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Recent researches have found that 7 Tesla SWI can detect the alteration of substantia nigra hyperintensity in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). The aim of this study was to investigate whether 3 Tesla SWI (3T SWI) can visualize anatomical alterations occurring in a hyperintense structure of the substantia nigra in PD and vascular parkinsonism (VP), and whether the evaluation of abnormal signal can be used as a factor in the differential diagnosis of PD and VP. Using 3 Tesla MRI, we evaluated 38 healthy subjects, 33 patients with PD and 34 patients with VP. Two blinded readers independently assessed the images. We found that the dorsolateral nigral hyperintensity was absent in 31 of 33 patients with PD and 15 of 34 patients with VP. The dorsolateral nigral hyperintensity was present in 19 of 34 patients with VP and 35 of 38 healthy controls. Group comparisons of absence of dorsolateral nigral hyperintensity revealed significant differences between the patients with PD and those with VP (P

Multi-infarct dementia (MID), a prominent subtype of vascular dementia (VD), is responsible for at least 15 to 20 percent of dementia in the elderly. Mitochondrial dysfunctions and glutamate neurotoxicity due to chronic hypoperfusion and oxidative stress were regarded as the major risk factors in the pathogenesis. Kaixin San (KXS), a classic prescription of Beiji Qianjin Yaofang, was applied to treatment for “amnesia” and has been demonstrated to alleviate the cognitive deficit in a variety of dementias, including MID. However, little is known whether mitochondria and glutamate are associated with the protection of KXS in MID treatment. The aim of this study was to investigate the role of KXS in improving the cognitive function of MID rats through strengthening mitochondrial functions and antagonizing glutamate neurotoxicity via the Shh/Ptch1 signaling pathway. Our data showed that KXS significantly ameliorated memory impairment and hippocampal neuron damage in MID rats. Moreover, KXS improved hippocampal mitochondrial functions by reducing the degree of mitochondrial swelling, increasing the mitochondrial membrane potential (MMP), and elevating the energy charge (EC) and ATP content in MID rats. As expected, the concentration of glutamate and the expression of p-NMDAR1 were significantly reduced by KXS in the brain tissue of MID rats. Furthermore, our results showed that KXS noticeably activated the Shh/Ptch1 signaling pathway which was demonstrated by remarkable elevations of Ptch1, Smo, and Gli1 protein levels in the brain tissue of MID rats. Intriguingly, the inhibition of the Shh signaling pathway with cyclopamine significantly inhibited the protective effects of KXS on glutamate-induced neurotoxicity in PC12 cells. To sum up, these findings suggested that KXS protected MID rats from memory loss by rescuing mitochondrial functions as well as against glutamate neurotoxicity through activating Shh/Ptch1 signaling pathway.

Background and Purpose— In spite of its high disease burden, there is no specific treatment for multi-infarct dementia. The preclinical evaluation of candidate drugs is limited because an appropriate animal model is lacking. Therefore, we aimed to evaluate whether a mouse model of recurrent photothrombotic stroke is suitable for the preclinical investigation of multi-infarct dementia. Methods— Recurrent photothrombotic cortical infarcts were induced in 25 adult C57BL/6 mice. Twenty-five sham-operated animals served as controls. The object recognition test and the Morris water maze test were performed >6 weeks to assess cognitive deficits. Afterward, histological analyses were performed to characterize histopathologic changes associated with recurrent photothrombotic infarcts. Results— After the first infarct, the object recognition test showed a trend toward an impaired formation of recognition memories ( P =0.08), and the Morris Water Maze test revealed significantly impaired spatial learning and memory functions ( P P P Conclusions— Our results show progressive cognitive deficits in a mouse model of recurrent photothrombotic stroke. The presented model resembles the clinical features of human multi-infarct dementia and enables the investigation of its pathophysiological mechanisms and the evaluation of treatment strategies.

