Middle Cerebral Artery Pulsatility Index is Associated with Cognitive Impairment in Lacunar Stroke.

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Progressive cognitive deficits in a mouse model of recurrent photothrombotic stroke.

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<0.05). After recurrent infarcts, the object recognition test showed significant recognition memory deficits (P<0.001) and the Morris water maze test demonstrated persisting spatial learning and memory deficits (P<0.05). Histological analyses revealed remote astrogliosis in the hippocampus. 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.

Cell-based therapy for patients with vascular dementia.

The homeostasis of neuronal cells is maintained by the cerebral circulation and blood-brain barrier. Circulating bone marrow-derived immature cells, including CD34-positive (CD34+) cells, have been implicated in homeostasis of the cerebral microvasculature. Decreased levels of circulating CD34+ cells, associated with ageing and/or cardiovascular risk factors, correlate with poor clinical outcomes in patients with cerebrovascular and cardiovascular diseases. Clinical trials with local transplantation of bone marrow-derived immature cells for patients with limb ischaemia, including Buerger's disease and arteriosclerosis obliterans, have been shown to improve impaired microcirculation. In the present review, current findings about the correlation between circulating immature cells and microcirculation are reviewed, and the possibility of novel cell-based therapy in patients with vascular dementia is discussed.

Vascular cognitive impairment in small vessel disease: clinical and neuropsychological features of lacunar state and Binswanger's disease.

BACKGROUND: ischaemic cerebrovascular small vessel disease (SVD) is a prevalent and under-diagnosed condition that triggers vascular cognitive impairment (VCI). OBJECTIVE: to describe the neuropsychological and clinical profiles in SVD (Binswanger's disease, BD; lacunar state, LS) from the clinician's perspective at the VCI stage. METHODS: a total of 1257 patients admitted to a tertiary center with a diagnosis of stroke, neuroradiological vascular disease, cognitive impairment/dementia, during a 13-year period were investigated. We prospectively assessed cognition in a subset of 141 patients with VCI (LS n = 28, BD n = 69, large vessel disease-LVD-n = 44) with MMSE, CAMDEX-H, WAIS-R, EXIT-25 and Trail making test. RESULTS: executive dysfunction (ECD) (n = 89, 91.7% versus n = 10, 22.7%; P < 0.001) and gait disturbances (n = 74, 76.3% versus n = 15, 34.1%; P < 0.001) characterized SVD. Prior strokes (n = 9, 9.3% versus n = 23, 52.3%; P < 0.001) and embologenous cardiopathy (n = 39, 40.2% versus n = 28, 63.6%; P < 0.04) featured LVD cases. BD was defined by hypertension (n = 52, 75.4% versus n = 30, 44.1%; P < 0.001), ECD (n = 65, 94.2% versus n = 34, 47.2%; P < 0.001) and VCI onset with cognitive impairment but not strokes (n = 44, 63.8% versus n = 34, 50%; P < 0.01). CONCLUSIONS: ECD and a frontal gait are SVD's clinical landmarks in our sample. LS and BD cases share a similar cognitive profile.

Patterns of neuropsychological impairment in MCI patients with small subcortical infarcts or hippocampal atrophy.

We investigated whether MCI patients with hippocampal atrophy or multiple subcortical infarcts demonstrate neuropsychological patterns and markers considered typical of Alzheimer's disease (AD) and of vascular dementia (VD), respectively. An extensive neuropsychological battery, including tests of memory, visual-spatial and executive functions, language, attention, praxis and psychomotor speed, was administered to 36 mild cognitive impairment (MCI) patients with hippocampal atrophy and 41 MCI patients with multiple subcortical infarcts. Both groups of MCI patients were very mildly impaired and well matched in terms of MMSE scores. A clear, disproportionately severe, episodic memory disorder was observed in MCI patients with hippocampal atrophy. A less specific neuropsychological profile, consisting of impairment on an Action Naming task that is sensitive to frontal lobe lesions, was observed in MCI patients with multiple subcortical infarcts. In MCI patients, a disproportionately severe episodic memory impairment strongly points to an Alzheimer's type brain pathology, whereas the prevalence of executive deficits and other frontal lobe symptoms are a much weaker diagnostic marker of small vessel subcortical disease.

[The cognitive rehabilitation process in a case of bithalamic infarction]. / Proceso de rehabilitación cognitiva en un caso de infarto bitalámico.

