Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum

IMPORTANCE

One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.

OBJECTIVE

To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.

EXPOSURES

Alzheimer disease biomarkers detected on PET or in CSF.

MAIN OUTCOMES AND MEASURES

Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.

RESULTS

Among the 19 097 participants (mean [SD] age, 69.1 [9.8] years; 10 148 women [53.1%]) included, 10 139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P = .04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P = .004), subjective cognitive decline (9%; 95% CI, 3%-15%; P = .005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P = .004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P = .18).

CONCLUSIONS AND RELEVANCE

This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.

Cerebrospinal fluid GAP-43 in early multiple sclerosis

Background/Objective

Novel biomarkers identifying and predicting disease activity in multiple sclerosis (MS) would be valuable for primary diagnosis and as outcome measures for monitoring therapeutic effects in clinical trials. Axonal loss is present from the earliest stages of MS and correlates with disability measures. Growth-associated protein 43 (GAP-43) is a presynaptic protein with induced expression during axonal growth. We hypothesized this protein could serve as a biomarker of axonal regeneration capacity in MS.

Methods

We developed a novel GAP-43 enzyme-linked immunosorbent assay for quantification in cerebrospinal fluid (CSF) and measured GAP-43 levels in 71 patients with clinically isolated syndrome, 139 MS patients and 51 controls.

Results

GAP-43 concentrations were similar in patients and controls. Nevertheless, GAP-43 levels were higher in patients with >10 T2-magnetic resonance imaging (MRI) lesions (p = 0.005). CSF GAP-43 concentrations correlated with CSF mononuclear cell counts (p = 0.031) and were inversely correlated with patient age (p = 0.038) with a trend for higher CSF GAP-43 concentrations in patients with gadolinium-enhancing MRI lesions and positive CSF oligoclonal immunoglobulin G status.

Conclusion

Our results suggest that axonal regeneration capacity is relatively preserved in early MS. CSF GAP-43 concentration is positively associated with markers of inflammation, suggesting possible inflammatory-driven expression of this growth-associated protein in early MS.

Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia

IMPORTANCE

Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.

OBJECTIVE

To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.

MAIN OUTCOMES AND MEASURES

Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.

RESULTS

Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P = .16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P < .001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P < .001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.

CONCLUSIONS AND RELEVANCE

Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.

Interferon beta preparations for the treatment of multiple sclerosis patients differ in neutralizing antibody seroprevalence and immunogenicity

Development of neutralizing antibodies (NAbs) reduces the clinical efficacy of interferon beta (IFNβ) treatment in multiple sclerosis (MS) patients. The aim of this study was to evaluate NAb seroprevalence (frequency of patients with NAbs) and immunogenicity (titer levels) of IFNβ preparations in a clinical setting. We analysed 1115 consecutive MS patients, treated with one of the three available IFNβ preparations, for an average of 40 months (1 – 120 months), for the presence of NAbs with the MxA protein induction assay. Overall, 32% of patients were positive for NAbs with neutralizing titers above 10. The frequency of NAbs, ie, the seroprevalence, was 13% in Avonex-treated patients, 43% for Betaferon, 39% for Rebif22 and 30% for Rebif44. In addition, the potential to induce high titer levels, ie, the immunogenicity, was observed to differ between preparations. Avonex, showing the lowest seroprevalence, also showed low immunogenicity and typically induced low titers. Betaferon, showing the highest seroprevalence when inducing NAbs, induced lower titers compared to Rebif22 and Rebif44. Treatment duration over five years only marginally correlated with decreased seroprevalence and titer levels.

In conclusion, NAbs to IFNβ are common in a clinical setting and the IFNβ preparations differ not only in NAb seroprevalence, but also in immunogenicity. Multiple Sclerosis 2007; 13: 208–214. http://msj.sagepub.com

Comparison of Different Matrices as Potential Quality Control Samples for Neurochemical Dementia Diagnostics

BACKGROUND

Assay-vendor independent quality control (QC) samples for neurochemical dementia diagnostics (NDD) biomarkers are so far commercially unavailable. This requires that NDD laboratories prepare their own QC samples, for example by pooling leftover cerebrospinal fluid (CSF) samples.

OBJECTIVE

To prepare and test alternative matrices for QC samples that could facilitate intra- and inter-laboratory QC of the NDD biomarkers.

METHODS

Three matrices were validated in this study: (A) human pooled CSF, (B) Aβ peptides spiked into human prediluted plasma, and (C) Aβ peptides spiked into solution of bovine serum albumin in phosphate-buffered saline. All matrices were tested also after supplementation with an antibacterial agent (sodium azide). We analyzed short- and long-term stability of the biomarkers with ELISA and chemiluminescence (Fujirebio Europe, MSD, IBL International), and performed an inter-laboratory variability study.

