Clinical Correlation of Multiple Sclerosis Immunopathologic Subtypes.

BACKGROUND AND OBJECTIVES: The goal of this work was to compare clinical characteristics across immunopathologic subtypes of patients with multiple sclerosis. METHODS: Immunopathologic subtyping was performed on specimens from 547 patients with biopsy- or autopsy-confirmed CNS demyelination. RESULTS: The frequency of immunopathologic subtypes was 23% for pattern I, 56% for pattern II, and 22% for pattern III. Immunopatterns were similar in terms of age at autopsy/biopsy (median age 41 years, range 4-83 years, p = 0.16) and proportion female (54%, p = 0.71). Median follow-up after symptom onset was 2.3 years (range 0-38 years). In addition to being overrepresented among autopsy cases (45% vs 19% in biopsy cohort, p < 0.001), index attack-related disability was higher in pattern III vs II (median Expanded Disability Status Scale score 4 vs 3, p = 0.02). Monophasic clinical course was more common in patients with pattern III than pattern I or II (59% vs 33% vs 32%, p < 0.001). Similarly, patients with pattern III pathology were likely to have progressive disease compared to patients with patterns I or II when followed up for ≥5 years (24% overall, p = 0.49), with no differences in long-term survival, despite a more fulminant attack presentation. CONCLUSION: All 3 immunopatterns can be detected in active lesions, although they are found less frequently later into the disease due to the lower number of active lesions. Pattern III is associated with a more fulminant initial attack than either pattern I or II. Biopsied patients appear to have similar long-term outcomes regardless of their immunopatterns. Progressive disease is less associated with the initial immunopattern and suggests convergence into a final common pathway related to the chronically denuded axon.

Somatotopic heat pain thresholds and intraepidermal nerve fibers in health.

INTRODUCTION: For sequential and somatotopic assessment of small fiber neuropathy, heat pain (HP) tests of hypoalgesia might be used instead of decreased counts of epidermal nerve fibers (ENFs), but then healthy subject reference values of HP thresholds are needed. METHODS: Using the Computer Assisted Sensation Evaluator IVc system, HP thresholds of hypoalgesia were estimated for 10 unilateral sites and counts of ENFs for 4 of them in healthy subjects. RESULTS: In healthy subjects, small but statistically significant differences of both HP thresholds of hypoalgesia and counts of ENFs were observed among tested sites. Significant correlations between HP thresholds and counts of ENFs were not found. DISCUSSION: For the studied somatotopic sites, we provide ≥95th and ≥99th percentile reference limits for HP 0.5 and 5 of 1-10 HP thresholds of hypoalgesia and decreased counts of ENFs at ≤5th and ≤1st percentile levels. Muscle Nerve 58: 509-516, 2018.

Beneficial plasma exchange response in central nervous system inflammatory demyelination.

BACKGROUND: Plasma exchange (PLEX) is a beneficial rescue therapy for acute, steroid-refractory central nervous system inflammatory demyelinating disease (CNS-IDD). Despite the approximately 45% PLEX response rate reported among patients with CNS-IDD, determinants of interindividual differences in PLEX response are not well characterized. OBJECTIVE: To perform an exploratory analysis of clinical, radiographic, and serological features associated with beneficial PLEX response. DESIGN: Historical cohort study. SETTING: Neurology practice, Mayo Clinic College of Medicine, Rochester, Minnesota. Patients All Mayo Clinic patients treated with PLEX between January 5, 1999, and November 12, 2007, for a steroid-refractory CNS-IDD attack. MAIN OUTCOME MEASURE: The PLEX response in attack-related, targeted neurological deficit(s) assessed within the 6-month period following PLEX. RESULTS: We identified 153 patients treated with PLEX for a steroid-refractory CNS-IDD, of whom 90 (59%) exhibited moderate to marked functional neurological improvement within 6 months following treatment. Pre-PLEX clinical features associated with a beneficial PLEX response were shorter disease duration (P = .02) and preserved deep tendon reflexes (P = .001); post-PLEX variables included a diagnosis of relapsing-remitting multiple sclerosis (P = .008) and a lower Expanded Disability Status Scale score (P < .001) at last follow-up. Plasma exchange was less effective for patients with multiple sclerosis who subsequently developed a progressive disease course (P = .046). Radiographic features associated with a beneficial PLEX response were presence of ring-enhancing lesions (odds ratio = 4.00; P = .03) and/or mass effect (odds ratio = 3.00; P = .02). No association was found between neuromyelitis optica-IgG serostatus and PLEX response. CONCLUSIONS: We have identified clinical and radiographic features that may aid in identifying patients with fulminant, steroid-refractory CNS-IDD attacks who are more likely to respond to PLEX.

Neuromyelitis optica IgG predicts relapse after longitudinally extensive transverse myelitis.

OBJECTIVE: We investigated whether neuromyelitis optica (NMO) IgG seropositivity at the initial presentation of longitudinally extensive transverse myelitis (LETM) predicts relapse of myelitis or development of optic neuritis. METHODS: Prospective study of patients with initial LETM who were tested for the presence of NMO-IgG. RESULTS: Eleven of 29 patients (37.9%) were seropositive after a first attack of LETM spanning three or more vertebral segments on magnetic resonance imaging. Of 23 patients followed up for 1 year, none of 14 who were seronegative experienced a relapse or developed optic neuritis. Of 9 seropositive patients, 5 developed a second event: 4 of 9 (44%) developed recurrent transverse myelitis and 1 of 9 (11%) developed optic neuritis (p = 0.004). INTERPRETATION: LETM represents an inaugural or limited form of NMO in a high proportion of patients. The 40% of patients who are seropositive for NMO-IgG are at high risk for relapse.