Brain energy disorders and oxidative stress due to chronic hypoperfusion were considered to be the major risk factors in the pathogenesis of dementia. In previous studies, we have demonstrated that acupuncture treatment improved cognitive function of VaD patients and multi-infarct dementia (MID) rats. Acupuncture therapy also increased the activities of glycometabolic enzymes in the brain. But it is not clear whether acupuncture treatment compensates neuronal energy deficit after cerebral ischemic through enhancing the activities of glucose metabolic enzymes and preserving mitochondrial function, and whether acupuncture neuroprotective effect is associated with activations of mitochondrial antioxidative defense system. So, the effect of acupuncture therapy on cognitive function, cerebral blood flow (CBF), mitochondrial respiratory function and oxidative stress in the brain of MID rats was investigated in this study. The results showed that acupuncture treatment significantly improved cognitive abilities and increased regional CBF of MID rats. Acupuncture elevated the activities of total SOD, CuZnSOD and MnSOD, decreased the level of malondialdehyde (MDA) and superoxide anion, regulated the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG) in mitochondria, and raised the level of the respiratory control index (RCI) and P/O ratio and the activities of mitochondrial respiratory enzymes of MID rats. These results indicated that acupuncture treatment improved cognitive function of MID rats; and this improvement might be due to increased CBF, which ameliorated mitochondrial dysfunction induced by ischemia and endogenous oxidative stress system of brain.

Objective Silent lacunar infarct (SLI) is associated with cognitive decline and linked to an increased risk of stroke and dementia. We examined the association of SLI with MRI measures of cortical thickness, subcortical and lateral ventricular shapes and cognition in 285 ethnic Chinese elderly. Methods SLI, cortical thickness, shapes of subcortical and ventricular structures were quantified using MRI. The cognitive performance was assessed using comprehensive neuropsychological tests. Linear regression was used to examine associations among SLI, brain measures and cognition. Results SLI was associated with atrophy in multiple subcortical structures, ventricular enlargement and widespread cortical thinning. Both SLI and atrophy were independently related to poorer performance in attention, memory and language domains. Only SLI was associated with visuomotor speed and executive function, while atrophy mediated the association between SLI and visuoconstruction. Conclusions Our findings support a vascular contribution to neurodegeneration and cognitive impairment.

SPECT images of the brain can be obtained using either 123I labelled amines or 99mTc-hexamethylpropyleneamineoxime (HM-PAO). Both materials produce images which are blood flow dominated and so appear similar in normal subjects, although the respective mechanisms of uptake are not yet finally established. It seems likely, however, that the different mechanisms of uptake are responsible for recent reports of some differences seen in images obtained with the two types of agent in patients with cerebral pathology, mainly cerebrovascular disease. In this study, 12 demented patients, 6 with dementia of the Alzheimer type (DAT) and 6 with multi infarct dementia (MID), were imaged with 123I-isopropylamphetamine (IMP) and 99mTc-HM-PAO and the images compared. Significantly more lesions were seen with IMP than HM-PAO (P less than 0.02); out of a possible 120 sites, 41 lesions were seen with IMP compared to 28 with HM-PAO, 23 being seen with both agents. However, it is concluded that either agent can be used for the differential diagnosis of dementia, a task for which the new cerebral blood flow agents seem well suited.

Objectives There is an increasing call for a stronger consideration of impairment in instrumental activities of daily living (IADL) in the diagnostic criteria of Mild Cognitive Impairment (MCI) to improve the prediction of dementia. Thus, the aim of the study was to determine the predictive capability of MCI and IADL impairment for incident dementia. Design Longitudinal cohort study with four assessments at 1.5-year intervals over a period of 4.5 years. Setting Primary care medical record registry sample. Participants As part of the German Study on Ageing, Cognition, and Dementia in Primary Care Patients, a sample of 3,327 patients from general practitioners, aged 75 years and older, was assessed. Measurements The predictive capability of MCI and IADL impairment for incident dementia was analysed using receiver operating characteristics, Kaplan-Meier survival analyses, and Cox proportional hazards models. Results MCI and IADL impairment were found to be significantly associated with higher conversion to, shorter time to, and better predictive power for future dementia. Regarding IADL, a significant impact was particularly found for impairment in responsibility for one's own medication, shopping, and housekeeping, and in the ability to use public transport. Conclusions Combining MCI with IADL impairment significantly improves the prediction of future dementia. Even though information on a set of risk factors is required to achieve a predictive accuracy for dementia in subjects with MCI being clinically useful, IADL impairment should be a very important element of such a risk factor set.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a small-vessel disease of the brain that is characterized by headache, recurring lacunar strokes, mood changes and progressive cognitive deterioration. The disease is transmitted with an autosomal dominant pattern and usually starts during midadulthood (at 30–50 years of age). Cognitive deficits in patients with CADASIL develop slowly. The dementia causes frontal-like symptoms and it typically develops after a history of recurrent stroke. We describe three patients from one Spanish family affected by this disease. All three cases underwent comprehensive clinical and neuropsychological examination, and were monitored for seven years. The results obtained in this study describe a) a significant loss of the intelligence quotient (IQ) and noticeable damage to abstract ability (g factor), b) mood and psychopathological disturbances (major depression and dysthymia), and c) a personality with neurotic features.

