Read the most current news on neurologic diseases here! And we want your input. Leave your comments at the end of each article.
Tuesday, September 30, 2014
by Rebecca Hiscott
Adults who notice their memory slipping may be at an increased risk of developing dementia later in life, even if they show no clinical signs of cognitive impairment, according to a study published in the Sept. 24 online issue of Neurology.
Image via amenclinicsphotosac on Flickr
The study followed 531 participants from the ongoing Biologically Resilient Adults in Neurological Studies (BRAiNS) from the University of Kentucky’s Alzheimer’s Disease Center, which looks at initially cognitively normal adults over the age of 60 who have agreed to donate their brains for analysis after death.
The participants underwent annual neurocognitive assessments, and were asked to report whether they had noticed any significant memory problems since their last visit. Those who reported problems with memory but were not formally diagnosed with dementia or mild cognitive impairment (MCI) were classified as having “subjective memory complaints.” Approximately half of the study population (243 participants) died during the study, and researchers biopsied their brains to look for clinical signs of Alzheimer’s disease or dementia.
Of the 296 participants who reported subjective memory complaints over the course of the study (55.7 percent), 72 progressed to MCI and 42 progressed to dementia, while 127 died. Those who reported cognitive complaints had a nearly three-fold risk of being diagnosed with cognitive impairment or dementia later in life, the researchers found. Nearly 69 percent of those diagnosed with MCI had reported cognitive complaints beforehand, while 79.6 percent of those who progressed to dementia had done the same.
Those who complained of memory problems were also more likely to have the hallmark plaques and tangles of Alzheimer’s disease in their brains upon autopsy, even when no formal diagnosis was made.
“Our study adds strong evidence to the idea that memory complaints are common among older adults and are sometimes indicators of future memory and thinking problems. Doctors should not minimize these complaints and should take them seriously,” study author Richard J. Kryscio, PhD, a professor of statistics and chair of the department of biostatistics at the University of Kentucky in Lexington, KY, said in a news release.
“What’s notable about our study is the time it took for this transition to dementia or clinical impairment to occur – about 12 years for dementia and nine years for clinical impairment – after the memory complaints began,” he added.
The average time between the first reported memory complaint and clinical diagnosis of MCI was 9.2 years, and those who progressed directly to dementia did so roughly 6.1 years after first reporting a memory complaint. Women and people with hypertension were more likely to progress directly to dementia. In addition, women, smokers, and those with high blood pressure tended to progress to dementia more rapidly, while in contrast, women taking hormone replacement therapy progressed to dementia at a slower pace.
Other known risk factors for Alzheimer’s disease and dementia were also found to have an impact on the time lag between reporting a memory complaint and progressing to dementia. Adults who possessed a variant APOE4 (apolipoprotein E4) genotype, which has been linked to Alzheimer’s disease, and those who had a history of smoking progressed to dementia more quickly than non-smokers and those without the genetic risk factor. Adults with the APOE4 variant had double the odds of progressing to cognitive impairment later in life.
In cases where modifiable risk factors for Alzheimer’s disease are present, such as a history of smoking, “these findings suggest that there may be a window for intervention before a diagnosable problem shows up,” Dr. Kryscio said. But, he added, “unfortunately we do not yet have preventive therapies for Alzheimer’s disease and other illnesses that cause memory problems.”
For more coverage of dementia and Alzheimer’s disease research, browse our archives here: http://bit.ly/NN-AlzheimersDementia.
Thursday, September 25, 2014
by Rebecca Hiscott
Adults who follow the DASH (Dietary Approach to Stop Hypertension) or Mediterranean diet – both of which emphasize the consumption of fruits, vegetables, whole grains, fish and legumes, and limit foods high in saturated fat and sugar – may have slower cognitive decline as they age, a study published online Sept. 17 in Neurology found.
Since both the DASH and Mediterranean diets have been shown in past research to protect against hypertension, obesity, cardiovascular disease, and diabetes – conditions that have been linked to increased risk of dementia and cognitive decline – researchers from the Rush University Medical Center in Chicago, IL, looked directly at the link between diet and cognitive function in aging adults.
The Mediterranean diet emphasizes olive oil as the primary source of fat, as well as high consumption of fish and moderate consumption of wine with meals, the study authors noted. The DASH diet includes a higher consumption of dairy products. Image via MonaLMtz on Flickr.
The study population consisted of 826 participants from the Rush Memory and Aging Project, an ongoing study of neurological conditions in aging adults. Participants completed a 144-item questionnaire about their dietary habits at the beginning of the study, and their diets were scored based on adherence to DASH or Mediterranean diet principles, with a score of 0-10 for accordance with the DASH diet and 0-55 for accordance with the Mediterranean diet.
