Stroke

As we all know, people are living longer and obesity is at appalling levels. For both these (completely separate!) reasons, we expect to see growing rates of dementia. A new analysis using data from the long-running Framingham Heart Study offers some hope to individuals, however.

Looking at the rate of dementia during four distinct periods in the late 1970s, late 1980s, 1990s, and 2000s, using data from 5205 older adults (60+), the researchers found that there was a progressive decline in the incidence of dementia at a given age, with an average reduction of 20% per decade since the 1970s (22%, 38%, and 44% during the second, third, and fourth epochs, respectively).

There are two important things to note about this finding:

  • the decline occurred only in people with a high school education and above
  • the decline was more pronounced with dementia caused by vascular diseases, such as stroke.

The cumulative risk over five years, adjusted for age and gender, were:

  • 3.6 per 100 persons during the first period (late 1970s and early 1980s)
  • 2.8 per 100 persons during the second period (late 1980s and early 1990s)
  • 2.2 per 100 persons during the third period (late 1990s and early 2000s)
  • 2.0 per 100 persons during the fourth period (late 2000s and early 2010s).

Part of the reason for the decline is put down to the decrease in vascular risk factors other than obesity and diabetes, and better management of cardiovascular diseases and stroke. But this doesn't completely explain the decrease. I would speculate that other reasons might include:

  • increased mental stimulation
  • improvements in lifestyle factors such as diet and exercise
  • better health care for infectious and inflammatory conditions.

The finding is not completely unexpected. Recent epidemiological studies in the U.S., Canada, England, the Netherlands, Sweden and Denmark have all suggested that “a 75- to 85-year-old has a lower risk of having Alzheimer’s today than 15 or 20 years ago.” Which actually cuts to the heart of the issue: individual risk of dementia has gone down (for those taking care of their brain and body), but because more and more people are living longer, the numbers of people with dementia are increasing.

http://www.futurity.org/dementia-rates-decline-1119512-2/

http://www.scientificamerican.com/article/is-dementia-risk-falling/

Data from 23,572 Americans from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study has revealed that those who survived a stroke went on to have significantly faster rates of cognitive decline as they aged.

Participants, who were aged 45 years or older, had no history of cognitive impairment at the beginning of the population-based study. Over the next five to seven years, 515 of them (2%) had a stroke.

Stroke was associated with an acute decline in global cognition, new learning, and verbal memory. Those who had a stroke showed faster declines in global cognition and executive function (but not new learning nor verbal memory) over the next years.

Global cognition was assessed using the Six-Item Screener [SIS]; new learning by the Consortium to Establish a Registry for Alzheimer Disease Word-List Learning; verbal memory by the Word-List Delayed Recall; executive function by the Animal Fluency Test.

The findings suggest a need for better long-term follow-up care for stroke survivors, including therapy to retain or even regain cognitive ability.

http://www.eurekalert.org/pub_releases/2015-07/uomh-mt070715.php

A ten-year study following 12,412 middle-aged and older adults (50+) has found that those who died after stroke had more severe memory loss in the years before stroke compared to those who survived stroke and those who didn't have a stroke.

Participants were tested every two years, using a standard word-recall list to measure memory loss (or caregiver assessment for those whose memory loss was too severe). During the decade of the study, 1,027 participants (8.3%) survived a stroke, 499 (4%) died after stroke, and 10,886 (87.7%) remained stroke-free over the study period.

Before having a stroke, those who later survived a stroke had worse average memory than similar individuals who never had a stroke, however their rate of memory decline was similar (0.034 and 0.028 points per year, respectively). Those who later died after a stroke, on the other hand, showed significantly faster memory decline (0.118 points per year).

Whether this is because those who die after stroke have a more compromised brain prior to the stroke, or because greater memory impairment makes people more vulnerable in the wake of a stroke, cannot be told from this data (and indeed, both factors may be involved).

Among survivors, stroke had a significant effect on memory decline, with memory scores dropping an average of 0.157 points at the time of the stroke — an amount equivalent to around 5.6 years of memory decline in similarly-aged stroke-free adults. However, in subsequent years, decline was only a little greater than it had been prior to the stroke (0.038 points per year).

(You can see a nice graph of these points here.)

Wang, Q., Capistrant, B.D., Ehntholt, A. & Glymour, M.M. 2012. Abstract 31: Rate of Change in Memory Functioning Before and After Stroke Onset. Presented at the American Stroke Association's International Stroke Conference 2012. http://stroke.ahajournals.org/cgi/content/meeting_abstract/43/2_MeetingAbstracts/A31?sid=960f2015-06d1-478f-8c03-c00994d35f2c

Following on from research showing an association between lower walking speed and increased risk of dementia, and weaker hand grip strength and increased dementia risk, a large study has explored whether this association extends to middle-aged and younger-old adults.