INTRODUCTION: One of the fundamental lines followed by Neuropsychology today focuses on rehabilitation processes and their effectiveness. Cognitive rehabilitation is an eclectic process that is dependent on a number of variables. This variability makes it necessary to establish a work plan that guides the intervention carried out by professionals and also makes it clear what objectives are to be achieved, as well as the strategies and tools that must be used to reach them. The purpose of this study is to offer a practical examination of the different points that must be developed in a cognitive rehabilitation process--exemplified here in a case of bithalamic infarction. CASE REPORT: From a single case and from the specific needs of the individual, a thorough work plan is drawn up. This plan includes a description of everything from the choice of a practical framework for intervention and its underlying principles up to the different training processes, learning techniques and tools that were used and finally proved to be effective. The efficacy and safety of the different strategies and tools used are demonstrated by the short and long term results of the different neuropsychological examinations carried out, which at the same time proved the effectiveness of the work plan that was selected for application. CONCLUSIONS: A clear understanding of the value of the cognitive rehabilitation processes chosen for use helps to improve the way clinical work is carried out, with the common purpose of restoring neuropsychological deficits and increasing the individual's independence and quality of life.

From Binswanger's disease to leuokoaraiosis: what we have learned about subcortical vascular dementia.

The literature regarding subcortical vascular dementia associated with periventricular and deep white matter alterations is reviewed. Information pertaining to neuropathological, neuropsychological, and neuroradiological studies is emphasized. Based on this review and prior neuropsychological studies associating subcortical vascular pathology with greater deficits on tests of executive dysfunction and with relatively better performance on tests of delayed recognition memory, we conclude that vascular dementia associated with periventricular and deep white matter alterations can and should be regarded as a subcortical dementing illness. Also, we support schemes suggested by Erkinjuntti et al. (2000) and Cosentino et al. (this issue) that attempt to integrate neuropsychological and neuroradiological data into a diagnostic paradigm that describes, as well as diagnoses, dementing disorders. We discuss questions and issues about vascular dementia that deserve further consideration and study.

Effects of acupuncture on hemorheology, blood lipid content and nail fold microcirculation in multiple infarct dementia patients.

Forty-six cases of multiple infarct dementia (MID) in the treatment group were treated by acupuncture with the principle of supplementing the inferiority to clear the superiority and regulating spirit to invigorate intelligence. Changes of the blood lipid content, hemorheological indexes and nail fold microcirculation in the treatment group were compared with those in the randomly assigned control group. The data collected showed that the changes in the treatment group were remarkable, and part of them were superior to their counterparts obtained in the control group by statistical analysis. It is indicated that acupuncture can effectively regulate the affected hemodynamic state in MID.

Hemodynamic evaluation of the optic nerve head in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND: Although cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is considered a cerebrovascular disorder with almost exclusively neurological symptoms, arteriopathy is generalized and also involves the choroid and retina. OBJECTIVE: To study optic nerve head microvascular function in CADASIL by assessing blood flow, volume, and velocity with a retina flowmeter. PATIENTS AND METHODS: Scanning laser Doppler flowmetry permits the noninvasive assessment of relative blood velocity, volume, and flow in a sample volume of either retina or anterior optic nerve head. Measurements were performed in a first group of 9 eyes of 5 patients with CADASIL and a second group of 8 eyes of 4 healthy subjects. Hemodynamic parameters were computed in 4 quadrants of the optic disc (superior nasal, superior temporal, inferior nasal, and inferior temporal). The Wilcoxon rank sum test was used to assess differences in relative flow, volume, and velocity in each quadrant and between the 2 groups and differences in overall optic nerve head blood flow, volume, and velocity. RESULTS: Patients with CADASIL had a significant decrease in overall blood flow and volume compared with healthy subjects (P<.05). The reduction in blood flow and volume was particularly significant in the superior and inferior temporal quadrants. No significant differences were found nasally between the patients and the control groups. CONCLUSION: Our results suggest that hemodynamic parameters are abnormal in the superficial nerve fiber layer of the optic nerve head of patients with CADASIL, especially in the temporal quadrants of the neuroretinal rim.

The validity and reliability of chinese frontal assessment battery in evaluating executive dysfunction among Chinese patients with small subcortical infarct.