Patients also received annual cognitive assessments over an average of 4.1 years; these consisted of 19 tests evaluating different aspects of memory and cognitive function, including episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability.
Although cognition did decline over time in these patients, as expected, the researchers found that for every single-point increase in adherence to the DASH or Mediterranean diet, participants had a slower rate of overall cognitive decline.
For both diets, the slower decline in cognition was specifically associated with episodic memory, which governs autobiographical events such as times, dates, and places, and semantic memory, which recalls facts, meanings, understandings, and general knowledge.
“These findings were not wholly unexpected because many of the food components that constitute the selected diet scores are those we have previously observed to be related to cognitive change,” the authors wrote. These food components include whole grains, vegetables, nuts, and legumes, which are staples of both the DASH and Mediterranean diets and which have been shown in past studies to slow cognitive decline, as well as to reduce cardiovascular events, stroke, and heart disease.
The authors noted that their findings were based on an observational study, and warned that the association between diet and cognitive function could not yet be interpreted as a cause-effect relationship. The current study, they wrote, “attest[s] to the need for more research to determine whether a food-based approach can attenuate neurocognitive decline in older populations at risk of Alzheimer disease or vascular cognitive impairment.”
For more coverage of the link between diet and cognitive decline, browse our archives here: http://bit.ly/Y50J5T.
Wednesday, September 24, 2014
by Rebecca Hiscott
Public health programs aimed at smoking cessation, reducing cardiovascular disease, and controlling high blood pressure and diabetes may significantly reduce dementia prevalence in the United States and elsewhere, according to a new report from Alzheimer’s Disease International (ADI), a United Kingdom-based organization comprising more than 80 Alzheimer’s associations around the world.
Image via Fried Dough on Flickr.
Published online September 17, the World Alzheimer Report 2014 urges policymakers and healthcare advocates to incorporate education and awareness of preventable dementia risk factors into global health campaigns geared toward preventing other non-communicable diseases such as diabetes and hypertension.
A team of researchers commissioned by ADI to evaluate the current evidence for modifiable risk factors for dementia identified a number of significant preventable dementia risk factors, including smoking, diabetes, and high blood pressure. Diabetes can increase the risk of dementia by as much as 50 percent, the researchers found. Meanwhile, smoking cessation was strongly associated with a decrease in dementia risk; ex-smokers were found to have comparable levels of dementia risk to non-smokers, while those who continued to smoke remained at much higher risk.
In addition, a higher level of education appears to be linked to lower risk of dementia, the researchers noted.
“The strongest evidence for possible causal associations with dementia…are those of low education in early life, hypertension in midlife, and smoking and diabetes across the life course,” they wrote. Therefore, “there is persuasive evidence that the dementia risk for populations can be modified through reduction in tobacco use and better control and detection for hypertension and diabetes, as well as cardiovascular risk factors. A good mantra is, ‘What is good for your heart is good for your brain.’”
On a positive note, the report found that dementia incidence appears to be declining in developed nations, and that adults who do develop dementia in these countries are doing so at progressively older ages. The authors attributed this phenomenon to “a general trend in high income countries towards less smoking, falling total cholesterol and blood pressure levels, and increasing physical activities.”
These benefits appear to have outweighed the harms of increasing rates of obesity and diabetes in most developed nations, they added. Since obesity is a leading cause of both diabetes and hypertension, the authors suggested it should be a target in future dementia risk reduction efforts.
“We need to do all we can to accentuate these trends” towards lower dementia risk, lead researcher Martin Prince, MD, a professor of epidemiological psychiatry, joint director of the Centre for Global Health, and head of the Department of Health Service and Population Research at King’s College London in the UK, said in a news release. “With a global cost of over US $600 billion, the stakes could hardly be higher.”
However, developing and middle-income nations have seen an increasing incidence of cardiovascular disease, hypertension, and diabetes in recent years, which will likely lead to increased incidence of dementia in these countries, the report noted. In China and other East Asian nations, for example, dementia incidence appears to be increasing, likely due to a concurrent increase in rates of stroke, ischemic heart disease morbidity and mortality, obesity, and high blood pressure.
“By 2050, we estimate that 71 percent of people living with dementia will live in these [developing] regions, so implementing effective public health campaigns may help to reduce the global risk,” said Marc Wortmann, executive director of ADI.
The report stressed that improved detection of diabetes and hypertension should be emphasized in public health campaigns and should target younger as well as older adults, who “are rarely specifically targeted in prevention programs.” Promoting smoking cessation, increased physical activity, and reduced levels of obesity will also be important in order to see future declines in dementia incidence, they added.
For more coverage of risk factors for dementia, browse our archives here: http://bit.ly/NN-DementiaRisk.
