Multiple Sclerosis patients carry an increased burden of exceedingly rare genetic variants in the inflammasome regulatory genes.

The role of rare genetic variation and the innate immune system in the etiology of multiple sclerosis (MS) is being increasingly recognized. Recently, we described several rare variants in the NLRP1 gene, presumably conveying an increased risk for familial MS. In the present study we aimed to assess rare genetic variation in the inflammasome regulatory network. We performed whole exome sequencing of 319 probands, comprising patients with familial MS, sporadic MS and control subjects. 62 genes involved in the NLRP1/NLRP3 inflammasome regulation were screened for potentially pathogenic rare genetic variation. Aggregate mutational burden was analyzed, considering the variants' predicted pathogenicity and frequency in the general population. We demonstrate an increased (p = 0.00004) variant burden among MS patients which was most pronounced for the exceedingly rare variants with high predicted pathogenicity. These variants were found in inflammasome genes (NLRP1/3, CASP1), genes mediating inflammasome inactivation via auto and mitophagy (RIPK2, MEFV), and genes involved in response to infection with DNA viruses (POLR3A, DHX58, IFIH1) and to type-1 interferons (TYK2, PTPRC). In conclusion, we present new evidence supporting the importance of rare genetic variation in the inflammasome signaling pathway and its regulation via autophagy and interferon-ß to the etiology of MS.

Association of circadian rhythm genes ARNTL/BMAL1 and CLOCK with multiple sclerosis.

Prevalence of multiple sclerosis varies with geographic latitude. We hypothesized that this fact might be partially associated with the influence of latitude on circadian rhythm and consequently that genetic variability of key circadian rhythm regulators, ARNTL and CLOCK genes, might contribute to the risk for multiple sclerosis. Our aim was to analyse selected polymorphisms of ARNTL and CLOCK, and their association with multiple sclerosis. A total of 900 Caucasian patients and 1024 healthy controls were compared for genetic signature at 8 SNPs, 4 for each of both genes. We found a statistically significant difference in genotype (ARNTL rs3789327, P = 7.5·10-5; CLOCK rs6811520 P = 0.02) distributions in patients and controls. The ARNTL rs3789327 CC genotype was associated with higher risk for multiple sclerosis at an OR of 1.67 (95% CI 1.35-2.07, P = 0.0001) and the CLOCK rs6811520 genotype CC at an OR of 1.40 (95% CI 1.13-1.73, P = 0.002). The results of this study suggest that genetic variability in the ARNTL and CLOCK genes might be associated with risk for multiple sclerosis.

Identification of rare genetic variation of NLRP1 gene in familial multiple sclerosis.

The genetic etiology and the contribution of rare genetic variation in multiple sclerosis (MS) has not yet been elucidated. Although familial forms of MS have been described, no convincing rare and penetrant variants have been reported to date. We aimed to characterize the contribution of rare genetic variation in familial and sporadic MS and have identified a family with two sibs affected by concomitant MS and malignant melanoma (MM). We performed whole exome sequencing in this primary family and 38 multiplex MS families and 44 sporadic MS cases and performed transcriptional and immunologic assessment of the identified variants. We identified a potentially causative homozygous missense variant in NLRP1 gene (Gly587Ser) in the primary family. Further possibly pathogenic NLRP1 variants were identified in the expanded cohort of patients. Stimulation of peripheral blood mononuclear cells from MS patients with putatively pathogenic NLRP1 variants showed an increase in IL-1B gene expression and active cytokine IL-1ß production, as well as global activation of NLRP1-driven immunologic pathways. We report a novel familial association of MS and MM, and propose a possible underlying genetic basis in NLRP1 gene. Furthermore, we provide initial evidence of the broader implications of NLRP1-related pathway dysfunction in MS.

Angiotensin-converting enzyme insertion/deletion gene polymorphism and interferon-ß treatment response in multiple sclerosis patients: a preliminary report.

