Biomedical subjects

Marino Zorzon

Publications and source records attributed to Marino Zorzon.

16 recordsLinked to original sources

PubMed2006

Positivity of cytomegalovirus antibodies predicts a better clinical and radiological outcome in multiple sclerosis patients.

OBJECTIVES: To establish the relationship between the presence and titer of virus-specific serum- and cerebrospinal fluid (CSF)-antibodies in multiple sclerosis (MS) patients and disease severity measured with different quantitative magnetic resonance imaging (MRI) techniques. METHODS: We investigated an association between clinical and MRI measures of disease activity and the presence and titer of IgG antibodies against seven common viruses (measles, rubella, herpes simplex virus type 1 and 2, varicella zoster virus, cytomegalovirus (CMV) and Epstein-Barr virus). One hundred and forty (90 female/50 male) patients with definite MS and 131 age and sex-matched controls participated in the study. Antibody positivity and titer were ascertained by the enzyme linked immunosorbent assay (ELISA) technique and clinical assessment was performed by evaluating the expanded disability status scale (EDSS) score and the lifetime relapse rate (LRR). T1- and T2-lesion loads (LL) and the brain parenchymal fraction (BPF) were calculated. RESULTS: Multiple analyses showed that there was an association between antibody positivity against CMV and higher titer and better clinical and MRI outcomes. The cluster analyses indicated that patients positive for antibodies against CMV had significantly older age at onset (uncorr p = 0.001 and corr p = 0.009), lower LRR (uncorr p = 0.003 and corr p = 0.03) and higher BPF (uncorr p = 0.004 and pcorr p = 0.04). CMV-positive patients who had higher antibody titer showed lower T2-LL (uncorr p = 0.003 and corr p = 0.03) and higher BPF (uncorr p = 0.006 and corr p = 0.05). DISCUSSION: Surprisingly, our results focused attention on the 'protective' role of a particular virus. CMV is probably capable of triggering some immunomodulating/immune evasion mechanisms which may decrease immune reactivity in MS patients. Further studies are needed to confirm and elucidate our study results on a larger sample of MS patients and in animal model studies.

Adolescent↗

PubMed2006

Effect of MRI coregistration on serial short-term brain volume changes in multiple sclerosis.

OBJECTIVE: To test the effect of serial magnetic resonance (MR) coregistration on short-term brain volume changes using different semiautomated and automated brain volume techniques in patients with relapsing-remitting (RR) multiple sclerosis (MS). Coregistration is frequently used to increase precision in serial MR imaging (MRI) analyses. However, the effect of coregistration on measurement of whole brain volume changes from serial scans in the short term has not been tested in MS patients. METHODS: Twenty-eight patients with RR MS [mean disease duration: 4.9 years, mean age: 34.4 years and mean expanded disability status scale (EDSS): 1.4] were scanned at baseline and monthly for a period of 3 months with 2D spin-echo T1-weighted sequences obtained with nongapped 3 mm axial slices. Percent brain parenchymal fraction change (PBPFC) was calculated by a semiautomated (Buffalo) and, separately, by two automated (Buffalo automated and SIENAX) techniques, whereas percent brain volume change (PBVC) was calculated by the SIENA technique. For coregistration of serial images we used a robust, fully automated linear image coregistration tool. PBPFC and PBVC were calculated before and after coregistration, comparing scans from the following time periods: (1) baseline to month 3; (2) baseline to month 1; (3) month 1 to 2 and (4) month 2 to 3. RESULTS: The highest median PBPFCs measured on non-coregistered images were detected for the baseline-to-month-3 time period and ranged from -0.11% for Buffalo semiautomated to -0.45% for Buffalo automated (p = ns). On coregistered images, the highest PBPFCs were detected for the baseline-to-month-3 time period and ranged from 0.3% for Buffalo semiautomated, -0.3% for Buffalo automated, 0.02% for SIENAX and -0.02% for SIENA (PBVC). At all time points of the study, no significant differences of median volume changes were measured on coregistered and non-coregistered images when comparing the results among the segmentation algorithms. CONCLUSIONS: Over a 3 month period we did not detect short-term changes in normalized brain volumes using different measurement techniques. A longer observation period is needed to assess whether coregistration can affect the measurement of long-term brain volume changes.

Adult↗

PubMed2005

Osteopontin gene haplotypes correlate with multiple sclerosis development and progression.

