Utility of Flexion and Extension MRI for Evaluating Isolated Cervical Spinal Cord Lesions: A Case Series.

The diagnosis of isolated spinal cord lesions is often challenging in clinical practice, and it is not uncommon for the etiology of such isolated lesions to remain unclear despite extensive workup and investigations. Magnetic resonance imaging (MRI) is extensively utilized for assessing spinal cord disease, despite certain radiological patterns suggesting certain pathologies, diagnostic uncertainty remains. Development of adjunct tests and techniques, radiographic or otherwise, is needed. Here, we present two cases in which flexion-extension cervical spine MRIs improved diagnostic ability by demonstrating dynamic cervical cord compression as an etiology for isolated intramedullary cervical spinal cord lesions.

James Walker Dawson: His fingers and their historical context.

Multiple Sclerosis (MS) is one of the most prevalent neurologic disorders in the world. James Walker Dawson examined, in considerable depth, the gross and histologic patterns of MS. Today, periventricular plaques that exhibit an appearance typical for demyelination are nicknamed "Dawson's Fingers." A literature review was conducted on PubMed and Google Scholar to find articles that chronicle the personal and professional life of James Walker Dawson. Research focused on Dawson's work with disseminated sclerosis, or MS as it is known today. Born in India, Dawson and his family moved to Scotland as a child, and he studied at the Edinburgh Institution. After earning his medical degree, Dawson started his career at the Royal College of Physicians of Edinburgh. While his early career focused on the study of wound healing and inflammation, Dawson transitioned into neurologic research under the guidance of Dr. Alexander Bruce in 1908. Dawson's landmark manuscript, "The Histology of Disseminated Sclerosis," published in 1916, featured findings from extensive research on the pathology of MS in nine patients. His findings earned him recognition as a founder of autoimmune neurology and foremost contributor to the current understanding of MS.

Post-vaccination SARS-Cov-2 T-cell receptor repertoires in patients with multiple sclerosis and related disorders.

BACKGROUND: Attenuation in post-vaccination SARS-CoV-2 humoral responses has been demonstrated in people treated with either anti-CD20 therapies or sphingosine-1-phosphate (S1P) receptor modulators. In the setting of disease modifying therapy (DMT) use, humoral response may not correlate with effective immunity, and analysis of vaccine-mediated SARS-CoV-2-specific memory T-cell responses is crucial. While vaccination in patients treated with anti-CD20 agents leads to deficient antibody production, emerging data from live cell assays suggests intact T-cell responses to vaccination. We evaluated post-vaccination SARS-CoV-2 T-cell receptor (TCR) repertoires in DMT-treated patients using the ImmunoSeqR assay, an assay that does not require live cells. METHODS: Adults 18-80 years old without prior COVID-19, with neuroimmune conditions, who had been vaccinated with two doses of Pfizer-BioNTech or Moderna mRNA vaccines at least 3 weeks and up to 6 months prior, were recruited. Whole blood was obtained for immunosequencing, and matched serum was obtained for humoral analysis. Immunosequencing of the CDR3 regions of human TCRß chains was completed using the immunoSEQR Assay (Adaptive Biotechnologies). TCR sequences were mapped across a set of TCR sequences reactive to SARS-CoV-2. Clonal diversity (breadth) and frequency (depth) of TCRs specific to SARS-CoV-2 spike protein were calculated and relationships with clinical variables were assessed. RESULTS: Forty patients were recruited into the study, aged 25-77, and 27 female. 37 had MS, 2 had neuromyelitis optica spectrum disorder (NMOSD), and 1 had hypophysitis. Subjects treated with anti-CD20 agents and S1P receptor modulators had severely attenuated humoral responses, but SARS-CoV-2-spike-specific TCR clonal depth and breadth were robust across all treatment classes except S1P modulators. No spike-specific or non-spike-specific SARS-CoV-2-associated TCRs were found in those treated with S1P modulators (p = 0.002 for both breadth and depth). Subjects treated with fumarates exhibited somewhat lower spike TCR breadth than subjects treated with other or no DMTs (median 2.27 × 10^-5 for fumarates and 4.96 × 10^-5 for all others, p = 0.008), but no statistically significant difference was demonstrated with spike TCR depth. No other significant associations with DMT type were found. We found no significant correlations between depth or breadth and age, duration of treatment, type of vaccination, or time interval since vaccination. CONCLUSION: This is the first study to characterize post-vaccination SARS-CoV-2 TCR repertoires in DMT-treated individuals. We demonstrated a dichotomous response to SARS-CoV-2 vaccination in anti-CD20-treated patients, with severely attenuated humoral response but intact TCR depth and breadth. It is unclear to what degree each arm of the adaptive immune system impacts post-vaccine immunity, both from the standpoint of incidence of post-vaccine infections and that of infection severity, and further clinical studies are necessary. S1P modulator-treated subjects exhibited both severely attenuated humoral responses and absent spike-specific TCR depth and breadth, information which is crucial for counseling of patients on these agents. Our methodology can be used in larger studies to determine the benefit of repeated vaccination doses, including those that are modified to better target modern or seasonal variants, without the use of live cell assays.

