151
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Jellinger KA. The enigma of vascular cognitive disorder and vascular dementia. Acta Neuropathol 2007; 113:349-88. [PMID: 17285295 DOI: 10.1007/s00401-006-0185-2] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 12/08/2006] [Accepted: 12/08/2006] [Indexed: 12/20/2022]
Abstract
The prevalence, morphology and pathogenesis of vascular dementia (VaD), recently termed vascular cognitive impairment, are a matter of discussion, and currently used clinical diagnostic criteria show moderate sensitivity (average 50%) and variable specificity (range 64-98%). In Western clinic-based series, VaD is suggested in 8-10% of cognitively impaired aged subjects. Its prevalence in autopsy series varies from 0.03 to 58%, with reasonable values of 8-15%, while in Japan it is seen in 22-35%. Neuropathologic changes associated with cognitive impairment include multifocal and/or diffuse disease and focal lesions: multi-infarct encephalopathy, white matter lesions or arteriosclerotic subcortical (leuko)encephalopathy, multilacunar state, mixed cortico-subcortical type, borderline/watershed lesions, rare granular cortical atrophy, post-ischemic encephalopathy and hippocampal sclerosis. They result from systemic, cardiac and local large or small vessel disease. Recent data indicate that cognitive decline is commonly associated with widespread small ischemic/vascular lesions (microinfarcts, lacunes) throughout the brain with predominant involvement of subcortical and functionally important brain areas. Their pathogenesis is multifactorial, and their pathophysiology affects neuronal networks involved in cognition, memory, behavior and executive functioning. Vascular lesions often coexist with Alzheimer disease (AD) and other pathologies. Minor cerebrovascular lesions, except for severe amyloid angiopathy, appear not essential for cognitive decline in full-blown AD, while both mild Alzheimer pathology and small vessel disease may interact synergistically. The lesion pattern of "pure" VaD, related to arteriosclerosis and microangiopathies, differs from that in mixed-type dementia (AD with vascular encephalopathy), more often showing large infarcts, which suggests different pathogenesis of both types of lesions. Due to the high variability of cerebrovascular pathology and its causative factors, no validated neuropathologic criteria for VaD are available, and a large variability across laboratories still exists in the procedures for morphologic examination and histology techniques.
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Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Kenyongasse 18, 1070, Vienna, Austria.
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152
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Abstract
The term Cerebral Amyloid Angiopathy (CAA) is used to describe the pathological changes occurring in cerebral blood vessels, both leptomeningeal and cortical that result from the deposition of amyloid proteins. This CNS vasculopathy is associated with a spectrum of clinical phenotypes that include both ischemic and hemorrhagic presentations. Dementia, cognitive impairment and transient neurological symptoms or signs are also being increasingly recognized as part of the CAA clinical spectrum. This review covers the clinical, pathological and neuroimaging aspects of CAA.
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Affiliation(s)
- Luís F Maia
- Department of Neurology, Hospital Geral Santo António, Porto, Portugal
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153
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Greenberg SM, Rosand J, Schneider AT, Creed Pettigrew L, Gandy SE, Rovner B, Fitzsimmons BF, Smith EE, Edip Gurol M, Schwab K, Laurin J, Garceau D. A phase 2 study of tramiprosate for cerebral amyloid angiopathy. Alzheimer Dis Assoc Disord 2007; 20:269-74. [PMID: 17132972 DOI: 10.1097/01.wad.0000213845.28624.f4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND AND PURPOSE No treatments have been identified to lower the risk of intracerebral hemorrhage due to cerebral amyloid angiopathy (CAA). A potential approach to prevention is the use of agents that interfere with the pathogenic cascade initiated by the beta-amyloid peptide (Abeta). Tramiprosate (3-amino-1-propanesulfonic acid) is a candidate molecule shown in preclinical studies to reduce CAA in a transgenic mouse model. METHODS We performed a 5-center phase 2 double-blinded trial to evaluate the safety, tolerability, and pharmacokinetics of tramiprosate in subjects with lobar intracerebral hemorrhage. Twenty-four subjects age > or =55 years with possible or probable CAA were randomized to receive 12 weeks of tramiprosate at 1 of 3 oral doses (50, 100, or 150 mg twice daily). Subjects were followed for clinical adverse effects, laboratory, vital sign, electrocardiogram, cognitive, or functional changes, appearance of new symptomatic or asymptomatic hemorrhages, and pharmacokinetic parameters. RESULTS Enrolled subjects were younger (mean age 70.8+/-5.4, range 61 to 78) and had more advanced baseline disease (measured by number of previous hemorrhages) than consecutive subjects in a CAA natural history cohort. No concerning safety issues were encountered with treatment. Nausea and vomiting were the most common adverse events and were more frequent at high doses. Nine subjects had new symptomatic or asymptomatic hemorrhages during treatment; all occurred in subjects with advanced baseline disease, with no apparent effect of drug dosing assignment. CONCLUSIONS These data suggest that tramiprosate can be given safely to subjects with suspected CAA and support future efficacy trials.