Osteopontin (OPN) is an inflammatory cytokine highly expressed in multiple sclerosis (MS) plaques. In a previous work, we showed that four OPN polymorphisms form three haplotypes (A, B, and C) and that homozygotes for haplotype-A display lower OPN levels than non-AA subjects. In this work, we evaluated the distribution of these OPN haplotypes in 425 MS patients and 688 controls. Haplotype-A homozygotes had about 1.5 lower risk of developing MS than non-AA subjects. Clinical analysis of 288 patients showed that AA patients displayed slower switching from a relapsing remitting to a secondary progressive form and milder disease with slower evolution of disability. MS patients displayed increased OPN serum levels, which were partly due to the increased frequency of non-AA subjects. Moreover in AA patients, OPN levels were higher than in AA controls and similar to those found in both non-AA patients and controls, which suggests a role of the activated immune response. These data suggest that OPN genotypes may influence MS development and progression due to their influence on OPN levels.

Adult↗

PubMed2005

Nontraumatic headache in the Emergency Department: a survey in the province of Trieste.

The objective was to study the demographics, diagnostic procedures and therapies employed in order to provide guidelines to Emergency Department (ED) physicians. A six-month retrospective analysis of the records of all patients presenting with nontraumatic headache (NTH) to the EDs of the Province of Trieste was performed. Of 38,238 patients screened, 300 (0.8%) presented with NTH and 49.7% were referred to specialists. Patients were classified as having secondary headache (41.3%), primary headache (24.3%) and headache with no obvious source (NOS) (34.4%). One hundred and seventy patients were treated with mono- or polytherapy. Of 50 patients with migraine, 36 were treated with NSAIDs and 4 with triptans. 68.4% of patients were referred to a general practitioner and 31.6% were admitted. The frequency of NTH was lower than in other studies. NOS headache was frequent. Only 10% of migraineurs received triptans. Diagnostic and therapeutic guidelines for ED physicians are needed.

Adult↗

PubMed2005

Reproducibility and accuracy of quantitative magnetic resonance imaging techniques of whole-brain atrophy measurement in multiple sclerosis.

BACKGROUND AND PURPOSE: Whole-brain atrophy is of growing interest as an outcome measure in multiple sclerosis (MS) clinical trials. The authors compared the reproducibility and accuracy of 3 quantitative techniques of measurement in patients with MS. METHODS: Thirty-four patients with relapsing-remitting MS (median Expanded Disability Status Scale disability score = 1.5) were studied. Brain parenchymal fraction (BPF) was quantified on spin-echo 2-dimensional T1-weighted axial 5-mm slice thickness sequences by semiautomated (Buffalo, Trieste) or automated (SIENAX) algorithms. RESULTS: Mean +/- SD BPFs were 0.830 +/- 0.04 with Buffalo, 0.824 +/- 0.04 with Trieste, and 0.826 +/- 0.04 with SIENAX methods (P = nonsignificant [NS]). Mean BPF scan-rescan coefficient of variation (COV) was 0.41% for Buffalo, 0.44% for Trieste, and 0.32% for SIENAX (P =NS).The semiautomated methods showed higher accuracy than the automated method in brain extraction (masking; P = .001). The errors of skull stripping included scalp, skull bone marrow, inferior parts of temporal lobes anterior to the brain stem, face structures, sagittal sinuses, eyes, and optic nerves. Buffalo (r = -0.37, P = .034) and Trieste (r = -.36, P = .039) BPFs showed stronger cor relation with disability than SIENAX (r = -0.16, P = .219). These differences were statistically significant (P = .0031 for Buffalo and P = .0037 for Trieste BPF). CONCLUSIONS: This study showed a high reproducibility of both semiautomated and automated methods for brain atrophy measurement. The semiautomated methods showed higher accuracy than the automated SIENAX method did in the evaluation of brain extraction, especially in infratentorial and cortical regions, where operator interaction during the masking processes was essential.

Adult↗

PubMed2004

Short-term brain atrophy changes in relapsing-remitting multiple sclerosis.