Vaccine-breakthrough SARS-CoV-2 infections in people with multiple sclerosis and related conditions: An observational study by the New York COVID-19 Neuro-Immunology Consortium (NYCNIC-2).

BACKGROUND: People with MS (PwMS) and related conditions treated with anti-CD20 and S1P modulating therapies exhibit attenuated immune responses to SARS-CoV-2 vaccines. It remains unclear whether humoral/T-cell responses are valid surrogates for postvaccine immunity. OBJECTIVE: To characterize COVID-19 vaccine-breakthrough infections in this population. METHODS: We conducted a prospective multicenter cohort study of PwMS and related CNS autoimmune conditions with confirmed breakthrough infections. Postvaccination antibody response, disease-modifying therapies (DMTs) at the time of vaccination, and DMT at the time of infection were assessed. RESULTS: Two hundred nine patients had 211 breakthrough infections. Use of anti-CD20 agents at time of infection was associated with increased infection severity (p = 0.0474, odds ratio (OR) = 5.923) for infections during the Omicron surge and demonstrated a trend among the total cohort (p = 0.0533). However, neither use of anti-CD20 agents at the time of vaccination nor postvaccination antibody response was associated with hospitalization risk. Anti-CD20 therapies were relatively overrepresented compared to a similar prevaccination-era COVID-19 cohort. CONCLUSION: Use of anti-CD20 therapies during vaccine breakthrough COVID-19 infection is associated with higher severity. However, the attenuated postvaccination humoral response associated with anti-CD20 therapy use during vaccination may not drive increased infection severity. Further studies are necessary to determine if this attenuated vaccine response may be associated with an increased likelihood of breakthrough infection.

Rare variants and HLA haplotypes associated in patients with neuromyelitis optica spectrum disorders.

Neuromyelitis optica spectrum disorders (NMOSD) are rare, debilitating autoimmune diseases of the central nervous system. Many NMOSD patients have antibodies to Aquaporin-4 (AQP4). Prior studies show associations of NMOSD with individual Human Leukocyte Antigen (HLA) alleles and with mutations in the complement pathway and potassium channels. HLA allele associations with NMOSD are inconsistent between populations, suggesting complex relationships between the identified alleles and risk of disease. We used a retrospective case-control approach to identify contributing genetic variants in patients who met the diagnostic criteria for NMOSD and their unaffected family members. Potentially deleterious variants identified in NMOSD patients were compared to members of their families who do not have the disease and to existing databases of human genetic variation. HLA sequences from patients from Belgrade, Serbia, were compared to the frequency of HLA haplotypes in the general population in Belgrade. We analyzed exome sequencing on 40 NMOSD patients and identified rare inherited variants in the complement pathway and potassium channel genes. Haplotype analysis further detected two haplotypes, HLA-A*01, B*08, DRB1*03 and HLA-A*01, B*08, C*07, DRB1*03, DQB1*02, which were more prevalent in NMOSD patients than in unaffected individuals. In silico modeling indicates that HLA molecules within these haplotypes are predicted to bind AQP4 at several sites, potentially contributing to the development of autoimmunity. Our results point to possible autoimmune and neurodegenerative mechanisms that cause NMOSD, and can be used to investigate potential NMOSD drug targets.