Journal of Stroke and C Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a single-gene disorder directly affecting the cerebral small blood vessels, that is caused by mutations in theHTRA1 gene encoding HtrA serine peptidase/protease 1 (HTRA1). CARASIL is the second known genetic form of ischemic, nonhypertensive, cerebral small-vessel disease with an identified gene, along with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The exact prevalence of CARASIL is currently unknown, and to date approximately 50 patients have been reported, most of them from Japan and two from China. Genetically, no founder haplotype has been identified, and thus the disease is expected to be found more widely. The main clinical manifestations of CARASIL are ischemic stroke or stepwise deterioration in brain functions, progressive dementia, premature baldness, and attacks of severe low back pain or spondylosis deformans/disk herniation. The most characteristic findings on brain magnetic resonance imaging are diffuse white matter changes and multiple lacunar infarctions in the basal ganglia and thalamus. Histopathologically, CARASIL is characterized by intense arteriosclerosis, mainly in the small penetrating arteries, without granular osmiophilic materials or amyloid deposition. CARASIL is a prototype single-gene disorder of cerebral small vessels secondary to and distinct from CADASIL. CARASIL-associated mutant HTRA1 exhibited decreased protease activity and failed to repress transforming growth factor-b family signaling, indicating that the increased signaling causes arteriopathy in CARASIL. Therefore, HTRA1 represents another new gene to be considered in future studies of cerebral small-vessel diseases, as well as alopecia and degenerative vertebral/disk diseases.

Acupuncture has exhibited therapeutic effects on vascular dementia in our previous research. The mechanism of its anti-dementia effects involves energy metabolism. For brain cells, glucose metabolism is almost the only source of energy, and glucose metabolism disorders are early signs of dementia. In addition, glucose metabolism associates closely with glycometabolic enzymes, thereby maintains normal energy supply in brains and neurological and mental activities. In order to investigate its anti-dementia mechanism, we studied the effects of acupuncture on behavior of multi-infarct dementia (MID) rats and glycometabolic enzymes protein expression and activities in their brains. Results showed acupuncture improved the cognitive disorder, and increased the activities of hexokinase, pyruvate kinase, and glucose 6 phosphate dehydrogenase. Accordingly, it suggests that the anti-dementia effects of acupuncture may be mediated by up regulation of hexokinase, pyruvate kinase, and glucose 6 phosphate dehydrogenase activities, influencing energy metabolic system and thus overcoming the dysfunctional cognition of MID.

Vascular dementia accounts for approximately 15-20% of all dementias. In addition, a significant subset of people with Alzheimer's disease have concurrent cerebrovascular disease. Vascular dementia is caused by different cerebrovascular morphological abnormalities including large artery territory infarction (multi-infarct vascular dementia) and sub-cortical ischaemic vascular dementia. Despite this distinction, there is a lack of studies examining the neurochemistry of individual vascular dementia subtypes. Serotonin is believed to play an important role in cognition, and serotonin receptors may provide a novel target for future anti-dementia therapeutics. This study aimed to determine levels of two serotonin receptors in subtypes of vascular dementia and relate any changes to cognition. We have determined, using saturation radioligand binding, the binding parameters (affinity and maximal binding) of ((3)H)-WAY 100635 binding to 5-HT(1A) receptors and ((3)H)-ketanserin binding to 5-HT(2A) receptors in post-mortem tissue from the frontal and temporal cortices of patients with either multi-infarct vascular dementia, sub-cortical ischaemic vascular dementia, mixed Alzheimer's disease/vascular dementia or stroke no dementia (SND). 5-HT(1A) and 5-HT(2A) receptor binding was significantly increased in the temporal cortex of patients with either multi-infarct vascular dementia or SND, compared to age-matched controls. 5-HT(1A) receptor maximal binding in the temporal cortex was also positively correlated with cognition as determined by Mini-Mental State Examination (MMSE) and Cambridge Assessment of Mental Health for the Elderly scores (CAMCOG). These results reveal an important distinction between the neurochemistry of multi-infarct vascular dementia/SND and sub-cortical ischaemic vascular dementia, suggesting that pharmacological manipulation of serotonin offers the possibility to develop novel therapies for stroke and multi-infarct vascular dementia patients. The results also highlight the importance of the cortical 5-HT(1A) receptor in mediating cognition.

