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1.  Modification of Multiple Sclerosis Phenotypes by African Ancestry at HLA 
Archives of neurology  2009;66(2):226-233.
Background
In those with multiple sclerosis (MS), African American individuals have a more severe disease course, an older age at onset, and more often have clinical manifestations restricted to the optic nerves and spinal cord (opticospinal MS) than white persons.
Objective
To determine whether genetic variation influences clinical MS patterns.
Design
Retrospective multicenter cohort study.
Participants
Six hundred seventy-three African American and 717 white patients with MS.
Main Outcome Measures
Patients with MS were geno-typed for HLA-DRB1 and HLA-DQB1 alleles. The proportion of European ancestry at HLA was estimated by genotyping single-nucleotide polymorphisms with known significant frequency differences in West African and European populations. These genotypes were correlated with the opticospinal disease phenotype, disability measures, and age at onset.
Results
Subjects with DRB1*15 alleles were twice as likely to have typical MS rather than opticospinal MS (P = .001). Of the subjects with opticospinal MS or a history of recurrent transverse myelitis who were seropositive for anti–aquaporin 4 antibodies (approximately 5%), none carried DRB1*15 alleles (P = .008). Independently of DRB1* 15, African ancestry at HLA correlated with disability as measured by the Multiple Sclerosis Severity Score (P < .001) andriskof cane dependency (hazard ratio, 1.36; P < .001); DRB1*15 alleles were associated with a 2.1-year earlier age at onset (P < .001).
Conclusions
These data indicate that the role of HLA in MS is not limited to disease susceptibility but that genes embedded in this locus also influence clinical outcomes.
doi:10.1001/archneurol.2008.541
PMCID: PMC4334456  PMID: 19204159
2.  A Renaissance for Antisense Oligonucleotide Drugs in Neurology 
Archives of neurology  2009;66(1):32-38.
Antisense oligonucleotides are short nucleic acid sequences designed for use as small-molecule drugs. They recognize and bind to specific messenger RNA (mRNA) or pre-mRNA sequences to create small double-stranded regions of the target mRNA that alter mRNA splicing patterns or inhibit protein translation. Antisense approaches have been actively pursued as a form of molecular medicine for more than 20 years, but only one has been translated to a marketed drug (intraocular human immunodeficiency virus treatment). Two recent advances foreshadow a change in clinical applications of antisense strategies. First is the development of synthetic DNA analogues that show outstanding stability and sequence specificity yet little or no binding to modulator proteins. Second is the publication of impressive preclinical and clinical data using antisense in an exon-skipping strategy to increase dystrophin production in Duchenne muscular dystrophy. As long-standing barriers are successfully circumvented, attention turns toward scale-up of production, long-term toxicity studies, and the challenges to traditional drug regulatory attitudes presented by tightly targeted sequence-specific drugs.
doi:10.1001/archneurol.2008.540
PMCID: PMC4111150  PMID: 19139297
3.  Disparate Diseases Due to Copycat Copy Number Variations 
Archives of neurology  2009;66(9):1158-1159.
doi:10.1001/archneurol.2009.197
PMCID: PMC3903580  PMID: 19752307
4.  Ganglionic Acetylcholine Receptor Autoantibody 
Archives of neurology  2009;66(6):735-741.
Objective
To describe the clinical utility of the nicotinic ganglionic acetylcholine receptor (α3-AChR) autoantibody as a marker of neurological autoimmunity and cancer.
Design
Case-control study.
Setting
Mayo Clinic, Rochester, Minnesota.
Patients
A total of 15 000 patients seen at Mayo Clinic (2005–2007) and evaluated on a service basis for paraneoplastic neurological autoimmunity for whom clinical information was obtained retrospectively by medical record review as well as 457 neurologically asymptomatic patients or control subjects of whom 173 were healthy, 245 had lung cancer, and 39 had systemic lupus erythematosus or Sjögren syndrome.
Outcome Measures
Neurological, oncological, and serological associations of α3-AChR autoantibody seropositivity.
Results
Of 15 000 patients tested on a service basis, 1% were seropositive (median, 0.12 nmol/L; range, 0.03–18.8 nmol/L; normal, ≤0.02 nmol/L), 55% were male, and the median age was 65 years. Cancer was found (new or by history) in 24 of 78 patients evaluated for cancer while at Mayo Clinic (30%); 43% had adenocarcinoma (more patients had breast cancer than prostate, lung, and gastrointestinal cancers; each of the latter groups had about the same number of patients). Of 12 patients with high antibody values (≥1.00 nmol/L), 83% had pandysautonomia. Of 85 patients with medium antibody values (0.10–0.99 nmol/L), neurological presentations were more diverse and included peripheral neuropathies (36%), dysautonomia (20%, usually limited), and encephalopathy (13%). Of 58 patients with low antibody values (0.03–0.09 nmol/L), 54% had a nonautoimmune neurological disorder or no neurological disorder. Of 245 control patients with lung cancer, 7.8% were seropositive. Only 1 of 212 control patients without cancer (0.5%) was seropositive (P<.001).
