Longitudinal stability of JCV antibody index in Natalizumab treated people with multiple sclerosis

OBJECTIVE

The aim of this study was to evaluate the evolution of JCV index over time in Natalizumab treated people with multiple sclerosis.

MATERIALS AND METHODS

We retrospectively reviewed antibody index values from pwMS who were treated with Natalizumab for greater than six months and had at least two antibody results available between 2011 and 2019. Survival analysis was performed on those who were JCV index value negative at baseline to evaluate time to seroconversion. In pwMS who had index values available at 48 and/or 96 months post Natalizumab initiation, t-tests were performed to evaluate change in index over time.

RESULTS

1144 JCV antibody index results were available for 132 pwMS. Median time to seroconversion based on survival analysis was 103 months. Annualised seroconversion rate was 5.8%. Initial antibody index and rate of seroconversion did not differ with regards to age or gender. Antibody index increased significantly over time on treatment for the cohort as a whole, initial antibody index (0.27) to final antibody testing (0.86), t(131)=6.45, p<.0005. There was a significant increase in those with initial positive index value, between first (0.95) and final index (2.14), t(33) = 4.85, p<.0005 over a median of 77 months.

CONCLUSIONS

In those who were seronegative at baseline there is a long median duration of treatment with Natalizumab prior to seroconversion. In individuals with positive JCV antibody index at treatment initiation, antibody index increases over time.

A Life-Saving Palsy: Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) Presenting As Hand Weakness during Cardiopulmonary Resuscitation (CPR) Training

Aim To describe a case of acute and transient hand weakness that developed during cardiopulmonary resuscitation (CPR) training. Hereditary neuropathy with liability to pressure palsies (HNPP) should be considered in patients with recurrent, painless motor or sensory neuropathies at sites of peripheral nerve compression. Methods Nerve conduction studies confirmed neuropraxia of the distal ulnar nerve with a mild background demyelinating peripheral neuropathy. Results A positive family history emerged and HNPP was confirmed by genetic testing. HNPP is most reliably diagnosed by molecular testing for peripheral myelin protein 22 (PMP22) gene deletion or point mutation on chromosome 17p11.2. Conclusion CPR, a procedure carried out by medical professionals on a daily basis, is a high-energy manual task and provides multiple opportunities for nerve compression. This case demonstrates the importance of having a high index of clinical suspicion of this disorder in patients. Recognising a diagnosis of HNPP may prevent unnecessary surgical decompression.

"Neurophobia": More Nurture than Nature?

AIM

"Neurophobia" is the fear of neurology experienced by medical students. The aim of this study was to investigate if neurology now has a stigma attached to it causing a preconceived negative perception of neurology by students.

METHODS

An online questionnaire was distributed to medical students via social media and email. Questions focused on students' perceptions of neurology before and after exposure to the subject.

RESULTS

There were one hundred and thirty-seven responses. Twenty percent of preclinical students, twenty-six percent of early clinical students and fifty-six percent of clinical students said that they would not consider neurology as a speciality in the future. Neurophysiology and neuroanatomy were considered to be the most difficult aspects of neurology. Integration of preclinical academic training with clinical training was highlighted as a point of difficulty for students.

DISCUSSION

Contrary to our initial hypothesis, "neurophobia" does not appear to be innate in medical students but is acquired during the course of their medical training.

An Audit of the Effectiveness of Large Group Neurology Tutorials for Irish Undergraduate Medical Students

The aim of this audit was to determine the effectiveness of large group tutorials for teaching neurology to medical students. Students were asked to complete a questionnaire rating their confidence on a ten point Likert scale in a number of domains in the undergraduate education guidelines from the Association of British Neurologists (ABN). We then arranged a series of interactive large group tutorials for the class and repeated the questionnaire one month after teaching. In the three core domains of neurological: history taking, examination and differential diagnosis, none of the students rated their confidence as nine or ten out of ten prior to teaching. This increased to 6% for history taking, 12 % in examination and 25% for differential diagnosis after eight weeks of tutorials. This audit demonstrates that in our centre, large group tutorials were an effective means of teaching, as measured by the ABN guidelines in undergraduate neurology.