Long-term survival was examined for 218 patients with Alzheimer's disease (AD) and 115 patients with multi-infarct dementia (MID). The 14-year survival rate for AD was 2.4% versus an expected rate of 16.6%, and for MID 1.7% versus 13.3% expected. MID showed a more malignant natural course than AD. Men carried a less favourable survival prognosis than women, both in AD and MID: the relative risk of dying for women was half that for men in both diseases. In MID, advanced disability indicated a relative risk of dying over twice as high. In both diseases the risk of death was substantially higher in the event of occurrence of primitive reflexes.

Cerebrovascular accidents (CVAs) and multi-infarct dementia have rarely been reported as presenting symptoms of giant cell arteritis (GCA), although 3%-4% of patients with GCA may present with CVAs during the course of the disease. We describe 7 patients with biopsy-proven GCA who presented with stroke or multi-infarct dementia. Most of them had other symptoms of GCA when the disease began that were misdiagnosed or not noticed. The internal carotid arteries were involved in 4 patients and the vertebrobasilar arteries in 3, with bilateral vertebral artery occlusion in 1. Small cerebral infarction foci on cranial computed tomography (CT) scan and magnetic resonance imaging (MRI) were found in 5 cases, and cerebellar infarction, in 2. MR angiography showed intracranial arteritis in 4 cases. Treatment with glucocorticoids and adjunctive antiplatelet or anticoagulant therapy was given in all cases, with neurologic improvement in 5. Two patients died. Necropsy demonstrated generalized GCA involving the medium and small cerebral vessels in 1 case. Central nervous system involvement is a rare complication in GCA but is important to recognize, as it can be reversible if diagnosed and treated promptly. Suspicion should arise in elderly patients suffering from strokes with a quickly progressing stepwise course and associated headache, fever, or inflammatory syndrome. In these cases, temporal artery biopsy should be performed without delay. Early diagnosis of GCA and immediate initiation of corticosteroid treatment may prevent progressive deterioration and death. Additional antiplatelet or anticoagulant therapy should be evaluated according to the individual risk and benefit to the patient under care.

There is evidence that brain lateralization underlying hemispheric specialization can be observed also at biochemical level. However, hemispheric differences in nitric oxide mediator system have not yet been evaluated. The hippocampus and planum temporale are highly asymmetrical regions but the degree of their laterality is altered in demented or psychotic people. In the study, l-glutamate/l-arginine/l-citrulline concentrations, nitric oxide synthase activities/expressions and nitrites/nitrates levels were estimated in autoptic hippocampi. Right/left laterality in endothelial synthase activity and in nitrites/nitrates was observed in controls. Lateral changes were estimated in patients with Alzheimer disease (a marked increase in activities of constitutive synthases and in expression of inducible enzyme in the left side) and schizophrenia (an increase in activities of all enzymes especially in the right side). Significant shifts from positive to negative correlations were found between laterality of some components of nitric oxide pathway and of planum temporale volumetry under pathological conditions. The hippocampal nitric oxide system appears to be globally right/left lateralized, especially via actions of highly asymmetrical endothelial synthase. The results suggest a specific involvement of all synthases in the development of selected diseases and show that lateral analyses are of sufficient sensitivity to reveal subtle links. The volumetric asymmetry of the planum temporale as a marker of handedness is not probably simply linked to brain laterality at biochemical level but reflects alterations due to pathological processes.