Part of the long-running Framingham study, the study involved 2,410 men and women with an average age of 62, who underwent brain scans and tests for walking speed, hand grip strength and cognitive function. During the follow-up period of up to 11 years, 34 people (1.4%) developed dementia (28 Alzheimer’s) and 79 people (3.3%) had a stroke.

Those who had a slower walking speed at the start of the study were one-and-a-half times more likely to develop dementia compared to people with faster walking speed, while stronger hand grip strength was associated with a 42% lower risk of stroke or transient ischemic attack in people over age 65.

Slower walking speed and weaker hand grip strength were also associated with lower brain volume and poorer cognitive performance. Specifically, those with slower walking speed scored significantly worse on tests of visual reproduction, paired associate learning, executive function, visual organization, and language (Boston Naming test). Higher hand grip strength was associated with higher scores on tests of visual reproduction, executive function, visual organization, language and abstraction (similarities test).

While the nature of the association is not yet understood, the findings do seem to support the benefits of physical fitness. At the least, these physical attributes can serve as pointers to the need for more investigation of an older person’s brain health. But they might also serve as a warning to improve physical fitness.

Camargo, E.C., Beiser, A., Tan, Z.S., Au, R., DeCarli, C., Pikula, A., Kelly-Hayes, M., Kase, C., Wolf, P. & Seshadri, S. 2012. Walking Speed, Handgrip Strength and Risk of Dementia and Stroke: The Framingham Offspring Study. To be presented April 25 at the American Academy of Neurology's 64th Annual Meeting in New Orleans.

In the last five years, three studies have linked lower neighborhood socioeconomic status to lower cognitive function in older adults. Neighborhood has also been linked to self-rated health, cardiovascular disease, and mortality. Such links between health and neighborhood may come about through exposure to pollutants or other environmental stressors, access to alcohol and cigarettes, barriers to physical activity, reduced social support, and reduced access to good health and social services.

Data from the large Women’s Health Initiative Memory Study has now been analyzed to assess whether the relationship between neighborhood socioeconomic status can be explained by various risk and protective factors for poor cognitive function.

Results confirmed that higher neighborhood socioeconomic status was associated with higher cognitive function, even after individual factors such as age, ethnicity, income, education, and marital status have been taken into account. A good deal of this was explained by vascular factors (coronary heart disease, diabetes, stroke, hypertension), health behaviors (amount of alcohol consumed, smoking, physical activity), and psychosocial factors (depression, social support). Nevertheless, the association was still (barely) significant after these factors were taken account of, suggesting some other factors may also be involved. Potential factors include cognitive activity, diet, and access to health services.

In contradiction of earlier research, the association appeared to be stronger among younger women. Consistent with other research, the association was stronger for non-White women.

Data from 7,479 older women (65-81) was included in the analysis. Cognitive function was assessed by the Modified MMSE (3MSE). Neighborhood socioeconomic status was assessed on the basis of: percentage of adults over 25 with less than a high school education, percentage of male unemployment, percentage of households below the poverty line, percentage of households receiving public assistance, percentage of female-headed households with children, and median household income. Around 87% of participants were White, 7% Black, 3% Hispanic, and 3% other. Some 92% had graduated high school, and around 70% had at least some college.

[2523] Shih RA, Ghosh-Dastidar B, Margolis KL, Slaughter ME, Jewell A, Bird CE, Eibner C, Denburg NL, Ockene J, Messina CR, et al. Neighborhood Socioeconomic Status and Cognitive Function in Women. Am J Public Health [Internet]. 2011 ;101(9):1721 - 1728. Available from: http://ajph.aphapublications.org/cgi/content/abstract/101/9/1721

Previous:

Lang IA, Llewellyn DJ, Langa KM, Wallace RB, Huppert FA, Melzer D. 2008. Neighborhood deprivation, individual socioeconomic status, and cognitive function in older people: analyses from the English Longitudinal Study of Ageing. J Am Geriatr Soc., 56(2), 191-198.

Sheffield KM, Peek MK. 2009. Neighborhood context and cognitive decline in older Mexican Americans: results from the Hispanic Established Populations for Epidemiologic Studies of the Elderly. Am J Epidemiol., 169(9), 1092-1101.

Wight RG, Aneshensel CS, Miller-Martinez D, et al. 2006. Urban neighborhood context, educational attainment, and cognitive function among older adults. Am J Epidemiol., 163(12), 1071-1078.

Another study showing the value of exercise for preserving your mental faculties in old age. This time it has to do with the development of small brain lesions or infarcts called "silent strokes." Don’t let the words “small” and “silent” fool you — these lesions have been linked to memory problems and even dementia, as well as stroke, an increased risk of falls and impaired mobility.