We investigated the effect of the functional insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene on the response to interferon-ß (IFN-ß) therapy in Croatian and Slovenian patients with multiple sclerosis (MS). A total of 275 IFN-ß treated MS patients [162 responders (Rs) and 113 nonresponders (NRs)] were genotyped by PCR. The ACE I/D genotype distribution and allele frequencies did not differ between female Rs and NRs. However, male NRs tended to have a greater prevalence of the DD genotype (P=0.073; odds ratio: 2.64; 95% confidence interval: 0.91-7.60) and a significantly higher frequency of the D allele (P=0.022; odds ratio: 2.43; 95% confidence interval: 1.13-5.20) than male Rs. Multiple forward stepwise regression analysis indicated that the negative response to IFN-ß therapy was associated with the ACE-DD genotype in men (ß=0.371; multiple R change: 0.132; P=0.009) and a higher pretreatment relapse rate in both men (ß=-0.438; multiple R change: 0.135; P=0.015) and women (ß=-0.208; multiple R change: 0.042; P=0.034). The ACE I/D polymorphism and pretreatment relapse rate accounted for ∼26.7% of the IFN-ß response variability among the men in the sample. Further studies of a larger number of MS patients from different populations are necessary to evaluate these preliminary findings.

The lack of association between angiotensin-converting enzyme gene insertion/deletion polymorphism and nicotine dependence in multiple sclerosis.

OBJECTIVE: Blood-borne angiotensin II is generated from angiotensinogen via cleavage by renin and angiotensin-converting enzyme (ACE), an enzymatic cascade known as the renin-angiotensin system (RAS). Several lines of evidence indicate that ACE, beyond its classical role of mediating blood pressure regulation, might contribute to the etiology of substance addictions by influencing dopaminergic signaling. A functional insertion/deletion (I/D) polymorphism of the ACE gene was associated with risk for being a smoker among individuals with depression and with smoking severity in studies comprising patients with depression and healthy controls. Several reports have described significantly increased ACE activity in cerebrospinal fluid and serum among MS patients. Furthermore, in our previous work with MS patients from Croatian and Slovenian populations, we demonstrated that the ACE-I/D polymorphism contributes to an elevated MS risk among male patients. Here we investigated whether the ACE-I/D polymorphism might influence smoking behavior among patients with MS. PATIENTS AND METHODS: Genotyping was performed in 521 patients (males/females: 139/382) using polymerase chain reaction. RESULTS: We revealed no significant differences in ACE genotype and allele frequencies between smokers and nonsmokers and no significant association between the ACE-I/D polymorphism and either pack-year smoking history or number of cigarettes smoked daily (p > .05, respectively). CONCLUSION: The ACE-I/D polymorphism does not contribute either to risk for nicotine dependence or to smoking severity among MS patients. In the context of reports on the ACE-I/D polymorphism and nicotine dependence among healthy controls and patients with depression, we may speculate that the mechanism by which this polymorphism influences nicotine dependence risk differs in MS compared to depression, although not compared to a healthy population. In addition to angiotensin II, other potential ACE substrates, such as substance P and neurotensin, which also influence dopaminergic neurotransmission (and are proposed to be associated with MS), may deserve study in future.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in multiple sclerosis: a meta-analysis.

The activity of angiotensin-converting enzyme (ACE) has been increased in the blood and cerebrospinal fluid of multiple sclerosis (MS) patients. In addition, there has been suppression of disease development in experimental autoimmune encephalomyelitis after blockade of ACE. These findings suggest that ACE may play a role in the MS pathogenesis. Since the previous studies investigating the association between the insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene and MS reported contradictory results, we performed a meta-analysis of four studies conducted in European populations of Slavic origin (1062 patients and 1067 controls) using the Comprehensive Meta-analysis 3.0 software. The results demonstrated that the ACE I/D polymorphism had no statistically significant association with an increased MS risk (all p ≥ 0.05) under all genetic comparison models: (1) allelic (D vs. I), (2) recessive (DD vs. ID + II), (3) dominant (DD + ID vs. II), and (4) additive (DD vs. ID vs. II). This meta-analysis indicates that the ACE I/D polymorphism is not associated with susceptibility to MS in Europeans of Slavic origin. Further studies with larger sample sizes from genetically different populations are warranted.

MMP-2 -1575G/A polymorphism modifies the onset of optic neuritis as a first presenting symptom in MS?

Previous studies show altered activities of matrix metalloproteinase (MMP)-2 and MMP-9 in serum and cerebrospinal fluid of multiple sclerosis (MS) and neuromyelitis optica (NMO) patients. Optic neuritis (ON) is a common symptom of both disorders. Here we investigated the impacts of MMP-2 -1575G/A and MMP-9 -1562 C/T gene polymorphisms on disease phenotype in 100 MS patients with ON as a first symptom and 376 MS patients with other initial symptomatology. The MMP-2 -1575G/A polymorphism led to a 5-year-earlier age of disease onset in MS patients with ON as a first symptom (p=0.009).

The role of TPA I/D and PAI-1 4G/5G polymorphisms in multiple sclerosis.