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Affiliation(s)
- Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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154
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Aguilar MI, Hart RG, Kase CS, Freeman WD, Hoeben BJ, García RC, Ansell JE, Mayer SA, Norrving B, Rosand J, Steiner T, Wijdicks EFM, Yamaguchi T, Yasaka M. Treatment of warfarin-associated intracerebral hemorrhage: literature review and expert opinion. Mayo Clin Proc 2007; 82:82-92. [PMID: 17285789 DOI: 10.4065/82.1.82] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Wider use of oral anticoagulants has led to an increasing frequency of warfarin-related intracerebral hemorrhage (ICH). The high early mortality of approximately 50% has remained stable in recent decades. In contrast to spontaneous ICH, the duration of bleeding is 12 to 24 hours in many patients, offering a longer opportunity for intervention. Treatment varies widely, and optimal therapy has yet to be defined. An OVID search was conducted from January 1996 to January 2006, combining the terms warfarin or anticoagulation with intracranial hemorrhage or intracerebral hemorrhage. Seven experts on clinical stroke, neurologic intensive care, and hematology were provided with the available information and were asked to independently address 3 clinical scenarios about acute reversal and resumption of anticoagulation in the setting of warfarin-associated ICH. No randomized trials assessing clinical outcomes were found on management of warfarin-associated ICH. All experts agreed that anticoagulation should be urgently reversed, but how to achieve it varied from use of prothrombin complex concentrates only (3 experts) to recombinant factor VIIa only (2 experts) to recombinant factor VIIa along with fresh frozen plasma (1 expert) and prothrombin complex concentrates or fresh frozen plasma (1 expert). All experts favored resumption of warfarin therapy within 3 to 10 days of ICH in stable patients in whom subsequent anticoagulation is mandatory. No general agreement occurred regarding subsequent anticoagulation of patients with atrial fibrillation who survived warfarin-associated ICH. For warfarin-associated ICH, discontinuing warfarin therapy with administration of vitamin K does not reverse the hemostatic defect for many hours and is inadequate. Reasonable management based on expert opinion includes a wide range of additional measures to reverse anticoagulation in the absence of solid evidence.
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Affiliation(s)
- Maria I Aguilar
- Department of Neurology, Mayo Clinic College of Medicine, 13400 E Shea Blvd, Scottsdale, AZ 85259, USA.
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155
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Abstract
Neuroimaging by CT or MR is necessary for the detection of hemorrhagic stroke and provides important data regarding the cause of stroke. Serial changes in the CT and MR appearance of hematoma attributable to temporal evolution must be assessed to assure accurate diagnosis. Emerging evidence suggests that the use of MR imaging alone may be adequate for identifying hemorrhage in acute stroke patients and that GRE MR imaging is superior to both CT and conventional spin-echo MR imaging sequences for the detection of chronic microbleeds and hemorrhagic conversion of infarction.
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Affiliation(s)
- Eric E Smith
- Vascular and Critical Care Neurology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA.