The study involved 1,238 people taken from the Northern Manhattan Study, a long-running study looking at stroke and vascular problems in a diverse community. Their brains were scanned some six years after completing an exercise questionnaire, when they were an average of 70 years old. The scans found that 16% of the participants had these small brain lesions.

Those who had reported engaging in moderate to intense exercise were 40% less likely to have these infarcts compared to people who did no regular exercise. Depressingly, there was no significant difference between those who engaged in light exercise and those who didn’t exercise (which is not to say that light exercise doesn’t help in other regards! a number of studies have pointed to the value of regular brisk walking for fighting cognitive decline). This is consistent with earlier findings that only the higher levels of activity consistently protect against stroke.

The results remained the same after other vascular risk factors such as high blood pressure, high cholesterol and smoking, were accounted for. Of the participants, 43% reported no regular exercise; 36% engaged in regular light exercise (e.g., golf, walking, bowling or dancing); 21% engaged in regular moderate to intense exercise (e.g., hiking, tennis, swimming, biking, jogging or racquetball).

However, there was no association with white matter lesions, which have also been associated with an increased risk of stroke and dementia.

Moreover, this effect was not seen among those with Medicaid or no health insurance, suggesting that lower socioeconomic status (or perhaps poorer access to health care) is associated with negative factors that counteract the benefits of exercise. Previous research has found that lower SES is associated with higher cardiovascular disease regardless of access to care.

Of the participants, 65% were Hispanic, 17% non-Hispanic black, and 15% non-Hispanic white. Over half (53%) had less than high school education, and 47% were on Medicaid or had no health insurance.

A study involved 117 older adults (mean age 78) found those at greater risk of coronary artery disease had substantially greater risk for decline in verbal fluency and the ability to ignore irrelevant information. Verbal memory was not affected.

The findings add to a growing body of research linking cardiovascular risk factors and age-related cognitive decline, leading to the mantra: What’s good for the heart is good for the brain.

The study also found that the common classification into high and low risk groups was less useful in predicting cognitive decline than treating risk as a continuous factor. This is consistent with a growing view that no cognitive decline is ‘normal’, but is always underpinned by some preventable damage.

Risk for coronary artery disease was measured with the Framingham Coronary Risk Score, which uses age, cholesterol levels, blood pressure, presence of diabetes, and smoking status to generate a person's risk of stroke within 10 years. 37 (31%) had high scores. Age, education, gender, and stroke history were controlled for in the analysis.

Gooblar, J., Mack, W.J., Chui, H.C., DeCarli, C., Mungas, D., Reed, B.R. & Kramer, J.H. 2011. Framingham Coronary Risk Profile Predicts Poorer Executive Functioning in Older Nondemented Adults. Presented at the American Academy of Neurology annual meeting on Tuesday, April 12, 2011.

What makes one person so much better than another in picking up a new motor skill, like playing the piano or driving or typing? Brain imaging research has now revealed that one of the reasons appears to lie in the production of a brain chemical called GABA, which inhibits neurons from responding.

The responsiveness of some brains to a procedure that decreases GABA levels (tDCS) correlated both with greater brain activity in the motor cortex and with faster learning of a sequence of finger movements. Additionally, those with higher GABA concentrations at the beginning tended to have slower reaction times and less brain activation during learning.

It’s simplistic to say that low GABA is good, however! GABA is a vital chemical. Interestingly, though, low GABA has been associated with stress — and of course, stress is associated with faster reaction times and relaxation with slower ones. The point is, we need it in just the right levels, and what’s ‘right’ depends on context. Which brings us back to ‘responsiveness’ — more important than actual level, is the ability of your brain to alter how much GABA it produces, in particular places, at particular times.

However, baseline levels are important, especially where something has gone wrong. GABA levels can change after brain injury, and also may decline with age. The findings support the idea that treatments designed to influence GABA levels might improve learning. Indeed, tDCS is already in use as a tool for motor rehabilitation in stroke patients — now we have an idea why it works.

A new molecular compound derived from curcumin (found in turmeric) holds promise for treating brain damage caused by stroke. Turmeric has a long history of use in Ayurvedic and Chinese traditional medicine. However, curcumin has several important drawbacks as far as treating stroke is concerned — mainly because it can’t cross the blood-brain barrier. The new compound can.

In rabbit experiments, the drug was effective when administered up to an hour after stroke, which correlates with about three hours in humans. This is the same time frame for which tPA — the only drug currently approved for ischemic stroke — is currently approved.

The new drug is expected to move to human clinical trials soon.

Paul A. Lapchak presented these findings at the American Heart Association International Stroke Conference in Los Angeles on February. 9.