A Single-Health System Case Series of New-Onset CNS Inflammatory Disorders Temporally Associated With mRNA-Based SARS-CoV-2 Vaccines.

Background: Since 2020, over 250 million doses of mRNA-based SARS-CoV-2 vaccines have been administered in the United States and hundreds of millions worldwide between the Pfizer-BioNTech and Moderna SARS-CoV-2 vaccines. To date, there have been rare reports associating mRNA-based SARS-CoV-2 vaccines with episodes of inflammatory and autoimmune CNS disorders. We report a case series of five patients with new-onset neurological disorders of inflammatory or immunological origin temporally associated with these vaccines. Methods: A case-series of five patients within a single 23-hospital health system who developed new-onset CNS inflammatory disease within 2 weeks of receiving a dose of an mRNA-based SARS-CoV-2 vaccine. Results: Five cases of post-vaccination CNS disorders of immune origin (fatal ADEM; n = 1, new-onset NMOSD; n = 2, new-clinical onset MS-like syndrome but with preexisting clinically silent mild demyelination; n = 1, meningoencephalitis; n = 1) observed within 2 weeks of inoculation with either the first or second dose of mRNA-based SARS-CoV-2 vaccines (Moderna = 3, Pfizer = 2). Discussion: To our knowledge, these are among the emerging cases of CNS adverse events of immunological or inflammatory origin. These findings should be interpreted with great caution as they neither prove a mechanistic link nor imply a potential long-term increased risk in post-vaccination CNS autoimmunity. Larger prospective studies assessing the potential association between mRNA-based vaccination and the development of neurological adverse events of suspected immune origin, particularly among those with underlying CNS or systemic autoimmune disorders, are needed. The use of mRNA-based SARS-CoV-2 vaccines should continue to be strongly encouraged given their high efficacy in overcoming this pandemic.

Case report: Bilateral globus pallidus lesions and delayed progressive leukoencephalopathy in COVID-19: Effects of hypoxia alone or combination of hypoxia and inflammation?

Background: The globus pallidus is a highly mitochondria-rich metabolic structure that is particularly sensitive to metabolic disturbances and hypoxia. Symmetric lesions of globus pallidus and delayed diffuse leukoencephalopathy were documented in toxic-metabolic disorders, hypoxia, a neurodegenerative disorder, and mitochondrial encephalopathies. Similar changes are also reported in individuals with active COVID-19 infections with associated hypoxia or critical illness. Case information: We describe a patient with post-COVID-19 infection who presented with rapid cognitive and neurological decline associated with similar neuroimaging structural changes but without toxic-metabolic changes or hypoxia. Despite multiple non-inflammatory cerebrospinal fluid studies, mechanisms involving post-COVID-19 inflammation and immune dysregulation are suspected, given the unexplained continued decline in the neurological status, lack of concurrent hypoxia or antecedent respiratory difficulties, and after a reasonable exclusion of alternative etiologies. Hypermetabolism of both anteromedial temporal structures and diffuse hypometabolism predominantly in the frontal region on PET scan provided indirect support for possible inflammatory mechanisms after reasonable exclusion of alternative etiologies, such as direct CNS infection, among others. The patient's neurological impairment improved substantially after treatment with pulse steroids, plasmapheresis, and rituximab. Conclusion: To the best of our knowledge, this is the first report of post-COVID-19 with bilateral symmetric contrast-enhancing necrotic lesions of globus pallidus with delayed diffuse supratentorial leukoencephalopathy with microhemorrhages without concurrent hypoxia or reported preceding symptoms suggestive of hypoxia. We suspect that these inflammatory mechanisms might be triggered by prior COVID-19 exposure/infection. Furthermore, the role of the cross-talk between inflammation and clinically mild or silent hypoxia linked to prior COVID-19 infection cannot be excluded. Awareness of these post-COVID-19 neurological sequelae and their potential pathophysiology among those with no known antecedent significant hypoxia are important for early recognition and treatment.

