Prevalence and incidence of multiple sclerosis in Oppland County: a cross-sectional population-based study in a landlocked county of Eastern Norway

Risberg G, Aarseth JH, Nyland H, Lauer K, Myhr K‐M, MidgardR. Prevalence and incidence of multiple sclerosis in Oppland County – a cross‐sectional population‐based study in a landlocked county of Eastern Norway.
Acta Neurol Scand: 2011: 124: 250–257.
© 2010 John Wiley & Sons A/S. Objectives – We report the prevalence and incidence rates of multiple sclerosis (MS) in Oppland County, Norway. Methods – Records from all patients diagnosed with MS at the two Oppland County hospitals, Gjøvik and Lillehammer during 1989–2001 were evaluated. In addition, all general practitioners in Oppland County reported their patients into the study. Results – The age‐adjusted prevalence rate of definite MS was 174.4/ 100 000 on the prevalence day 1 January 2002. When the probable cases were included, the prevalence rate rose to 185.6/100 000. The highest prevalence rates were detected in the northern mountain areas, thus corroborating the results from previous local surveys 30–50 years ago. The prevalence of MS was statistically significantly associated with climatic, socioeconomic and geographic variables in the county. The age‐adjusted incidence of definite and probable MS in Oppland County was 6.6/100 000 during 1989–1993 increasing to 7.6/100 000 during 1994–1998. Discussion – We found the highest prevalence rates of MS ever reported in Norway. Our findings indicate a possible influence of environmental factors.     

Multiple sclerosis in Nord-Trøndelag County, Norway: a prevalence and incidence study

Objective – To calculate the prevalence and incidence of multiple sclerosis (MS) in Nord‐Trøndelag County, Norway. Material and methods – The study comprised everyone diagnosed with MS according to the Poser criteria. On 1 January 2000 a total of 208 were identified: 130 women (62.5%) and 78 men (37.5%). We calculated the crude and age‐adjusted annual incidence rates from 1974 to 1999. Results – The prevalence on 1 January 2000 was 163.6 of 100,000, 204.8 of 100,000 for women and 122.6 of 100,000 for men. The age‐adjusted annual incidence increased from 3.9 to 5.6 per 100,000 from 1974 to 1999; women from 4.6 to 6.3 and men from 2.2 to 4.4. After 1984, the incidence among women increased most, peaking at 10.2 per 100,000 in 1984–88. Conclusions – MS incidence is increasing in Nord‐Trøndelag County. The prevalence is among the highest ever in Norway.     

Myelin glycosphingolipid immunoreactivity and CSF levels in multiple sclerosis

Haghighi S, Lekman A, Nilsson S, Blomqvist M, Andersen O. Myelin glycosphingolipid immunoreactivity and CSF levels in multiple sclerosis.
Acta Neurol Scand: 2012: 125: 64–70.
© 2011 John Wiley & Sons A/S. Objectives – Patients with multiple sclerosis were reported to harbour antibodies not only against proteins and glycoproteins but also against glycolipids, including sulfatide and galactosylceramide (GalCer), the two major glycosphingolipids of myelin. However, previous results were inconsistent concerning glycosphingolipid levels, antibody type, dominance of serum or Cerebrospinal fluid compartments and relationship to the multiple sclerosis (MS) course. Results – We hereby report that the cerebrospinal fluid levels of sulfatide were increased in patients with MS (n = 46) compared with controls (n = 50, P < 0.001). In addition, patients had higher serum IgM anti‐glycosphingolipid titres than controls (P = 0.03 for sulfatide, <0.001 for GalCer), while the anti‐glycosphingolipid IgM antibodies in the cerebrospinal fluid were essentially normal. However, in seven of 46 patients cerebrospinal fluid IgG antibodies against GalCer (P = 0.004) could be detected, which was not found in any of the control individuals, and this finding might mirror the occurrence of more specific B‐cell clones behind the blood–brain barrier. Conclusions – The IgM immunoreactivity in serum did not show any relationship to the type of course or severity of MS, arguing against a phenomenon secondary to myelin damage. Thus, the IgM antibody findings are compatible with an early antigen challenge or autoimmunity associated with natural antibodies.     