The new label of ‘metabolic syndrome’ applies to those having three or more of the following risk factors: high blood pressure, excess belly fat, higher than normal triglycerides, high blood sugar and low high-density lipoprotein (HDL) cholesterol (the "good" cholesterol). Metabolic syndrome has been linked to increased risk of heart attack.

A new French study, involving over 7,000 older adults (65+) has found that those with metabolic syndrome were 20% more likely to show cognitive decline on a memory test (MMSE) over a two or four year interval. They were also 13% more likely to show cognitive decline on a visual working memory test. Specifically, higher triglycerides and low HDL cholesterol were linked to poorer memory scores; diabetes (but not higher fasting blood sugar) was linked to poorer visual working memory and word fluency scores.

The findings point to the importance of managing the symptoms of metabolic syndrome.

High cholesterol and blood pressure in middle age tied to early memory problems

Another study, involving some 4800 middle-aged adults (average age 55), has found that those with higher cardiovascular risk were more likely to have lower cognitive function and a faster rate of cognitive decline over a 10-year period. A 10% higher cardiovascular risk was associated not only with increased rate of overall mental decline, but also poorer cognitive test scores in all areas except reasoning for men and fluency for women.

The cardiovascular risk score is based on age, sex, HDL cholesterol, total cholesterol, systolic blood pressure and whether participants smoked or had diabetes.

Memory problems may be sign of stroke risk

A very large study (part of the REGARDS study) tested people age 45 and older (average age 67) who had never had a stroke. Some 14,842 people took a verbal fluency test, and 17,851 people took a word recall memory test. In the next 4.5 years, 123 participants who had taken the verbal fluency test and 129 participants who had taken the memory test experienced a stroke.

Those who had scored in the bottom 20% for verbal fluency were 3.6 times more likely to develop a stroke than those who scored in the top 20%. For the memory test, those who scored in the bottom 20% were 3.5 times more likely to have a stroke than those in the top quintile.

The effect was greatest at the younger ages. At age 50, those who scored in the bottom quintile of the memory test were 9.4 times more likely to later have a stroke than those in the top quintile.

 

Together, these studies, which are consistent with many previous studies, confirm that cardiovascular problems and diabetes add to the risk of greater cognitive decline (and possible dementia) in old age. And point to the importance of treating these problems as soon as they appear.

[2147] Raffaitin C, Féart C, Le Goff M, Amieva H, Helmer C, Akbaraly TN, Tzourio C, Gin H, Barberger-Gateau P. Metabolic syndrome and cognitive decline in French elders. Neurology [Internet]. 2011 ;76(6):518 - 525. Available from: http://www.neurology.org/content/76/6/518.abstract

The findings of the second and third studies are to be presented at the American Academy of Neurology's 63rd Annual Meeting in Honolulu April 9 to April 16, 2011

Following indications that the curry spice curcumin (the active ingredient in turmeric) may help protect brain cells from damage, two new studies have been testing a compound called CNB-001, derived from curcumin.

The first (rabbit) study found that CNB-001 is at least as effective as the only existing drug used to treat stroke (TPA), without the unwanted side-effect of reducing clotting in the blood vessels of the brain.

The second study found that CNB-001 dramatically reversed the behavioral deficits in both locomotion and memory in brain-injured rats. As with stroke, CNB-001 was again found to maintain the critical signaling pathways required for nerve cell survival, as well as the connections between nerve cells that are lost with the injury.

At present, there is no treatment for TBI, and only one FDA-approved drug for ischemic stroke

When stroke or brain injury damages a part of the brain controlling movement or sensation or language, other parts of the brain can learn to compensate for this damage. It’s been thought that this is a case of one region taking over the lost function. Two new studies show us the story is not so simple, and help us understand the limits of this plasticity.

In the first study, six stroke patients who have lost partial function in their prefrontal cortex, and six controls, were briefly shown a series of pictures to test the ability to remember images for a brief time (visual working memory) while electrodes recorded their EEGs. When the images were shown to the eye connected to the damaged hemisphere, the intact prefrontal cortex (that is, the one not in the hemisphere directly receiving that visual input) responded within 300 to 600 milliseconds.

Visual working memory involves a network of brain regions, of which the prefrontal cortex is one important element, and the basal ganglia, deep within the brain, are another. In the second study, the researchers extended the experiment to patients with damage not only to the prefrontal cortex, but also to the basal ganglia. Those with basal ganglia damage had problems with visual working memory no matter which part of the visual field was shown the image.

In other words, basal ganglia lesions caused a more broad network deficit, while prefrontal cortex lesions resulted in a more limited, and recoverable, deficit. The findings help us understand the different roles these brain regions play in attention, and emphasize how memory and attention are held in networks. They also show us that the plasticity compensating for brain damage is more dynamic and flexible than we realized, with intact regions stepping in on a case by case basis, very quickly, but only when the usual region fails.