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156
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Nakata-Kudo Y, Mizuno T, Yamada K, Shiga K, Yoshikawa K, Mori S, Nishimura T, Nakajima K, Nakagawa M. Microbleeds in Alzheimer disease are more related to cerebral amyloid angiopathy than cerebrovascular disease. Dement Geriatr Cogn Disord 2006; 22:8-14. [PMID: 16645275 DOI: 10.1159/000092958] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/28/2005] [Indexed: 11/19/2022] Open
Abstract
Cerebral amyloid angiopathy (CAA) is one of the cardinal pathological features in the vascular components of Alzheimer's disease (AD). CAA itself results in disrupted microvasculature, mainly in the cerebral cortex, eventually leading to a brain cortical or subcortical hemorrhage in a population of elderly people, but clinically overt brain hemorrhages are not so frequent in AD patients. Here we assessed 50 AD patients and 26 controls to detect latent brain hemorrhages with gradient-echo T(2)*-weighted images, a sensitive magnetic resonance imaging technique to detect hemosiderin components in the brain. Microbleeds, demarcated as low-intensity spots in T(2)*-weighted images, were detected in 16.7% of AD patients without cerebrovascular disease (CVD) and in 12.5% of those with CVD, while no microbleeding was detected in the control subjects. No significant difference was observed between the microbleed-positive group and the microbleed-negative counterpart in their clinical background, such as hypertension, the use of antiplatelet drugs and smoking. In addition, white matter high intensities in the T(2)-weighted image were significantly more confluent in the microbleed-positive AD group than its negative counterpart. In conclusion, our evaluation of AD brains revealed that latent microbleeds in AD patients are more frequent than in normal controls. Microbleeds not being related to common hemorrhagic risk factors, but being significantly related to white matter pathologies suggested that microbleeds in AD may be associated with CAA, but not with hypertension or CVD.
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Affiliation(s)
- Yuriko Nakata-Kudo
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, Japan
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157
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Chen YW, Gurol ME, Rosand J, Viswanathan A, Rakich SM, Groover TR, Greenberg SM, Smith EE. Progression of white matter lesions and hemorrhages in cerebral amyloid angiopathy. Neurology 2006; 67:83-7. [PMID: 16832082 PMCID: PMC1502246 DOI: 10.1212/01.wnl.0000223613.57229.24] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the rate of progression of white matter lesions and hemorrhages in a cohort with cerebral amyloid angiopathy (CAA). METHODS The authors analyzed data from 26 patients with possible (3) or probable (23) CAA, diagnosed by the Boston Criteria. Brain maps of white matter hyperintensities, normalized to head size (nWMH), were created by blinded computer-assisted segmentation of MRI images obtained at baseline and after a median follow-up interval of 1.1 year. RESULTS There was a substantial nWMH volume increase over the interscan interval (median 0.5 mL/year, interquartile range 0.1 to 2.8, p < 0.001). The median yearly increase, expressed as a percentage of the baseline WMH volume, was 18%. The characteristic most strongly associated with nWMH volume increase was the baseline nWMH volume (r = 0.57, p = 0.002). The volume of nWMH progression was also associated with history of cognitive impairment (median 5.0 mL/year in cognitively impaired subjects vs 0.3 mL/year in cognitively unimpaired, p = 0.02) but not age or hypertension. This association remained present in an analysis stratified by baseline WMH volume. New hemorrhages, including asymptomatic microbleeds, were seen in 46% of subjects. The number of new MRI hemorrhages correlated strongly with baseline nWMH (r = 0.53, p = 0.005) but not with nWMH progression (r = 0.22, p = 0.28). CONCLUSIONS There is a progressive increase in white matter lesions in subjects with cerebral amyloid angiopathy. The association of white matter lesions with incident lobar hemorrhages suggests that white matter damage may reflect a progressive microangiopathy due to cerebral amyloid angiopathy.