Conclusion
The detection of α3-AChR autoantibody aids the diagnosis of neurological autoimmunity and cancer.
doi:10.1001/archneurol.2009.78
PMCID: PMC3764484  PMID: 19506133
5.  A Specific ELISA for Measuring Amyloid β-Protein Oligomers in Human Plasma and the Brains of Alzheimer Patients 
Archives of neurology  2009;66(2):190-199.
1. Objective
A new ELISA specific for oligomeric assemblies of amyloid β protein (oAβ) was developed to examine in vivo levels of oAβ vs. monomeric Aβ in sporadic and familial Alzheimer disease (AD) plasma and brain tissue.
2. Design
To establish the oAβ ELISA, the same N-terminal Aβ antibody was used for antigen capture and detection. Plasmas and postmortem brains from AD and control subjects were systematically analyzed by conventional monomeric Aβ and new oAβ ELISAs.
3. Subjects
We measured oAβ species in plasma samples from 36 clinically well-characterized AD patients and 10 controls. In addition, postmortem samples were obtained from brain autopsies of 9 verified AD and 7 control subjects.
4. Results
The specificity of oAβ ELISA was validated with a disulfide crossed-linked, synthetic Aβ1–40Ser26Cys dimer that was specifically detected before but not after the dissociation of the dimers in β-mercaptoethanol. Plasma assays showed that relative oAβ levels were closely associated with relative Aβ42 monomer levels across all subjects. Analysis of sequential plasma samples from a subset of the AD patients, including a patient with AD caused by a presenilin mutation, revealed decreases in both oAβ and Aβ42 monomer levels over a 1–2 year period. In brain tissue from 9 AD and 7 control subjects, both oAβ and monomeric Aβ42 were consistently higher in the AD cases.
6. Conclusions
An oAβ-specific ELISA reveals a tight link between oAβ and Aβ42 monomer levels in plasma and brain, and both forms can decline over time in plasma, presumably reflecting their increasing insolubility in the brain.
doi:10.1001/archneurol.2008.565
PMCID: PMC3618974  PMID: 19204155
6.  Mid- and Late-Life Obesity: Risk of Dementia in the Cardiovascular Health Cognition Study 
Archives of neurology  2009;66(3):336-342.
Objectives
To evaluate associations between mid- and late-life obesity and risk of dementia.
Design
Prospective cohort followed 5.4 years from 1992/4 through 1999.
Setting
Community-dwelling sample in four US sites recruited from Medicare eligibility files.
Participants
2,798 adults without dementia, mean age 74.7 years, 59.1% women, participating in the Cardiovascular Health Cognition Study completing a magnetic resonance image, measured for height and weight at baseline (late-life) and self-reporting weight at age 50 (mid-life). Body mass index (BMI) was calculated at both times.
Main Outcome Measures
Dementia, Alzheimer’s disease (AD) and vascular dementia (VaD) classified by a multidisciplinary committee using standardized criteria.
Results
Classification resulted in 480 persons with incident dementia, 245 with AD (no VaD) and 213 with VaD (with or without AD). In evaluations of mid-life obesity, an increased risk of dementia was found for obese (BMI >30) compared to normal (BMI 20-25) persons adjusted for demographics (HR: 1.39, 95% CI: 1.03-1.87) and for caradiovascularl risk factors (HR: 1.36, 95% CI: 0.94-1.95). The risk estimates reversed in assessments of late-life BMI. Underweight persons (BMI < 20) had an increased risk of dementia (HR: 1.62, 95% CI: 1.02-2.64) while being overweight (BMI 25-30) was not associated (HR: 0.92, 95% CI: 0.72-1.18) and being obese reduced the risk of dementia (HR: 0.63, 95% CI: 0.44-0.91) compared to those with normal BMI.
Conclusions
These results help explain the “obesity paradox” as differences in dementia risk over time are consistent with physical changes in the trajectory toward disability.
doi:10.1001/archneurol.2008.582
PMCID: PMC3513375  PMID: 19273752
7.  Elevated Serum Pesticide Levels and Risk of Parkinson Disease 
Archives of Neurology  2009;66(7):870-875.
Background
Exposure to pesticides has been reported to increase the risk of Parkinson disease (PD), but identification of the specific pesticides is lacking. Three studies have found elevated levels of organochlorine pesticides in postmortem PD brains.
Objective
To determine whether elevated levels of organochlorine pesticides are present in the serum of patients with PD.
Design
Case-control study.
Setting
An academic medical center.
Participants
Fifty patients with PD, 43 controls, and 20 patients with Alzheimer disease.
Main Outcome Measures
Levels of 16 organochlorine pesticides in serum samples.
Results
β-Hexachlorocyclohexane (β-HCH) was more often detectable in patients with PD (76%) compared with controls (40%) and patients with Alzheimer disease (30%). The median level of β-HCH was higher in patients with PD compared with controls and patients with Alzheimer disease. There were no marked differences in detection between controls and patients with PD concerning any of the other 15 organochlorine pesticides. Finally, we observed a significant odds ratio for the presence of β-HCH in serum to predict a diagnosis of PD vs control (odds ratio, 4.39; 95% confidence interval, 1.67–11.6) and PD vs Alzheimer disease (odds ratio, 5.20), which provides further evidence for the apparent association between serum β-HCH and PD.