The influence of warm versus cold climate on the effect of physiotherapy in multiple sclerosis

Smedal T, Myhr K‐M, Aarseth JH, Gjelsvik B, Beiske AG, Glad SB, Strand LI. The influence of warm versus cold climate on the effect of physiotherapy in multiple sclerosis.
Acta Neurol Scand: 2011: 124: 45–52.
© 2010 John Wiley & Sons A/S. Objective – To compare the effect of inpatient physiotherapy in a warm versus cold climate in short‐ and long‐term perspectives. Methods – Sixty multiple sclerosis (MS) patients with gait problems, without heat intolerance, were included in a randomized cross‐over study of 4‐week inpatient physiotherapy in warm (Spain) and cold (Norway) climate. The primary outcome, 6‐min walk test (6MWT), and secondary physical performance and self‐reported measures were scored at screening, baseline, after treatment and at 3 and 6 months of follow‐up. Treatment effects were analysed by mixed models. Results – After treatment, the mean walking distance had increased by 70 m in Spain and 49 m in Norway (P = 0.060). Improvement in favour of warm climate was demonstrated at 6 months of follow‐up, 43 m (Spain) compared to 20 m (Norway) (P = 0.048). The patients reported less exertion after walking (6MWT) in favour of treatment in Spain at all time points (P < 0.05). No significant differences in change were detected for the other physical performance measures. Most self‐reported measures showed more improvement after treatment in Spain, but these improvements were not sustained at follow‐up. Conclusion – The results indicate that MS patients without heat intolerance have additional benefits from physiotherapy in a warm climate.     

Clinical features of Sjogren’s syndrome in patients with multiple sclerosis

Annunziata P, De Santi L, Di Rezze S, Millefiorini E, Capello E, Mancardi G, De Riz M, Scarpini E, Vecchio R, Patti F. Clinical features of Sjogren’s syndrome in patients with multiple sclerosis.
Acta Neurol Scand: 2011: 124: 109–114.
© 2010 John Wiley & Sons A/S. Objectives – To assess the frequency of clinical features of Sjogren’s syndrome (SS) in patients with multiple sclerosis (MS) receiving treatment with disease‐modifying drugs (DMDs) or naïve to treatment and the possible association with clinical, cerebrospinal fluid (CSF) and magnetic resonance imaging (MRI) parameters. Methods – A multicentre cross‐sectional observational study was designed, based on a structured neurologist‐administered questionnaire to 440 patients. Results – Twenty‐eight of 230 (12%) patients receiving treatment with DMDs (DMDs⁺) and 14 of 210 (6.6%) treatment‐naïve patients (DMDs⁻) showed clinical features of SS. Four primary SS were diagnosed, two of which were DMDs⁺ and two were DMDs⁻. Sicca symptoms were significantly associated with higher EDSS scores (P = 0.018), a low frequency of gadolinium‐enhanced MRI‐positive lesions (P = 0.018) and cerebral disturbances (P = 0.001). Conclusions – Screening for the clinical features of SS should be performed in patients with MS both receiving treatment with immunomodulatory drugs and without therapy.     

Comparison of carbamazepine rash in multiple sclerosis and epilepsy

Shirzadi M, Alvestad S, Hovdal H, Espeset K, Lydersen S, Brodtkorb E. Comparison of carbamazepine rash in multiple sclerosis and epilepsy.
Acta Neurol Scand: 2012: 125: 60–63.
© 2011 John Wiley & Sons A/S. Objectives – Studies on the comorbidity of multiple sclerosis (MS) and allergic disorders have shown conflicting results. Carbamazepine (CBZ) is widely used in MS to control pain. We have compared the incidence of rash from CBZ use in MS and epilepsy. Materials and Methods – Consecutive adult patients with MS and epilepsy were studied retrospectively. A detailed survey of medical records concerning CBZ treatment was performed. Results – A total of 495 patients with epilepsy and 442 patients with MS were included. Sixty‐five per cent of patients with epilepsy and 20% of patients with MS had used CBZ. In CBZ‐exposed patients, rash occurred in 15/89 (17%) in MS and in 43/323 (13%) in epilepsy, a difference which was not significant. Women below 50 years experienced more skin reactions than older women and men. The unadjusted odds ratio (OR) for rash in the MS vs epilepsy group was 1.32 (CI 0.70–2.51, P = 0.40). Adjusting groups for gender and age reduced the OR to 1.11 (CI 0.56–2.19, P = 0.76). Conclusion – Compared with epilepsy, which is only rarely caused by immunological mechanisms, the autoimmune disorder MS was not associated with a different occurrence of CBZ skin reactions. The trend towards an increased occurrence of rashes in MS can partly be explained by a higher predisposition to CBZ rash in women of fertile age.     