OBJECTIVES: Frontal Assessment Battery (FAB) is a valid and reliable screening test for evaluating executive dysfunction among whites with frontal and subcortical degenerative lesions. We studied the properties of a Chinese version of FAB (CFAB) in evaluating executive dysfunction among Chinese stroke patients with small subcortical infarct. METHODS: Concurrent validity was evaluated using Wisconsin Card Sorting Tst (WCST) and Mattis Dementia Rating Scale-Initiation/Perseveration Subset (MDRS I/P) among 41 controls and 30 stroke patients with small subcortical infarct. Discriminant validities of CFAB and its subitems were compared with those of Mini-Mental State Examination (MMSE). Internal consistency, test-retest, and interrater reliability of CFAB were evaluated. RESULTS: The CFAB had low to good correlation with various executive measures: MDRS I/P (r = 0.63, p < 0.001), number of category completed (r = 0.45, p < 0.001), and number of perseverative errors (r = -0.37, p < 0.01) of WCST. Among the executive measures, only number of category completed had significant but small contribution (6.5%, p = 0.001) to the variance of CFAB. A short version of CFAB using three items yielded higher overall classification accuracy (86.6%) than that of CFAB full version (80.6%) and MMSE (77.6%). Internal consistency (alpha = 0.77), test-retest reliability (rho = 0.89, p < 0.001), and interrater reliability (rho = 0.85, p < 0.001) of CFAB were good. CONCLUSION: Although CFAB is reliable, it is only moderately valid in evaluating executive dysfunction among Chinese stroke patients with small subcortical infarct. The clinical use of CFAB in the evaluation of executive dysfunction among this group of patients cannot be recommended at this stage.

Retinal abnormalities in CADASIL: a retrospective study of 18 patients.

BACKGROUND: CADASIL is an inherited small vessel disease related to Notch3 gene mutations. AIM: To report retinal findings in symptomatic CADASIL patients. METHODS: Assessment of visual acuity (VA), testing of visual fields (VF), funduscopic examination (FE), and fluorescein angiography (FA) were carried out in 18 symptomatic patients. RESULTS: No visual symptoms were presented by our patients. VA was normal in all. Ophthalmologic abnormalities were found in 8 patients. VF were normal except for a right hemianopia in one subject due to ischemic stroke. FE and FA revealed significant abnormalities in seven other subjects (mean age: 55 years; range: 39-74): nerve fibre loss (n = 4), cotton wool spots (n = 3), sheathed arteries (n = 1), and tortuous arteries (n = 1). Only one patient with both tortuous arteries and nerve fibre loss had multiple vascular risk factors, and another patient with cotton wool spots was a current smoker. DISCUSSION: FE and FA revealed silent retinal abnormalities in CADASIL patients with nerve fibre loss in 22% and cotton wool spots in 17%. The presence of these abnormal retinal findings does not seem related to the severity of the disorder but may be considered as peripheral markers of this genetic disease.

Cognitive functioning after stroke: a one-year follow-up study.

Cognitive disorders after stroke are one of the main causes of disability in daily activities. The main aim of this study was to investigate the frequency of post-stroke dementia, post-stroke mild cognitive impairment (MCI) and post-stroke amnestic MCI at different times after first-ever stroke; 196 patients were included in the study. In addition, cognitive disorders and their clinical course were studied. Frequency of post-stroke dementia was about 10% at all evaluation times; most patients had post-stroke MCI. Of the cognitive functions investigated, mental speed and calculation were most frequently affected. Performance on almost all cognitive tests was improved 6 and 12 months after stroke. Thus, while the frequency of post-stroke dementia is low, the frequency of post-stroke MCI is high, but improvement of cognitive function is possible.

Insidious cognitive decline in CADASIL.

BACKGROUND AND PURPOSE: Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) causes repeated ischemic attacks leading to subcortical vascular dementia. The aim of this study was to characterize cognitive function in subjects with a C475T (R133C) mutation in the Notch3 gene, leading to CADASIL. METHODS: Prestroke (n=13) and poststroke (n=13) mutation carriers and mutation carriers with dementia (n=8) were compared with healthy noncarriers from the same families using a comprehensive set of neuropsychological tests. RESULTS: Changes in working memory and executive function were observed in the very early phase of the disease before transient ischemic attack (TIA) or stroke. Later, in the poststroke phase, the cognitive impairment concerned also mental speed and visuospatial ability. Finally, the subjects with dementia had multiple cognitive deficits, which engaged even verbal functions, verbal episodic memory, and motor speed. The 2 mutation carrier groups without dementia and the controls could be reliably distinguished using 3 tests that assessed working memory/attention, executive function, and mental speed. Episodic memory was relatively well-preserved late in the disease. CONCLUSIONS: A deterioration of working memory and executive function was already observed in the prestroke phase, which means that cognitive decline may start insidiously before the first onset of symptomatic ischemic episodes.