Conclusions
These data suggest that β-HCH is associated with a diagnosis of PD. Further research is warranted regarding the potential role of β-HCH as a etiologic agent for some cases of PD.
doi:10.1001/archneurol.2009.89
PMCID: PMC3383784  PMID: 19597089
8.  Contribution of vascular risk factors to disease progression in Alzheimer’s Disease 
Archives of neurology  2009;66(3):343-348.
Objective
To determine whether pre-diagnosis vascular risk factors are associated with Alzheimer’s disease progression.
Design
Inception cohort followed longitudinally for a mean of 3.5 (up to 10.2) years.
Setting
Washington Heights Inwood Columbia Aging Project, New York City
Participants
156 incident AD patients (mean age 83 years at diagnosis)
Predictor variables
Vascular factors including medical history (heart disease, stroke, diabetes, hypertension), smoking, and pre-diagnosis blood lipid measurements (total cholesterol, High density lipoproteins (HDL-C), Low density lipoproteins (LDL-C) and triglycerides).
Main Outcome Measure
Change in a composite score of cognitive ability from diagnosis on.
Results
In Generalized Estimating Equation (GEE) models (adjusted for age, race/ethnicity and education), higher cholesterol (total and LDL-C), and diabetes history were associated with faster cognitive decline. Each 10-unit increase in cholesterol and LDL-C was associated with a 10% of a standard deviation decrease in cognitive score per year of follow-up (p<0.001 for total cholesterol, p=0.001 for LDL-C). HDL and triglycerides were not associated with rate of decline. Diabetes history was associated with an additional 50% of a standard deviation decrease in cognitive score per year (p=0.05). History of heart disease and stroke were associated with cognitive decline among APOE-ε4 carriers only. In a final GEE model that included HDL-C, LDL-C and diabetes, only higher LDL-C was independently associated with faster cognitive decline.
Conclusions
Higher pre-diagnosis total cholesterol, LDL-C, and diabetes were associated with faster cognitive decline among incident AD patients, providing further evidence for the role of vascular risk factors in Alzheimer’s disease course.
doi:10.1001/archneur.66.3.343
PMCID: PMC3105324  PMID: 19273753
Alzheimer’s Disease; Natural History; Epidemiology; Cholesterol; Vascular factors
9.  Association of Subdural Hematoma With Increased Mortality in Lobar Intracerebral Hemorrhage 
Archives of neurology  2009;66(1):79-84.
Objective
To determine the prevalence of subdural hematoma (SDH) in patients presenting with primary non-traumatic lobar intracerebral hemorrhage (ICH) and characteristics associated with the presence of SDH.
Design
Retrospective analysis of data collected in a prospective cohort study.
Setting
Hospital.
Patients
Consecutive sample of 200 patients with primary lobar ICH and 75 patients with deep hemispheric ICH.
Main Outcome Measures
Presence of SDH and mortality.
Results
Subdural hematoma was present in 40 of 200 patients (20%) with primary lobar ICH. By contrast, SDH was not present in any of 75 consecutive patients with deep hemispheric ICH (P<.001 for comparison with lobar ICH). Intracerebral hemorrhage volume higher than 60 cm3 was the only independent predictor of SDH (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.14–6.34; P=.02). Subdural hematoma thickness more than 5 mm was an independent predictor of increased 30-day mortality (OR, 7.60; 95% CI, 1.86–30.99; P=.005) after controlling for other factors including ICH volume. Further analysis showed that the effect of SDH on mortality depended on ICH volume, with larger odds for mortality in those with low ICH volume (OR, 12.85; 95% CI, 2.42–68.23; P=.003 for those with ICH volume <30 cm3). Cerebral amyloid angiopathy was present in 8 of 9 patients with pathological specimens.
Conclusions
Nontraumatic SDH frequently accompanies primary lobar ICH and is associated with higher 30-day mortality, particularly when the ICH volume is relatively low. Rupture of an amyloid-laden leptomeningeal vessel, with extravasation into the brain parenchyma and subdural space, may be the pathogenic mechanism.
doi:10.1001/archneur.66.1.79
PMCID: PMC3085991  PMID: 19139303
10.  Mild Cognitive Impairment: Ten Years Later 
Archives of neurology  2009;66(12):1447-1455.
In the past 10 years, there has been a virtual explosion in the literature concerning the construct of mild cognitive impairment. The interest in this topic demonstrates the increasing emphasis on the identification of the earliest features of cognitive disorders such as Alzheimer’s disease and other dementias. Mild cognitive impairment represents the earliest clinical features of these conditions and, hence, has become a focus of clinical, epidemiological, neuroimaging, biomarker, neuropathological, disease mechanism and clinical trials research. This review summarizes the progress that has been made while also recognizing the challenges that remain.
doi:10.1001/archneurol.2009.266
PMCID: PMC3081688  PMID: 20008648
Mild cognitive impairment; Alzheimer’s disease; Imaging; Cognitive decline
11.  PGC-1α Expression Decreases in the Alzheimer Disease Brain as a Function of Dementia 
Archives of neurology  2009;66(3):352-361.