BACKGROUND: Previous studies have shown impaired fibrinolysis in multiple sclerosis (MS) and implicated extracellular proteolytic enzymes as important factors in demyelinating neuroinflammatory disorders. Tissue-type plasminogen activator (t-PA) and its inhibitor (PAI-1) are key molecules in both fibrinolysis and extracellular proteolysis. In the present study, an association of the TPA Alu I/D and PAI-1 4G/5G polymorphisms with MS was analyzed within the Genomic Network for Multiple Sclerosis (GENoMS). METHODS: The GENoMS includes four populations (Croatian, Slovenian, Serbian, and Bosnian and Herzegovinian) sharing the same geographic location and a similar ethnic background. A total of 885 patients and 656 ethnically matched healthy blood donors with no history of MS in their families were genotyped using PCR-RFLP. RESULTS: TPA DD homozygosity was protective (OR = 0.79, 95% CI 0.63-0.99, P = 0.037) and PAI 5G5G was a risk factor for MS (OR = 1.30, 95% CI 1.01-1.66, P = 0.038). A significant effect of the genotype/carrier combination was detected in 5G5G/I carriers (OR = 1.39 95% CI 1.06-1.82, P = 0.017). CONCLUSIONS: We found a significantly harmful effect of the combination of the PAI-1 5G/5G genotype and TPA I allele on MS susceptibility, which indicates the importance of gene-gene interactions in complex diseases such as MS.

Angiotensin-converting enzyme gene polymorphism in patients with multiple sclerosis from Bosnia and Herzegovina.

BACKGROUND: Increased activity of angiotensin-converting enzyme (ACE) in the blood and cerebrospinal fluid of patients with multiple sclerosis (MS), and the inhibition of ACE in experimental autoimmune encephalomyelitis, suggested that ACE may play a role in the pathogenesis and progression of MS. We recently published the first report on the potential association of MS and ACE I/D polymorphism in Slovenian and Croatian patients with MS, in which it was shown that the DD genotype might contribute to a higher risk of developing MS in men. To confirm these findings in a similar ethnic population, we analyzed ACE I/D gene polymorphism in patients with MS from Bosnia and Herzegovina. SUBJECTS AND METHODS: One hundred and seventy patients with MS and 170 healthy controls were genotyped by the polymerase chain reaction method. RESULTS: There was no significant difference in the distribution of ACE I/D genotypes (p=0.783) or in the allelic frequencies (p=0.538) between patients with MS and control subjects. When patients with MS were stratified by sex, no statistically significant differences in allele or genotype distributions were observed. Finally, there was no indication of an impact of the ACE I/D genotype on disease course or severity. CONCLUSION: The ACE I/D polymorphism is not a risk factor for development of MS, nor does it contribute to disease severity in this Bosnia and Herzegovina population.

Drug-induced aseptic meningitis, sensorineural hearing loss and vestibulopaty.

We report clinically rare and serious adverse reactions that occurred after the co-administration of ranitidine, ibuprofen and ciprofloxacin: completely reversible aseptic meningitis and irreversible bilateral sensorineural hearing loss, tinnitus, and vestibulopathy. Recurrent urinary inflammations treated with antibacterials, classic familial migraine, and allergy to trimethoprim-sulfamethoxazole and chromium were favourable predisposing factors for the adverse event in this patient. A close chronological relation between administration of drugs (especially ibuprofen) and adverse reactions was noted. No evidence of infection and/or autoimmune disease was found. The mechanism of these serious events may be explained as a hypersensitive reaction affecting the meninges and, partially, cochlea.

Interleukin 7 receptor alpha polymorphism rs6897932 and susceptibility to multiple sclerosis in the Western Balkans.

The interleukin 7 receptor alpha single nucleotide polymorphism rs6897932 was identified as a multiple sclerosis susceptibility-modifying polymorphism in genome-wide and gene scan studies, mainly in populations in western countries. The aim of this study was to investigate the association of interleukin 7 receptor alpha rs6897932 with multiple sclerosis in populations from the Western Balkans: Serbia, Croatia, and Slovenia. A total of 678 unrelated white patients and 597 unrelated, ethnically matched healthy controls were included in the study. Genotyping was performed by real-time polymerase chain reaction. We found no significant difference in genotype or allele frequencies between controls and patients with multiple sclerosis either separately in Serbian, Croatian, and Slovenian populations or in the whole sample from the Western Balkans. The odds ratio for multiple sclerosis in this study was 1.04 (0.86-1.25) for the C allele. It is known that demographic as well as environmental factors have a substantial role in multiple sclerosis development, as well as population genetic background. The results of this study indicate that other types of genome variants should be required for the development and/or progression of multiple sclerosis, which may vary among populations.

