Lidia Glodzik-Sobanska

Inflammation and Alzheimer's disease: possible role of periodontal diseases.

The molecular and cellular mechanisms responsible for the etiology and pathogenesis of Alzheimers disease (AD) have not been defined; however, inflammation within the brain is thought to play a pivotal role. Studies suggest that peripheral infection/inflammation might affect the inflammatory state of the central nervous system. Chronic periodontitis is a prevalent peripheral infection that is associated with gram‐negative anaerobic bacteria and the elevation of serum inflammatory markers including C‐reactive protein. Recently, chronic periodontitis has been associated with several systemic diseases including AD. In this article we review the pathogenesis of chronic periodontitis and the role of inflammation in AD. In addition, we propose several potential mechanisms through which chronic periodontitis can possibly contribute to the clinical onset and progression of AD. Because chronic periodontitis is a treatable infection, it might be a readily modifiable risk factor for AD.

Prediction and longitudinal study of CSF biomarkers in mild cognitive impairment

OBJECTIVES To longitudinally evaluate five cerebrospinal fluid (CSF) biomarkers in the transition from mild cognitive impairment (MCI) to Alzheimers disease (AD). METHODS A baseline and 2-year follow-up clinical and CSF study of 86 subjects, including 22 MCI patients that declined to AD (MCI-AD), 43 MCI that did not deteriorate (MCI-MCI) and 21 controls (NL-NL). All subjects were studied for total and phosphorylated tau (T-tau, P-tau(231)), amyloid beta (Abeta) Abeta(42)/Abeta(40) ratio, isoprostane (IP) as well as P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios. RESULTS At baseline and at follow-up MCI-AD showed higher levels P-tau(231), T-tau, IP, P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios and lower Abeta(42)/Abeta(40) than MCI-MCI or NL-NL. Baseline P-tau(231) best predicted MCI-AD (80%, p<0.001) followed in accuracy by P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios (both 75%, ps<0.001), T-tau (74%, p<0.001), Abeta(42)/Abeta(40) (69%, p<0.01), and IP (68%, p<0.01). Only IP showed longitudinal effects (p<0.05). CONCLUSIONS P-tau(231) is the strongest predictor of the decline from MCI to AD. IP levels uniquely show longitudinal progression effects. These results suggest the use of CSF biomarkers in secondary prevention trials.

Hypometabolism and Altered Cerebrospinal Fluid Markers in Normal Apolipoprotein E E4 Carriers with Subjective Memory Complaints

BACKGROUND We examined whether cerebral metabolic rates for glucose (CMRglc) on 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) and cerebrospinal fluid (CSF) markers of Alzheimers disease (AD) are altered in cognitively normal apolipoprotein E (ApoE) E4 carriers with subjective memory complaints (SMC). METHODS Twenty-eight middle-aged normal subjects (NL) were examined, including 13 E4 carriers (E4+; 6 with SMC [SMC+] and 7 without SMC [SMC-]) and 15 noncarriers (E4-; 7 SMC+ and 8 SMC-). Subjects received an FDG-PET scan and a lumbar puncture to measure CSF total (T-Tau) and hyperphosphorylated tau(231) (P-Tau), 40 and 42 amino acid forms of beta-amyloid (Abeta40 and Abeta42), and F(2)-isoprostane (IP). RESULTS As compared with E4-, E4+ subjects showed decreased CMRglc in AD-related brain regions and associated higher CSF IP, P-Tau, T-Tau, and P-Tau/Abeta42 levels (ps < .05). As compared with SMC-, SMC+ subjects showed reduced parietotemporal and parahippocampal gyrus (PHG) CMRglc. A significant ApoE by SMC status interaction was found, with the E4+/SMC+ showing the lowest PHG CMRglc and the highest CSF IP, P-Tau, and P-Tau/Abeta42 levels as compared with all other subgroups (ps < or = .05). The combination of CSF and CMRglc measures significantly improved the accuracy of either measures alone in discriminating ApoE groups (86% accuracy, odds ratio [OR] = 4.1, p < .001) and E4+/SMC+ from all other subgroups (86% accuracy, OR = 3.7, p = .005). Parahippocampal gyrus CMRglc was the most accurate discriminator of SMC groups (75% accuracy, OR = 2.4, p < .001). CONCLUSIONS Normal E4 carriers with SMC show altered AD-related CSF and FDG-PET measures. Longitudinal studies are needed to assess whether these brain abnormalities foreshadow clinical decline.