Objectives
To explore mechanisms through which altered peroxisome proliferator–activated receptor γ coactivator 1α (PGC-1α) expression may influence Alzheimer disease (AD) amyloid neuropathology and to test the hypothesis that promotion of PGC-1α expression in neurons might be developed as a novel therapeutic strategy in AD.
Design
Case-control.
Patients
Human postmortem brain (hippocampal formation) samples from AD cases and age-matched non-AD cases.
Results
Using genome-wide complementary DNA microarray analysis, we found that PGC-1α messenger RNA expression was significantly decreased as a function of progression of clinical dementia in the AD brain. Following confirmatory real-time polymerase chain reaction assay, we continued to explore the role of PGC-1α in clinical dementia and found that PGC-1α protein content was negatively associated with both AD-type neuritic plaque pathology and β-amyloid (Aβ)X-42 contents. Moreover, we found that the predicted elevation of amyloidogenic Aβ1-42 and Aβ1-40 peptide accumulation in embryonic cortico-hippocampal neurons derived from Tg2576 AD mice under hyperglycemic conditions (glucose level, 182-273 mg/dL) coincided with a dose-dependent attenuation in PGC-1α expression. Most importantly, we found that the reconstitution of exogenous PGC-1α expression in Tg2576 neurons attenuated the hyperglycemic-mediated β-amyloidogenesis through mechanisms involving the promotion of the “nonamyloidogenic” α-secretase processing of amyloid precursor protein through the attenuation of the forkheadlike transcription factor 1 (FoxO3a) expression.
Conclusion
Therapeutic preservation of neuronal PGC-1α expression promotes the nonamyloidogenic processing of amyloid precursor protein precluding the generation of amyloidogenic Aβ peptides.
doi:10.1001/archneurol.2008.588
PMCID: PMC3052997  PMID: 19273754
12.  Association of Prior Stroke with Cognitive Function and Cognitive Impairment: A Population-based Study 
Archives of neurology  2009;66(5):614-619.
Background
Defining the nature of the contribution of stroke to cognitive impairment remains challenging.
Methods
We randomly selected Olmsted County, MN residents aged 70–89 years on October 1, 2004 and invited eligible non-demented subjects to participate. Participants (n = 2,050) were evaluated with an informant interview, a neurological evaluation, and neuropsychological testing. Neuropsychological testing included 9 tests to assess memory, attention and executive function, visuospatial cognition and language. Subjects were diagnosed by consensus as cognitively normal, MCI (either amnestic (a-) or non-amnestic (na-)), or dementia. A history of stroke was obtained from the subject and confirmed in the medical record. We computed the odds ratios (OR) for a clinical diagnosis of MCI or for scoring in the lowest quartile on each cognitive domain.
Results
There were 1640 cognitively normal and 329 MCI subjects, 241 a-MCI and 88 na-MCI. In fully adjusted models with non-demented subjects only, a history of stroke was associated with a higher odds ratio (OR) of na-MCI (OR= 2.85, 95% CI 1.61 – 5.04) than a-MCI (OR= 1.77, 95% CI 1.14 – 2.74). A history of stroke was also associated with impaired function in each cognitive domain except memory. The association was strongest for attention and executive function (OR=2.48, 95% CI 1.73 – 3.53). APOE e4 genotype was associated only with a-MCI and with impaired memory function.
Conclusions
In this population-based sample of non-demented persons, a history of stroke was particularly associated with na-MCI and with impairment in non-memory cognition. APOE e4 genotype was associated with memory impairment and a-MCI.
doi:10.1001/archneurol.2009.30
PMCID: PMC3050015  PMID: 19433661
13.  Infectious Burden and Risk of Stroke: The Northern Manhattan Study 
Archives of neurology  2009;67(1):33-38.
Background
Common infections may be associated with stroke risk, though no single infection is likely a major independent predictor.
Objective
To determine the association between a composite measure of serologies to common infections (Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, Herpes Simplex Virus 1 and 2) and stroke risk in a prospective cohort study.
Design
Prospective cohort followed longitudinally for median 8 years.
Patients
Randomly selected stroke-free participants from a multiethnic urban community.
Setting
Northern Manhattan Study (NOMAS).
Main Outcome measure
Incident stroke and other vascular events.
Results
All five infectious serologies were available from baseline samples in 1625 participants (mean age 68.5 ± 10.1 years; 64.9% women). Cox proportional hazards models were used to estimate associations of each positive serology with stroke. Individual parameter estimates were then combined into a weighted index of infectious burden (IB) and used to calculate hazard ratios and confidence intervals (HR, 95% CI) for association with risk of stroke and other outcomes, adjusted for risk factors. Each individual infection was positively though not significantly associated with stroke risk after adjusting for other risk factors. The IB index was associated with an increased risk of all strokes (adjusted HR per standard deviation 1.39, 95% CI 1.02–1.90) after adjusting for demographics and risk factors. Results were similar after excluding those with coronary disease (adjusted HR 1.50, 95% CI 1.05–2.13) and adjusting for inflammatory biomarkers.