The objective of this study was to establish whether the time interval of 3 months is sufficient to detect whole-brain atrophy changes in patients with relapsing-remitting (RR) multiple sclerosis (MS). Another aim was to assess the value of monthly gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) and of different Gd-enhancement patterns as predictors of brain atrophy. Thirty patients with RRMS (mean disease duration 4.9 years, mean age 34.4 years and mean Expanded Disability Status Scale [EDSS] 1.4) were assessed at baseline and monthly for a period of 3 months with clinical and MRI examinations. Calculations of baseline and monthly absolute and percent changes of MRI measures have been obtained using two semiautomated (Buffalo and Trieste) and one automated (SPM99) segmentation method. Changes of brain parenchymal fraction (BPF) were investigated according to Gd-enhancement patterns. Mean absolute and percent changes of BPF did not significantly differ at any time point in the study for any of the three methods. There was slight but not significant decrease of BPF from baseline to month 3: -0.0004 (0.05%), p=0.093 for Trieste; -0.0006 (0.07%), p=0.078 for Buffalo; and -0.0006 (0.08%), p=0.081 for SPM99 method. In ring-enhancement positive patients, there was a significant difference between baseline and month 3 changes of BPF, EDSS, and number of relapses. Over the study period, we did not demonstrate differences between changes of BPF according to the presence of Gd enhancement. Longitudinally, multiple regression analysis demonstrated that the only clinical or MRI parameter that predicted BPF decrease was the mean absolute change of ring-enhancing lesion load (R=0.62, p=0.003). The noteworthy findings of this study are (1) the observation that a significant brain atrophy progression cannot be detected over a 3-month period in RRMS; (2) the demonstration that the ring-enhancement pattern may contribute to more severe brain tissue loss in the short term; and (3) the lack of relationship between the presence and duration of Gd-enhancement activity and brain volume changes in the short term.

Adult↗

PubMed2004

MMP-9 microsatellite polymorphism and multiple sclerosis.

A polymorphism (PM) in the microsatellite of the promoter region of matrix metalloproteinase 9 (MMP-9), modulating its expression, could play a role in susceptibility to multiple sclerosis (MS). MMP-9 PM was determined in 95 patients with MS (MS Group) and 95 age- and sex-matched controls (Control Group). Comparison of allelic frequencies showed that a higher number of CA repeats characterized the MS group (P<0.0001) and prevalence of carriers of > or =22 CA repeats was higher in the MS than in the Control Group (OR 3.4, 95% CI: 1.7-6.8, P<0.0001). An earlier age at disease onset was a characteristic of patients with >22 CA repeats (33+/-10 vs. 28+/-10, P=0.027). No differences were found in the main MRI parameters.

Adolescent↗

PubMed2004

Headache induced by chronic substance use: analysis of medication overused and minimum dose required to induce headache.

BACKGROUND: The International Headache Society has defined the diagnostic criteria for headache induced by substance use. Recently, a revision to these criteria has been proposed. OBJECTIVE: To consider whether the International Headache Society criteria for headache induced by substance use and the proposed revisions for the classification of daily and near-daily headache with medication abuse permit classification of patients commonly seen in a headache center. METHODS: One hundred fourteen consecutive patients (96 women [84.2%] and 18 men [15.8%]; mean age, 54.2 years [SD, 14]) with headache and chronic overuse of medications, admitted for detoxification to the inpatient unit of a headache center, participated in the study. The initial headache, medications and doses used, duration of daily medication use, and means of medication administration were studied. RESULTS: Eighty-one patients (71%) had an initial headache of migraine without aura, 13 patients (11.4%) had migraine without aura and coexistent tension-type headache, 11 (9.7%) patients had migraine with and without aura, and 9 patients (7.9%) had episodic tension-type headache. Medications overused by patients included analgesics combined with barbiturates or other nonnarcotic substances in 39.5%, simple analgesics in 38.6%, triptans in 11.4%, and ergotamine in 10.5%. Using the International Headache Society diagnostic criteria, we were able to classify only 28.1% of our patients; the proposed revised criteria for daily and near-daily headaches with medication abuse permitted the classification of 46.4% of patients. CONCLUSION: The minimum dose of medication required to induce chronic headache should be revised because a high proportion of patients are not classifiable using either the International Headache Society diagnostic criteria or the revised criteria recently proposed. A more comprehensive definition for the required minimum dose might be used. Triptan abuse can cause chronic headache and should be included in the International Headache Society classification.

Analgesics, Non-Narcotic↗

PubMed2004

Frontal parenchymal atrophy measures in multiple sclerosis.