Multiple sclerosis and cancers in Croatia--a possible protective role of the "Mediterranean diet".

Multiple sclerosis (MS) is an autoimmune disease triggered by a combination of genetic and environmental risk factors which are however individually insufficient to provoke the disease. Previous investigations studied the coexistence of cancer in MS patients, and only a few relations between the geographic distribution of MS and that of cancer. The aim of this research was to find an environmental link between the aetiology of MS and cancers in Croatia. Incidence and prevalence of MS in Croatia were compared with the incidence of the most frequent cancer sites: stomach cancer, cancer of the colon and the rectum, pancreatic cancer, lung cancer, cancer of the kidneys and brain cancer. Data for MS were collected from seven population-based epidemiologic studies which used Poser's diagnostic criteria and reported the number of cases and the magnitude of the studied population. Data for cancers were drawn from the Croatian National Cancer Registry. The analysis was done for single municipalities, grouped in their belonging regions or counties, and separately for the continental and the coastal area. For each rate a 95% confidence interval was calculated. The differences between rates were tested with the chi-square test as well. In addition, MS incidence or prevalence were correlated with the corresponding cancer incidence data. Pearson's correlation coefficients were used to measure the correlation between both diseases. Calculations were done with the statistical package Statistica V 7.1. and the Smith's Statistical Package freeware In the continental area of Croatia the mean annual incidence (per 100,000 inhabitants) of MS was nearly two folds higher than in the coastal area: 2.1 vs. 1.3 (p = 0.0029). The difference was lower when expressed by prevalence: 46.5 vs. 36.7 (p = 0.0601). Among the malignant neoplasms, in the continental area significantly higher incidence rates were found for stomach (32.9 vs. 20.8; p = 3.14E-14) and lung cancer (55.8 vs. 46.4; p = 1.21E-05), whilst colon cancer alone (20.4 vs. 15.7; p = 9.44E-05) or colorectal cancer (38.3 vs. 31.6; p = 8.18E-05) had a significantly higher incidence in the coastal area. The geographic distribution of MS expressed by incidence was significantly correlated with pancreatic (r = 0.62024, df=23, p = 0.00094) and lung cancer (r = 0.46380, df=23, p = 0.01953). This research adds further malignant neoplasms, possibly exposure-related, to the list of diseases with geographic distribution like MS. The similarity of MS distribution with the named malignancies is unlikely to be incidental. MS in Gorski Kotar and Slavonia seems to be associated with a diet rich in meat and fat. A diet rich in fat and meat and poor in vegetables is a risk factor for stomach, colorectum, pancreatic as well as lung cancers. Some authors have documented a possible protective role of the "Mediterranean diet" for the named cancers. Olive oil is the main source of fat in the "Mediterranean diet". Oleocanthal, aphenolic compound of the extra-virgin olive oil was found to inhibit the cyclooxigenase enzymes which are involved in demyelination and tumorigenesis. We hypothesize that the "Mediterranean diet", olive oil and particularly oleocanthal, to have a protective role in MS too.

[Adverse effects and interactions of fluoroquinolones]. / Nuspojave i interakcije fluorokinolona.

Floroquinolones are derivatives of nalidixic acid that act as a large-spectrum antibiotics. Adverse effects and interactions of the particular fluoroquinolone depend on its chemical structure and, often, on predisposing factors in patients, including the age, hidden or previous neurological diseases, metabolic disturbances, and allergies. The adverse effects do not significantly differ among different fluoroquinolones. They can be considered as mild, moderate and severe, and their incidence is irrespective of the gender. They can occur even after the short-term administration of these antibiotics, and usually vanish after diminishing the dose or cessation of the therapy in 24-48 hours. The adverse effects can affect nervous, digestive, urinary, cutaneous, musculo-skeletal, cardiovascular, and immune system. Rarely, fluoroquinolones can harm the spermatogenesis. Their use is not advised during pregnancy due to their possible teratogenic effects. Fluoroquinolones can interact with a variety of drugs: antacides, non-steroid antirheumatics, xantines, warfarin, and others. These drug combinations often occur during the therapeutic process in the clinical practice. The incidence of adverse effects and interactions of fluoroquinolones are low; however they can result in serious complications. The post-marketing control of these antibacterial drugs is therefore highly recommended.