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Affiliation(s)
- Y W Chen
- Department of Neurology, Li-Shin Hospital and National Taiwan University Hospital, Taipei
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158
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Abstract
White matter lesions representing ischemic demyelination have evolved in terms of our understanding of their pathogenesis and potential clinical significance. Low density lesions on CT brain scan, most commonly seen in the periventricular region, also frequently seen in the centrum semiovale, have been termed 'leukoaraiosis'. In the past years, it was not uncommon at all to hear the term 'Binswanger's disease' used in an attempt to define the neurological sequelae of such lesions. Further refinement came with the advent of magnetic resonance imaging (MRI) brain scan which is particularly sensitive to such white matter areas of increased signal intensity, which tend to be seen particularly well on T2-weighted and fluid attenuation inversion recovery (FLAIR) scans. The major challenge has been to correlate the clinical attributes with such relatively frequent findings in the elderly population. Recent studies have looked at lesion load in a fashion analogous to that seen with multiple sclerosis. A particularly relevant clinical model for white matter disease is cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) which combines the potential components of small vessel disease, resulting in progressive neurological deficit, with a common association with migraine which can also be associated with white matter lesions. However, the most common pathogenic factor associated with the microangiopathy, which appears to be at the heart of ischemic demyelination, continues to be hypertension. How well we are able to tie in the various pathological mechanisms associated with this end organ damage of the brain will determine how well we can arrive at effective interventions for a common contributor to neurological deficits in the elderly.
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Affiliation(s)
- Roger E Kelley
- Department of Neurology, LSU Health Sciences Center, Shreveport, LA 71103, USA.
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159
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Salat DH, Smith EE, Tuch DS, Benner T, Pappu V, Schwab KM, Gurol ME, Rosas HD, Rosand J, Greenberg SM. White matter alterations in cerebral amyloid angiopathy measured by diffusion tensor imaging. Stroke 2006; 37:1759-64. [PMID: 16763176 DOI: 10.1161/01.str.0000227328.86353.a7] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral amyloid angiopathy (CAA) represents beta-amyloid deposition in the small- and medium-sized vessels of the brain and meninges. CAA contributes to altered vessel function and is associated with white matter damage, cognitive impairment, and most salient, hemorrhagic stroke. We used diffusion tensor imaging to evaluate the anatomic distribution of white matter degeneration in participants diagnosed with advanced CAA. METHODS Diffusion tensor imaging was obtained from 11 participants diagnosed with CAA-related intracerebral hemorrhage and 13 matched healthy control participants. Fractional anisotropy (FA) and diffusivity maps were compared using voxel based t test and region-of-interest analyses. RESULTS FA was reduced in CAA in temporal white matter and in the splenium of the corpus callosum (P<0.001 with approximately 17% reduction in temporal white matter and 15% reduction in the splenium). FA was marginally increased in CAA in the posterior limb of the internal capsule and subthalamic gray matter regions (approximately 7% increase in subthalamic gray). FA changes were bilateral, remained significant in cluster analysis controlling for multiple comparisons, and did not depend on the hemisphere of the cerebral hemorrhage. Diffusivity was not substantially altered. CONCLUSIONS These findings suggest that a pattern of regional brain tissue degeneration is a characteristic feature of advanced CAA.
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Affiliation(s)
- David H Salat
- Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Mass 02129-2060, USA.
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160
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Zhang‐Nunes SX, Maat‐Schieman MLC, van Duinen SG, Roos RAC, Frosch MP, Greenberg SM. The cerebral beta-amyloid angiopathies: hereditary and sporadic. Brain Pathol 2006; 16:30-9. [PMID: 16612980 PMCID: PMC8095991 DOI: 10.1111/j.1750-3639.2006.tb00559.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We review the clinical, radiologic, and neuropathologic features of the hereditary and sporadic forms of cerebral amyloid angiopathy (CAA) associated with vascular deposition of the beta-amyloid peptide. Amino acid substitutions at 4 sites in the beta-amyloid precursor protein, all situated within the beta-amyloid peptide sequence itself, have been shown to cause heritable forms of CAA. The vascular diseases caused by these mutations are associated primarily with cerebral hemorrhages, white matter lesions, and cognitive impairment, and only variable extents of the plaque and neurofibrillary pathologies characteristic of Alzheimer disease. Sporadic CAA typically presents 20 or more years later than hereditary CAA, but is otherwise characterized by a comparable constellation of recurrent cerebral hemorrhages, white matter lesions, and cognitive impairment. The clinical, radiologic and pathologic similarities between hereditary and sporadic CAA suggest that important lessons for this common age-related process can be learned from the mechanisms by which mutation makes beta-amyloid tropic or toxic to vessels.