The aim of this study was to establish whether, in a cross-sectional study, the normalized measures of whole and regional brain atrophy correlate better with tests assessing the cognitive function than the absolute brain atrophy measures. The neuropsychological performances and disability have been assessed in 39 patients with relapsing-remitting multiple sclerosis (MS). T1- and T2-lesion load (LL) of total brain and frontal lobes (FLs) were measured using a reproducible semiautomated technique. The whole brain volume and the regional brain parenchymal volume (RBPV) of FLs were obtained using a computerized interactive program, which incorporates semiautomated and automated segmentation processes. Normalized measures of brain atrophy, i.e., brain parenchymal fraction (BPF) and regional brain parenchymal fraction (RBPF) of FLs, were calculated. The scan-rescan, inter- and intrarater coefficient of variation (COV) and intraclass correlation coefficient (ICC) have been estimated. The RBPF of FLs showed an acceptable level of reproducibility which ranged from 1.7% for intrarater variability to 3.2% for scan-rescan variability. The mean ICC was 0.88 (CI 0.82-0.93). The RBPF of FLs demonstrated stronger magnitudes of correlation with neuropsychological functioning, disability and quantitative MRI lesion measures than RBPV. These differences were statistically significant: P<0.001 for Stroop Color Word Interference test, P<0.001 for Paced Auditory Serial Addition Test, P=0.04 for Standard Raven Progressive Matrices, P=0.049 for Expanded Disability Status Scale, P=0.01 for T2-LL of FLs and P<0.001 for T1-LL of FLs. BPF demonstrated significant correlations with tests assessing cognitive functions, whereas BPAV did not. The correlation analysis results were supported by the results of multiple regression analysis which showed that only the normalized brain atrophy measures were associated with tests exploring the cognitive functions. These data suggest that RBPF is a reproducible and sensitive method for measuring frontal parenchymal atrophy. The normalized measures of whole and regional brain parenchymal atrophy should be preferred to absolute measures in future studies that correlate neuropsychological performances and brain atrophy measures in patients with MS.

Adult↗

PubMed2003

A longitudinal study of quality of life and side effects in patients with multiple sclerosis treated with interferon beta-1a.

In a 12-month follow-up study, we evaluated 27 patients (18 F and 9 M) with relapsing-remitting (RR) multiple sclerosis (MS), who had started treatment with interferon beta-1a (IFNbeta-1a) (Avonex), 30 microg i.m. once weekly, 6-18 months (median 10 months) before study entry. Quality of life (QOL), disability, independence, cognitive performances, symptoms of depression and anxiety, and fatigue were assessed at baseline, 6 months and 12 months. The frequency and severity of the side effects of treatment, at hours 0-12, 13-48 and 49-168 after the injection, were self-reported weekly in a structured questionnaire. QOL did not change significantly during the follow-up. The percentage of patients who reported side effects after the injection of IFNbeta-1a remained constant during the 52 weeks. The mean number of side effects increased significantly from the 6th to the 12th month. The general linear model analysis of variance disclosed significant changes over time for almost all side effects, but we did not find any correlation between QOL and number of side effects. In conclusion, 1-year treatment with IFNbeta-1a did not significantly change patient's QOL. Disability progression correlated with patient's QOL. Side effects, which were mild, did not diminish over time, did not induce treatment discontinuation and did not interfere with QOL.

Activities of Daily Living↗

PubMed2003

Normalized regional brain atrophy measurements in multiple sclerosis.

There is still a controversy regarding the best regional brain atrophy measurements in multiple sclerosis (MS) studies. The aim of this study was to establish whether, in a cross-sectional study, the normalized measurements of regional brain atrophy correlate better with the MRI-defined regional brain lesions than the absolute measurements of regional brain atrophy. We assessed 45 patients with clinically definite relapsing-remitting (RR) MS (median disease duration 12 years), and measured T1-lesion load (LL) and T2-LL of frontal lobes and pons, using a reproducible semi-automated technique. The regional brain parenchymal volume (RBPV) of frontal lobes and pons was obtained by use of a computerized interactive program, which incorporates semi-automated and automated segmentation processes. A normalized measurement, the regional brain parenchymal fraction (RBPF), was calculated as the ratio of RBPV to the total volume of the parenchyma and the cerebrospinal fluid (CSF) in the frontal lobes and in the region of the pons. The total regional brain volume fraction (TRBVF) was obtained after we had corrected for the total volume of the parenchyma and the CSF in the frontal lobes and in the region of the pons for the total intracranial volume. The mean coefficient of variation (CV) for RBPF of the pons was 1% for intra-observer reproducibility and 1.4% for inter-observer reproducibility. Generally, the normalized measurements of regional brain atrophy correlated with regional brain volumes and disability better than did the absolute measurements. RBPF and TRBVF correlated with T2-LL of the pons (r=-0.37, P=0.011, and r= -0.40, P=0.0005 respectively) and with T1-LL of the pons (r=-0.27, P=0.046, and r=-0.31, P=0.04, respectively), whereas RBPV did not (r=-0.18, P = NS). T1-LL of the frontal lobes was related to RBPF (r=-0.32, P=0.033) and TRBVF (r=-0.29, P=0.05), but not to RBPV (R=-0.27, P= NS). There was only a trend of correlation between T2-LL of the frontal lobes and RBPF (r=-0.27, P=0.06) and TRBVF (r=-0.28, P=0.057), and no correlation with RBPV (r=-0.23, P= NS). The magnitude of correlation between the expanded disability status scale (EDSS) and pontine and frontal lobe RBPF and TRBVF was more than twice as high as the correlation between EDSS and RBPV of the same regions. These data suggest that normalized regional brain atrophy measurements are preferable to absolute regional measurements in cross-sectional studies.