Background and purpose: We investigated whether patients with a lacunar infarct (LI) syndrome exhibiting unique LI or multiple LI on magnetic resonance imaging (MRI) examinations differed in terms of topography and severity of white matter hyperintensities (WMH) ratings. Methods: Forty consecutive patients with a first-ever acute LI, who presented a lacunar syndrome according to Miller–Fishers classification were recruited and were classified into a group presenting isolated LI on MRI (n = 17) or multiple LI (n = 23). Results: Despite equivalent demographic, clinical and cognitive characteristics, patients with multiple LI had increased ratings of WMH in frontal, occipital and subcortical regions. No significant correlations could be evidenced between the number of LI and WMH ratings. Conclusions: Present findings provide support to previous hypothesis considering single and multiple LI MRI presentations of lacunar infarct patients as distinct entities.

The prevalence, morphology and pathogenesis of vascular dementia (VaD), recently termed vascular cognitive disorder (VCD), are a matter of discussion.VaD is suggested in 8-15% of cognitively impaired aged subjects. Its prevalence in autopsy series ranges from 0.03 to 58% (mean 8-15% in Western series, 22-35% in Japan). Neuropathology shows multifocal and/or diffuse lesions, ranging from lacunes and microinfarcts, often involving subcortical and strategically important brain areas (thalamus, frontobasal, limbic system), white matter lesions and hippocampal sclerosis to multi-infarct encephalopathy and diffuse post-ischemic lesions. They result from systemic, cardiac and local large and small vessel disease. Pathogenesis is multifactorial and pathophysiology affects neuronal networks involved in cognition, behavior, execution and memory. Vascular lesions often coexist with Alzheimer's disease (AD) and other pathologies. Minor vascular lesions hardly contribute to cognitive decline in full-blown AD, while both mild Alzheimer pathology and small vessel disease interact synergistically. AD pathology is less severe in the presence of vascular lesions. The lesion pattern in "pure" VaD/VCD) related to microangiopathies differs from that in "mixed dementia" (AD + vascular encephalopathy), often associated with large infarcts, suggesting different pathogenesis. Due to the heterogeneity of cerebrovascular pathology and its causative factors, no validated neuropathologic criteria for VaD are currently available, and a large variability across laboratories still exists in morphologic examination procedures and techniques. Further prospective clinico-pathologic studies are needed to validate diagnostic criteria for VaD and to clarify the impact of vascular lesions on cognitive impairment.

The present study aimed to determine whether Nicotiflorin, a natural flavonoid extracted from coronal of Carthamus tinctorius, has a protective effect on cerebral multi-infarct dementia in rats. The multi-infarct dementia model rats were prepared by injecting man-made micro-thrombi into the right hemisphere. The administration groups were treated once daily with 30, 60 and 120 mg/kg Nicotiflorin (i.g.) from 5 days before ischemia operation to 3 days after the operation for biochemical examination, 10 days for Morris water maze study and morphological observations and 20 days for eight-arm radial maze task. 2,3,5-triphenyltetrazolium chloride (TTC) staining showed that infarct volume of each Nicotiflorin administration group was much smaller than that of vehicle-treated multi-infarct dementia group, and hematoxylin and eosin (HE) staining showed that histopathological abnormalities of each Nicotiflorin group were also much lighter than that of vehicle-treated multi-infarct dementia group. Each Nicotiflorin group showed much better spatial memory performance in Morris water maze tests and eight-arm radial maze task compared with the vehicle-treated multi-infarct dementia group, significantly attenuated the elevation of lactic acid and malondialdehyde (MDA) contents and the decrease in lactate dehydrogenase (LDH), Na(+)K(+)ATPase, Ca(2+)Mg(2+)ATPase and superoxide dismutase (SOD) activity in the brain tissue which was composed of striatum, cortex and hippocampus of the ischemia hemisphere at day 3 after ischemia operation. These results suggest that Nicotiflorin has protective effects on reducing memory dysfunction, energy metabolism failure and oxidative stress in multi-infarct dementia model rats.