Outcomes of COVID-19 infection in multiple sclerosis and related conditions: One-year pandemic experience of the multicenter New York COVID-19 Neuroimmunology Consortium (NYCNIC).

OBJECTIVE: To determine outcomes of COVID-19 in patients with Multiple Sclerosis (MS) and related conditions, and to determine predictors of these outcomes. METHODS: This was a multicenter, observational cohort study of patients with MS or related CNS autoimmune disorders who developed confirmed or highly suspected COVID-19 infection from 2/1/2020 to 12/31/2020. MAIN OUTCOME AND MEASURE: The primary outcome measure was hospitalization status due to COVID-19. Severity of infection was measured using a 4-point ordinal scale: 1. home care; 2. hospitalization without mechanical ventilation; 3. hospitalization and mechanical ventilation, and 4. death. RESULTS: Of 474 patients in the study, 63.3% had confirmed COVID-19 infection and 93.9% were diagnosed with an MS phenotype. Mean age was 45 ± 13 (mean±SD) years, 72% were female, and 86% were treated with a DMT at the time of infection. 58 patients (12.2%) were hospitalized. 24 patients (5.1%) were critically ill (requiring ICU care or outcome of death), of which 15 patients (3.2%) died. Higher neurological disability and older age independently predicted hospitalization. 85% (102/120) of patients with known antibody results not treated with anti-CD20 therapies were seropositive while only 39.5% (17/43) of patients treated with anti-CD20 demonstrated seropositivity (p < 0.0001). Only 25% (2/8) of patients with PCR-confirmed COVID-19 being treated with anti-CD20 therapies demonstrated seropositivity. CONCLUSIONS: Neurological disability and older age independently predicted hospitalization due to COVID-19. Additionally, the results demonstrate that anti-CD20 therapies significantly blunt humoral responses post-infection, a finding that carries implications with regards to natural or vaccine-mediated immunity.

Large Adult Spinal Diffuse Midline Histone H3 Lysine27-to-Methionine-Mutant Glioma With Intramedullary and Extramedullary Components Presenting With Progressive Hydrocephalus: A Case Report Highlighting Unique Imaging Findings and Treatment.

Diffuse midline glioma with histone H3 lysine27-to-methionine mutation (H3 K27M mutation) is a rare, aggressive tumor that is designated as World Health Organization (WHO) grade IV regardless of histologic features. Preoperative diagnosis remains challenging due to limited evidence regarding distinctive clinical and imaging characteristics. We describe the case of a young woman who presented with progressively worsening headaches due to communicating hydrocephalus. MR imaging with contrast of the cervical and thoracic spine revealed diffuse leptomeningeal enhancement with focal areas of intramedullary and subarachnoid T2 hyperintensity and enhancement, suggestive of a potential infectious process. Intraoperatively, no epidural pathology was identified, and with the differential diagnosis remaining broad, a second procedure was conducted involving intradural exploration and biopsy of a lesion. This was then identified as a diffuse midline glioma with H3 K27M mutation. The nonfocal clinical presentation in the setting of communicating hydrocephalus as well as the significant exophytic tumor growth and imaging findings made the initial diagnosis unique and challenging. This case, therefore, emphasizes the rare presentation of this tumor, and the need for further understanding of the clinical and imaging characteristics of this disease as well as the need for effective therapeutics.

A patient with concurrent multiple sclerosis and moyamoya disease.

BACKGROUND: Moyamoya disease (MMD) is a rare vasculopathy and Multiple Sclerosis (MS) is an autoimmune disease which causes CNS demyelination. While most literature has focused on misdiagnosis of MMD as an "MS-mimic", we present a patient in which both co-existed. METHODS: Case Report RESULTS: A 57-year-old woman presented with gait dysfunction and paresthesias in both feet. MRI revealed brain and spinal cord lesions consistent with MS. Vessel imaging revealed multivessel stenosis consistent with MMD. Lumbar puncture demonstrated oligoclonal bands, leading to two diagnoses, MS and MMD. CONCLUSIONS: MS can exist concurrently with MMD, potentially due to underlying propensity for autoimmunity.

