Familial multiple sclerosis: volumetric assessment in clinically symptomatic and asymptomatic individuals

Silent findings: Examination of asymptomatic demyelination in a pediatric US cohort

BACKGROUND AND OBJECTIVES

Limited data is available on children with evidence of silent central nervous system demyelination on MRI. We sought to characterize the population in a US cohort and identify predictors of clinical and radiologic outcomes.

METHODS

We identified 56 patients such patients who presented with incidental MRI findings suspect for demyelination, enrolled through our US Network of Pediatric Multiple Sclerosis Centers, and conducted a retrospective review of 38 patients with MR images, and examined risk factors for development of first clinical event or new MRI activity. MRI were rated based on published MS and radiologically isolated syndrome (RIS) imaging diagnostic criteria.

RESULTS

One-third had a clinical attack and ¾ developed new MRI activity over a mean follow-up time of 3.7 years. Individuals in our cohort shared similar demographics to those with clinically definite pediatric-onset MS. We show that sex, presence of infratentorial lesions, T1 hypointense lesions, juxtacortical lesion count, and callosal lesions were predictors of disease progression. Interestingly, the presence of T1 hypointense and infratentorial lesions typically associated with worse outcomes were instead predictive of delayed disease progression on imaging in subgroup analysis. Additionally, currently utilized diagnostic criteria (both McDonald 2017 and RIS criteria) did not provide statistically significant benefit in risk stratification.

CONCLUSION

Our findings underscore the need for further study to determine if criteria currently used for pediatric patients with purely radiographic evidence of demyelination are sufficient.

Multiple sclerosis and subclinical neuropathology in healthy individuals with familial risk: A scoping review of MRI studies

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MRI evidence of MS pathology in healthy individuals reflects a subclinical period.

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First-degree relatives of MS patients are ideal to study MS subclinical neuropathology.

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MRI found WM focal inflammation in a substantial proportion of these healthy relatives.

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Diffuse tissue damage is also found by MRI in healthy relatives of MS patients.

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MS prodromal phase can be characterized by studying healthy subjects at high risk.

Multiple genetic and non-heritable factors have been linked to the risk of multiple sclerosis (MS). These factors seem to contribute to disease pathogenesis before the onset of clinical symptoms, as suggested by incidental MRI evidence of subclinical MS neuropathology in individuals without clinical symptoms. Individuals with high familial risk for MS, such as first-degree relatives of patients with MS, can be studied by MRI to characterize the neuropathology during a subclinical period of MS. 16 studies published in English, which performed brain MRI on healthy individuals with high familial risk of MS were included in this scoping review. Studies suggest either no conclusive (5), or inconclusive yet considerable (4), or conclusive evidence (7) for the incidence of subclinical neuropathology, including focal and diffuse tissue damage. Across all studies, white matter lesions fulfilling MS criteria were observed in 86 of 613 individuals (14%). Future research is needed to evaluate the longitudinal dynamics and clinical relevance of preclinical imaging abnormalities in MS.

Genes and Environment in Multiple Sclerosis project: A platform to investigate multiple sclerosis risk

The Genes and Environment in Multiple Sclerosis project establishes a platform to investigate the events leading to multiple sclerosis (MS) in at-risk individuals. It has recruited 2,632 first-degree relatives from across the USA. Using an integrated genetic and environmental risk score, we identified subjects with twice the MS risk when compared to the average family member, and we report an initial incidence rate in these subjects that is 30 times greater than that of sporadic MS. We discuss the feasibility of large-scale studies of asymptomatic at-risk subjects that leverage modern tools of subject recruitment to execute collaborative projects.

MRI characteristics of familial and sporadic multiple sclerosis patients

PURPOSE

To investigate the MRI characteristics in a large cohort of multiple sclerosis (MS) patients with and without a family history of MS.