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Affiliation(s)
- Sandy X. Zhang‐Nunes
- Neurology Clinical Trials Unit and MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Boston
| | | | | | - Raymund A. C. Roos
- Departments of Neurology, Leiden University Medical Center, The Netherlands
| | - Matthew P. Frosch
- C.S. Kubik Laboratory for Neuropathology, Department of Pathology, Massachusetts General Hospital, Boston
| | - Steven M. Greenberg
- Neurology Clinical Trials Unit and MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Boston
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161
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Maia LF, Vasconcelos C, Seixas S, Magalhães R, Correia M. Lobar brain hemorrhages and white matter changes: Clinical, radiological and laboratorial profiles. Cerebrovasc Dis 2006; 22:155-61. [PMID: 16691025 DOI: 10.1159/000093245] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 02/09/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND White matter changes have several histopathologic correlates including cerebral amyloid angiopathy (CAA). The aim of this study was to characterize the clinical, laboratorial and neuroradiological profile of a CAA-related lobar hemorrhages case series. METHODS A cohort of 50 consecutive patients with cerebral lobar hemorrhages was studied and clinical, radiological data and ApoE polymorphisms were analyzed. White matter changes were graded and microbleeds were characterized according to number and location using T2* MRI. RESULTS A statistically significant association was found between the prestroke cognitive performance and poststroke dementia and between hemorrhage volume and mortality. More severe white matter changes were found in probable CAA when comparing to possible CAA. The most prominent white matter lesions are associated with the presence and the number of microbleeds. The frequency of APOE epsilon 2 and epsilon 4 alleles was higher in this cohort when compared to a Northern Portuguese population. CONCLUSION White matter changes are frequent in lobar hemorrhage patients and are associated with cortical microbleeds, the radiological hallmark of CAA. Therefore, white matter changes may be the sole phenotype of CAA and, potentially, involved in the pre-stroke cognitive impairment presented by the patients, which are genetically distinct from the population in general.
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Affiliation(s)
- Luís F Maia
- Department of Neurology, Hospital Geral Santo António, Porto, Portugal
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162
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Abstract
Intracerebral haemorrhage (ICH) is a common and serious disease. About 1 to 2 out of 10 patients with stroke have an ICH. The mortality of ICH is higher than that of ischaemic stroke. Only 31% are functionally independent at 3 months. Only 38% of the patients survive the 1(st) year. The cost of ICH is high. Hypertension is the major risk factor, increasing the risk of ICH about 4x. Up to half of hypertensive patients who suffer a ICH are either unaware of their hypertension, non-compliant with the medication or fail to control periodically their blood pressure levels Microbleeds and white matter changes are MRI markers of the risk of ICH. ICH has 3 main pathophysiological phases: arterial rupture and haematoma formation, haematoma enlargement and peri-haematoma oedema. Up to 40% of the haematomas grow in the first hours post-rupture. ICH growth is associated with early clinical deterioration. Two randomised clinical trials (RCTs) demonstrated that treatment with rFVIIa limited haematoma growth and improved outcome, but was associated with a increase in thromboembolic complications. Ventricular drainage with thrombolytics might improve outcome for patients with intraventricular bleeding. A large RCT and meta-analysis failed to show a benefit of surgery over conservative treatment in acute ICH.
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Affiliation(s)
- José M Ferro
- Centro de Estudos Egas Moniz, Hospital de Santa Maria, Lisboa 1649-035, Portugal.
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163
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Keyserling H, Mukundan S. The Role of Conventional MR and CT in the Work-Up of Dementia Patients. Magn Reson Imaging Clin N Am 2006; 14:169-82. [PMID: 16873009 DOI: 10.1016/j.mric.2006.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Dementia is a clinical syndrome with many causes. There often is overlap in the clinical manifestations of various forms of dementia, making them difficult to categorize. Neuroimaging can play an important role in distinguishing one form of dementia from another. Advanced imaging techniques continue to provide greater insight into the underlying pathologic processes in patients who have dementia. Conventional MRI and CT, however, still can contribute useful information when interpreting radiologists are familiar with the patterns of volume loss and signal or density changes that are characteristic of various forms of dementia.