MRI and visual-evoked potentials in partners of multiple sclerosis patients

Hawkes CH, Chawda S, Derakshani S, Muhammed N, Visentin E, Boniface D. MRI and visual‐evoked potentials in partners of multiple sclerosis patients.
Acta Neurol Scand: 2012: 125: 424–430.
© 2011 John Wiley & Sons A/S. Objective – Some epidemiological evidence, particularly concerning the role of Epstein Barr Virus implies that multiple sclerosis (MS) may be transmissible and if correct, this might be revealed by increased prevalence of MS in cohabiting partners. Methods – We addressed this problem by neurological assessment, visual‐evoked potentials (VEP) and magnetic resonance imaging (MRI) in 112 partners of patients with MS in comparison to a control group of 93 individuals with clinically non‐significant head or neck pain and in comparison to UK prevalence. Results – We found one instance of conjugal definite MS. Including this case, VEP were abnormal in five instances with either significant delay (n = 3) or increased interocular latency difference (IOLD) (n = 2) in partners of MS patients thus raising the possibility of subclinical optic nerve demyelination. The mean absolute value of IOLD in partners was greater than the value in controls (P = 0.033). There were no significant differences in MRI findings between the two groups. Conclusion – The finding of one conjugal pair and abnormal VEP in a further four MS partners could have several explanations. It is compatible with the concept of a transmissible agent, although our observations could be due to several biases as well as the play of chance alone.     

Chronic polyneuropathies in Vest-Agder, Norway

Epidemiological data on chronic polyneuropathies, especially inflammatory types, is limited. The purpose of this study was to examine the spectrum of causes and estimated prevalence of various polyneuropathy types in Vest‐Agder, and to examine the clinical features of the Vest‐Agder population of chronic inflammatory demyelinating polyneuropathy (CIDP). In Vest‐Agder county (population of 155 464), polyneuropathy patients are registered in a database and followed prospectively. We did a measure of the database on October 31 1999. A total of 192 patients were registered. The prevalence for chronic inflammatory demyelinating polyneuropathy (CIDP) was 7.7 per 100 000 population. The course was relapsing in five of fifteen patients, progressive in four patients and slowly progressive in six of fifteen patients. Two of the fifteen patients had pure sensory symptoms. The mean Rankin disability score was 3.4 at maximal deficit and 2.1 at last follow‐up. The prevalence of paraproteinemic polyneuropathy was 5.1 per 100 000 population. None of the patients with paraproteinemic polyneuropathy were worse than slightly disabled (disability score ≤ 2). The prevalences for other polyneuropathies were as follows: polyneuropathy and RA, 1.3; polyneuropathy and Sjögren's syndrome or sicca complex, 4.5 (polyneuropathy was the presenting symptom in five of seven patients); sarcoidosis 1.9; polyneuropathy and chronic Lyme, 0.6; paraneoplastic polyneuropathy, 1.9; diabetic polyneuropathy 23.2; vitamin deficiency, 5.1; alcoholic and toxic polyneuropathy, 19.9; hereditary polyneuropathy, 14.8. Cryptogenic polyneuropathies made up 26% of all polyneuropathies. The mean disability score was 2.0 (SD 1.1). In conclusion, prevalence of CIDP was significantly higher than previously reported, and the prognosis was good in the majority of patients. Patients with paraproteinemic polyneuropathy were not severely disabled. Polyneuropathy was the presenting symptom in the majority of patients with Sjögren's syndrome or sicca complex.     