The pre–mild cognitive impairment, subjective cognitive impairment stage of Alzheimer’s disease

Subjective cognitive impairment (SCI) has been a common, but poorly understood condition, frequently occurring in older persons.

Early detection of Alzheimer's disease using neuroimaging.

Neuroimaging is being increasingly used to complement clinical assessments in the early detection of Alzheimers disease (AD). Structural magnetic resonance imaging (MRI) and metabolic positron emission tomography (FDG-PET) are the most clinically used and promising modalities to detect brain abnormalities in individuals who might be at risk for AD but who have not yet developed symptoms. The knowledge of established risk factors for AD enabled investigators to develop enrichment strategies for longitudinal imaging studies to reduce the sample sizes and study duration. The present review focuses on the results obtained by MRI and FDG-PET studies that examined the preclinical AD stages in several at risk populations: (1) individuals from families with autosomal dominant early-onset AD (FAD), (2) patients with mild cognitive impairment (MCI), particularly in memory, who are at very high risk for declining to AD with an estimated decline rate of 10-30% per year, (3) normal young and middle-age subjects carriers of known susceptibility genes for late-onset AD such as the Apolipoprotein E (ApoE) E4 allele, and (4) as age is the main risk factor for AD, normal elderly individuals followed to the onset of MCI and AD. Overall, these studies show that the use of imaging for the early detection of AD is successful even in the earlier stages of disease when clinical symptoms are not fully expressed and the regional brain damage may be limited.

Subjective Memory Complaints: Presence, Severity and Future Outcome in Normal Older Subjects

Background/Aims: Subjective memory complaint (SMC) in normal individuals may predict future cognitive decline. The goal of this study was to examine whether the probability of decline increases with growing intensity of complaint. Methods: Normal subjects over the age of 50 years were included in a longitudinal retrospective study (mean follow-up time = 8 years). All subjects (n = 230) underwent cognitive and medical examination at baseline. The presence of SMC was determined based on Global Deterioration Scale staging. A subgroup of 83 participants also received baseline assessment for the intensity of SMC. Logistic regression was used to predict outcome from baseline variables. Three outcome groups were established at the final visit: nondeclining, declining and diagnostically unstable (i.e. the diagnosis changed over time: from normal to mild cognitive impairment, then back to normal). Results: The presence of SMC was a predictor of future decline but also increased the likelihood of the unstable diagnosis. Increasing intensity of SMC did not further raise the risk for decline. High intensity of complaints and more pronounced affective symptoms predicted the unstable clinical diagnosis. Conclusions: The presence of SMC contributes to the risk of future decline, however, the increasing intensity of the perceived impairment does not further enhance the risk.

Alzheimer's Disease and Peripheral Infections: The Possible Contribution from Periodontal Infections, Model and Hypothesis

Alzheimers disease (AD) affects approximately 4.5 million people in the U.S. and this number will increase as the population ages and the life-span increases. Therefore, of paramount importance is identifying mechanisms and factors that affect the risk of developing AD. The etiology and pathogenic mechanisms for AD have not been defined, although inflammation within the brain is thought to play a role. Consistent with this hypothesis, studies suggest that peripheral infections contribute to the inflammatory state of the central nervous system. Periodontitis is a prevalent, persistent peripheral infection associated with gram negative, anaerobic bacteria that are capable of exhibiting localized and systemic infections in the host. This review offers a hypothetical link between periodontitis and AD and will present possible mechanistic links between periodontitis related inflammation and AD. It will review the pathogenesis of periodontitis and the mechanisms by which periodontal infections may affect the onset and progression of AD. Since periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD.

The effects of normal aging and ApoE genotype on the levels of CSF biomarkers for Alzheimer's disease.