A long-running study involving 930 70-year-old Swedish men has found that those who were among the bottom 25% on the Trail Making Test B were three times more likely to have a stroke or a brain infarction compared to those in the top 25%. Performance on the Trail Making Test A and the MMSE did not predict brain infarction or stroke. Test B measures the ability to execute and modify a plan, while Test A measures attention and visual-motor abilities, and the MMSE is a standard test of general cognitive decline.

Following on from studies showing that a Mediterranean-like diet may be associated with a lower risk of Alzheimer's disease and may lengthen survival in people with Alzheimer's, a six-year study of 712 New Yorkers has revealed that those who were most closely following a Mediterranean-like diet were 36% less likely to have brain infarcts (small areas of dead tissue linked to thinking problems), compared to those who were least following the diet. Those moderately following the diet were 21% less likely to have brain damage. The association was comparable to the effects of high blood pressure — that is, not eating a Mediterranean-like diet was like having high blood pressure. The Mediterranean diet includes high intake of vegetables, legumes, fruits, cereals, fish and monounsaturated fatty acids such as olive oil; low intake of saturated fatty acids, dairy products, meat and poultry; and mild to moderate amounts of alcohol.

The study will be presented at the American Academy of Neurology's 62nd Annual Meeting in Toronto April 10 to April 17, 2010.

And in another pilot study, people deprived of speech following a stroke were taught to sing words instead of speaking them in a technique known as 'melodic intonation therapy'. Brain scans also showed functional and structural changes in the undamaged hemisphere after they had received the therapy. Doctors are now testing the therapy in 30 stroke patients to assess how many people who lose their speech after a stroke would benefit.

The findings were reported at the American Association for the Advancement of Science meeting in San Diego.

A pilot study suggests that video games for the Nintendo Wii could help stroke victims recover fine motor function (such as finger dexterity) and gross motor function (such as arm movements) two months after a stroke. The ten patients randomly assigned to playing these games for about six hours over the course of two weeks showed significantly better recovery, and none of the adverse effects (like nausea or dizziness) that were reported in the other group assigned to recreational games such as cards or the block-stacking game Jenga. A clinical trial is now underway.

The research was presented February 25 at the American Stroke Association's International Stroke Conference.

A 12-year study following the drinking and smoking habits of 22,524 people aged 39-79 has found that in non-smokers, people who consumed moderate amounts of alcohol were 37% less likely to develop stroke than non-drinkers. This association was not found among smokers. The finding may explain the inconsistency in previous studies into the relationship between light to moderate drinking and stroke.

The findings were presented at the American Academy of Neurology's 62nd Annual Meeting in Toronto, April 10 - 17, 2010.

Older news items (pre-2010) brought over from the old website

Different effects of ministrokes & strokes

A study involving 679 seniors (65+) has found that those with small areas of brain damage called white matter hyperintensities, often referred to as ministrokes, were nearly twice as likely to have mild cognitive impairment that included memory loss (amnestic MCI), while those who had infarcts (areas of dead tissue usually called strokes) were more likely to experience mild cognitive impairment in abilities other than memory loss (non-amnestic MCI). In other words, ministrokes predicted memory problems, while strokes predicted non-memory problems.

Luchsinger, J.A. et al. 2009. Subclinical cerebrovascular disease in mild cognitive impairment. Neurology, 73, 450-456.

http://www.eurekalert.org/pub_releases/2009-08/aaon-bds080409.php

Stroke patients regain sight after intensive brain training

In a surprising and exciting finding, stroke victims left partially blind have been trained to use undamaged parts of their brains to improve their vision. The training program, involving an hour a day for at least nine months, forced them to process visual signals with parts of their brain that had not been damaged by the stroke. The seven patients in the study ranged in age from their 30s to 80s, and had suffered a stroke between eight months and three-and-a-half years previously. Impaired vision is a very common result of a stroke.

Huxlin, K.R. et al. 2009. Perceptual Relearning of Complex Visual Motion after V1 Damage in Humans. Journal of Neuroscience, 29, 3981-3991.

 http://www.guardian.co.uk/science/2009/mar/31/stroke-brain-training-blind-sight

Social support may protect brain during stroke

A mouse study has found that male mice that lived with a female partner before and after a stroke had a much higher survival rate compared to those mice that lived alone, and also suffered much less brain damage. The findings suggest that high levels of social support may provide some protection against strokes by reducing the amount of damaging inflammation in the brain, and provides some idea of the mechanism. Significantly fewer neurons died in the brains of pair-housed mice. They also had significantly less edema (excess water in the brain), less expression of two genes associated with damaging inflammation in the brain, and significantly higher levels of interleukin-6 (IL-6), a cytokine that has an anti-inflammatory response in the brain.