Validation of the multiple sclerosis international quality of life (MusiQoL) questionnaire in Norwegian patients

Beiske AG, Baumstarck K, Nilsen RM, Simeoni M‐C. Validation of the multiple sclerosis international quality of life (MusiQoL) questionnaire in Norwegian patients.
Acta Neurol Scand: 2012: 125: 171–179.
© 2011 John Wiley & Sons A/S. Objectives – To assess the validity and reliability of the multidimensional, self‐administered Multiple Sclerosis International Quality of Life (MusiQoL) questionnaire, previously validated in a large international sample, in Norwegian patients. Patients and methods – Patients with different types and severities of multiple sclerosis (MS) were recruited from a single MS centre in Norway. All patients completed the MusiQoL and Short Form‐36 (SF‐36) QoL questionnaires at baseline and a mean of 21 (SD 7) days later. A neurologist collected sociodemographic, MS history and outcome data. Construct validity, internal consistency, reproducibility and external consistency were tested. Results – One hundred and four patients were evaluated. Construct validity was confirmed in terms of satisfactory item internal consistency correlations in eight of nine MusiQoL dimensions (Spearman’s correlation: 0.34–0.79) and scaling success of item discriminant validity (75.0–100%). All dimensions of the MusiQoL questionnaire exhibited satisfactory internal consistency (Cronbach’s alpha: 0.44–0.87) and reproducibility (intraclass correlation coefficients: 0.36–0.86). External validity testing showed that the global MusiQoL score correlated significantly with all but one individual SF‐36 dimension score (Spearman’s correlation: 0.29–0.56). Conclusions – These results demonstrate that the Norwegian‐language version of the MusiQoL questionnaire is a valid and reliable instrument for assessing health‐related QoL in Norwegian patients with MS.     

EBNA1 and LMP1 variants in multiple sclerosis cases and controls

Simon KC, Yang X, Munger KL, Ascherio A. EBNA1 and LMP1 variants in multiple sclerosis cases and controls.
Acta Neurol Scand: 2011: 124: 53–58.
© 2010 John Wiley & Sons A/S. Background – Prior infection with Epstein–Barr virus (EBV) is an established risk factor for multiple sclerosis (MS). Some findings from observational studies, including possible epidemics and differences in prevalence, may be explained if different strains of EBV conferred different MS risk. Methods – DNA was extracted from peripheral lymphocytes obtained from 66 MS cases and 66 age‐ and cohort‐matched controls. Nested polymerase chain reaction (PCR) was performed to amplify the N‐ and C‐terminus regions of EBNA1 and the hyper‐variable region of the LMP1 gene. For EBNA1, we compared the presence of the prototype B95.8 vs variant sequence and the presence of multiple strains in MS cases and controls. For LMP1, we considered differences in the proportions of mutations between cases and controls. Results – Comparing the proportion of mutant sequence between MS cases and controls in the EBNA1 N‐terminal (0/28 vs 1/27) and C‐terminal regions (3/40 vs 8/36) revealed no significant differences (P > 0.05). No individual variants in LMP1 were associated with risk of MS (all P > 0.05). Neither EBNA1 nor LMP1 variation was associated with anti‐EBNA1 IgG antibody titers. Conclusions – These findings do not support a strong role for variation in EBNA1 N‐terminus, EBNA1 C‐terminus or LMP1 contributing to MS risk.     