La fibrilación auricular (FA) es la arritmia más frecuente en la población adulta. Es sabido que la FA se asocia con un aumento del riesgo de presentar muchos eventos adversos, entre los que se incluyen accidente cerebrovascular, insuficiencia cardíaca, muerte por todas las causas, así como muerte súbita cardíaca. Más recientemente también ha habido un creciente interés en la asociación de FA con deterioro cognitivo y demencia. En esta revisión narrativa describimos la actual evidencia a favor de la relación entre la FA y la declinación cognitiva, el deterioro cognitivo o la demencia en pacientes sin antecedentes de accidente cerebrovascular. Aun cuando no queda muy claro cuáles son los mecanismos exactos que explican la asociación entre la FA y la declinación cognitiva, los mecanismos propuestos incluyen isquemia silente, estado pro inflamatorio, microsangrados cerebrales e hipoperfusión cerebral. Se necesitan más estudios para dilucidar los mecanismos de base que faciliten el descubrimiento de alguna estrategia de prevención. Atrial fibrillation (AF) is the most common arrhythmia in the adult population. AF is widely known to be associated with an increased risk of many adverse outcomes including stroke, heart failure, all-cause death, as well as sudden cardiac death. More recently, there has also been growing interest in the association of AF with cognitive impairment and dementia. In this narrative review, we describe the current evidence that supports the relationship of AF to cognitive decline, cognitive impairment, or dementia in patients without a history of stroke. The exact mechanisms underlying the association of AF with cognitive decline are unclear; however, proposed mechanisms include silent ischemia, pro-inflammatory state, cerebral microbleeds, and cerebral hypoperfusion. Further research is needed to elucidate the underlying mechanisms to facilitate discovery of prevention strategies.

Pulsatility index (PI) of the middle cerebral artery is postulated to reflect the vascular resistance in the artery distal of the probe, and has been reported to increase in small vessel disease, diabetes mellitus, ageing, and dementia. Lacunar infarcts are considered to be related to cognitive impairment. We therefore conducted a study to assess the association between cognitive impairment and PI in patients with a lacunar infarct.Consecutive patients presenting with an acute lacunar syndrome who were admitted to the stroke unit were enrolled. The patients were examined with Doppler ultrasonography of the intracranial arteries, and the PI of the middle cerebral artery was recorded. Cognitive function was evaluated by mini-mental state examination (MMSE), clock drawing test, and trail making test (TMT) A and B.Among the 113 patients included, 85 patients had an acute lacunar infarct and 28 had one or more nonlacunar infarcts. The mean PI was 1.46 (SD = .33). PI was significantly (P.05) associated with MMSE, TMT A and TMT B in patients with lacunar infarct, even after adjustment for multiple patient characteristics (age, sex, prestroke hypertension, smoking, previous stroke, and diabetes).PI was associated with the cognitive performance in patients with lacunar infarcts and a lacunar syndrome. An elevated PI may be related to impairment in several cognitive domains. These findings suggest that transcranial Doppler ultrasonography could be an adjunct tool for early diagnosis of cognitive impairment after stroke.

Dementias are one of the most serious health and socioeconomic issues. Multi-infarct dementia (MID) and Alzheimer´s type dementia (AD) exhibit differences in cerebrovascular blood flow velocity profiles and in presence of microemboli, detected by transcranial Doppler sonography.A group of 77 persons was divided into 4 subgroups: 1. subgroup of patients with MID (n=19; 10 male and 9 female, mean age was 74.32±8.30 years); 2. subgroup of patients with AD (n=19; 11 male and 8 female, mean age was 70.37±87.85 years); 3. subgroup of patients with hypertension (n=19; 11 male and 8 female, age adjusted) and 4. sex and age adjusted control group (CG) of 20 persons without hypertension or other serious risk factors. The duplex ultrasonographic examination of extracranial and intracranial circulation was preceded by neurologic, neuropsychological and psychiatric examination. The presence of microemboli was determined using Multi Dop X2 device (maker DWL), 60 minutes monitoring. All patients underwent brain computer tomography (CT) or magnetic resonance imaging (MRI).We found significantly higher incidence (68.4%, p=0.5267) of asymptomatic microemboli in ACM in the group of patients with MID compared to the AD group, the group of patients with hypertension and CG.The occurrence of "asymptomatic" emboli in the middle cerebral artery in patients with multi-infarct dementia is higher in the current study. Although these microemboli do not cause immediate symptoms, the evidence suggests, that they may be a risk factor for cognitive impairment, especially for multi-infarct dementia.