The Face-Symbol Test and the Symbol-Digit Test are not reliable surrogates for the Paced Auditory Serial Addition Test in multiple sclerosis

The Paced Auditory Serial Addition Test (PASAT) is the chosen task for cognitive assessment in the multiple sclerosis functional composite (MSFC) and a widely used task in neuropsychological studies of people with multiple sclerosis (MS), but is unpopular with patients. The Face-Symbol Test (FST) and Symbol-Digit Tests (SDT) are alternative methods of cognitive testing in MS, which are easily administered and patient-friendly. In order to evaluate the potential of the FST as a possible surrogate for the PASAT, we directly compared the FST to the PASAT and the SDT in a cohort of 50 MS patients with varying levels of disability. There was significant correlation between SDT and FST scores (Spearman’s rho 0.80, 95% CI 0.66 - 0.88), R2 65%, with moderate inter-test agreement (κ = 0.52). In contrast, SDT and FST scores were less predictive of PASAT scores. We concluded that neither the FST nor SDT are reliable surrogates for the PASAT.

Myasthenia gravis: a population-based epidemiological study

Myasthenia Gravis (MG) is a disorder affecting components of the neuromuscular junction. Epidemiological studies show rising incidence and prevalence rates. The aim of this study was to determine the incidence and prevalence of MG in the Republic of Ireland. Data sources included patient lists from consultant neurologists and ophthalmologists, a neuroimmunology laboratory, general practitioners and the Myasthenia Gravis Association. A total of 1715 cases were identified, of which 706 definite, probable or possible autoimmune and congenital MG cases were included. The overall prevalence rate from the data obtained is 15.38/100,000. The study demonstrated a female preponderance (female:male of 1.3: 1) and some geographical variation within Ireland. The average incidence rate for the years 2000 to 2009 was 11.3 per year; the rate for the current decade is 18 per year. The increasing number of diagnoses may be due to improved access to diagnostic investigations and increasing awareness of the clinical manifestations.

Headaches, neurologists and the emergency department

This study explores the claim that headache management can be improved by evaluating current emergent care. A retrospective chart review investigated primary complaints of headache during a three-month period. Two hundred and twenty seven patients were identified for review and three-month follow-up using fully available records and imaging. A total of 543/8,759 had a neurological condition. The most common conditions were headaches (42% or 227 cases), cerebrovascular problems (26%) and seizures (17%). No 'usual headache' patterns showed abnormal imaging. In contrast, those with 'sudden-onset' type or clinical findings had an abnormal scan 17% of the time. Of the MRIs ordered, one-quarter changed management. On discharge, 39% of patients left without a specific headache diagnosis. In the discussion, we evaluate how well a tertiary referral ED treats its most common neurological complaint, focusing on the controversial topics of when to investigate and prevention of re-attendance.

Diagnostic Efficacy of Conventional MRI Pulse Sequences in the Detection of Lesions Causing Internuclear Ophthalmoplegia in Multiple Sclerosis Patients

PURPOSE

The purpose of this study was to investigate the diagnostic efficacy of a range of conventional magnetic resonance imaging (MRI) pulse sequences in the identification of internuclear ophthalmoplegia (INO) caused by medial longitudinal fasciculus (MLF) lesions in multiple sclerosis patients using a receiver-operating characteristic (ROC) methodology.

METHODS

A total of 15 clinically confirmed INO and 15 control subjects underwent conventional MRI at 1.5 T consisting of T2-weighted, proton density (PD)-weighted, and fluid-attenuated inversion recovery (FLAIR) sequences, following full institutional approval. A free-response, multiple-reader multiple-case design ROC study was used to evaluate the diagnostic efficacy of each sequence. All imaging sequences were evaluated by 10 board-certified neuroradiologists. Area under the curve (AUC), sensitivity, and specificity were analysed statistically for all three pulse sequences using repeated-measures analyses of variance and post-test analysis using Bonferroni's multiple comparison test of differences.

