Eduard L. E. M. Bollen

TNF-α promoter polymorphisms, production and susceptibility to multiple sclerosis in different groups of patients

TNF-alpha production in whole blood cultures upon stimulation with LPS was determined in 179 individuals from 61 families in order to characterise the magnitude of inherited differences in TNF-alpha production. The three families characterised by highest TNF production showed 7.1 +/- 0.3 ng TNF/ml upon culture with 10 ng LPS and 10.2 +/- 0.2 ng TNF/ml upon culture with 1000 ng LPS. in contrast to the three families characterised by the lowest TNF production that showed a production of 1.6 +/- 0.1 ng TNF upon culture with 10 ng and 2.5 +/- 0.2 ng/ml upon culture with 1000 ng LPS/ml. This difference could not be attributed to the promoter polymorphisms -308 G to A. -238 G to A or -376 G to A, although the -238 GA donors produced 2.1 +/- 0.9 ng TNF upon culture with 10 ng endotoxin compared to 3.2 +/- 2.2 ng TNF for the -238 GG donors. In line with these results the frequency of the -238 GG genotype was increased in hospitalized MS patients in a nursing home (100% 238GG, n = 57) compared to MS patients in an outpatients clinic (94% 238GG, n = 98) or Dutch controls (90% 238GG, n = 180). These results suggest that the -238 GG genotype is differently distributed in hospitalized MS patients in a nursing home.

Magnetization transfer imaging in normal aging, mild cognitive impairment, and Alzheimer's disease.

The purpose of this study was to assess whether structural brain damage as detected by volumetric magnetization transfer imaging (MTI) is present in mild cognitive impairment (MCI) and Alzheimers disease (AD) and, if so, whether these abnormalities are global in character or restricted to the temporal lobe. Volumetric MTI analysis of the whole brain and temporal and frontal lobes was performed in 25 patients with probable AD, in 13 patients with MCI, and in 28 controls. Magnetization transfer ratio (MTR) histograms were produced, from which we derived measures for structural brain damage and atrophy. The peak heights of the MTR histograms of MCI and AD patients were lower than those of controls for the whole brain and temporal and frontal lobes, reflecting structural brain damage. AD patients had more atrophy than controls in all regions that were studied. MCI patients differed from controls for temporal lobe atrophy only. Volumetric MTI demonstrates structural changes that are related to cognitive decline in large parts of the brain of AD patients. Moreover, structural changes also were observed in MCI patients, indicating that widespread brain damage can be demonstrated before patients are clinically demented.

Pathophysiology of chorea and bradykinesia in Huntington's disease

This article reviews the neurophysiological abnormalities described in Huntingtons disease. Among the typical features of choreic movements are variable and random patterns of electromyographic (EMG) activity, including cocontraction of agonist and antagonist muscles. Studies of premotor potentials show that choreic movements are not preceded by a Bereitschaftspotential, therefore demonstrating that choreic movement is involuntary. Early cortical median‐nerve somatosensory‐evoked potentials have reduced amplitudes and the reduction correlates with reduced glucose consumption in the caudate nucleus. Long‐latency stretch reflexes evoked in the small hand muscles are depressed. These findings may reflect failed thalamocortical relay of sensory information. In Huntingtons disease, the R2 response of the blink reflex has prolonged latencies, diminished amplitudes, and greater habituation than normal. These abnormalities correlate with the severity of chorea in the face. Patients with Huntingtons disease perform simple voluntary movements more slowly than normal subjects and with an abnormal triphasic EMG pattern. Bradykinesia is also present during their performance of simultaneous and sequential movements. Eye movements show abnormalities similar to those seen in arm movements. In Huntingtons disease, arm movement execution is associated with reduced PET activation of cortical frontal areas. Studies using transcranial magnetic stimulation show that patients with Huntingtons disease have normal corticospinal conduction but some patients have a prolonged cortical silent period. Bradykinesia results from degeneration of the basal ganglia output to the supplementary motor areas concerned with the initiation and maintenance of sequential movements. The coexisting hyperkinetic and hypokinetic movement disorders in patients with Huntingtons disease probably reflect the involvement of direct and indirect pathways in the basal ganglia–thalamus–cortical motor circuit.

Memory complaints in patients with normal cognition are associated with smaller hippocampal volumes.