Wallerian degeneration as a mimic of recurrence of myelitis.

A middle-aged woman with idiopathic longitudinally extensive myelitis underwent repeat MR scan of cervical spine at 5-month follow-up, which showed new non-enhancing T2 hyperintensities, initially reported as myelitis recurrence. However, the hyperintensities involved both lateral corticospinal tracts caudal to the initial lesion and both dorsal columns rostral to the initial lesion and were therefore compatible with Wallerian degeneration. This radiological mimic should be considered in the differential of recurrence of myelitis.

Progressive Multifocal Leukoencephalopathy in a Patient With Progressive Multiple Sclerosis Treated With Ocrelizumab Monotherapy.

Importance: Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection caused by the JC virus that has no proven effective treatment. Although rare cases of PML have occurred with other anti-CD20 therapies, there had been no prior cases associated with ocrelizumab. Objective: To report the first ever case of PML occurring with ocrelizumab monotherapy in a patient with progressive multiple sclerosis without prior immunomodulation. Design, Setting, and Participant: This case was reported from an academic medical center. The patient had multiple sclerosis while receiving ocrelizumab monotherapy. Exposures: Ocrelizumab monotherapy. Results: A 78-year-old man with progressive multiple sclerosis treated with ocrelizumab monotherapy for 2 years presented with 2 weeks of progressive visual disturbance and confusion. Examination demonstrated a right homonymous hemianopia, and magnetic resonance imaging revealed an enlarging nonenhancing left parietal lesion without mass effect. Cerebrospinal fluid revealed 1000 copies/mL of JC virus, confirming the diagnosis of PML. Blood work on diagnosis revealed grade 2 lymphopenia, with absolute lymphocyte count of 710/µL, CD4 of 294/µL (reference range, 325-1251/µL), CD8 of 85/µL (reference range, 90-775/µL), CD19 of 1/µL, preserved CD4/CD8 ratio (3.45), and negative HIV serology. Retrospective absolute lymphocyte count revealed intermittent grade 1 lymphopenia that preceded ocrelizumab (absolute lymphocyte count range, 800-1200/µL). The patient's symptoms progressed over weeks to involve bilateral visual loss, right-sided facial droop, and dysphasia. Ocrelizumab was discontinued and off-label pembrolizumab treatment was initiated. The patient nevertheless declined rapidly and ultimately died. PML was confirmed at autopsy. Conclusions and Relevance: In this case report, PML occurrence was likely a result of the immunomodulatory function of ocrelizumab as well as age-related immunosenescence. This case report emphasizes the importance of a thorough discussion of the risks and benefits of ocrelizumab, especially in patients at higher risk for infections such as elderly patients.

Dietary factors in experimental autoimmune encephalomyelitis and multiple sclerosis: A comprehensive review.

BACKGROUND: Dietary intervention in multiple sclerosis carries potential therapeutic implications. While studies utilizing animal models of multiple sclerosis (MS) have demonstrated intriguing findings, well-designed clinical trials are few in number. OBJECTIVE: The objective of this study is to review the animal model and clinical literature regarding dietary factors in experimental autoimmune encephalitis (EAE) and MS. METHODS: This manuscript provides a comprehensive review of current animal model and clinical knowledge related to dietary factors in MS. RESULTS: While there is currently little data for any specific diet in MS, there is growing evidence that certain dietary factors may influence the disease. CONCLUSIONS: Definitive information regarding dietary factors as a modifiable risk factor in MS will require larger randomized clinical trials.

Defining the role of T lymphocytes in the immunopathogenesis of neuromyelitis optica spectrum disorder.