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Affiliation(s)
- Harold Keyserling
- Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA
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164
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Keyserling H, Mukundan S. The role of conventional MR and CT in the work-up of dementia patients. Neuroimaging Clin N Am 2006; 15:789-802, x. [PMID: 16443491 DOI: 10.1016/j.nic.2005.09.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neuroimaging can play an important role in distinguishing one form of dementia from another. Advanced imaging techniques continue to provide greater insight into the underlying pathologic processes in patients who have dementia. Conventional MRI and CT, however, can contribute useful information when interpreting radiologists are familiar with the patterns of volume loss and signal or density changes that are characteristic of various forms of dementia.
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Affiliation(s)
- Harold Keyserling
- Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA
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165
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Abstract
The amyloid beta-protein (Abeta) E22Q mutation of the rare disorder hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) causes severe cerebral amyloid angiopathy (CAA) with hemorrhagic strokes of mid-life onset and dementia. The mutation does not affect total Abeta production but may alter the Abeta1-42:Abeta1-40 ratio, and affect the proteolytic degradation of Abeta and its transport across the blood-brain barrier. Abeta E22Q aggregates faster into more stable amyloid-like fibrils than wild-type Abeta. Non-fibrillar Abeta(x-42) deposits precede the appearance of fibrils and the deposition of Abeta(x-40) in the vascular basement membrane. CAA severity tends to increase with age but may vary greatly among patients of comparable ages. Lumenal narrowing of affected blood vessels, leukoencephalopathy, CAA-associated vasculopathies, and perivascular astrocytosis, microgliosis, and neuritic degeneration complicate the development of HCHWA-D CAA. Parenchymal Abeta deposition is also enhanced in the HCHWA-D brain with non-fibrillar membrane-bound Abeta(x-42) deposits evolving into relatively fibrillar diffuse plaques variously associated with reactive astrocytes, activated microglia, and degenerating neurites. Plaque density tends to decrease with age. Neurofibrillary degeneration is absent or limited. HCHWA-D dementia is associated with CAA severity independently of Braak stage, age, and plaque density. Particularly, microaneurysms may contribute to the development of (small) hemorrhages/infarcts and the latter to cognitive decline in affected subjects. However, the relative importance of cerebral hemorrhages/infarcts, white matter damage and/or other CAA- or Abeta-related factors for cognitive deterioration in HCHWA-D remains to be determined.
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Affiliation(s)
- Marion Maat-Schieman
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
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166
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Abstract
OBJECTIVE The aim of this article is to review the role of immunotherapy in the removal of proteins which accumulate abnormally in neurodegenerative disorders associated with dementia, in particular amyloid-beta accumulation in Alzheimer's disease. RESULTS In both transgenic mouse models and in two trials of amyloid-beta immunotherapy for human Alzheimer's disease, active immunization with amyloid-beta 1-42 results in the removal of amyloid-beta plaques from the cerebral cortex associated with, in the mouse models, improvement in cognitive function. Cerebral amyloid angiopathy and neurofibrillary tangles persist, however, and there is also concern about T lymphocyte immune reactions in the meninges in the human cases. Active immunization schedules are being developed to minimize T lymphocyte reactions and to maximize antibody production and passive immunization protocols are being devised. Immunotherapy for removal of the proteins which accumulate in other neurodegenerative disorders associated with dementia such as prion proteins and alpha-synuclein are in the early stages of development. CONCLUSION Dementias in the elderly are an increasing medical, social and economic problem and current treatments are only effective. In the majority of dementias, proteins accumulate within cells and in the extracellular compartments of the brain. In the most common dementia, Alzheimer's disease, amyloid-beta accumulates as plaques in the extracellular space of the grey matter and in artery walls as cerebral amyloid angiopathy and tau protein accumulates as neurofibrillary tangles within neurons.