RESULTS

NDD biomarkers turned out to be stable in almost all samples stored at the tested conditions for up to 14 days as well as in samples stored deep-frozen (at - 80°C) for up to one year. Sodium azide did not influence biomarker stability. Inter-center variability of the samples sent at room temperature (pooled CSF, freeze-dried CSF, and four artificial matrices) was comparable to the results obtained on deep-frozen samples in other large-scale projects.

CONCLUSION

Our results suggest that it is possible to replace self-made, CSF-based QC samples with large-scale volumes of QC materials prepared with artificial peptides and matrices. This would greatly facilitate intra- and inter-laboratory QC schedules for NDD measurements.

Step initiation interferes with working memory in nondisabled patients with the earliest multiple sclerosis-A dual-task study

Balance and cognition are affected by multiple sclerosis (MS). Cognitive-motor interference (CMI) is important for balance impairment in MS, however little is known about CMI at the earliest stages of the disease. Step initiation (SI) with anticipatory postural adjustments (APAs) has been linked to postural instability and falls in subjects with MS, therefore we aimed to assess CMI between SI and the two storage systems of working memory in patients with clinically isolated syndrome (presented as optic neuritis-ON) suggestive of MS. Twenty patients with normal/near normal visual acuity and 20 age-, weight-, height-, sex- and education-matched control subjects were included. APAs were studied using center of pressure measures in three conditions: SI alone, SI+Brooks' spatial- and SI+2-back verbal working memory task. Decrements (% change) in performance on cognitive tasks and in APA parameters were calculated. CMI was assessed combining the two decrements scores. Performance on both cognitive tasks was more affected by dual-tasking in patients compared to healthy subjects. In both groups APA parameters were not influenced by dual-tasking. CMI was higher in patients compared to healthy subjects. Our results suggest that the disease affects CMI in its earliest stages. Since both cognitive tasks were similarly affected by dual-tasking in patients and controls central executive seems to play the major role in CMI between SI and working memory. Patients prioritizing motor over cognitive task for balance maintenance suggests reduced divided attention capacity as a cause of increased CMI in the earliest MS.

The Central Biobank and Virtual Biobank of BIOMARKAPD: A Resource for Studies on Neurodegenerative Diseases

Biobanks are important resources for biomarker discovery and assay development. Biomarkers for Alzheimer’s and Parkinson’s disease (BIOMARKAPD) is a European multicenter study, funded by the EU Joint Programme-Neurodegenerative Disease Research, which aims to improve the clinical use of body fluid markers for the diagnosis and prognosis of Alzheimer’s disease (AD) and Parkinson’s disease (PD). The objective was to standardize the assessment of existing assays and to validate novel fluid biomarkers for AD and PD. To support the validation of novel biomarkers and assays, a central and a virtual biobank for body fluids and associated data from subjects with neurodegenerative diseases have been established. In the central biobank, cerebrospinal fluid (CSF) and blood samples were collected according to the BIOMARKAPD standardized pre-analytical procedures and stored at Integrated BioBank of Luxembourg. The virtual biobank provides an overview of available CSF, plasma, serum, and DNA samples at each site. Currently, at the central biobank of BIOMARKAPD samples are available from over 400 subjects with normal cognition, mild cognitive impairment (MCI), AD, frontotemporal dementia (FTD), vascular dementia, multiple system atrophy, progressive supranuclear palsy, PD, PD with dementia, and dementia with Lewy bodies. The virtual biobank contains information on over 8,600 subjects with varying diagnoses from 21 local biobanks. A website has been launched to enable sample requests from the central biobank and virtual biobank.

Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis

IMPORTANCE

Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies.

OBJECTIVE

To use individual participant data meta-analysis to estimate the prevalence of amyloid pathology as measured with biomarkers in participants with normal cognition, subjective cognitive impairment (SCI), or mild cognitive impairment (MCI).

DATA SOURCES

Relevant biomarker studies identified by searching studies published before April 2015 using the MEDLINE and Web of Science databases and through personal communication with investigators.

STUDY SELECTION

Studies were included if they provided individual participant data for participants without dementia and used an a priori defined cutoff for amyloid positivity.

DATA EXTRACTION AND SYNTHESIS

Individual records were provided for 2914 participants with normal cognition, 697 with SCI, and 3972 with MCI aged 18 to 100 years from 55 studies.