Conclusion
A quantitative weighted index of infectious burden was associated with risk of first stroke in this cohort. Future studies are needed to confirm these findings and to further define optimal measures of IB as a stroke risk factor.
doi:10.1001/archneurol.2009.271
PMCID: PMC2830860  PMID: 19901154
14.  Urate predicts rate of clinical decline in Parkinson disease 
Archives of neurology  2009;66(12):1460-1468.
Context
The risk of Parkinson disease (PD) and its rate of progression may decline with increasing blood urate, a major antioxidant.
Objective
To determine whether serum and cerebrospinal fluid (CSF) concentrations of urate predict clinical progression in patients with PD.
Design, Setting, and Participants
800 subjects with early PD enrolled in the DATATOP trial. Pre-treatment urate was measured in serum for 774 subjects and in CSF for 713.
Main Outcome Measures
Treatment-, age- and sex-adjusted hazard ratios (HRs) for clinical disability requiring levodopa therapy, the pre-specified primary endpoint.
Results
The HR of progressing to endpoint decreased with increasing serum urate (HR for 1 standard deviation increase = 0.82; 95% CI = 0.73 to 0.93). In analyses stratified by α-tocopherol treatment (2,000 IU/day), a decrease in the HR for the primary endpoint was seen only among subjects not treated with α-tocopherol (HR = 0.75; 95% CI = 0.62 to 0.89, versus those treated HR = 0.90; 95% CI = 0.75 to 1.08). Results were similar for the rate of change in the United Parkinson Disease Rating Scale (UPDRS). CSF urate was also inversely related to both the primary endpoint (HR for highest versus lowest quintile = 0.65; 95% CI: 0.54 to 0.96) and to the rate of change in UPDRS. As with serum urate, these associations were present only among subjects not treated with α-tocopherol.
Conclusion
Higher serum and CSF urate at baseline were associated with slower rates of clinical decline. The findings strengthen the link between urate and PD and the rationale for considering CNS urate elevation as a potential strategy to slow PD progression.
doi:10.1001/archneurol.2009.247
PMCID: PMC2795011  PMID: 19822770
15.  Cognitive decline and brain volume loss are signatures of cerebral Aβ deposition identified with PIB 
Archives of neurology  2009;66(12):1476-1481.
Objective
To examine the relation of amyloid-beta (Aβ) levels in cerebral cortex with structural brain integrity and cognitive performance in older people with a Clinical Dementia Rating (CDR) of 0 (cognitively normal).
Methods
The relations between mean cortical [11C] PIB binding potential values, proportional to the density of fibrillar Aβ binding sites in the brain, concurrent regional brain volumes as assessed by magnetic resonance imaging, and both concurrent and longitudinal (up to 19 years) cognitive performance in multiple domains were examined in 135 CDR 0 individuals aged 65 to 88 years.
Results
Elevated cerebral Aβ levels, in some cases comparable to that seen in individuals with Alzheimer's disease, were observed in 29 CDR 0 individuals. Significantly smaller regional volumes in the hippocampus, temporal neocortex, anterior cingulate, and posterior cingulate were observed in these CDR 0 individuals with elevated Aβ levels. Concurrent cognitive performance was unrelated to Aβ levels but was related to regional brain volumes with the exception of caudate. Longitudinal cognitive decline was associated with elevated Aβ levels and decreased hippocampal volume. Decline was not limited to episodic memory but included working memory and visuospatial abilities as well.
Interpretation
[11C] PIB, an in vivo measure of cerebral amyloidosis, is associated with regionally specific brain atrophy cross-sectionally and a pattern of longitudinal cognitive decline in multiple cognitive domains that occurs prior to the clinical diagnosis of Alzheimer' disease. These findings contribute to the understanding of the cognitive and structural consequences of Aβ levels in CDR 0 older adults.
doi:10.1001/archneurol.2009.272
PMCID: PMC2796577  PMID: 20008651
Cognitive decline; cerebral Aβ; PIB; brain volumetry; preclinical Alzheimer's disease
16.  QUANTITATIVE TEMPLATE FOR SUBTYPING PRIMARY PROGRESSIVE APHASIA 
Archives of neurology  2009;66(12):1545-1551.
Objective
To provide a quantitative algorithm for classifying primary progressive aphasia (PPA) into agrammatic (PPA-G), semantic (PPA-S) and logopenic (PPA-L) variants, each of which is known to have a different probability of association with Alzheimer’s disease (AD) versus frontotemporal lobar degeneration (FTLD).
Design
Prospectively and consecutively enrolled 16 PPA patients tested with neuropsychological instruments and magnetic resonance imaging (MRI).
Setting
University medical center.
Participants
PPA patients recruited nationally in the USA as part of a longitudinal study.
Results
A two-dimensional template, reflecting performance on tests of syntax (Northwestern Anagram Test) and lexical semantics (Peabody Picture Vocabulary Test), classified all 16 patients in concordance with a clinical diagnosis that had been made prior to the administration of the quantitative tests. All three subtypes had distinctly asymmetrical atrophy of the left perisylvian language network. Each subtype also had distinctive peak atrophy sites. Only PPA-G had peak atrophy in the IFG (Broca’s area), only PPA-S had peak atrophy in the anterior temporal lobe, and only PPA-L had peak atrophy in area 37.