More CLEC16A gene variants associated with multiple sclerosis

Nischwitz S, Cepok S, Kroner A, Wolf C, Knop M, Müller‐Sarnowski F, Pfister H, Rieckmann P, Hemmer B, Ising M, Uhr M, Bettecken T, Holsboer F, Müller‐Myhsok B, Weber F. More CLEC16A gene variants associated with multiple sclerosis.
Acta Neurol Scand: 2011: 123: 400–406.
© 2010 John Wiley & Sons A/S. Objectives – Recently, associations of several single‐nucleotide polymorphisms (SNPs) within the CLEC16A gene with multiple sclerosis (MS), type‐I diabetes, and primary adrenal insufficiency were reported. Methods – We performed linkage disequilibrium (LD) fine mapping with 31 SNPs from this gene, searching for the region of highest association with MS in a German sample consisting of 603 patients and 825 controls. Results – Four SNPs located in intron 19 of the CLEC16A gene were found associated. We could replicate the finding for SNP rs725613 and were able to show for the first time the association of rs2041670, rs2080272 and rs998592 with MS. Conclusion – All described base polymorphisms are mapping to one LD block of approximately 50 kb within intron 19 of the CLEC16A gene, suggesting a pivotal role of this region for susceptibility of MS and possibly also for other autoimmune diseases.     

Cumulative impact of comorbidity on quality of life in MS

Marrie RA, Horwitz R, Cutter G, Tyry T. Cumulative Impact of Comorbidity on Quality of Life in MS.
Acta Neurol Scand: 2012: 125: 180–186.

© 2011 John Wiley & Sons A/S. Background – Little is known about the impact of comorbidity on health‐related quality of life (HRQOL) in multiple sclerosis (MS). We investigated the association of comorbidity and health‐related HRQOL among participants in the North American Research Committee on Multiple Sclerosis (NARCOMS). Materials and Methods – In 2006, we queried NARCOMS participants regarding physical and mental comorbidities and HRQOL, using the Short‐Form 12. We summarized physical HRQOL using the aggregate Physical Component Scale (PCS‐12) score and mental HRQOL using the aggregate Mental Component Scale (MCS‐12) score. We assessed multivariable associations between comorbidity and HRQOL using a general linear model, adjusting for potential confounders. Results – Among 8983 respondents, the mean (SD) PCS‐12 was 36.9 (11.8) and MCS‐12 was 45.6 (11.6). After adjustment for sociodemographic and clinical factors, participants with any physical comorbidity had a lower PCS‐12 (37.2; 95% CI: 36.4–38.1) than those without any physical comorbidity (40.1; 95% CI: 39.0–41.1). As the number of physical comorbidities increased, PCS‐12 scores decreased (r = ?0.25; 95% CI: ?0.23 to ?0.27) indicating lower reported HRQOL. Participants with any mental comorbidity had a lower MCS‐12 (40.7; 95% CI: 39.8–41.6) than those without any mental comorbidity (48.5; 95% CI: 47.7–49.4). Conclusions – Comorbidity is associated with reduced HRQOL in MS. Further research should evaluate whether more aggressive treatment of comorbidities improves the HRQOL of MS patients.     

Impact of cladribine on soluble adhesion molecules in multiple sclerosis

Mitosek‐Szewczyk K, Stelmasiak Z, Bartosik‐Psujek H, Belniak E. Impact of cladribine on soluble adhesion molecules in multiple sclerosis.
Acta Neurol Scand: 2010: 122: 409–413.
© 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Background – Soluble forms of vascular cell adhesion molecule‐1 (VCAM‐1), intracellular adhesion molecule‐1 (ICAM‐1) and E‐Selectin play a role in the regulation of blood–brain barrier damage and represent markers of the clinical course of multiple sclerosis (MS) and magnetic resonance imaging activity. We determined sICAM, sVCAM and sE‐Selectin concentrations in the cerebrospinal fluid (CSF) and serum of patients with remitting–relapsing multiple sclerosis before and after cladribine treatment as well as in a control group. Methods – We examined 17 patients diagnosed according to McDonald’s criteria. Thirteen healthy age‐matched subjects served as controls. The ELISA method was used to measure sICAM‐1, sVCAM‐1 and sE‐Selectin. Results – The concentration of sICAM and sE‐Selectin decreased in sera (difference between patients and controls was statistically significant, in the former P < 0.04, in the latter P < 0.0003) but not in the CSF of MS patients after cladribine treatment. Conclusions – The reduction in sICAM and sE‐Selectin concentrations after cladribine treatment indicates an immuno‐suppressive effect of the drug. The changes in levels of sICAM and sE‐Selectin after cladribine treatment reflect disease activity and indicate a reduction in the inflammatory reaction.     