RESULTS

No significant AUC differences were found between the three sequences (p = 0.0697), with T2 recording the highest AUC (0.8346). Sensitivity differences between PD (0.7927) and FLAIR (0.6329) were significant (p < 0.05). Non-significant differences were also evident between T2 and FLAIR (p = 0.0511). The specificity analysis revealed an overall difference (p = 0.0005), with specific inter-sequence differences shown between T2 and PD (p < 0.05) and PD and FLAIR (p < 0.001) with the PD values being lower than those provided with the other two sequences.

CONCLUSION

T2-weighted axial imaging through the MLF region resulted in the greatest overall diagnostic efficacy when viewing a combination of mean AUC, sensitivity, and specificity, in terms of the identification of INO-causing lesions.

Parkinson's disease: how is employment affected?

BACKGROUND

Rates of unemployment and early retirement are increased in Parkinson's disease (PD) and contribute to disease burden.

AIMS

To investigate time to loss of employment from PD onset and predictors of continued employment; to identify common issues and possible interventions in the workplace.

METHODS

Eighty-eight patients with PD diagnosed at age≤65 years took part in a retrospective cohort study. Veterans RAND Short Form-36 and an employment survey were administered.

RESULTS

Unemployment rates for males were increased compared to the general Irish population (standardized ratio of 1.6, 95% CI 1.2-2.2, P<0.05). There was no significant difference for females. Median retirement age was 58 years for males and 61 years for females compared to 63.5 and 65 years, respectively, in the general population. In survival analysis, median time to loss of employment was 7 years (95% CI 4.8-9.2). After 5 years, 40% remained working and 14% after 10 years. Early age of PD onset (P<0.001), early diagnosis (P<0.002) and high scores in vitality (P<0.005) were associated with prolonged employment. There was no association with sex, education, type or hours of work. Slowness, fatigue and tremor were the most challenging symptoms at work. Changes in work schedule and type of work were suggested helpful adjustments.

CONCLUSION

Loss of employment places a significant socioeconomic burden on young PD patients. More detailed examination of specific issues and reasonable adjustments is needed, along with patient and employer education.

A proposed modification to the McDonald 2010 criteria for the diagnosis of primary progressive multiple sclerosis

Background:

The diagnostic criteria for primary–progressive multiple sclerosis (PPMS) have undergone revision over the last 20 years. Cerebrospinal fluid oligoclonal bands (CSFOBs) have received less emphasis in recent revisions of the McDonald criteria. The aim of this study was to examine the sensitivity of the diagnostic criteria for PPMS with particular reference to spinal cord criteria and examine the utility of CSFOBs in a cohort of PPMS patients.

Methods:

All new PPMS diagnoses between 1990 and 2011 were identified. Baseline clinical details and paraclinical evaluations including MRI of the brain, spinal cord, CSF and visually evoked responses (VERs) were assessed. The proportion of patients who met the requirements for diagnosis of PPMS on the basis of Thompson’s and the McDonald Criteria (2001, 2005, 2010) were determined.

Results:

There were 88/95 PPMS patients who had at least two diagnostic investigations. The sensitivity of Thompson’s and the McDonald 2001 criteria was 64%; the McDonald 2010 revisions gave the highest sensitivity (77%); the McDonald 2005 criteria had intermediate sensitivity (74%). The combination of CSFOBs and MRI of the brain yielded the greatest number of patients demonstrating dissemination in space (DIS) on only two investigations. VERs did not aid diagnosis. Reducing requirements for the number of spinal cord lesions (symptomatic or not) to one increased diagnostic sensitivity to 84%.

Conclusion:

An alternative criterion requiring two of: i) MRI of the brain with one or more lesions in two of three regions typical for demyelination; ii) the presence of one T2-weighted spinal cord plaque (typical for demyelination); iii) CSFOBs; would increase the diagnostic sensitivity for PPMS.

A web-based electronic neurology referral system: a solution for an overburdened healthcare system?

