Several lines of evidence suggest that multiple sclerosis (MS), like other autoimmune diseases, may be triggered by microbial infections. Pathogens associated with development or exacerbation of MS include bacteria, such as Chlamydia pneumoniae, Staphylococcus aureus-produced enterotoxins that function as superantigens, and viruses of the Herpesviridae (Epstein–Barr virus and human herpes virus 6) and human endogenous retrovirus families. However, to date, no single pathogen has been accepted as causal agent. In addition, common upper respiratory, gastrointestinal, and urogenital tract infections have also been associated with MS exacerbations. Although evidence of an infectious etiology as cause of MS in humans remains inconclusive, microbial agents may modulate the neuroimmunological system of genetically susceptible individuals. Decoding the epidemiological contribution of different microorganisms to MS, along with their pathogenic mechanisms, may help develop new treatment strategies and prevent relapses.

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The risk of recurrence of new amnesia events in patients having previously experienced transient global amnesia (TGA) ranges between 2.9-23.8%. Objective: Our objective was to search for recurrence predictors in TGA patients. Methods: Retrospective analysis to identify recurrence predictors in a cohort of 203 TGA patients from a single center in Buenos Aires, Argentina, diagnosed between January 2011 and March 2017 Clinical features and complementary studies (laboratory results, jugular vein Doppler ultrasound and brain MRI) were analyzed. Comparison between patients with recurrent versus single episode TGA was performed, applying a multivariate logistic regression model. Results: Mean age at presentation was 65 years (20-84); 52% were female. Median time elapsed between symptom onset and ER visit was two hours, with the average episode duration lasting four hours. Mean follow-up was 22 months. Sixty-six percent of patients referred to an identifiable trigger. Jugular reflux was present in 66% of patients; and 22% showed images with hippocampus restriction on diffusion-weighted MRI. Eight percent of patients had TGA recurrence. Patients with recurrent TGA had a more frequent history of migraine than patients without recurrence (37.5% vs. 14%; p = 0.03). None of the other clinical characteristics and complementary studies were predictors of increased risk of recurrence. Conclusions: Patients with migraine may have a higher risk of recurrent TGA. None of the other clinical characteristics evaluated allowed us to predict an increased risk of recurrence. Although the complementary studies allowed us to guide the diagnosis, they did not appear to have a significant impact on the prediction of recurrence risk.

BackgroundAcute transverse myelitis (ATM) is an infrequent but severe complication of systemic lupus erythematosus (SLE). The purpose of study was to describe clinical features and prognostic factors of patients with SLE-related ATM.MethodsIn this medical records review study, data were collected from 60 patients from 16 centers seen between 1996 and 2017 who met diagnostic criteria for SLE and myelitis as defined by the American College of Rheumatology/Systemic International Collaborating Clinics and the Working Group of the Transverse Myelitis Consortium, respectively. Objective neurological impairment was measured with American Spinal Injury Association Impairment Scale (AIS) and European Database for Multiple Sclerosis Grade Scale (EGS).ResultsAmong patients included, 95% (n = 57) were female, and the average age was 31.6 ± 9.6 years. Myelitis developed after diagnosis of SLE in 60% (n = 36). Symmetrical paraparesis with hypoesthesia, flaccidity, sphincter dysfunction, AIS = A/B, and EGS ≥ 8 was the most common presentation. Intravenous methylprednisolone was used in 95% (n = 57), and 78.3% (n = 47) received intravenous cyclophosphamide. Sensory/motor recovery at 6 months was observed in 75% (42 of 56), but only in 16.1% (9 of 56) was complete. Hypoglycorrhachia and EGS ≥ 7 in the nadir were associated with an unfavorable neurological outcome at 6 months (p < 0.05). A relapse rate during follow-up was observed in 30.4% (17 of 56). Hypoglycorrhachia and hypocomplementemia seem to be protective factors for relapse. Intravenous cyclophosphamide was associated with time delay to relapse.ConclusionsSystemic lupus erythematosus–related ATM may occur at any time of SLE course, leading to significant disability despite treatment. Relapses are infrequent and intravenous cyclophosphamide seems to delay it. Hypoglycorrhachia, hypocomplementemia, and EGS at nadir are the most important prognostic factors.

Acute inflammatory demyelinating polyneuropathy (AIDP) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) are conditions presenting overlapping clinical features during early stages (first 4 weeks), although the latter may progress after 8 weeks. The aim of this study was to identify predictive factors contributing to their differential diagnosis. Clinical records of adult patients with AIDP or A-CIDP diagnosed at our institution between January 2006 and July 2017 were retrospectively reviewed. Demographic characteristics, clinical manifestations, cerebrospinal-fluid (CSF) findings, treatment and clinical evolution were analyzed. Nerve conduction studies were performed in all patients with at least 12 months follow-up. A total of 91 patients were included (AIDP, n = 77; A-CIDP, n = 14). The median age was 55.5 years in patients with A-CIDP vs 43 years in AIDP (P = .07). The history of diabetes mellitus was more frequent in A-CIDP (29% vs 8%, P = .04). No significant differences between groups were observed with respect to: human immunodeficiency virus (HIV) status, presence of auto-immune disorder or oncologic disease. Cranial, motor and autonomic nerve involvement rates were similar in both groups. Patients in the A-CIDP group showed higher frequency of proprioceptive disturbances (83% vs 28%; P < .001), sensory ataxia (46% vs 16%; P = .01), and the use of combined immunotherapy with corticoids (29% vs 3%; P = .005). There were no significant differences in CSF findings, intensive care unit (ICU) admission, or mortality rates. During the first 8 weeks both entities are practically indistinguishable. Alterations in proprioception could suggest A-CIDP. Searching for markers that allow early differentiation could favor the onset of corticotherapy without delay.