The guiding theme of this year’s world stroke congress was “Little stroke, big trouble”. The so-called “silent stroke” occurs five times more often than the obvious stroke. Unnoticedly, it renders parts of the brain “out of order” – the word “silent” is a misnomer. It is preferable to talk about “subclinical” because the consequences show clearly not only on images of the brain but also in neuropsychological tests. Vladimir Hachinski at the Canadian University of Western Ontario and chief editor of the professional journal “Stroke” says: “From a practical viewpoint it becomes important to recognize that some of the symptoms that elderly individuals manifest, such as changes in judgment, in intellectual ability, personality change, particularly depression, may be associated with subclinical strokes and white matter changes in the brain.”
The 5-minute screening test shows the unnoticed attack
The “silent stroke” was one of the major topics at the 6th “World Stroke Day” taking place in Vienna a month ago. Hachinski presented the about 3000 participants with data that every fourth in the age between seventy and seventy-five is a candidate for such an occurrence. In addition to the brain damage, the subclinical form is associated with an increased chance of having others and of experiencing a clinical stroke causing larger deficiencies in the nerve system. Some studies have calculated a risk there with a factor 20. From the Framingham Heart Study scientists calculated that the combination of subclinical strokes and subclinical Alzheimer lesions may be a background for the association of stroke and dementia given that the risk of developing either or both is one in three.
Not always a sophisticated brain scan technology is required to discover a silent stroke. A 5-minute screening instrument for cognitive impairment supplies initial leads which can be checked with an extensive screening of memory abilities or reaction- and association tests. Afterwards, the expensive imaging can locate the damage in the brain. And what comes then? In their summary article in the Lancet Neurology, Sarah Vermeer and her colleagues at the Erasmus Medical Center in Rotterdam/The Netherlands emphasize: “After a silent stroke, in patients without any brain infarct history or a transient ischaemia , the search for cardiovascular risk factors is important, especially concerning the regulation of blood pressure.”
Experience shows though that it rarely is enough to point out to the patient that he or she has to change life style. One of Hachinski’s projects in Canada is the frequent support by medical personnel or trained laypersons. First results show that for example weight reduction became easier: While the control group gained about 4.5 kilograms during the examination period, the nursing personnel managed to get their patients to loose an average of 2 kilograms.
Larger time slot for thrombolysis
Vienna also showed encouraging results concerning care and therapy of heavy attacks: If in earlier days three hours were the limit to dissolve a clot in a thrombolysis, two new studies in Lancet and New England Journal of Medicine show now that this time span is longer. Until four and a half hour after the stroke, the treatment with the tissue specific Plasminogen activator alteplase works. Compared to the control group, chances to survive without any permanent damages, increased within the time window of three to four and a half hours.
During rehabilitation, the neurologist can out-manoeuvre the brain with simple means and stimulate motor pathways. Hemiplegia, i. e. palsy of one side of the patient, is one of the most frequent after-effects of a stroke. A mirror in the middle leads the patient to believe that he can move his paralyzed leg just as he does his healthy one. If you force the brain to process such symmetric patterns of movement, it simulates the repair for the affected centers better than exercises concentrating on the immobile body part. Kazu Amimoto of Tokyo Metropolitan University compared conventional therapy with the mirror method in 14 patients with hemiplegia in regard to the flection of a paralyzed ankle. Although the approved methods did improve the flection ankle marginally, they did not have any effect on the speed of performance of the movement. After all, the mirror therapy achieved twelve percent faster movements. “If such a progress can be achieved only by visual stimuli of movements of the healthy half of the body, we should much more take the mental aspect in rehabilitation into consideration”, says Amimoto.
At the first intimation already, patient and physician should keep an eye on the mental aspect. Because rehabilitation afterwards costs a whole lot more than the effort to keep body weight and a lack of exercise under control and thus avoid a silent stroke.