While cerebrospinal fluid (CSF) biomarkers are of use in the prediction and diagnosis of Alzheimers disease our understanding of the background effects of age and the ApoE genotype is limited. Seventy-eight community-based normal volunteers (mean age 60+/-10 years, range 36-86) were examined to determine the relationships between CSF measures of total tau (T-tau), hyperphosphorylated tau (P-tau 231), amyloid beta (Abeta42/Abeta40 ratio), and isoprostane (IP) with age and ApoE genotype. The results showed that age by epsilon4 genotype interactions were found for P-tau231 (beta=1.82; p<0.05) and IP (beta=1.6; p<0.05). T-tau CSF concentration increased with age. The increasing CSF concentrations of P-tau and IP in epsilon4 carriers suggest that early tauopathy and oxidative stress may be related to the increased risk for AD. The data also suggest that T-tau changes are more age dependent than Abeta changes. The evidence that P-tau231 and IP are the earliest markers for the neuronal damage related to AD awaits longitudinal study.

A2 Alelle of GpIIIa Gene Is a Risk Factor for Stroke Caused by Large-Vessel Disease in Males

Background and Purpose— Glycoprotein IIIa (GpIIIa) is a platelet membrane receptor for fibrinogen and von Willebrand factor. It plays a key role in platelet aggregation. Previous studies in stroke patients, without analysis based on specific subtypes of stroke cause, have not shown any link between GpIIIa A1/A2 polymorphism and stroke risk. We studied the significance of the GpIIIa gene A1/A2 polymorphism in stroke patients with different stroke causes. Methods— We genotyped 92 patients with stroke caused by large-vessel disease (LVD stroke) and 184 matched controls; 103 patients with stroke caused by small-vessel disease (SVD stroke) and 206 controls; and 182 patients with cardioembolic stroke (CE stroke) and 182 controls (TOAST criteria). The GpIIIa A1/A2 polymorphism was analyzed by polymerase chain reaction followed by restriction enzyme digestion and electrophoresis. Results— The genotype distribution of the GpIIIa gene in patients with LVD stroke (A1/A1, 63%; A1/A2, 34.8%; A2/A2, 2.2%) differed significantly from their controls (A1A1, 79.3%; A1/A2, 20.1%; A2/A2, 0.6%). The distribution of the GpIIIa A1/A2 polymorphism in patients with SVD stroke and CE stroke was similar to that of their controls. In contrast to females with LVD stroke, we found that males with LVD stroke presented with an overrepresentation of at least 1 A2 allele of the GpIIIa gene when compared with their controls (39.7% versus 23.0%; P =0.003). Conditional logistic regression analysis showed that possession of at least 1 A2 allele of the GpIIIa gene was an independent risk factor for LVD stroke in males (OR, 2.51; 95% CI, 1.21 to 5.20). Conclusion— A2 allele of the GpIIIa gene is an independent risk factor for LVD stroke in males.

Reduced prefrontal N-acetylaspartate in stroke patients with apathy

BACKGROUND Although substantial numbers of stroke patients suffer from apathy, its causes are still poorly understood. Previous studies suggest that dysfunction of the frontal lobes is implicated in the pathophysiology of motivation. Our aim was to investigate the association between proton magnetic resonance spectroscopy (H1-MRS) measurements in unaffected frontal lobes and apathy in a group of first-time stroke patients. METHODS 31 patients with a first-time ischemic stroke located outside the frontal lobes and 20 healthy subjects were included in the study. The authors performed single voxel H1-MRS in order to measure the N-acetylaspartate/creatine (NAA)/Cr, glutamate+glutamine (Glx)/Cr, choline (Cho)/Cr and myo-inositol (mI)/Cr ratios in the frontal lobes. Patients were assessed between days 7 and 12 post stroke. Diagnosis of apathy was made on the basis of clinical observation, interview and Apathy Scale. RESULTS 13 out of 31 patients (42%) demonstrated apathy. Patients with apathy had lower NAA/Cr ratios in the right frontal lobe than non-apathetic subjects. The patient group was divided into two subgroups: Those with left hemisphere strokes, and those with right hemisphere strokes. Of these subjects, significantly lowered NAA/Cr ratios were found in the right hemispheres of apathetic patients in the subgroup with left-sided brain lesions. CONCLUSIONS These findings point to the association between apathy and frontal lobe integrity, suggest different reactions of the hemispheres and indicate that changes in the NAA/Cr ratio are related to the apathy.