Conclusions
Once an accurate root diagnosis of PPA is made, subtyping can be quantitatively guided using a two-dimensional template based on orthogonal tasks of grammatical competence and word comprehension. Although the choice of tasks and precise cut-off levels may evolve in time, this set of 16 patients demonstrates the feasibility of using a simple algorithm for clinico-anatomical classification in PPA. Prospective studies will show whether this suptyping can improve the clinical prediction of underlying neuropathology.
doi:10.1001/archneurol.2009.288
PMCID: PMC2796598  PMID: 20008661
17.  Cellular Mechanisms of CNS Repair by Natural Autoreactive Monoclonal Antibodies 
Archives of neurology  2009;66(12):1456-1459.
Natural autoreactive monoclonal IgMs have demonstrated potential as therapeutic agents for CNS disease. These antibodies bind surface antigens on specific CNS cells activating intracellular repair-promoting signals. IgMs that bind to surface antigens on oligodendrocytes enhanced remyelination in animal models of multiple sclerosis. IgMs that bind to neurons stimulate neurite outgrowth and prevent neuron apoptosis. The neuron-binding IgMs may have utility in CNS axon- or neuron-damaging diseases such as amyotrophic lateral sclerosis, stroke, spinal cord injury or secondary progressive multiple sclerosis. Recombinant remyelination-promoting IgMs have been generated for formal toxicology studies and, after FDA approval, a Phase I clinical trial. Natural autoreactive monoclonal antibodies directed against CNS cells represent novel therapeutic molecules to induce repair of the nervous system.
doi:10.1001/archneurol.2009.262
PMCID: PMC2796600  PMID: 20008649
18.  PIB Imaging Predicts Progression from Cognitively Normal to Symptomatic Alzheimer’s Disease 
Archives of neurology  2009;66(12):1469-1475.
Objective
To determine whether preclinical Alzheimer’s disease (AD), as detected by the amyloid imaging agent Pittsburgh Compound B (PIB) in cognitively normal older adults, is associated with risk of symptomatic AD.
Design
A longitudinal cohort study of cognitively normal older adults assessed with positron emission tomography (PET) to determine the mean cortical binding potential for PIB and followed with annual clinical and cognitive assessments for progression to very mild dementia of the Alzheimer type (DAT).
Setting
Alzheimer’s Disease Research Center
Participants
One hundred and fifty-nine participants with mean age of 71.5 y in a longitudinal study of memory and aging had a PET PIB scan when cognitively normal with Clinical Dementia Rating (CDR) of 0.
Outcome Measure
Progression from CDR 0 status to CDR 0.5 (very mild dementia).
Results
Twenty-three participants progressed to CDR 0.5 at follow-up assessment (range: 1–5 assessments after PET PIB). Of these, 9 also were diagnosed with DAT. Higher MCBP values for PIB (hazard ratio 4.85, 95% CI, 1.22–19.01, p = .02) and age (hazard ratio 1.14, 95% CI 1.02–1.28, p = .03) predicted progression to CDR 0.5 DAT. The CDR 0.5 DAT group showed decline in three cognitive domains (episodic memory, semantic memory, and visuospatial performance) and had volume loss in the parahippocampal gyrus (includes entorhinal cortex) compared with individuals who remained CDR 0.
Conclusions
Preclinical AD, as detected by PET PIB, is not benign as it is associated with progression to symptomatic AD.
doi:10.1001/archneurol.2009.269
PMCID: PMC2798814  PMID: 20008650
19.  Motor phenotype of LRRK2 G2019S carriers in Early Onset Parkinson Disease 
Archives of neurology  2009;66(12):1517-1522.
Objective
To determine the motor phenotype of LRRK2 G2019S mutation carriers
Background
LRRK2 mutation carriers were previously reported to manifest the tremor-dominant (TD) motor phenotype, which has been associated with slower motor progression and less cognitive impairment compared to the postural instability gait difficulty (PIGD) phenotype.
Design
Cross sectional observational study
Setting
13 movement disorders centers
Participants
925 Early Onset Parkinson Disease (EOPD) cases defined as age at onset (AAO) ≤50.
Main Outcome Measures
LRRK2 mutation status and PD motor phenotype: TD or PIGD
Methods
Demographic information, family history of PD (FHPD), and the Unified Parkinson Disease Rating Scale (UPDRS) were collected on all participants. DNA samples were genotyped for LRRK2 mutations (G2019S, I2020T, R1441C and Y1699C). Logistic regression was used to examine associations of G2019S mutation status with motor phenotype adjusting for disease duration, Ashkenazi Jewish (AJ) ancestry, levodopa dose, and FHPD.
Results
34 cases (3.7%) (14 previously reported) were G2019S carriers. No other mutations were found. Carriers were more likely to be AJ (55.9% vs. 11.9% p<0.001), but did not significantly differ in any other demographic or disease characteristics. Carriers had a lower tremor score (p=0.026) and were more likely to have a PIGD phenotype (92.3% vs. 58.9% p=0.003). The association of the G2019S mutation with PIGD phenotype remained after controlling for disease duration and AJ (OR= 17.7, p< 0.001).