METHODS

Enrolled in this prospective study were 758 consecutive MS patients (mean age 46.2 ± 10.1 years, disease duration 13.6 ± 9.2 years and EDSS 3.4 ± 2.1), of whom 477 had relapsing-remitting, 222 secondary-progressive, and 30 primary-progressive disease courses and 29 had clinically isolated syndrome. One hundred and ninety-six patients (25.9%) had a positive family history of MS. Patients were assessed using measurements of lesions, brain atrophy, magnetization transfer ratio (MTR) and diffusion-weighted imaging.

RESULTS

The familial MS group had greater T1-lesion volume (p=0.009) and a trend for lower MTR of T1-lesion volume (p=0.047) than the sporadic MS group. No clinical differences were found between familial versus sporadic group, or by a degree of affected relative subgroups.

CONCLUSIONS

While familial MS was associated with more severe T1-lesion volume and its MTR characteristics, there were no clinical status differences between familial and sporadic MS patients. Therefore, a better understanding of the genetic and/or epigenetic influences causing these differences can advance the understanding and management of MS.

Multiple sclerosis risk in radiologically uncovered asymptomatic possible inflammatory-demyelinating disease

BACKGROUND

Natural history of patients with incidentally discovered lesions that fulfill magnetic resonance imaging (MRI) criteria for multiple sclerosis (MS) in the absence of objective clinical symptoms suggestive of central nervous system (CNS) inflammatory-demyelinating disease is not well defined.

OBJECTIVE

We evaluated the risk of developing symptomatic MS in patients with radiologically uncovered asymptomatic possible inflammatory-demyelinating disease (RAPIDD).

METHODS

We identified and longitudinally followed a cohort of 22 patients from two tertiary care MS centers: Istanbul University, Cerrahpasa School of Medicine, Istanbul, Turkey, and Mayo Clinic, Rochester, Minnesota, after an initial MRI study fulfilling the Barkhof-Tintore MRI criteria completed for other reasons unrelated to MS.

RESULTS

Eight of 22 patients developed an objective clinical symptom consistent with a CNS inflammatory-demyelinating syndrome and fulfilled dissemination in space and time criteria for definite MS. Median age at the time of diagnosis of MS was 44.8 years (range 28.3-71.4 years). Time taken for the development of definite MS was studied by survival analysis. Cumulative event rates were; 12 months: 9%, 24 months: 15%, 36 months: 30.4%, and 60 months: 44.6%. Six of 22 patients were followed beyond 60 months. Two of these six patients developed MS later (at 66 and 112 months, respectively). Three patients remained asymptomatic despite follow-up of 10 years.

CONCLUSIONS

PATIENTS

with RAPIDD develop MS at a similar rate to treated patients (and less frequently than placebo groups) with clinically isolated syndromes from prior randomized controlled studies. Some patients with RAPIDD continue to have radiological evolution of subclinical disease without MS symptoms despite long follow-up periods.

Imaging brain damage in first-degree relatives of sporadic and familial multiple sclerosis

OBJECTIVE

Our objective was to assess brain damage in first-degree relatives of patients with sporadic and familial multiple sclerosis (MS).

METHODS

Asymptomatic first-degree relatives of sporadic (sMS, n = 152) and familial MS (fMS, n = 88) and healthy volunteers (NC, n = 56) underwent brain MRI and magnetization transfer (MT) imaging on a mobile MR scan. On MR examinations, we visually assessed white matter (WM) lesions and quantified WM lesion volumes, brain volumes, and MT ratio (MTr) in lesions and normal-appearing WM (NAWM).

RESULTS

A lesional MR pattern similar to that of MS patients was found in 4% sMS and 10% fMS. In these WM lesions, MTr was lower (p < 0.0001) than in the WM of NC. In contrast, there was no difference in NAWM-MTr and brain volume values between the three groups.

INTERPRETATION

Focal brain abnormalities indistinguishable from those of MS occur in asymptomatic first-degree relatives of MS patients. These are twice more frequent in fMS than in sMS but do not lead to the widespread tissue damage commonly found in MS patients. Although there is a genetic susceptibility to develop brain abnormalities suggestive of focal demyelination in first-degree relatives of MS patients, other factors are probably critical for the development of a diffuse, clinically relevant, pathology.