A two-year clinical follow-up study in 80 CADASIL subjects: progression patterns and implications for clinical trials.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small vessel disease causing stroke and dementia. The aim of this study was to explore the patterns of clinical progression in CADASIL, to check for prognostic variables, and to provide sample size estimates for future therapeutic trials. METHODS: Eighty CADASIL subjects (aged 45.7+/-9.9 years [mean+SD]) were followed prospectively during a mean period of 26.3+/-1.1 months. Standardized scales on disability (Rankin), activities of daily living (Barthel index), neurological outcome (National Institutes of Health Stroke Scale [NIHSS]), and cognition (structural interview for diagnosis of Alzheimer dementia and multi-infarct dementia [SIDAM] and Mattis dementia rating scale [MDRS]) were assessed at baseline and at follow-up. RESULTS: All but 1 individual completed the protocol. At follow-up, the cohort had deteriorated with respect to all clinical scales: Rankin scores (0.3+/-0.7 [mean change+/-SD]; P=0.001), Barthel index (-5.4+/-15.9; P<0.001), NIHSS scores (1.0+/-2.6; P=0.001), SIDAM scores (-2.1+/-6.4; P=0.004), and MDRS scores (-4.3+18.5; P=0.09). The spectrum ranged from marked worsening to some degree of improvement. Seventeen patients experienced a new stroke. Overall, there were 18 strokes within 173 person-years, giving an average incidence rate of stroke of 10.4 per 100 person-years (95% CI, 5.6 to 15.2). Age at baseline was found to be a predictor of clinical progression. Sample size estimates show that the number of individuals needed to include in an interventional trial (assumed duration 2 years, assumed treatment effect 40%) is 602 when using stroke occurrence as an outcome measure. CONCLUSIONS: The clinical course of CADASIL includes periods of acute worsening, chronic progression, stabilization, and improvement. Sample size calculations emphasize the need for surrogate markers of disease progression for future interventional trials.

Abnormal vasoconstrictor responses to angiotensin II and noradrenaline in isolated small arteries from patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is characterized by ultrastructural abnormalities in small cerebral and systemic vessels. We assessed vasomotor function in systemic small arteries in CADASIL. METHODS: We studied 10 CADASIL patients and 10 control subjects. Resistance arteries isolated from gluteal biopsies were mounted on small-vessel myographs, and concentration responses were determined for vasoconstrictors (noradrenaline, angiotensin II, and endothelin-I) and vasodilators (acetylcholine, bradykinin, spermine-NONOate, and nifedipine). Maximum data are shown as percent potassium contraction. RESULTS: There was reduced potency for noradrenaline in CADASIL (CADASIL [38 arteries]: EC50, 240 nmol/L; control subjects [27 arteries]: EC50, 100 nmol/L; 2-way analysis of variance, F=9.76, P=0.002). Maximum response to angiotensin II was greater in CADASIL (120+/-8% versus 97+/-5% in control subjects; F=4.28, P=0.043). Tachyphylaxis to angiotensin II occurred in all control subjects studied but in only 3 of 9 CADASIL subjects (P=0.011, Fisher's exact test). Vasodilation was similar in CADASIL patients compared with control subjects for endothelium-dependent dilators (acetylcholine and bradykinin) and endothelium-independent dilators (spermine-NONOate and nifedipine). CONCLUSIONS: These results suggest a selective systemic microvascular vasoconstrictor abnormality in CADASIL in noradrenaline and angiotensin II pathways that is not explained by vasodilator impairment in endothelium or vascular smooth muscle. This could have important implications for prophylaxis and treatment of CADASIL.

Distribution pattern of Notch3 mutations suggests a gain-of-function mechanism for CADASIL.

Mutations in Notch3 cause the syndrome CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). The mechanism by which these mutations result in a CADASIL phenotype has been widely speculated upon. A first step toward understanding a disease mechanism is to learn whether the mutations result in the loss of Notch3 function, in particular, its role in signaling or in the gain of a novel function. Notch3 genomic sequences were analyzed for sites of conservation across species. We present here a bioinformatic analysis of the Notch paralogs and orthologs that suggest that CADASIL mutations result in a gain of function. This finding diminishes the likelihood that a Notch3 signaling deficit is responsible for the phenotype and increases the likelihood that CADASIL joins the growing list of neurological diseases with protein deposits due to misfolding and aggregation.