Abstract.We aimed to investigate volumetry of the medial temporal lobe in patients with subjective memory complaints without any cognitive impairment. This study included 20 patients with subjective memory complaints and normal cognitive function and 28 controls without memory complaints. Volumes of the hippocampus and parahippocampal gyrus (PHG) were measured using coronal T1-weighted MR images. Cognitive functions were assessed using the Cambridge Cognitive Examination. Depressive symptoms were assessed using the Geriatric Depression Scale. Differences between groups were analysed using t-tests. Patients with subjective memory complaints had a higher education and more depressive symptoms than controls (p < 0.01). Moreover, they had smaller left hippocampal volumes than controls (p < 0.01). There were no differences between groups in the volume of the right hippocampus or PHG. There was a moderate association between the volume of left hippocampus and left PHG and memory-score (r = 0.32, p = 0.03; r = 0.34, p = 0.02). We concluded that memory complaints in patients without any cognitive impairment were associated with smaller left hippocampal volumes and more depressive symptoms. These preliminary results suggest that memory complaints may reflect minimal brain deficits associated with impending dementia, depression or a combination of both disorders.

Testing cognitive function in elderly populations: the PROSPER study

Objectives: For large scale follow up studies with non-demented patients in which cognition is an endpoint, there is a need for short, inexpensive, sensitive, and reliable neuropsychological tests that are suitable for repeated measurements. The commonly used Mini-Mental-State-Examination fulfils only the first two requirements. Methods: In the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5804 elderly subjects aged 70 to 82 years were examined using a learning test (memory), a coding test (general speed), and a short version of the Stroop test (attention). Data presented here were collected at dual baseline, before randomisation for active treatment. Results: The tests proved to be reliable (with test/retest reliabilities ranging from acceptable (r=0.63) to high (r=0.88) and sensitive to detect small differences in subjects from different age categories. All tests showed significant practice effects: performance increased from the first measurement to the first follow up after two weeks. Conclusion: Normative data are provided that can be used for one time neuropsychological testing as well as for assessing individual and group change. Methods for analysing cognitive change are proposed.

A prospective analysis of elevated fasting glucose levels and cognitive function in older people: Results from PROSPER and the Rotterdam Study

OBJECTIVE To investigate the relationship between fasting glucose levels, insulin resistance, and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated fasting glucose levels and insulin resistance in nondiabetic individuals, and the risk of cognitive impairment is unclear. RESEARCH DESIGN AND METHODS We analyzed data from, in total, 8,447 participants in two independent prospective studies: the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5,019 participants, aged 69–84 years, and the Rotterdam Study, 3,428 participants, aged 61–97 years. Fasting glucose levels were assessed at baseline in both studies; fasting insulin levels were assessed in the Rotterdam Study only. Cognitive function was assessed in both studies at baseline and during follow-up. RESULTS Subjects with diabetes had impaired cognitive function at baseline. In contrast, in people without a history of diabetes, there was no clear association between baseline fasting glucose levels and executive function and memory, nor was there a consistent relationship between elevated baseline fasting glucose levels and the rate of cognitive decline in either cohort. Insulin resistance (homeostasis model assessment index) was also unrelated to cognitive function and decline. CONCLUSIONS Elevated fasting glucose levels and insulin resistance are not associated with worse cognitive function in older people without a history of diabetes. These data suggest either that there is a threshold for effects of dysglycemia on cognitive function or that factors other than hyperglycemia contribute to cognitive impairment in individuals with frank diabetes.

Genetic variation in the interleukin-10 gene promoter and risk of coronary and cerebrovascular events: the PROSPER study.

Abstract:  Proinflammatory cytokines, like interleukin‐6 (IL‐6) and tumor necrosis factor‐alpha (TNF‐α), are implicated in the development of atherosclerosis. The role of anti‐inflammatory cytokines, like IL‐10, is largely unknown. We investigated the association of four single nucleotide polymorphisms (SNPs) in the promoter region of the IL‐10 gene (4259AG, −1082GA, −592CA, and −2849GA), with coronary and cerebrovascular disease in participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) trial. All associations were assessed with Cox proportional hazards models adjusted for sex, age, pravastatin use, and country. Haplotype analysis of the four SNPs showed a significant association between haplotype 4 (containing the −592A variant allele) and risk of coronary events (P= 0.019). Moreover, analysis of separate SNPs found a significant association between −2849AA carriers with incident stroke (HR (95%CI) 1.50 (1.04–2.17), P value = 0.02). Our study suggests that not only proinflammatory processes contribute to atherosclerosis, but that also anti‐inflammatory cytokines may play an important role.