Ireland has the lowest number of consultant neurologists per capita in Europe. This results in long waiting lists, overbooked clinics, unnecessary emergency department presentations and patient frustration. In 2006, the neurology department in St. Vincent's University Hospital and the National Healthlink project, launched an internet referral system (Neurolink) for GPs, to alleviate the administrative burden on staff, reduce unnecessary visits for patients, shorten waiting lists and improve patient care. 710 electronic referrals from GPs between December 2006 and January 2011 were analysed. The average time taken to for a consultant to reply to a GP referral was 19hours 8minutes. When asked their opinion as to the suspected aetiology 33.7% (239/710) of GPs selected the option "unknown", followed by epilepsy 12.1% (86/710), migraine 12% (85/710), and multiple sclerosis 7.6% (54/710). Significantly, 19% (127/662) of referrals did not require a neurology outpatient appointment and the GP was given advice. The results highlight the benefits of using an electronic communication system with primary care; allowing prompt response to GP enquires, early initiation of treatment and reducing the number of patients attending hospital clinics.

Multiple sclerosis, from referral to confirmed diagnosis: an audit of clinical practice

Background: The National Institute for Health and Clinical Excellence (NICE) guidelines recommend a timeline of 6 weeks from referral to neurology consultation and then 6 weeks to a diagnosis of multiple sclerosis (MS).

Objectives: We audited the clinical management of all new outpatient referrals diagnosed with MS between January 2007 and May 2010.

Methods: We analysed the timelines from referral to first clinic visit, to MRI studies and lumbar puncture (LP) (if performed) and the overall interval from first visit to the time the diagnosis was given to the patient.

Results: Of the 119 diagnoses of MS/Clinically Isolated Syndrome (CIS), 93 (78%) were seen within 6 weeks of referral. MRI was performed before first visit in 61% and within 6 weeks in a further 27%. A lumbar puncture (LP) was performed in 83% of all patients and was done within 6 weeks in 78%. In total, 63 (53%) patients received their final diagnosis within 6 weeks of their first clinic visit, with 57 (48%) patients having their diagnosis delayed. The main rate-limiting steps were the availability of imaging and LP, and administrative issues.

Conclusions: We conclude that, even with careful scheduling, it is difficult for a specialist service to obtain MRI scans and LP results so as to fulfil NICE guidelines within the optimal six-week period. An improved service would require MRI scans to be arranged before the first clinic visit in all patients with suspected MS.

Multiple sclerosis prevalence in Ireland: relationship to vitamin D status and HLA genotype

BACKGROUND

The relationship between prevalence of multiple sclerosis (MS) and latitude may be due to both genetic and environmental factors. The hypothesis that, in Ireland, MS prevalence is increasing and that north-south differences relate to variation in serum 25-hydroxyvitamin D (25(OH)D) levels was tested in this study.

PATIENTS AND METHODS

Patients and matched control subjects were identified in counties Donegal, Wexford and South Dublin through multiple sources. Prevalence was determined. Blood samples were taken for serum 25(OH)D and serum intact parathyroid hormone measurement, and DNA was extracted.

RESULTS

Prevalence in 2007 was significantly greater in Donegal (northwest) (290.3/105, 95% CI 262.3 to 321.7) compared with 2001 (184.6/105; 162 to 209.5). In Wexford (southeast), there was a non-significant increase in prevalence in 2007 compared with 2001. Prevalence was significantly higher in Donegal than in Wexford (144.8/105; 126.7 to 167.8, p<0.0001) and South Dublin (127.8/105; 111.3 to 148.2, p<0.0001). Overall, mean 25(OH)D levels were low and did not differ between patients (38.6 nmol/l) and controls (36.4 nmol/l) However, significantly more patients than controls had 25(OH)D levels <25 nmol/l (deficiency) (p=0.004). Levels of 25(OH)D (mean 50.74 nmol/l) were significantly higher in South Dublin (area with lowest prevalence) (p<0.0001) than in Donegal or Wexford. HLA DRB1*15 occurred most frequently in Donegal (greatest MS prevalence) and least frequently in South Dublin.

CONCLUSION

Vitamin D deficiency is common in Ireland. Latitudinal variation in MS probably relates to an interaction between genetic factors and environment (25(OH)D levels), and MS risk may be modified by vitamin D in genetically susceptible individuals.