The research was presented November 18 at the annual meeting of the Society for Neuroscience in Washington, D.C.

http://www.eurekalert.org/pub_releases/2008-11/osu-ssh111408.php

Daily dose of ginkgo may prevent brain cell damage after a stroke

A study using genetically engineered mice has found that daily doses of ginkgo biloba can prevent or reduce brain damage after an induced stroke. More research is needed before its use in humans can be recommended, but the finding does lend support to other evidence that ginkgo biloba triggers a cascade of events that neutralizes free radicals known to cause cell death.

Saleem, S. et al. 2008. Ginkgo Biloba Extract Neuroprotective Action Is Dependent on Heme Oxygenase 1 in Ischemic Reperfusion Brain Injury. Stroke, published online October 9

http://www.eurekalert.org/pub_releases/2008-10/jhmi-mss100708.php

Psychological distress, not depression, linked to increased risk of stroke

A study following 20,627 people for an average of 8.5 years has found that psychological distress was associated with an increased risk of stroke and that the risk of stroke increased the more distress the participants reported. This association remained the same regardless of cigarette smoking, systolic blood pressure, overall blood cholesterol, obesity, previous heart attack, diabetes, social class, education, high blood pressure treatment, family history of stroke and recent antidepressant medication use. However, there was no increased risk for people who had experienced an episode of major depression in the past year or at any point in their lifetime.

Surtees, P.G. et al. 2008. Psychological distress, major depressive disorder, and risk of stroke. Neurology, 70, 788-794.

http://www.eurekalert.org/pub_releases/2008-03/aaon-pdn022608.php

Listening to music improves stroke patients' recovery

A Finnish study involving 60 patients who had suffered a stroke of the left or right hemisphere middle cerebral artery (MCA) has found that if stroke patients listened to music for a couple of hours a day, their verbal memory and focused attention recovered better and they had a more positive mood than patients who did not listen to anything or who listened to audio books. Patients were randomly assigned to a music listening group, a language group or a control group. During the next two months the music and language groups listened daily to music they chose themselves or to audio books respectively, while the control group received no listening material. All groups received standard stroke rehabilitation. Three months after the stroke, verbal memory improved from the first week post-stroke by 60% in music listeners, by 18% in audio book listeners and by 29% in non-listeners. Similarly, focused attention improved by 17% in music listeners, but no improvement was observed in audio book listeners and non-listeners. The differences were essentially the same six months after the stroke. The music listening group also experienced less depressed and confused mood than the patients in the control group.

Särkämö, T. et al. 2008. Music listening enhances cognitive recovery and mood after middle cerebral artery stroke. Brain Advance Access published online on February 20, 2008.

http://www.eurekalert.org/pub_releases/2008-02/uoh-ltm021508.php

Not enough 'good' cholesterol makes it harder to recover from stroke

A large study involving men and women over age 35 in the United States, Canada, and Scotland who had suffered a mild to moderate stroke within the past three months, found several factors predicted memory and disability problems after stroke: increased age, non-Caucasian race, recurrent stroke, diabetes, stroke in the left hemisphere of the brain, higher levels of homocysteine and lower levels of high-density lipoproteins (HDL), otherwise known as “good” cholesterol. “People with low levels of HDL, high levels of homocysteine, and diabetes are twice as likely as those without such problems to have poorer cognitive function and greater disability after stroke … (and) stroke recovery was the most difficult for people over the age of 57 with high levels of homocysteine ...”

Newman, G.C., Bang, H., Hussain, S.I. & Toole, J.F. 2007. Association of diabetes, homocysteine, and HDL with cognition and disability after stroke. Neurology, 69, 2054-2062.

http://www.eurekalert.org/pub_releases/2007-11/aaon-ne112007.php

Antidepressants improve thinking after a stroke

Executive dysfunction is common after stroke andmay impair long-term outcome. A small study of people who had had a stroke during the previous six months has found that, although there was no difference in executive function between those given antidepressants and those given a placebo at the end of the 12-week treatment period, there was a significant difference 21 months after the treatment ended. Those who had been given the placebo showed continued worsening of executive functions, whereas the group treated with antidepressants had clear and significant improvement, regardless of how their depressive symptoms changed. The researchers speculate that antidepressants may foster recovery of neural tissue not directly destroyed by the stroke, yet because the process is slow, it takes months.