Multiple sclerosis in Móstoles,central Spain

Objectives– Until relatively recently southern Europe was regarded as having a medium to low multiple sclerosis prevalence, of about 20 or less per 100,000. However, recent studies in Sardinia, Sicily, continental Italy, Cyprus and Spain have yielded higher MS prevalence rates, between 32 and 102.6 per 100,000. We present the results of a prevalence study of MS in the municipality of Móstoles, central Spain. Material and methods– To ascertain the prevalence of multiple sclerosis in Móstoles (195,979 inhabitants), an intensive study was undertaken using several sources of information. We used the Poser criteria in diagnosis. Results– There were 85 patients (53 women and 32 men) classified as definite or probable, prevalence 43.4/100,000 (95% CI, 34.7 to 53.7). The incidence rate was 3.8/100,000/year (95% CI, 2.7 to 5.3) in the last 5 years. Mean age on prevalence day was 38.8±10.9 years. Mean age at onset was 31.7±9.3 years. Mean interval between initial symptoms and diagnosis was 1.7 years. Mean duration of disease was 7.6±6.1 years. Overall, 70.6% had a relapsing–remitting course, 18.8% had a primary progressive and 10.5% had a secondary progressive. Mean EDSS score was 2.7±1.9. Conclusion– The Móstoles study confirms the conclusions of previous smaller population studies that Spain is a moderately high or medium MS risk zone.     

Non‐adherence to interferon‐beta therapy in Swedish patients with multiple sclerosis

Cunningham A, Gottberg K, von Koch L, Hillert J. Non‐adherence to interferon‐beta therapy in Swedish patients with multiple sclerosis.
Acta Neurol Scand: 2010: 121: 154–160.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives – To explore the occurrence and reasons for stopping, switching or continuing first prescribed interferon‐beta therapy in patients with multiple sclerosis in Sweden, with respect to demographic, clinical and/or therapy‐related factors. Materials and methods – A retrospective study reviewing the medical charts of 259 patients with multiple sclerosis, comparing patients continuing therapy for at least 3 years with those switching or stopping therapy. Results – Sixty 9% stopped (15%), or switched (54%), interferon‐beta therapy within 3 years. Stoppers had longer disease duration before starting therapy (P = 0.002), less frequently relapsing‐remitting multiple sclerosis (P = 0.046), and more often Expanded Disability Status Scale scores 6–9.5 (P = 0.045) compared to Switchers. The most common reasons for switching/stopping therapy were perceived lack of effect and side‐effects. Conclusions – Adherence to initial immune‐modulating therapy is low; identification of patients at higher risk of stopping therapy and provision of adequate support are essential.     

Multiple sclerosis incidence in the Faroe Islands 1986–2007

Joensen P. Multiple sclerosis incidence in the Faroe Islands 1986–2007. Acta Neurol Scand: 2010: 121: 348–353.
© 2009 The Author Journal compilation © 2009 Blackwell Munksgaard. Objective – Epidemiological studies of the isolated Faroese population in 1945 identified a high annual incidence of multiple sclerosis (MS) of 10/100,000. At the time, there was speculation that the disease was brought to the country by British occupation forces resident in the islands from 1940 to 1945. The objective of the current study is to determine the incidence of diagnosis of MS in the Faroe Islands during the period 1986–2007. Methods – All patients in the Faroe Islands diagnosed with MS from July 1, 1986 to July 1, 2007 are documented in the current longitudinal, prospective study. The diagnosis is based on clinical observation, magnetic resonance imaging scanning, cerebrospinal fluid tests, and visual evoked potential response testing. Results – The incidence of MS during the period 1986–2007 is 4.5/100,000 annually. This is generally of the same order of magnitude as other research findings in Scandinavia and Iceland. The incidence of MS from 1986 to 2007 is about double the incidence in the Faroe Islands for the period from 1940 to 1986, calculated to be 2.7/100,000 annually. Conclusion – The observed incidence of MS in the Faroe Islands, where the population is genetically homogeneous and where the diet exposes the population to neuro‐toxic contamination, is at the same level as found in other high‐risk regions. The former detected epidemics of MS in Faroe Islands seems apparently to have leveled out and could not be recognized in the recent period covered by the present survey.     