Conclusion
EOPD G2019S LRRK2 carriers are more likely to manifest the PIGD phenotype, which may have implications for disease course.
doi:10.1001/archneurol.2009.267
PMCID: PMC2837584  PMID: 20008657
20.  Olfactory Function in Corticobasal Syndrome and Frontotemporal Dementia 
Archives of neurology  2009;66(1):92-96.
Background
Formal olfactory testing may be useful as a bedside tool to help differentiate between conditions such as atypical parkinsonism, dementia, and psychiatric conditions. However, the neural basis of olfactory dysfunction, the effect of concurrent cognitive deficits on olfactory testing results, and the exact prevalence of olfactory deficits in populations with corticobasal syndrome (CBS) and the frontal variant of frontotemporal dementia (FTD-FV) are to date unclear.
Objective
To assess the prevalence and the neural basis of olfactory recognition deficits in patients with a clinical diagnosis of CBS or FTD-FV.
Design
Retrospective study of clinical, neuropsychological, and imaging data.
Setting
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
Participants
Twenty-five patients with CBS, 22 with FTD-FV, and 12 age-matched control subjects.
Main Outcome Measures
Results of neuropsychological evaluation, formal olfactory recognition testing (University of Pennsylvania Smell Identification Test [UPSIT]), and voxel-based morphometry analysis of structural magnetic resonance images of the brain.
Results
Mean UPSIT percentile scores were 31.6% for the CBS group and 9.5% for the FTD-FV group. The voxel-based morphometry correlations between local gray matter and UPSIT scores showed a significant volume effect in the right midfrontal gyrus for the FTD-FV patients and in the right insula, right midfrontal gyrus, and bilateral inferior frontal gyrus for the patients with CBS. A linear regression analysis of the UPSIT scores revealed as significant predictors the general memory score of the Wechsler Memory Scale and the Boston Naming Test total score for the patients with FTD-FV and the Mattis Dementia Rating Scale total score for the patients with CBS.
Conclusions
Our data showed a more severe olfactory impairment for CBS patients than previously reported. We also showed a significant relationship between formal olfactory recognition testing scores and specific cognitive domains. These findings could be useful to clinically differentiate FTD-FV and CBS from other dementing illnesses and movement disorders.
doi:10.1001/archneurol.2008.521
PMCID: PMC2987736  PMID: 19139305
21.  Association of Ideomotor Apraxia With Frontal Gray Matter Volume Loss in Corticobasal Syndrome 
Archives of neurology  2009;66(10):1274-1280.
Objective
To determine the brain areas associated with specific components of ideomotor apraxia (IMA) in corticobasal syndrome (CBS).
Design
Case-control and cross-sectional study.
Participants
Forty-eight patients with CBS and 14 control subjects.
Intervention
Administration of the Test of Oral and Limb Apraxia.
Main Outcome Measures
Differences between patients with CBS and healthy controls and associations between areas of gray matter volume and IMA determined by voxel-based morphometry in patients with CBS.
Results
Overall, IMA was associated with decreased gray matter volume in the left supplemental motor area, pre-motor cortex, and caudate nucleus of patients with CBS. The overall degree of apraxia was independent of the side of motor impairment. Praxis to imitation (vs command) was particularly impaired in the patients with CBS. Patients demonstrated equal impairment in transitive and intransitive praxis.
Conclusions
In patients with CBS, IMA is associated with left posterior frontal cortical and subcortical volume loss. Despite showing left frontal volume loss associated with IMA, patients with CBS have particularly impaired imitation of gestures. These findings suggest either that the IMA of CBS affects a route of praxis that bypasses motor engrams or that motor engrams are affected but that they exist in areas other than the inferior parietal cortex.
doi:10.1001/archneurol.2009.218
PMCID: PMC2981036  PMID: 19822784
22.  Dysfunction of the Default Mode Network in Parkinson Disease 
Archives of neurology  2009;66(7):877-883.
Objective
To examine the integrity of the default mode network in patients with Parkinson disease (PD). Previous functional neuroimaging experiments have studied executive deficits in patients with PD with regard to task-related brain activation. However, recent studies suggest that executive performance also relies on the integrity of the default mode network (ie, medial prefrontal cortex, posterior cingulate cortex, precuneus, and lateral parietal and medial temporal cortices), characterized by a deactivation of these cortical areas during the performance of executive tasks.
Design
We used functional magnetic resonance imaging to investigate cortical deactivations during a card-sorting task (retrieval and manipulation of short-term memory contents) compared with a simple sensory-motor matching task. In addition, a functional connectivity analysis was performed.
Setting
Tertiary outpatient clinic.
Participants
Seven patients with mild to moderate PD (not taking medication) and 7 healthy controls.
Main Outcome Measure
Cortical deactivations.
Results
Both groups showed comparable deactivation of the medial prefrontal cortex but different deactivation in the posterior cingulate cortex and the precuneus. Compared with controls, patients with PD not only showed less deactivation of the posterior cingulate cortex and the precuneus, they even demonstrated a reversed pattern of activation and deactivation. Connectivity analysis yielded that in contrast to healthy individuals, medial prefrontal cortex and the rostral ventromedial caudate nucleus were functionally disconnected in PD.