Narushima, K., Paradiso, S., Moser, D.J., Jorge, R. & Robinson, R.G. 2007. Effect of antidepressant therapy on executive function after stroke. British Journal of Psychiatry, 190, 260-265.

http://www.eurekalert.org/pub_releases/2007-03/uoi-aip030207.php

Restoring flexibility to old brains

Researchers have identified a protein, PirB, that stops new neural connections forming in adult brains, possibly explaining why older brains become less adaptable. The study found that the brains of adult mice that lacked PirB retained the same rewiring ability of much younger brains. Without PirB to hold them back, the old mice were, in effect, able to learn new tricks. The findings could offer hope for victims of brain injury and strokes.

[808] Syken J, Grandpre T, Kanold PO, Shatz CJ. PirB restricts ocular-dominance plasticity in visual cortex. Science (New York, N.Y.) [Internet]. 2006 ;313(5794):1795 - 1800. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16917027

http://www.sciencedaily.com/releases/2006/08/060818012553.htm

Simulator training benefits stroke patients

A study involving 83 stroke patients found that a 5-week 15-hour training program improved driving ability. Those given experimental simulator-based training improved more than those given driving-related cognitive tasks. Those with more education and those with less disability benefited most. 73% of the simulator group were legally allowed to resume driving compared to 42% of the other group. However, there were a large number of dropouts.

Akinwuntan, A.E., De Weerdt, W., Feys, H., Pauwels, J., Baten, G., Arno, P. & Kiekens, C. 2005. Effect of simulator training on driving after stroke: A randomized controlled trial. Neurology, 65 (6), 843-850. 

Carotid artery stenting improves thought process

Around a quarter of strokes are caused by a narrowing of the carotid arteries. A less invasive technique — carotid artery stenting — is increasingly taking the place of surgery to treat this problem. A study involving 26 patients who had undergone the procedure has tested their cognitive function at least 24 hours before and three months after the stenting procedure. The results showed that cognitive speed increased significantly after stenting, regardless of the patient's age or the severity of the stenosis, and an increase in memory function in patients with decreased blood flow in the brain.

Grunwald, I.Q. et al. 2005. The research was presented at the annual meeting of the Radiological Society of North America.

http://www.eurekalert.org/pub_releases/2005-11/rson-cas112005.php

Shift in brain's language-control site offers rehab hope

Language activity in right-handed people is initially localized in the left side of the brain, but a new study shows that this gradually becomes a function shared by both sides. From ages 5 to 25, language activity increases in the dominant hemisphere; from 25 to 67, the nondominant hemisphere increasingly shares the load. The discovery gives new hope for rehabilitation of brain function in adults after stroke or traumatic brain injuries.

Szaflarski, J. P., Holland, S. K., Schmithorst, V. J., & Byars, A. W. (2006). fMRI study of language lateralization in children and adults. Human Brain Mapping, 27(3), 202-212.

http://www.eurekalert.org/pub_releases/2005-10/uoc-sib100605.php

Antioxidant-rich diets reduce brain damage from stroke in rats

A new rat study suggests antioxidant-rich fruits and vegetables may limit brain damage from stroke and other neurological disorders. The study built upon previous research showing that diets enriched with blueberries, spinach or spirulina reversed normal age-related declines in memory and learning in old rats, and found that the same diet significantly reduced brain cell loss and improved recovery of movement in rats who had an ischemic stroke induced. The size of the stroke in the rats fed blueberry or spinach supplements was half that seen in the brains of untreated rats. Rats fed spirulina-enriched diets had stroke lesions 75 percent smaller than their untreated counterparts.

Wang, Y., Chang, C-F., Chou, J., Chen, H-L., Deng, X., Harvey, B.K., Cadet, J.L. & Bickford, P.C. 2005. Dietary supplementation with blueberries, spinach, or spirulina reduces ischemic brain damage. Experimental Neurology, 193 (1), 75-84.

http://www.eurekalert.org/pub_releases/2005-04/uosf-adr041205.php

Saving the most vulnerable brain cells in stroke

New research reveals why particular neurons in the hippocampus are most vulnerable to death from oxygen starvation during a stroke, and may lead to drugs that selectively protect those cells, leaving other brain cells unaffected. The findings could also lead to drugs that protect vulnerable brain cells in sufferers of amyotrophic lateral sclerosis, or Lou Gehrig's disease.

Liu, S-H., Lau, L., Wei, J-S., Zhu, D-Y., Zou, S., Sun, H-S., Fu, Y-P., Liu, F. & Lu, Y-M. 2004. Expression of Ca2+-Permeable AMPA Receptor Channels Primes Cell Death in Transient Forebrain Ischemia. Neuron, 43 (1), 43-55.

http://www.eurekalert.org/pub_releases/2004-07/cp-stm070204.php

Risk for lowered cognitive performance greater in people at high risk for stroke

A new large-scale study supports earlier suggestions that those with a high risk for stroke within 10 years are also at risk for lowered cognitive function and show a pattern of deficits similar to that seen in mild vascular cognitive impairment. It is speculated that the reason may lie in structural and functional changes in the brain that do not rise to the level of clinical detection, and this is supported by a recent brain imaging study showing that abnormal brain atrophy is related both to higher risk of stroke and poorer cognitive ability. The probability of experiencing stroke within 10 years was calculated using weighted combinations of age, systolic blood-pressure, presence of diabetes, cigarette smoking, history of cardiovascular disease, treatment for hypertension and atrial fibrillation.