Prevalence of multiple sclerosis in Västerbotten County in northern Sweden

Objective – To estimate the prevalence and clinical characteristics of multiple sclerosis (MS) in Västerbotten County in northern Sweden. Methods–Individuals with MS were identified from several sources. A follow‐up interview and/or examination was performed in 94% of cases still living in the area during 1997–99. Onset adjusted prevalence and a definition of onset symptoms were applied. Results– A total of 313 cases were identified, resulting in an onset adjusted crude prevalence of MS for January 1990 of 125/10⁵ (95% confidence interval (CI): 112–140). Female predominance was evident (163/10⁵ (95% CI: 142–187) vs 86/10⁵ (95% CI: 71–104)). Diagnostic coding registers were the most important source for identification of cases. Conclusions– The crude prevalence of MS in Västerbotten was higher than previous reports from other major areas in Scandinavia. The adjusted prevalence was significantly higher when compared with a previous study from Göteborg, south‐western Sweden. The methodology used in this study gives a high degree of case ascertainment and increases the comparability of multiple sclerosis epidemiological studies.     

Incidence of amyotrophic lateral sclerosis in the Faroe Islands

Joensen P. Incidence of amyotrophic lateral sclerosis in the Faroe Islands.
Acta Neurol Scand: 2012: 126: 62–66.
© 2011 John Wiley & Sons A/S. Objectives – The establishment of variations in the incidence of amyotrophic lateral sclerosis (ALS) in the Faroese population from that found in other general populations may point to risk factors for the development of this disease among the Faroese. The aim of this study was to estimate the annual incidence of ALS during the period 1987–2009 and to compare the occurrence of ALS in the Faroe Islands with data from three European countries. Method – All Faroese patients diagnosed with ALS in this period are documented in the current longitudinal prospective study. Results – The incidence of ALS in the Faroe Islands during the period 1987–2009 is 2.6 (1.7–3.7) per 100,000 annually. The results yielded no strong evidence of a difference (P = 0.09) in the incidence of ALS between Faroe Islands and Europe. The sample population is small, and this, of course, impacts the statistical precision of the findings. Conclusion – The data clearly suggest, however, that the Faroese population is probably not subject to an increased risk of ALS, even though certain risk factors are present in the general population: (i) a fish‐based diet contaminated with mercury and polychlorinated biphenyl; (ii) the high occurrence of the recessive carnitine transporter genetic defect; and (iii) the anticipated high degree of inbreeding at the fifth generation.     

Bilateral and recurrent optic neuritis in multiple sclerosis

Burman J, Raininko R, Fagius J. Bilateral and recurrent optic neuritis in multiple sclerosis.
Acta Neurol Scand: 2011: 123: 207–210.
© 2010 John Wiley & Sons A/S. Objective – To assess the frequency of bilateral and recurrent optic neuritis (ON) in multiple sclerosis (MS) and to compare these results with epidemiological data of ON in neuromyelitis optica (NMO) and recurrent ON without other signs of disease. Methods – We identified 472 patients with diagnosis of MS from the Swedish Multiple Sclerosis Register. These patients were evaluated for the presence of ON and whether the ON was the presenting symptom of MS; unilateral or bilateral; monophasic or recurrent. Results – Twenty‐one percent presented with ON as their first manifestation of MS. The proportion of patients developing a second attack of ON before demonstration of other manifestations of MS was 5.5% and the frequency of recurrent bilateral ON as the presenting symptom was 3.8%. Only two patients presented with simultaneously appearing bilateral ON corresponding to 0.42%. Conclusion – Recurrent ON, whether unilateral or bilateral, is a common presentation of MS. As MS is a much more common disease than NMO, care must be taken when evaluating the work‐up of patients with recurrent ON. In some cases repeated MRI and lumbar punctures are warranted to improve diagnostic accuracy, even in the presence of the serological marker NMO‐IgG.