MAIN OUTCOMES AND MEASURES

Prevalence of amyloid pathology on positron emission tomography or in cerebrospinal fluid according to AD risk factors (age, apolipoprotein E [APOE] genotype, sex, and education) estimated by generalized estimating equations.

RESULTS

The prevalence of amyloid pathology increased from age 50 to 90 years from 10% (95% CI, 8%-13%) to 44% (95% CI, 37%-51%) among participants with normal cognition; from 12% (95% CI, 8%-18%) to 43% (95% CI, 32%-55%) among patients with SCI; and from 27% (95% CI, 23%-32%) to 71% (95% CI, 66%-76%) among patients with MCI. APOE-ε4 carriers had 2 to 3 times higher prevalence estimates than noncarriers. The age at which 15% of the participants with normal cognition were amyloid positive was approximately 40 years for APOE ε4ε4 carriers, 50 years for ε2ε4 carriers, 55 years for ε3ε4 carriers, 65 years for ε3ε3 carriers, and 95 years for ε2ε3 carriers. Amyloid positivity was more common in highly educated participants but not associated with sex or biomarker modality.

CONCLUSIONS AND RELEVANCE

Among persons without dementia, the prevalence of cerebral amyloid pathology as determined by positron emission tomography or cerebrospinal fluid findings was associated with age, APOE genotype, and presence of cognitive impairment. These findings suggest a 20- to 30-year interval between first development of amyloid positivity and onset of dementia.

Validation of a quantitative cerebrospinal fluid alpha-synuclein assay in a European-wide interlaboratory study

Decreased levels of alpha-synuclein (aSyn) in cerebrospinal fluid (CSF) in Parkinson's disease and related synucleinopathies have been reported, however, not consistently in all cross-sectional studies. To test the performance of one recently released human-specific enzyme-linked immunosorbent assay (ELISA) for the quantification of aSyn in CSF, we carried out a round robin trial with 18 participating laboratories trained in CSF ELISA analyses within the BIOMARKAPD project in the EU Joint Program - Neurodegenerative Disease Research. CSF samples (homogeneous aliquots from pools) and ELISA kits (one lot) were provided centrally and data reported back to one laboratory for data analysis. Our study showed that although factors such as preanalytical sample handling and lot-to-lot variability were minimized by our study design, we identified high variation in absolute values of CSF aSyn even when the same samples and same lots of assays were applied. We further demonstrate that although absolute concentrations differ between laboratories the quantitative results are comparable. With further standardization this assay may become an attractive tool for comparing aSyn measurements in diverse settings. Recommendations for further validation experiments and improvement of the interlaboratory results obtained are given.

Pulmonary arterial hypertension associated with interferon beta treatment for multiple sclerosis: a case report

A 23-year-old woman with multiple sclerosis developed respiratory symptoms 3 years after introduction of interferon beta-1b. The diagnosis of pulmonary arterial hypertension (PAH) was established. The patient partially responded to sildenafil and bosetan treatment. This is the first report of PAH, associated with interferon beta therapy. As shown in experimental models, interferon treatment can induce PAH by stimulation of thromboxane cascade and secretion of various inflammatory mediators.

Impression of Clinical Worsening Fails to Predict Interferon-β Neutralizing Antibody Status

The development of neutralizing antibodies (NAbs) against interferon-β (IFNβ) reduces clinical efficacy and markers of bioactivity in patients with multiple sclerosis (MS), although it has also been shown that a poor response to IFNβ coincided with unexpectedly low NAb levels. To try and resolve this incoherency, this study investigated 2822 patients referred to a NAb testing facility. The reason for NAb testing was indicated for 2506 patients: routine testing (76%), worsening of disease (14%) and other reasons (10%). Overall, 31% of patients were NAb positive and 17% had titres high enough to obliterate IFNβ bioactivity. The frequency of NAbs was similar in patients in the routine testing group compared with the worsening group. Samples showing high titres failed to be associated with worsening of symptoms. The study failed to show low NAb levels in patients responding poorly to IFNβ. It is concluded that it is not possible to predict NAb status by clinical impression of treatment response. This is likely to be an effect of the partial efficacy of IFNβ. Thus routine testing for NAbs must be carried out in order to identify NAb status in patients with MS.

Ian McEwan--novels about neurological and psychiatric patients

Ian McEwan, a respected contemporary British writer, sometimes uses neurological and psychiatric patients as main characters of his stories. In his recent novels one can find beautiful descriptions of patients with Huntington's disease, variant Creutzfeldt-Jakob disease, de Clerambault syndrome and also details about some neurosurgical procedures.

