dichgans M. Early MoCA predicts long-term cognitive and functional outcome and mortality after stroke. Neurology. 2018 Nov 13;91(20):e1838-e1850. doi: 10.1212/WNL.0000000000006506. Epub 2018 Oct 17. PMID: 30333158.

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