Auto-reactive T cells are fundamental to many autoimmune processes, including neuromyelitis optica spectrum disorder (NMOSD). Several lines of evidence indicate that an antibody against aquaporin-4 (AQP4) is present in NMOSD patients. Further, this AQP4 antibody is pathogenic and can cause profound neurological damage. T cells are fundamental to many autoimmune processes, including NMOSD. Here we review work from animal models to discuss mechanisms by which auto-reactive T cells modulate the process by which antibodies cross the blood-brain barrier and orchestrate the local inflammatory milieu underlying NMOSD pathophysiology. We also examine clinical studies that document the presence of AQP4-specific T cells and the unique cytokine profile of NMOSD patients. This work encourages a renewed and broadened attention to the fundamental role of T cells in neuroautoimmune conditions which will hopefully lead to new therapies and better patients' outcomes.

Negative SARS-CoV-2 antibody testing following COVID-19 infection in Two MS patients treated with ocrelizumab.

BACKGROUND: It is unknown whether MS disease modifying therapies impact ability to mount an antibody response to SARS-CoV-2. METHODS: Case series and literature review. We report a series of two MS patients who developed COVID-19 while on Ocrelizumab therapy and subsequently exhibited negative SARS-CoV-2 serology. RESULTS: A 42-year-old man and 39-year-old woman with MS developed COVID-19 while on Ocrelizumab therapy. Neither patient required hospitalization. The man exhibited negative serology at 7- and 9-weeks post-infection. The woman exhibited negative serology at 6- and 12-weeks post-infection. CONCLUSIONS: Large studies are essential to determine whether certain DMTs may blunt SARS-CoV-2 antibody production.

Retinal vasculopathy with cerebral leukoencephalopathy (RVCL): A rare mimic of tumefactive MS.

OBJECTIVE: We report a series of 2 brothers who each developed tumefactive brain lesions, initially thought to have brain tumors or tumefactive multiple sclerosis (MS), but who were ultimately diagnosed with a rare autosomal dominant condition known as retinal vasculopathy with cerebral leukoencephalopathy (RVCL). METHODS: Case series and literature review. RESULTS: We present 2 brothers who developed tumefactive right frontal brain lesions leading to gait disturbances and cognitive changes. Both brothers also had nonspecific brain calcifications and T2-hyperintense lesions, and both had ophthalmic and liver disease of unclear etiology. The first brother had been extensively evaluated by various specialists, underwent inconclusive brain and liver biopsies, and was ultimately unsuccessfully treated for a diagnosis of tumefactive MS. The second brother also underwent unrevealing evaluation with CSF analysis and brain biopsy. Further family history revealed that the patients' father developed a tumefactive brain lesion in the 1980s and had been diagnosed with CNS vasculitis. Given the familial link, RVCL was suspected, and genetic analysis confirmed the diagnosis with a 3-prime repair exonuclease 1 (TREX1) C-terminal mutation. CONCLUSION: The presence of tumefactive brain lesions, nonspecific brain calcifications, liver disease, and retinal vasculopathy, coupled with suggestive family history, led to the RVCL diagnosis. This report contributes to the limited understanding of RVCL, which can cause brain lesions that mimic gliomas or tumefactive MS. Recognition of this entity may prevent unnecessary invasive procedures and inappropriate therapeutic interventions, and would allow for proper counseling of family members.

Successful treatment of progressive multifocal leukoencephalopathy with recombinant interleukin-7 and maraviroc in a patient with idiopathic CD4 lymphocytopenia.