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Affiliation(s)
- Delphine Boche
- Division of Clinical Neurosciences, University of Southampton, School of Medicine, Southampton General Hospital, Southampton, SO166YD, UK.
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167
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Abstract
Neuroimaging by CT or MR imaging is necessary for the identification of hemorrhagic stroke and provides information about its cause. The appearance of intracranial hematoma (ICH) on CT and MR imaging evolves over time and must be understood to facilitate accurate diagnosis. The cause of ICH varies by location. New evidence suggests that MR imaging alone may be adequate to identify hemorrhagic stroke in the acute setting, and that MR imaging is superior to CT for identification of chronic microbleeds and hemorrhagic conversion of infarction.
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Affiliation(s)
- Eric E Smith
- Vascular and Critical Care Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.
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168
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Abstract
PURPOSE OF REVIEW The aim of this article is to review the role of immunotherapy in the removal of proteins which accumulate abnormally in neurodegenerative disorders associated with dementia, in particular amyloid-beta accumulation in Alzheimer's disease. RECENT FINDINGS In both transgenic mouse models and in two trials of amyloid-beta immunotherapy for human Alzheimer's disease, active immunization with amyloid-beta 1-42 results in the removal of amyloid-beta plaques from the cerebral cortex associated with, in the mouse models, improvement in cognitive function. Cerebral amyloid angiopathy and neurofibrillary tangles persist, however, and there is also concern about T lymphocyte immune reactions in the meninges in the human cases. Active immunization schedules are being developed to minimize T lymphocyte reactions and to maximize antibody production and passive immunization protocols are being devised. Immunotherapy for removal of the proteins which accumulate in other neurodegenerative disorders associated with dementia such as prion proteins and alpha-synuclein are in the early stages of development. SUMMARY Dementias in the elderly are an increasing medical, social and economic problem and current treatments are only effective. In the majority of dementias, proteins accumulate within cells and in the extracellular compartments of the brain. In the most common dementia, Alzheimer's disease, amyloid-beta accumulates as plaques in the extracellular space of the grey matter and in artery walls as cerebral amyloid angiopathy and tau protein accumulates as neurofibrillary tangles within neurons.
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Affiliation(s)
- Delphine Boche
- Division of Clinical Neurosciences, University of Southampton, School of Medicine, Southampton General Hospital, Southampton, SO16 6YD, UK.
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169
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Katchanov J, Bohner G, Könneker M, Kopp U, Izadpanah K, Larmann E, Klingebiel R, van Landeghem F, Masuhr F, Zschenderlein R. Sporadische zerebrale Amyloidangiopathie mit ischämischer Leukenzephalopathie und Mikroblutungen. DER NERVENARZT 2005; 76:1250-4. [PMID: 15776260 DOI: 10.1007/s00115-005-1884-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We describe a 72-year-old patient with rapidly progressive dementia and a complex focal seizure. Magnetic resonance (MR) imaging revealed leukoencephalopathy with the involvement of the U-fibers as well as cortical and subcortical microbleeds. Brain biopsy confirmed the diagnosis of cerebral Abeta amyloid angiopathy (CAA). The presented case illustrates the significance of CAA as a cause of rapidly progressive dementia and leukoencephalopathy and points out the importance of T2-weighted MR imaging in the evaluation of dementia.
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Affiliation(s)
- J Katchanov
- Klinik für Neurologie, Universitätsmedizin Charité, Berlin.
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Kern R, Kreisel S, Zoubaa S, Szabo K, Gass A, Hennerici M. Cognitive impairment, aphasia, and seizures in a 51-year-old man. Lancet Neurol 2005; 4:445-50. [PMID: 15963448 DOI: 10.1016/s1474-4422(05)70122-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Rolf Kern
- Department of Neurology, Universitätsklinikum Mannheim, Germany.
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Sloan MA. USE OF ANTICOAGULANT AGENTS FOR STROKE PREVENTION. Continuum (Minneap Minn) 2005. [DOI: 10.1212/01.con.0000293709.69205.ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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