Elias, M.F., Sullivan, L.M., D’Agostino, R.B., Elias, P.K., Beiser, A., Au, R., Seshadri, S., DeCarli, C. & Wolf, P.A. 2004. Framingham Stroke Risk Profile and Lowered Cognitive Performance. Stroke, 35, 404-9.

http://www.eurekalert.org/pub_releases/2004-01/ama-rfl010804.php

Chinese herb effective in treating vascular dementia

The herb gastrodine has been used in China for centuries to treat disorders such as dizziness, headache and even ischemic stroke. Now a 12-week, randomized, double-blind trial comparing gastrodine with Duxilâ (a drug used to treat stroke patients in China) has been done in Beijing Dongzhimen Hospital. The trial involved 120 stroke patients who were diagnosed with mild to moderate vascular dementia. Both treatment groups showed similar improvement in memory, orientation, calculation, and language (as measured by the MMSE). The gastrodine group also showed a significant difference in the Blessed Behavioral Scale (BBS) score - including behavior, activities of daily living, and also suffered fewer side effects. Researchers say combined results showed the gastrodine group improvement was 51.43 percent, with 16 of the 70 cases showing much improvement, 20 cases with some improvement, and 34 cases with no change. The improvement rate for patients treated with Duxilâ was 52 percent, with seven of the 50 cases showing much improvement, 19 cases with some improvement, and 24 cases with no change.

The research was presented at the American Heart Association's Second Asia Pacific Scientific Forum in Honolulu on June 10.

http://www.eurekalert.org/pub_releases/2003-06/aha-nhd052303.php

Pilot study finds ginseng may improve memory in stroke dementia patients

Following mouse studies showing that ginseng increased the activities of the brain chemicals acetylcholine and choline acetyltransferase, a pilot study of 40 patients (average age 67) with mild to moderate vascular dementia was undertaken by Chinese researchers. 25 patients were randomly selected to receive ginseng extract, while 15 received the drug Duxil® (used to improve memory in elderly dementia patients). Overall, researchers found that patients who took the ginseng compound significantly improved their average memory function after 12 weeks. More research (larger samples, placebo-controls) is needed before this finding can be confirmed.

The study was reported at the American Stroke Association's 28th International Stroke Conference on February 14 in Phoenix.

http://www.eurekalert.org/pub_releases/2003-02/aha-gmi020403.php

Right side of brain learns language skills after stroke

Every year, about 750,000 Americans suffer a loss of blood flow to the brain, an ischemic stroke. When the stroke occurs on the left side of the brain, language abilities may be lost (aphasia). However, many of those who initially lose language abilities after a stroke recover much of their ability within six to 12 months. Several studies have suggested that such language recovery occurs because the right hemisphere of the brain takes over language functions. A new imaging study demonstrates that, indeed, areas on the opposite side of the brain to the damaged language areas are active during language tasks, and demonstrate expected patterns of activation with practice.

Blasi, V., Young, A.C., Tansy, A.P., Petersen, S.E., Snyder, A.Z., Corbetta, M. 2002. Word retrieval learning modulates right frontal cortex in patients with left frontal damage. Neuron, 36, 1-20.

http://www.eurekalert.org/pub_releases/2002-09/wuso-rso092502.php

Skill-specific exercises better for people who suffer from attention problems following stroke or brain injury

Treatment programs for people who suffer from attention problems following a stroke or other traumatic brain injuries often involve abstract cognitive exercises designed to directly restore impaired attention processes. But a review of 30 studies involving a total of 359 participants shows that an alternative and lesser-used therapy that teaches patients to relearn the tasks that affect their daily lives the most may be more effective. In this specific skills approach, people with brain damage learn to perform attention skills in a way that is different from non-brain-damaged people. In one study, for example, participants whose brain injuries affected their ability to drive a car used small electric cars in the lab to practice specific driving exercises, such as steering between pylons that were moved closer and closer together. Those that practiced specific exercises showed substantial improvement on a variety of driving related tasks compared to those who drove the car, but did not practice the exercises.

58. Park, N. W., & Ingles, J. L. (2001). Effectiveness of attention rehabilitation after an acquired brain injury: A meta-analysis. Neuropsychology, 15(2), 199-210.

http://www.eurekalert.org/pub_releases/2001-04/APA-Rlsm-0704101.php