Tuesday, September 23, 2014
by Rebecca Hiscott
Levodopa remains the most effective treatment for the motor symptoms of Parkinson’s disease (PD), but in recent years, research has suggested that early initiation of levodopa therapy can increase the risk of motor complications and dyskinesias in PD patients. As a result, some neurologists have advocated delaying the treatment in order to improve patients’ mobility and quality of life.
But a new study published in the September 19 issue of Brain has reported that motor complications are not associated with duration of levodopa therapy. Instead, these complications appear to be linked with longer disease duration and higher levodopa dose, and as such, “the practice to withhold levodopa therapy with the objective of delaying the occurrence of motor complications is not justified,” the study authors wrote.
The four-year multicenter study looked at 91 Parkinson’s disease (PD) patients from different regions in Ghana, where access to medication is limited and levodopa therapy is generally initiated several years after onset of the disease. Patients were assessed for motor fluctuations and dyskinesias during follow-up visits performed every six months during the study period. The Ghanaian group was compared with 2,282 PD patients from Italy who had comparable disease duration and disability, but who had begun levodopa treatment earlier in the disease.
Thirty-five percent of the Ghanian PD patients were drug-naïve, compared with 6 percent of patients in the Italy cohort; at baseline, both groups had had the disease approximately five years. However, the Italian cohort had been receiving levodopa therapy for roughly 2.5 years, while the Ghanaian patients were treated with levodopa for about one year. The prevalence of motor fluctuations and dyskinesias in Ghanaian patients was 56 and 14 percent, respectively; the mean levodopa daily dose adjusted for body weight was similar in both groups.
“Median disease duration at the first appearance of motor fluctuations and dyskinesias was comparable between Ghanaians and Italian patients…despite significantly shorter median duration of levodopa therapy at their onset in Ghanaians,” the authors wrote.
Evaluation of motor fluctuation rate in another control group consisting of PD patients who had never been exposed to dopamine agonists or COMT inhibitors – which are generally unavailable in Ghana and other sub-Saharan African nations – confirmed that “disease duration was similar at the onset of motor complications, despite significant differences in the duration of exposure to levodopa,” they wrote. “Therefore, there is no reason to delay the initiation of adequate levodopa therapy in patients with Parkinson’s disease.”
For more coverage of the use of levodopa in Parkinson’s disease, browse our archives here: http://bit.ly/1odT5Nr.
Monday, September 22, 2014
by Rebecca Hiscott
Adults who experience migraine in middle age may have an increased risk of developing Parkinson’s disease or restless legs syndrome (RLS, or Willis-Ekbom disease) later in life, according to a new study published in the Sept. 17 online issue of Neurology. Those who experience migraine with aura – a form of migraine accompanied by symptoms such as dizziness, light sensitivity, and visual disturbances before the onset of the headache – may be at double the risk of developing Parkinson’s disease as those without migraine or headache symptoms.
Image via Alvaro A. Novo on Flickr
Migraine “has been linked in other studies to cerebrovascular and heart disease,” study author Ann I. Scher, PhD, an associate professor of epidemiology at Uniformed Services University in Bethesda, MD, said in a news release. “This new possible association is one more reason research is needed to understand, prevent and treat the condition.”
The study population consisted of 5,620 adults between the ages of 33 and 65 selected from the AGES-Reykjavic Study, which prospectively examined cardiovascular disease incidence in Iceland. Of the study participants, 3,924 reported no headaches; 1,028 had headaches with no symptoms of migraine; 238 reported migraine symptoms; and 430 had migraine with aura. The researchers then looked at how many of the participants developed Parkinson’s disease or restless legs syndrome.
The researchers found that adults who experienced migraine with aura were twice as likely to be diagnosed with Parkinson’s disease (PD) as those who experienced no headache or migraine symptoms; 2.4 percent of participants with migraine with aura were diagnosed with PD, while only 1.1 percent of those with no headaches received a PD diagnosis. Restless legs syndrome was also more common in participants who reported headaches.
In addition, 19.7 percent of adults who experienced migraine with aura showed some symptoms associated with PD, compared with 12.6 percent of those with migraine with no aura and 7.5 percent of adults with no headache or migraine symptoms. Women with migraine with aura were also more likely to have a parent or sibling with Parkinson’s disease.
“Risk of late-life RLS/WED was increased for all types of headache,” the authors wrote. “In contrast, increased risk of late-life parkinsonism, diagnosed PD, and family history of PD was limited to, or more evident for, those with a history of migraine with aura.”
In the news release, Dr. Scher sounded a cautious note, adding that "While the history of migraine is associated with an increased risk for Parkinson’s, that risk is still quite low."
For more coverage of Parkinson’s disease and movement disorders, browse our archives at http://bit.ly/PD-MovementDisorders. To read the latest news on migraine research and treatment, visit http://bit.ly/NN-Migraine.