Conclusions
We describe specific malfunctioning of the default mode network during an executive task in PD. This finding is plausibly linked to dopamine depletion and may critically contribute to the understanding of executive deficits in PD.
doi:10.1001/archneurol.2009.97
PMCID: PMC2972248  PMID: 19597090 CAMSID: cams1533
23.  Lipid Profile Components and Risk of Ischemic Stroke 
Archives of neurology  2009;66(11):1400-1406.
Objective
To explore the relationship between lipid profile components and incident ischemic stroke in a stroke-free prospective cohort.
Design
Population-based prospective cohort study.
Setting
Northern Manhattan, New York.
Patients
Stroke-free community residents.
Intervention
As part of the Northern Manhattan Study, baseline fasting blood samples were collected on stroke-free community residents followed up for a mean of 7.5 years.
Main Outcome Measures
Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals for lipid profile components and ischemic stroke after adjusting for demographic and risk factors. In secondary analyses, we used repeated lipid measures over 5 years from a 10% sample of the population to calculate the change per year of each of the lipid parameters and to impute time-dependent lipid parameters for the full cohort.
Results
After excluding those with a history of myocardial infarction, 2940 participants were available for analysis. Baseline high-density lipoprotein cholesterol, triglyceride, and total cholesterol levels were not associated with risk of ischemic stroke. Low-density lipoprotein cholesterol (LDL-C) and non–high-density lipoprotein cholesterol levels were associated with a paradoxical reduction in risk of stroke. There was an interaction with use of cholesterol-lowering medication on follow-up, such that LDL-C level was only associated with a reduction in stroke risk among those taking medications. An LDL-C level greater than 130 mg/dL as a time-dependent covariate showed an increased risk of ischemic stroke (adjusted hazard ratio, 3.81; 95% confidence interval, 1.53–9.51).
Conclusions
Baseline lipid panel components were not associated with an increased stroke risk in this cohort. Treatment with cholesterol-lowering medications and changes in LDL-C level over time may have attenuated the risk in this population, and lipid measurements at several points may be a better marker of stroke risk.
doi:10.1001/archneurol.2009.210
PMCID: PMC2830863  PMID: 19901173
24.  Association of Muscle Strength with the Risk of Alzheimer’s Disease and the Rate of Cognitive Decline in Community-Dwelling Older Persons 
Archives of neurology  2009;66(11):1339-1344.
Objective
Loss of muscle strength is common and associated with a variety of adverse health outcomes in old age, but few studies have examined the association of muscle strength with the risk of Alzheimer’s disease (AD) or mild cognitive impairment (MCI). We tested the hypothesis that muscle strength is associated with incident AD and MCI.
Design
Prospective, observational cohort study.
Setting
Retirement communities across the Chicago metropolitan area.
Participants
More than 900 community-based older persons without dementia at the baseline evaluation and in whom strength was measured in nine muscle groups in both arms and legs as well as in the axial muscles and summarized into a composite measure of muscle strength.
Main Outcome Measures
Incident AD, MCI and rate of change in global cognitive function.
Results
During a mean follow-up of 3.6 years, 138 persons developed AD. In a proportional hazards model adjusted for age, sex, and education, each 1 unit increase in muscle strength at baseline was associated with about a 43% decrease in the risk of AD (HR, 0.57; 95% CI, 0.41,0.79). The association of muscle strength with AD persisted even after adjustment for several covariates, including body mass index, physical activity, pulmonary function, vascular risk factors, vascular diseases and apolipoprotein E4 status. Further, in a mixed-effects model adjusted for age, sex, education, and baseline level of global cognition, increased muscle strength was associated with a slower rate of decline in global cognitive function (p<0.001). Finally, muscle strength was associated with a decreased risk of MCI, the precursor to AD (HR, 0.67; 95% CI, 0.54, 0.84).
Conclusion
These findings suggest a link between muscle strength, AD and cognitive decline in older persons.
doi:10.1001/archneurol.2009.240
PMCID: PMC2838435  PMID: 19901164
25.  Cellular Prion Protein Mediates the Toxicity of β-Amyloid Oligomers 
Archives of neurology  2009;66(11):1325-1328.
Alzheimer disease (AD) is the most common cause of age-related dementia, affecting more than 25 million people worldwide. The accumulation of insoluble β-amyloid (Aβ) plaques in the brain has long been considered central to the pathogenesis of AD. However, recent evidence suggests that soluble oligomeric assemblies of Aβ may be of greater importance. β-Amyloid oligomers have been found to be potent synaptotoxins, but the mechanism by which they exert their action has remained elusive. Herein, we review the recently published finding that cellular prion protein (PrPc) is a high-affinity receptor for Aβ oligomers, mediating their toxic effects on synaptic plasticity. We further discuss the relationship between AD and PrPc and the potential clinical implications. Cellular prion protein may provide a novel target for therapeutic intervention in AD.
doi:10.1001/archneurol.2009.223
PMCID: PMC2849161  PMID: 19901162

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