Adult↗

PubMed2003

Sexual dysfunction in multiple sclerosis: a MRI, neurophysiological and urodynamic study.

We studied 31 patients with relapsing-remitting (RR) multiple sclerosis (MS) in which we performed an urodynamic study, the pudendal cortical evoked potentials, the tibial cortical evoked potentials and the cranial and cervical spinal cord magnetic resonance imaging (MRI). We calculated the T(1) and T(2) lesion load (LL) and brain parenchymal fraction (BPF) of whole brain, frontal lobes, pons and cervical spinal cord. We also estimated the cross-sectional area at C(2) level. Spearman's rank correlation analysis showed a relationship between symptoms of sexual dysfunction and age (r=0.73, p<0.0001), cognitive performances (r=-0.63, p<0.0001), level of independence (r=-0.63, p<0.0001), disability (r=0.56, p<0.001), symptoms of anxiety (r=0.55, p<0.001) and depression (r=0.50, p<0.005), disease duration (r=0.42, p<0.02) and parenchymal atrophy in the pons (r=-0.38, p=0.031). Sexual dysfunction was not correlated with any other MRI measure, urodynamic patterns or cortical evoked potentials. In multiple regression analysis, sexual dysfunction was predicted only by T(1) lesion load of the pons. In conclusion, we confirmed previous correlations of sexual dysfunction with various clinical variables and demonstrated an association between sexual dysfunction and destructive lesions in the pons, as detected by MRI, in patients with relapsing-remitting multiple sclerosis.

Adult↗

PubMed2003

HLA genotypes and disease severity assessed by magnetic resonance imaging findings in patients with multiple sclerosis.

The objective of the study was to examine the relationship between HLA genotypes and disease severity as measured by brain MRI quantitative markers of demyelinating and destructive pathology in patients with multiple sclerosis (MS). We studied 100 patients with MS and 122 age, sex-, ethnic- and residence-matched controls. The DNA extraction and the genomic typing (A, B, DRB1 and DQB1 loci) were obtained with sequence-specific oligonucleotide method, using a commercially available reversible line blot assay (INNO-LIPA). All patients underwent a 1.5 tesla MRI examination of the brain. Disease severity was assessed by clinical (Expanded Disability Status Scale (EDSS)) and MRI (T2- and T1-lesion load (LL) and brain parenchymal fraction (BPF)) outcome measures. HLA-DQB1* 02 (OR 19.9, 95% C. I. 16.2-24.3, uncorrected (uncorr)- p<0.00001, corr-p<0.0006), -DQB1*03 (OR 16.8, 95% C. I. 13.6-20.5, uncorr-p<0.00001, corrp< 0.0006), -DRB1*15 (OR 4.6, 95% C. I. 3.7-5.6, uncorr-p= 0.0001, corr-p=0.006), and -DRB1*03 (OR 3.9, 95% C. I. 3.2-4.8, uncorr-p=0.0001, corr-p= 0.006) alleles were associated with MS. T2-, T1-LL, BPF and EDSS were not significantly different according to the carrier status of these HLA alleles. No differences were found in the ratios of disease severity/disease duration according to the HLA carrier status. Multiple regression analysis showed that a higher T2-LL was associated with the presence of DRB1*04 (uncorr-R2=0.15, p=0.006 and corr-R2=0.11, p=0.025) and B7 alleles (uncorr-R2=0.08, p=0.02 and corr-R2=0.07, p=0.018), T1-LL was associated with B7 (uncorr-R2=0.30, p<0.0001 and corr-R2=0.27, p=0.0001) and DRB1*12 (uncorr-R2=0.25, p<0.0001 and corr-R2=0.21, p=0.0002) alleles, whereas the BPF was predicted only by the presence of DRB1*12 allele (uncorr-R2=0.24, p=0.002 and corr-R2=0.20, p=0.004). The study findings suggest that some HLA alleles may predict the destructive pathological processes visible on MRI. Since the size of the sample studied is relatively small, further studies are needed to draw any firm conclusion about genotype/phenotype correlation in patients with MS.