[Zvonimir Susic--doyen of Croatian neuropsychiatry in the 20th century]. / Zvonimir Susic--velikan hrvatske neuropsihijatrije 20. stoljeca.

There are three distinct phases in the life of Zvonimir Susic--neurologist, psychiatrist, forensic expert, educator, teacher, translator, and erudite of general and professional knowledge--Zagreb, Rijeka and Zadar phase. In Zagreb (1926-1946) he was promoted to physician (1932), there he was a student tutor, then the assistant at the Physiology Institute of the Medical Faculty; volunteer, hospital doctor (he got the specialization in 1938), assistant and head doctor of the Hospital for Mental Diseases in Vrapce, and the assistant professor (1941) at the Neuropsychiatric Department of the Zagreb University. In Rijeka (1947-1959) he reorganized Psychiatric and established the Neurology Department of the General Hospital "Brothers Dr. Sobol" and, at first, he was the honorary professor, then assistant professor and associate professor of neurology and psychiatry at the Medical Faculty of Rijeka. In Zadar (1960-1968) he was the manager of the Ugljan Hospital. He published approximately 100 works in the field of clinical neurology, neuropathology, psychiatry, and forensic psychiatry, His works on cortical presentation of the body scheme, hallucinations, tuberous sclerosis, pregnancy and multiple sclerosis, pathohistology of demyelisation, toxic neuritis, epilepsies, nervous manifestations of Malta fever, herpetic infections, pathogenesis of convulsive syndromes, psychiatric terminology, therapies of Parkinson disease and schizophrenia, ability of making will, organization of the psychiatric service, were published in national and prestigious European journals, and often cited. He wrote chapters in psychiatric handbooks and special notes in encyclopedic editions. Together with Stanislav Zupic he was the author of the first and only psychodrama in Croatia. He was one of the pioneers of neuropathology in Croatia because he founded the Neuropathology Laboratory in Vrapce Hospital in 1936. He had a remarkable preciseness in examining the patient. He was frequent and imaginative lecturer in various sections in Croatian Medical Association and other public institutions. As a gifted polyglot he was occupied by the translation work when retired. In our, till then Middle-European culture-oriented medical area, he introduced values and patterns of French neurological and German neuropathological schools.

PAI and TPA gene polymorphisms in multiple sclerosis.

Multiple sclerosis (MS) is an immune-mediated chronic inflammatory demyelinating disease of the central nervous system. It manifests as acute focal inflammatory demyelination and axonal loss with limited remyelination and results in the chronic multifocal sclerotic plaques. Previously published data showed impaired fibrinolysis in MS. Tissue plasminogen activator t-PA is a serine protease that catalyses the activation of plasmin, which mediates the effects of fibrinolytic system. Alu insertion/deletion (I/D) genetic polymorphism in TPA gene in MS patients has not been analysed previously. The major inhibitor of t-PA is plasminogen activator inhibitor-1 (PAI-1). Its gene expression is modulated by functional genetic polymorphism in the promoter (4G/5G). In the present study, an association of two genetic polymorphisms with MS, its progression and subtype were analysed. TPA DD/PAI-1 4G4G genotype combination has reached a borderline significance for reduced risk for MS (OR = 0.543, 95% CI 0.301-0.978, P = 0.04), suggesting a gene-gene interaction. The explanation for this interaction may be a complex interplay between these two pleiotropic proteins within the brain tissue and in plasma.

HLA class II polymorphism in autochthonous population of Gorski kotar, Croatia.

The aim of this study was to examine frequencies and haplotypic associations of HLA class II alleles in autochthonous population of Gorski kotar (Croatia). HLA-DRB1, -DQA1 and -DQB1 alleles were determined by DNA based PCR typing in 63 unrelated inhabitants from Gorski kotar whose parents and ancestors were born and lived in tested area for at least over four generations. A total of 13 HLA-DRB1, 12 DQA1 and 14 DQB1 alleles were identified. The most frequent HLA class II genes in Gorski kotar population are: HLA-DRB1*13 (af = 0.150), -DRB1*03 (af = 0.142), -DRB1*07 (af = 0.119), and -DRB1*11 (af = 0.119), HLA-DQA1*0501 (af = 0.278), -DQA1*0102 (af = 0.183), -DQA1*0201 (af = 0.127) and HLA-DQB1*0301 (af = 0.157), -DQB1*0201 (af = 0.139), -DQB1*0501 (af = 0.111). We have identified 24 HLA class II three-locus haplotypes. The most common haplotypes in Gorski kotar population are DRB1*03-DQA* 0501-DQB1*0201 (0.120), DRB1*11-DQA1*0501-DQB1*0301 (0.111) and DRB1*07-DQA1*0201-DQB1*0202 (0.094). The allelic frequencies and populations distance dendrogram revealed the closest relationships of Gorski kotar population with Slovenians, Germans, Hungarians and general Croatian population, which is the result of turbulent migrations within this microregion during history.