Proton magnetic resonance spectroscopy of normal appearing white matter in familial and sporadic multiple sclerosis

OBJECTIVE

To assess metabolite levels in normal-appearing white matter in sporadic and familial multiple sclerosis (MS).

METHODS

Using H-MRS and applying one voxel measure we assessed NAA/Cho, NAA/Cr and Cho/Cr ratios in 26 patients with sporadic and in 25 with familial MS and compared them with healthy subjects.

RESULTS

In both MS groups NAA/Cho and NAA/Cr ratio were significantly lower than in healthy individuals whereas Cho/Cr ratio was higher in MS patients. In sporadic MS patients NAA/Cho and NAA/Cr ratios were lower, although not significantly, than in familial cases. The Cho/Cr ratio was similar in both MS groups.

CONCLUSION

These results suggest that subtle differences in H-MRS measures corresponding to axonal rather than to myelin pathology might occur in sporadic and familial MS.

Multiple sclerosis as a generalized CNS disease--comparative microarray analysis of normal appearing white matter and lesions in secondary progressive MS

We used microarrays to compare the gene expression profile in active lesions and donor-matched normal appearing white matter (NAWM) from brain autopsy samples of patients with secondary progressive multiple sclerosis (MS) with that from controls who died from non-neurological diseases. The 123 genes in lesions, and 47 genes in NAWM(MS) were differentially expressed. Lesions distinguished from NAWM(MS) by a higher expression of genes related to immunoglobulin synthesis and neuroglial differentiation, while cellular immune response elements were equally dysregulated in both tissue compartments. Current results provide molecular evidence of a continuum of dysfunctional homeostasis and inflammatory changes between lesions and NAWM(MS), and support the concept of MS pathogenesis being a generalised process that involves the entire CNS.

A whole genome screen for association in Polish multiple sclerosis patients

We have performed the first systematic search for MS susceptibility genes completed in the Polish population. This screen was performed using 6000 microsatellite markers typed in pooled DNA from cases (n=200), controls (n=200) and trio families (n=129). Five associated markers are identified, one (D6S2444) from the HLA region and four are from novel regions not previously associated with MS, 2p16 (D2S2153), 3p13 (D3S3568), 7p22 (D7S2521) and 15q26 (D15S649).

MTR discloses subtle changes in the normal-appearing tissue from relatives of patients with MS

The presence of normal-appearing brain tissue (NABT) changes was investigated in 30 first-degree relatives of patients with MS, using magnetization transfer ratio (MTR) histograms. When compared with controls, relatives of patients with familial (p = 0.01) and sporadic (p = 0.01) MS had lower NABT MTR histogram peak heights. This study suggests a reduction of truly normal NABT in asymptomatic relatives of patients with MS.

Magnetisation transfer ratio analysis of normal appearing white matter in patients with familial and sporadic multiple sclerosis

OBJECTIVES

To assess differences in magnetisation transfer ratio (MTR) analysis of normal appearing white matter (NAWM) in patients with familial multiple sclerosis (MS) and those with sporadic MS.

METHODS

10 patients with familial MS, 10 patients with sporadic MS, and 10 healthy subjects were included in the study. Groups were matched according to the sex, age, disease duration, type of disease, EDSS, and MRI T1 and T2 lesion load. Magnetisation transfer imaging (MTI) with and without saturation pulse were performed. On the MTR map 16 different regions of interest of normal appearing white matter were analyzed.

RESULTS

The mean MTR value of normal appearing white matter was significantly lower both in familial patients and those with sporadic MS compared with healthy subjects (33.8% v 46.4%; 38.6% v 46.4% respectively, p< 0.05). Additionally, patients with familial MS showed significantly lower mean MTR value than patients with sporadic MS (33.8% v 38.6%, p<0.05). There was also significant regional variation of MTR values between these two groups of patients.

CONCLUSIONS

Lower and more widespread MTR abnormalities in patients with familial MS might indicate differences in the extent and nature of white matter pathology between familial and sporadic MS.