Innate production of interleukin‐10 and tumor necrosis factor affects the risk of multiple sclerosis

Multiple sclerosis (MS) typically presents with a relapsing‐remitting onset. This can be distinguished from primary progressive MS. Typical MS is characterized by a profound inflammatory reaction in which anti‐inflammatory cytokine interleukin‐10 (IL‐10) and pro‐inflammatory cytokine tumor necrosis factor (TNF) may play a pivotal role. We tested the hypothesis that patients with MS have a distinct innate cytokine production that contributes to the susceptibility for and outcome of MS. The innate cytokine production of patients was estimated as the average production of cytokines in lipopolysaccharide ‐stimulated whole‐blood cultures of 2 to 5 first‐degree healthy family members. A total of 126 family members of 50 patients with typical MS, 61 family members of 25 patients with primary progressive MS, and 129 control subjects of 54 families were enrolled in this study. We found that members of families with low IL‐10 and high TNF production had a fourfold increased risk of developing typical MS compared with members of families with high IL‐10 and low TNF production. Patients with MS were eightfold more likely to develop typical MS than primary progressive MS when they belonged to families with low IL‐10 and high TNF production. The presence of human leukocyte antigen–DR2 was associated with MS but not with TNF production. This study shows that typical MS is associated with an innate pro‐inflammatory cytokine profile in contrast to primary progressive MS. Ann Neurol 2000;48:641–646

Neuropsychiatric manifestations in patients with systemic lupus erythematosus: epidemiology and radiology pointing to an immune-mediated cause

Background Different pathogenetic pathways have been proposed for neuropsychiatric (NP) manifestations in systemic lupus erythematosus (SLE). Objective To describe the patient characteristics of a large cohort of patients with SLE with NP manifestations (NPSLE) in a single centre and to review whether these and other data are compatible with immune-mediated mechanisms. Methods A total of 212 patients were identified from MRI scans of the brain ordered for suspected NPSLE. Data were collected from the medical records. NP syndromes were classified according to the American College of Rheumatology (ACR) nomenclature and case definitions. Results 155 patients fulfilled the criteria for SLE. In 102 patients NP manifestations were attributed to SLE itself (primary NPSLE) whereas, in the remaining patients, the NP symptoms were due to other causes. The median age at the time of SLE diagnosis in patients with primary NPSLE was 27.5 years and the median duration prior to NPSLE was 2.8 years. Forty patients (39%) had a NP manifestation in the first year of the disease. Cerebrovascular disease, cognitive dysfunction, seizures and headache were the most prevalent syndromes. In 47% of patients with primary NPSLE the MRI scan of the brain showed no abnormalities. Conclusions Most NP manifestations in SLE occur early in the disease. This finding, as well as data from quantitative imaging studies and recent pathological studies, point to an immune-mediated pathogenesis.

MMSE scores correlate with local ventricular enlargement in the spectrum from cognitively normal to Alzheimer disease

In this work, we aimed at correlating focal atrophy in periventricular structures with cognitive function, in the spectrum from healthy subjects to severe Alzheimer disease: 28 subjects with normal cognition and 84 patients presenting various degrees of cognitive impairment were included in the study. The cognitive level of each subject was assessed with the Mini-Mental State Examination (MMSE). Atrophy in periventricular structures was inferred by modeling and analyzing local shape variations of brain ventricles: for a given subject, we distinguished between the severity of atrophy, estimated as local enlargement (in mm) of the ventricular surface relative to an average normal subject, and the extent of atrophy, defined as the percentage of the ventricular surface (global or per anatomical region) significantly different from an average control. Linear regression across subjects was performed to evaluate the correlation between atrophy and MMSE score. The severity of atrophy showed good correlation with MMSE score in the left thalamus, the left temporal horn, the left corona radiata, and the right caudate nuclei. The extent of atrophy showed no significant correlations. In conclusion, the MMSE scores correlate with localized depth of atrophy in well-defined periventricular structures.