Adult↗

PubMed2003

[Clinical surveillance of patients with multiple sclerosis].

Clinical management of people with multiple sclerosis (MS) is based not only on the control of side-effects of disease-modifying drugs but also on the recognition and treatment of disease exacerbations, on the evaluation of disease progression and on the management of the wide range of MS symptoms. A multidisciplinary approach is essential to achieve the best results and improve the quality of life of MS patients.

Acute Disease↗

PubMed2002

Is gadolinium enhancement predictive of the development of brain atrophy in multiple sclerosis? A review of the literature.

BACKGROUND AND PURPOSE: Several studies have demonstrated that brain atrophy can be detected over relatively short intervals from the earliest stages of multiple sclerosis (MS). Reviewing the published data, the authors highlight some hypothetical pathological mechanisms proposed as determinants of brain atrophy. METHODS: Using the terms multiple sclerosis, MRI (magnetic resonance imaging), and brain atrophy, 181 citations were identified. The authors considered only studies with prospective designs with natural-course MS patients and/or placebo-treated patients of therapeutic trials, in which patients underwent baseline and follow-up scans with a T1-weighted gadolinium diethylenetriamine penta-acetic acid sequence (0.1 mmol/kg body weight), and correlation analyses between Gd enhancement activity and brain atrophy progression. RESULTS: Five hundred thirty-two patients of 5 natural history studies and 5 therapeutic trial studies participated in the review process. The main observation was that in patients with a relapsing-remitting (RR) disease course, there was a correlation between Gd enhancement activity and brain atrophy progression. This correlation was not influenced by any other demographic and clinical additional data considered in the review process. CONCLUSIONS: Examination of the pathological mechanisms proposed in the reviewed studies led the authors to believe that inflammation is only in part responsible for the development of brain atrophy. This conclusion may have an implication for the strategies of tissue protection advocated in the early stages of the RR course and strengthen recent evidence indicating that anti-inflammatory immunomodulatory agents and immunosuppressive treatments, which predominantly act against the inflammatory component of disease activity, may not have similar effects on progressive tissue loss, either in RR or progressive MS.

Atrophy↗

PubMedDate not supplied

The use of standardized incidence and prevalence rates in epidemiological studies on multiple sclerosis. A meta-analysis study.

OBJECTIVE: To demonstrate whether or not the age and sex adjustment of incidence and prevalence rates in multiple sclerosis (MS) could allow more reliable comparison between epidemiological studies performed in different areas of the world and to establish if the latitude gradient theory could be confirmed after the standardization for age and sex distribution. METHODS: A meta-analysis of population-based incidence and prevalence studies on MS from 1980 through 1998 using the terms 'multiple sclerosis', 'prevalence' and 'incidence' in the bibliographic databases MEDLINE and EMBASE was performed. We included studies that reported the diagnostic criteria, number of cases and the population studied, the date of the study, the latitude, and the age- and sex-specific crude incidence and prevalence rates. According to the inclusion criteria, 69 of 127 papers on prevalence and 22 of 70 papers on incidence were considered for age adjustment and 27 prevalence and 8 incidence studies for sex adjustment. The mean incidence and prevalencerates and the 95% confidence intervals age- and sex-adjusted to the World and the European standard populations were calculated. RESULTS: The Spearman rank correlation and the multiple regression analyses indicated that age adjustment to standard populations could overcome the limitations in comparing the crude prevalence and incidence rates of different epidemiological studies on MS. When the mean crude and age- and sex-adjusted prevalence and age-adjusted incidence rates were stratified by latitude (from south to north), the latitudinal gradient, which was highly significant for the crude rates, became less remarkable for the age- and sex-adjusted prevalence rates and not significant for the age-adjusted incidence rates. CONCLUSIONS: The crude incidence and prevalence rates in epidemiological studies on MS should be age- and sex-adjusted to a common standard population to permit a more reliable comparison among studies performed in different countries. Our findings support the opinion that the latitude does not play a key role in determining the onset of MS. Whenever possible, the crude incidence and prevalence rates should be adjusted to the ethnic origin and migration characteristics.

Adolescent↗