Progressive multifocal leukoencephalopathy (PML) is a rapidly progressive, often fatal viral infection of the brain without a known treatment. Recently, case reports have demonstrated survival from PML with therapies that improve cell-mediated immunity, including interleukin-7 (IL-7) or the chemokine receptor type 5 (CCR5) antagonist, maraviroc (MVC). We present the first known case of a patient with PML successfully treated with both IL-7 and MVC. A 63-year-old woman presented to our center with a 6-month history of progressive left hemiparesis. Extensive laboratory testing was negative except for a severe CD4 lymphocytopenia (140/µL). Serial brain MRIs done prior to presentation revealed an enlarging, non-enhancing T2-hyperintense lesion in the right fronto-parietal white matter. PML was confirmed through detection of the JC virus by PCR in the cerebrospinal fluid and by brain biopsy, and she was started on mirtazapine and mefloquine. She continued to deteriorate and was then given a course of recombinant IL-7. Though she remained clinically stable after IL-7 treatment and serum JCV PCR decreased from 1000 copies/mL to a nadir of 238 copies/mL, a repeat MRI 3 months later showed lesion enlargement. MVC was then initiated. Now, more than 2 years after initial presentation, she remains stable and serum JCV PCR is undetectable. This case demonstrates successful treatment of PML in a patient with idiopathic CD4 lymphocytopenia and highlights the potential benefits of IL-7 and MVC in the treatment of PML. Treatment with IL-7 and MVC led to clinical stability and improvement in JC virus titers.

Brain microstructural injury occurs in patients with RRMS despite 'no evidence of disease activity'.

OBJECTIVES: The accuracy of 'no evidence of disease activity' (NEDA) in predicting long-term clinical outcome in patients with relapsing remitting multiple sclerosis (RRMS) is unproven, and there is growing evidence that NEDA does not rule out disease worsening. We used diffusion tensor imaging (DTI) to investigate whether ongoing brain microstructural injury occurs in patients with RRMS meeting NEDA criteria. METHODS: We performed a retrospective study to identify patients with RRMS visiting our centre over a 3-month period who had undergone prior longitudinal DTI evaluation at our facility spanning ≥2 years. Patients meeting NEDA criteria throughout the evaluation period were included in the NEDA group, and those not meeting NEDA criteria were included in an 'evidence of disease activity' (EDA) group. Fractional anisotropy (FA) and mean diffusivity (MD) maps were created, and annual rates of change were calculated. RESULTS: We enrolled 85 patients, 39 meeting NEDA criteria. Both NEDA and EDA groups showed longitudinal DTI worsening. Yearly FA decrease was lower in the NEDA group (0.5%, p<0.0001) than in the EDA group (1.2%, p=0.003), while yearly MD increase was similar in both groups (0.8% for NEDA and EDA, both p<0.01). There was no statistical difference in deterioration within and outside of T2 lesions. DTI parameters correlated with disability scores and fatigue complaints. CONCLUSIONS: White matter microstructural deterioration occurs in patients with RRMS over short-term follow-up in patients with NEDA, providing further evidence of the limitations of conventional measures and arguing for DTI in monitoring of the disease process.

The relationship between cortical lesions and periventricular NAWM abnormalities suggests a shared mechanism of injury in primary-progressive MS.

In subjects with multiple sclerosis (MS), pathology is more frequent near the inner and outer surfaces of the brain. Here, we sought to explore if in subjects with primary progressive MS (PPMS) cortical lesion load is selectively associated with the severity of periventricular normal appearing white matter (NAWM) damage, as assessed with diffusion weighted imaging. To this aim, twenty-four subjects with PPMS and twenty healthy controls were included in the study. Using diffusion data, skeletonized mean diffusivity (MD) NAWM maps were computed excluding WM lesions and a 2 mm-thick peri-lesional rim. The supra-tentorial voxels between 2 and 6 mm of distance from the lateral ventricles were included in the periventricular NAWM mask while the voxels between 6 and 10 mm from the lateral ventricles were included in the deep NAWM mask; mean MD values were then computed separately for these two masks. Lastly, cortical lesions were assessed on phase-sensitive inversion recovery (PSIR) images and cortical thickness was quantified on volumetric T1 images. Our main result was the observation in the PPMS group of a significant correlation between periventricular NAWM MD values and cortical lesion load, with a greater cortical lesion burden being associated with more abnormal periventricular NAWM MD. Conversely, there was no correlation between cortical lesion load and deep NAWM MD values or periventricular WM lesions. Our data thus suggest that a common - and relatively selective - factor plays a role in the development of both cortical lesion and periventricular NAWM abnormalities in PPMS.