T cells in multiple sclerosis and experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS), which involves autoimmune responses to myelin antigens. Studies in experimental autoimmune encephalomyelitis (EAE), an animal model for MS, have provided convincing evidence that T cells specific for self-antigens mediate pathology in these diseases. Until recently, T helper type 1 (Th1) cells were thought to be the main effector T cells responsible for the autoimmune inflammation. However more recent studies have highlighted an important pathogenic role for CD4(+) T cells that secrete interleukin (IL)-17, termed Th17, but also IL-17-secreting γδ T cells in EAE as well as other autoimmune and chronic inflammatory conditions. This has prompted intensive study of the induction, function and regulation of IL-17-producing T cells in MS and EAE. In this paper, we review the contribution of Th1, Th17, γδ, CD8(+) and regulatory T cells as well as the possible development of new therapeutic approaches for MS based on manipulating these T cell subtypes.

Expansion of the Spectrum of FLNA Mutations Associated with Melnick-Needles Syndrome

Melnick-Needles syndrome (MNS) is a rare X-linked bone dysplasia characterised by facial dysmorphology and radiographic abnormalities [Melnick and Needles, 1966;97:39-48]. Previously, all published cases of MNS were associated with only 4 mutations [Robertson et al., 2003;33:487-491; Santos et al., 2010;152A:726-731], all localised within exon 22 of FLNA, the gene encoding the cytoskeletal protein filamin A. Here we report 3 new mutations in FLNA that are associated with MNS. One affected member of the first family with the mutation p.Y1229S presented with a stroke while this patient's daughter, previously known to be affected from a young age, developed multiple sclerosis. A second unrelated patient with a typical phenotype is shown to have the mutation c.1054G>T (p.G352W) within exon 7 of FLNA. A third individual with an atypical presentation but radiological findings very similar to those seen in classic MNS has a deletion likely to affect residues within repeat domain 14. These findings indicate that the mutational spectrum for MNS is wider than previously appreciated and has implications for genetic testing strategies employed to confirm a diagnosis of this rare disorder.

OAS1: a multiple sclerosis susceptibility gene that influences disease severity

BACKGROUND

Type 1 interferons upregulate oligoadenylate synthetase 1 (OAS1). A single nucleotide polymorphism (SNP) in exon 7 of OAS1 results in differential RNAseL enzyme activity, the A allele coding for a truncated form with low activity and the G conferring high activity. We hypothesized that OAS1 genotypes would influence both susceptibility to multiple sclerosis (MS) and disease activity with the AA genotype being overrepresented and the GG genotype underrepresented in relapsing-remitting MS (RRMS) with increased disease activity.

METHODS

We examined OAS1 genotype distribution in 401 patients with MS, 394 healthy controls, and 178 patients with RRMS receiving interferon-beta (IFNbeta) assessed as 1) having no or minimal disease activity on IFNbeta, 2) having disease activity despite IFNbeta, and 3) 65 patients with RRMS with highly active disease.

RESULTS

The OAS1 genotype distribution differed between patients with MS and controls (p = 0.000003), with lower frequency of GG homozygotes in patients with MS (6%) compared with controls (17%). In relation to disease severity, 34 (32%) patients with no or minimal disease activity on IFNbeta had the AA and 8 (8%) the GG genotype; of patients with disease activity despite IFNbeta, 27 (51%) were AA, while only 1 (2%) was GG (p = 0.03). Median time to first relapse on IFNbeta was 24 months in patients with RRMS with AA genotype and 33 months with AG or GG genotype (p = 0.04). The GG genotype was absent in 65 patients with highly active RRMS (p = 0.03).

CONCLUSIONS

A functional OAS1 SNP, AA genotype, confers susceptibility to MS and the GG genotype may protect against increased disease activity.

Impaired information processing speed and attention allocation in multiple sclerosis patients versus controls: a high-density EEG study

BACKGROUND

The no-go P3a is a variant of the P300 event-related potential (ERP) that indexes speed of information processing and attention allocation. The aim of this study was to compare ERP findings with results from the paced auditory serial addition test (PASAT) and to quantify latency, amplitude and topographical differences in P3a ERP components between multiple sclerosis (MS) patients and controls.