Clinical, magnetic resonance imaging, cerebrospinal fluid and electrophysiological characteristics of the earliest multiple sclerosis

OBJECTIVES

The vast majority of clinically isolated syndrome (CIS) patients with at least two silent brain MRI lesions progress to multiple sclerosis (MS) as early as after 2 years meaning that they actually have MS, the earliest MS. Effective therapy with interferon beta preparations in patients with the earliest MS demands early and accurate diagnosis of the disease.

PATIENTS AND METHODS

In order to find the differentiating clinical and paraclinical characteristics of patients with the earliest MS we compared clinical, MRI, CSF and evoked potential findings in patients with the earliest MS and patients with relapsing-remitting (RR) MS. Retrospective analysis included 149 patients (103 women), among them 40 patients with the earliest MS and 95 patients with RR MS.

RESULTS

Patients with the earliest MS had more often predominant afferent symptoms (p=0.023) but less often predominant cerebellar (p=0.033) and efferent symptoms (p=0.012) than patients with RR MS. They were less likely to fulfill the Barkhof brain MRI criteria (p=0.050) and had less often prolonged latencies of visual evoked potentials (VEP) (p=0.006) than patients with RR MS. On the other hand they were more likely to have elevated CSF cells (p=0.010) than patients with RR MS and had as often present CSF oligoclonal bands (p=0.112).

CONCLUSION

The differentiating characteristics of patients with the earliest MS are predominance of afferent symptoms, less brain MRI dissemination and more frequently normal VEP, but on the other hand abnormal CSF findings with elevated CSF cells and positive oligoclonal bands.

Evidence of hypercoagulability and inflammation in young patients long after acute cerebral ischaemia

INTRODUCTION

Young subjects with acute cerebral ischaemia - stroke or transient ischaemic attack - form an etiologically heterogeneous and often not clearly explained group of patients. The aim was to investigate possible disturbances in haemostasis and inflammation long after an acute cerebral ischaemic event.

MATERIALS AND METHODS

Forty-four consecutive patients referred after having suffered from acute cerebral ischaemia before the age of 45 participated 1 to 9 years (median value 5 years) after the event. At the time of blood sampling 33 (75%) patients were receiving antithrombotic treatment. Forty-six apparently healthy subjects of the same age group served as controls. In all subjects global haemostasis parameters (overall haemostasis, coagulation and fibrinolytic potential), thrombophilia, several markers of haemostasis activation and inflammation were determined.

RESULTS

Patients did not differ from controls in most of the conventional risk factors and the presence of most forms of thrombophilia, although in seven (17.5%) patients the weak presence of lupus anticoagulants was observed. Patients had significantly increased overall haemostasis and coagulation potential, increased soluble P-selectin and D-dimer, decreased overall fibrinolysis potential and increased fibrinogen and C-reactive protein compared to controls. The subgroups of patients receiving antiplatelet treatment, with thrombophilia and recurrent acute cerebral ischaemia, did not differ significantly from the other patients.

CONCLUSIONS

In young patients long after acute cerebral ischaemia an imbalance in the haemostatic system and a minor, but significant degree of inflammation was detected. The mechanisms behind haemostatic imbalance seem to be enhanced thrombin generation, platelet activation and depressed fibrinolysis.

The thymus is a source of B-cell-survival factors-APRIL and BAFF-in myasthenia gravis

The accumulation of B cells in the thymus is a common feature of myasthenia gravis (MG). To understand whether factors enhancing B-cell survival are increased in MG, we studied the expression of APRIL, BAFF and three of their receptors in the thymus. In hyperplastic thymi, macrophages expressed APRIL and BAFF, and germinal-center B cells, BAFF-R. CD138-positive plasma cells were abundant in MG thymi. By contrast, BCMA-positive plasma cells were scarce. The expression of APRIL and BAFF in MG thymi may reflect the establishment of an environment favorable to B-cell survival.

Clinical, MRI, CSF and electrophysiological findings in different stages of multiple sclerosis