Epidemiology of multiple sclerosis in western Herzegovina.

OBJECTIVES: To determine epidemiological rates of multiple sclerosis (MS) in western Herzegovina. PATIENTS AND METHODS: We analysed data from 81 MS patients (49 females, 32 males) on the prevalence day, 31 December 2003. Patient information was obtained from a search of all available medical records from the period 1994-2003 in the investigated area. RESULTS: Crude prevalence of MS was 27/100,000 (95% confidence interval (CI) 20-34). Prevalence was highest in the mountainous municipality of Posusje (56/100,000) and lowest in the coastal municipality of Neum (0 incidence). The annual incidence of MS was 1.6/100,000 (95% CI 0-3.3). The female/male ratio of MS was 1.5. The mean age of the patients on prevalence day was 40.0+/-11.6 years, and the mean age at disease onset was 31.0+/-7.1 years. Eight (10%) of the patients had a first-degree relative with MS. The primary progressive (PP) disease course was observed only in females. Visual symptoms were the initial symptom of MS in 6 (7%) of the patients. CONCLUSIONS: Western Herzegovina is an area of moderate risk for MS, and the distribution of MS in western Herzegovina is heterogeneous. PP-MS occurred only in females, and involvement of the visual pathways as the initial symptom of MS was low.

Tumor necrosis factor-alpha-308 gene polymorphism in Croatian and Slovenian multiple sclerosis patients.

Previous findings regarding the role of TNF-alpha-308 gene polymorphism in multiple sclerosis (MS) are contradictory. The aim of this study was to investigate the possible influence of TNF-alpha-308 polymorphism on MS susceptibility and the MS disease process in a Croatian and Slovenian population. Genotyping was performed in 338 patients and 460 healthy controls. The TNF2 allele was present in 123 (26.8%) healthy controls vs. 67 (19.9%) MS patients (p = 0.023, odds ratio = 0.68, 95% confidence interval = 0.48-0.95), suggesting that carriage of the TNF2 allele might decrease MS risk. The difference in TNF2 allele carrier frequency between patients and controls was identified in the relapsing-remitting MS group. There was no association between TNF2 allele carrier status and age at disease onset or disease progression. Our results suggest that, in the study populations, the TNF-alpha-308 polymorphism may play a role in MS susceptibility.

[Use of magnetic resonance imaging in the diagnosis and prognosis of multiple sclerosis]. / Upotreba magnetske rezonancije u dijagnozi i prognozi multiple skleroze.

Multiple sclerosis is an autoimmune disease characterized by demyelination and axonal loss. Conventional magnetic resonance imaging allows the demonstration of spatial and temporal dissemination of multiple sclerosis lesions earlier than is possible from clinical assessments. A variety of conventional magnetic resonance imaging protocols, in conjunction with clinical assessment, are now routinely used to increase the accuracy of diagnosis and long-term prognosis of multiple sclerosis. T2-weighted hyperintense lesions are related primarily to increased water content and thus cannot distinguish between inflammation, edema, demyelination, Wallerian degeneration, and axonal loss, whereas the contrast gadolinium-enhanced lesions on T1-weighted images reflect increased blood-brain barrier permeability associated with active inflammatory activity. Conventional magnetic resonance imaging metrics are not sufficiently sensitive to detect invisible brain damage in the normal appearing brain tissue, and they do not show a reliable correlation with clinical measures of disability. However, numerous studies showed that they can improve accuracy in the diagnosis and prognosis of multiple sclerosis. Recently, non-conventional magnetic resonance imaging techniques have been introduced to increase the accuracy of diagnosis and prognosis of multiple sclerosis. Several studies have used brain atrophy, T1-hypointense lesion volume, magnetization transfer imaging, diffusion-weighted imaging and magnetic resonance spectroscopy to test whether the extent and severity of tissue loss in lesions and in normal appearing gray and white matter at the time of clinically isolated syndrome may have diagnostic and prognostic value. These magnetic resonance imaging techniques represent a powerful tool to non-invasively study different pathological substrates of lesions and microscopic tissue changes. Additional short- and long-term prospective studies are requested to establish their value in the diagnosis and prognosis of multiple sclerosis.