PATIENTS AND METHODS

Seventy-four subjects (20 relapsing remitting (RRMS) patients, 20 secondary progressive (SPMS) patients and 34 controls) completed a three-stimulus oddball paradigm (target, standard, and non-target). Subjects participated in separate visual and auditory tasks while data were recorded from 134 EEG channels. Latency differences were tested using an ANCOVA. Topographical differences were tested using statistical parametric mapping.

RESULTS

Visual P3a amplitude correlated with PASAT score in all MS patients over frontal and parietal areas. There were significant differences in latency, amplitude, and topography between MS patients and controls in the visual condition. RRMS and SPMS patients differed in visual P3a latency and amplitude at frontal and parietal scalp regions. In the auditory condition, there were latency differences between MS patients and controls only over the parietal region.

CONCLUSION

The present results demonstrate that information processing speed and attention allocation are impaired in MS.

A pernicious leucoencephalopathy

Pernicious anaemia may manifest various neurological symptoms and signs ranging from the subtle to the dramatic. We describe a young man with cobalamin deficiency presenting with sensorimotor deficits, ataxia, dysarthria, mild cognitive deterioration and altered mood of insidious onset. The MRI brain findings were in keeping with a leucoencephalopathy without evidence of MRI changes in the spinal cord. This constellation of features has been reported rarely. His response to treatment as well as the marked improvement of the leucoencephalopathy on imaging suggests at least partial reversibility of the neurological deficits.

Large scale calcium channel gene rearrangements in episodic ataxia and hemiplegic migraine: implications for diagnostic testing

BACKGROUND

Episodic ataxia type 2 (EA2) and familial hemiplegic migraine type 1 (FHM1) are autosomal dominant disorders characterised by paroxysmal ataxia and migraine, respectively. Point mutations in CACNA1A, which encodes the neuronal P/Q-type calcium channel, have been detected in many cases of EA2 and FHM1. The genetic basis of typical cases without CACNA1A point mutations is not fully known. Standard DNA sequencing methods may miss large scale genetic rearrangements such as deletions and duplications. The authors investigated whether large scale genetic rearrangements in CACNA1A can cause EA2 and FHM1.

METHODS

The authors used multiplex ligation dependent probe amplification (MLPA) to screen for intragenic CACNA1A rearrangements.

RESULTS

The authors identified five previously unreported large scale deletions in CACNA1A in seven families with episodic ataxia and in one case with hemiplegic migraine. One of the deletions (exon 6 of CACNA1A) segregated with episodic ataxia in a four generation family with eight affected individuals previously mapped to 19p13. In addition, the authors identified the first pathogenic duplication in CACNA1A in an index case with isolated episodic diplopia without ataxia and in a first degree relative with episodic ataxia.

CONCLUSIONS

Large scale deletions and duplications can cause CACNA1A associated channelopathies. Direct DNA sequencing alone is not sufficient as a diagnostic screening test.

Superior orbital fissure syndrome in herpes zoster ophthalmicus

AIM

To report a case of superior orbital fissure syndrome (SOFS) in a patient with herpes zoster ophthalmicus (HZO).

MATERIALS AND METHODS

A case report.

RESULTS

A 71-year-old male with HZO presented acutely to accident and emergency complaining of right vision loss, double vision and drowsiness. The right visual acuity was counting fingers. There was no relative afferent pupillary defect. He had interstitial keratitis, ptosis, proptosis and total ophthalmoplaegia. The signs indicated HZO complicated by SOFS. Brain imaging and lumbar puncture confirmed the diagnosis of varicella zoster encephalitis. Systemic acyclovir and prednisolone led to recovery of visual acuity and ocular motility in addition to resolution of his proptosis and ptosis.

CONCLUSION

SOFS is a rare complication of herpes zoster infection. With the appropriate treatment and follow-up, patients may be reassured that recovery of their visual acuity and ocular motility will occur.

Long-term clinical relevance of criteria for designating multiple sclerosis as benign after 10 years of disease

OBJECTIVES

To determine the long-term outcome of a cohort of 436 patients with multiple sclerosis (MS) seen in 1985 and long-term predictors of benign MS.