Effective therapy in the earliest stages of multiple sclerosis (MS) demands early correct diagnosis. Retrospective analysis included 130 patients (90 women) with a median age of 35.5 years, median duration of the disease of 2 years and median EDSS score of 3.0. Twenty-seven patients had clinically isolated syndrome (CIS) suggestive of MS, 66 relapsing-remitting (RR) MS, 19 secondary progressive (SP) MS and 18 primary progressive (PP) MS. The predominant symptoms were sensory in 52% of the patients with CIS compared to 27% in patients with RRMS, whereas they were more often motor in patients with PPMS. Patients with CIS had higher CSF cell counts than patients diagnosed in later stages of the disease and oligoclonal bands were found in 89% of all patients without statistically significant differences between the subgroups. Prolonged latencies of visual evoked potentials (VEP) were found in only 29% of patients with CIS compared to 66% in RRMS, 75% in SPMS and 65% of PPMS patients. Fifty-six percent of patients with CIS, 88% with RRMS, 74% with SPMS and 78% of patients with PPMS fulfilled modified the Barkhof et al. MRI criteria at the time of diagnosis. Patients in early MS often present with sensory symptoms. Brain MRI can be inconclusive in over 40% of patients with CIS but the elevated CSF cell count and positive oligoclonal bands are helpful in establishing the diagnosis of CIS suggestive of MS. In later stages of the disease the combination of clinical features, MRI, prolonged VEP latencies and positive CSF oligoclonal bands secures the correct diagnosis.

Increased levels of APRIL (a proliferation-inducing ligand) mRNA in multiple sclerosis

B cells play an indispensable, yet indeterminate, role in the pathogenesis of multiple sclerosis (MS). We measured mRNA of APRIL-a promotor of B-cell survival-in peripheral blood and quantified protein levels in plasma and cerebrospinal fluid in MS patients and controls. APRIL mRNA levels in monocytes and T cells were significantly higher in MS patients than in controls. Levels of soluble APRIL in plasma were higher in patients with chronic progressive MS than in patients with relapsing-remitting MS, albeit not significantly. MS may thus be associated with increased transcription in peripheral blood of factors promoting B-cell survival, including APRIL.

Multiple sclerosis with uncommon cerebrospinal fluid findings

AIM

To determine the frequency and clinical and laboratory features of patients with multiple sclerosis characterized by uncommon cerebrospinal findings, ie, negative oligoclonal band or increased number of mononuclear cells in cerebrospinal fluid.

METHODS

The retrospective analysis included medical records of 233 patients (158 women and 75 men) admitted to the Department of Neurology, Ljubljana Medical Center, between January 1, 1990, and December 31, 1999 and discharged with the diagnosis of multiple sclerosis. We determined clinical features and cerebrospinal fluid parameters of patients with oligoclonal band-negative multiple sclerosis and > or =15 mononuclear cells/mm( 3) in cerebrospinal fluid and compared them with patients with oligoclonal band-positive multiple sclerosis and expected number of mononuclear cells in cerebrospinal fluid, respectively. There were 26 patients with oligoclonal band-negative finding and 26 with > or =15 mononuclear cells/mm(3) in cerebrospinal fluid. The two groups of patients did not overlap, except for one patient, who had 19 mononuclear cells/mm(3) and was oligoclonal band-negative.

RESULTS

The diagnosis was delayed in oligoclonal band-negative multiple sclerosis patients, their cerebrospinal fluid contained less leukocytes, and lower concentration of IgG. The patients with > or =15 leukocytes/mm( 3) in cerebrospinal fluid were diagnosed earlier and had increased cerebrospinal fluid protein and IgG concentrations.

CONCLUSION

Multiple sclerosis with negative oligoclonal band or increased count of leukocytes in cerebrospinal fluid were found in approximately 10% of patients with the disease. Because of the absence of oligoclonal band and less active cerebrospinal fluid, the diagnosis in these patients may be delayed.

The current availability of neurological in-patient services in post-communist central and eastern European countries

BACKGROUND AND PURPOSE

Limited information can be obtained as to the availability of neurological in-patient services in the former communist countries of Eastern and Central Europe. The objective was to analyse data received directly from representatives of the particular countries.

METHODS

The data were collected under the auspices of the 'First European Cooperation Neurology Workshop' held in April 2000, in Trest, Czech Republic. Neurologists from 15 post-communist countries provided information from their respective countries. Linear trends in graphs including the reliability value R(2) were used in the analysis of correlations.

RESULTS

Data from 14 countries were assembled and trends were analysed.

CONCLUSIONS

Direct relationships were found between: (1) the average department size and the average catchment area (R(2) = 0.1015); (2) the percentage of districts with a neurological in-patient department and the gross national product (GNP) per capita (R(2) = 0.1359); (3) the average neurological department size and the GNP per capita (R(2) = 0.1135), and (4) the average length of treatment and the number of neurological beds/100,000 inhabitants (R(2) = 0.1745). Inverse relationships were found between: (1) the number of neurological beds/100,000 inhabitants and the average hospital catchment area (R(2) = 0.2105), and (2) the number of neurological beds/100,000 inhabitants and the GNP per capita (R(2) = 0.1144).