METHODS

The initial 1985 group of 436 patients with possible MS, including 53 benign patients, were followed for 21 years. Disability was recorded using the Expanded Disability Status Scale (EDSS). Survival from disease onset was calculated. The indicators of benign MS in the initial 1985 cohort and in the survivors in 2006 were determined.

RESULTS

Of the original 436 patients, the 21-year follow-up outcome in 397 (91%) was established. The diagnosis of MS was incorrect in 41/397 (10%) of the whole cohort and in 2/53 (4%) of the benign group. Median survival of 356 patients with MS was 43.6 years from disease onset. Of 47/51 (92%) patients with benign MS followed in 2006, 7 (15%) remained benign, 18 had died and 22 were disabled. Median survival advantage for the 47 benign patients in 1985 compared to the 88 non-benign patients, when corrected for age, was 6 years (p<0.08). In 2006, 40/356 (11%) patients had a benign outcome at a mean follow-up of 26.1 years. A benign course was significantly associated with female sex, younger age of onset and absence of motor symptoms at presentation.

CONCLUSIONS

Although designating patients as having a benign course after 10 years has a poor predictive value, three factors at presentation indicate a better prognosis.

Replication of KIAA0350, IL2RA, RPL5 and CD58 as multiple sclerosis susceptibility genes in Australians

A recent genome-wide association study (GWAS) conducted by the International Multiple Sclerosis Genetics Consortium (IMSGC) identified a number of putative MS susceptibility genes. Here we have performed a replication study in 1134 Australian MS cases and 1265 controls for 17 risk-associated single nucleotide polymorphisms (SNPs) reported by the IMSGC. Of 16 SNPs that passed quality control filters, four, each corresponding to a different non-human leukocyte antigen (HLA) gene, were associated with disease susceptibility: KIAA0350 (rs6498169) P=0.001, IL2RA (rs2104286) P=0.033, RPL5 (rs6604026) P=0.041 and CD58 (rs12044852) P=0.042. There was no association (P=0.58) between rs6897932 in the IL7R gene and the risk of MS. No interactions were detected between the replicated IMSGC SNPs and HLA-DRB1*15, gender, disease course, disease progression or age-at-onset. We used a novel Bayesian approach to estimate the extent to which our data increased or decreased evidence for association with the six most-associated IMSGC loci. These analyses indicated that even modest P-values, such as those reported here, can contribute markedly to the posterior probability of 'true' association in replication studies. In conclusion, these data provide support for the involvement of four non-HLA genes in the pathogenesis of MS, and combined with previous data, increase to genome-wide significance (P=3 x 10(-8)) evidence of an association between KIAA0350 and risk of disease.

Illness perception and health-related quality of life in multiple sclerosis

AIMS - A number of physical and psychological factors have been shown to affect health-related quality of life (HRQoL) in patients with multiple sclerosis (MS). Among these, the role of illness perceptions has not been established as an independent factor. This study, the first of its kind in an Australian population, aimed to use a large sample to determine the relative importance of individual factors to each domain of HRQoL, in particular the role of illness perception. MATERIALS AND METHODS - 580 patients with confirmed MS were assessed cross sectionally in a designated research clinic to determine the relative impact of physical factors (illness severity, duration, age, fatigue and pain) and psychological factors (mood, cognition and illness representations) on each domain of the SF-36. RESULTS - Categorical regression analysis showed that a combination of physical and psychological factors predicted 38-71% of variance in HRQoL. Illness perception was shown to have an independent effect on HRQoL in MS. The Extended Disability Status Scale was a significant determinant in all domains except for mental health. Depression was less prevalent than anxiety, but had a greater effect on function. CONCLUSION - Illness perception is an independent factor contributing to HRQoL in people with MS. Individual domains of HRQoL are associated with different patterns of physical and psychological factors. In the domains of role and social function, activities most highly valued by patients with MS, depression, anxiety, fatigue and illness perceptions are key determinants, all of which have the potential to be improved through specific interventions.