Brain MRI volumetric changes in the follow-up of patients with anti-NMDAr encephalitis.

INTRODUCTION: Autoimmune anti-NMDAr encephalitis is an antibody-mediated disorder characterized by psychiatric symptoms followed by decreased consciousness, dysautonomia and seizures. The pathophysiology of the disease is related to the internalization of NR1 subtype NMDA receptors and the dysfunction of structures where they are abundant (frontotemporal and insular regions). Some reports suggest the existence of cerebral atrophy in the follow-up of these patients, with conflicting evidence regarding its presence and usefulness as a marker of prognosis. METHODS: In a longitudinal, observational study, all patients with the diagnosis of definite anti-NMDAr autoimmune encephalitis with initial and control MRI studies were included. Conventional MR Brain acquisition was performed using a 3-Tesla Skyra MRI System. Automated brain segmental analysis was performed using the Volbrain volumetry system. The differences between baseline MRI volumetric characteristics and volumetric measures at follow-up was assessed. RESULTS: 25 patients were included (mean age 26.6, SD 9.6). 44% were females. The mean time between the studies was 24 (SD 21.4, 3-24) months. Significant volume loss was identified in the total brain volume (- 0.02%, p = 0.029), cerebellar volume (- 0.27%, p = 0.048) and brainstem volume (- 0.16%, p = 0.021). CONCLUSIONS: This study supports previous observations regarding volume loss in several brain regions of patients with antiNMDAr encephalitis. Further analyses are required to understand the role of treatment and severe clinical forms, as well as the relationship between volume loss and functional outcome.

Pleasant parosmia with regard to own stool after SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) has had a significant global impact due to the millions of deaths it has caused secondary to respiratory failure. However, the disease has also been associated with a wide array of manifestations in other organ systems. Among them, the presence of anosmia, which occurs in up to half the patients, has become a new sign of alarm to suspect the infection. Although up to 90% of affected patients will experience an improvement of their olfactory alterations within a month after the infection, the variety and severity of olfactory disturbances clearly cannot be summarized by the dichotomy of having anosmia or not. Parosmias are a type of olfactory dysfunction characterized by altered perception of odors, which can reflect both damage at some level of the olfactory tract, as well as the possibility of reversibility of said damage. The present manuscript describes possible olfactory disturbances associated with COVID-19, their pathophysiology, and potential clinical significance.

La enfermedad por coronavirus 2019 (COVID-19) ha tenido un impacto mundial trascendente por los millones de muertes que ha causado secundarias a insuficiencia respiratoria. Sin embargo, la enfermedad también se ha asociado a una amplia gama de manifestaciones en otros sistemas. Entre ellas, la presencia de anosmia, la cual ocurre en hasta mitad de los pacientes, se ha vuelto un nuevo dato de alarma para sospechar la infección. Aunque hasta el 90% de los pacientes afectados presentarán mejoría de sus alteraciones olfatorias dentro del mes posterior a su cuadro, la variedad y gravedad de alteraciones olfatorias claramente no pueden resumirse en la dicotomía de tener o no anosmia. Las parosmias son un tipo de alteración olfatoria caracterizadas por percepciones alteradas de los olores, las cuales pueden reflejar tanto daño a algún nivel del tracto olfatorio, así como la posibilidad de reversibilidad de dicho daño. En el presente manuscrito se describen las posibles alteraciones olfatorias asociadas a COVID-19, su fisiopatología, y potencial significancia clínica.

Rituximab efficacy at different initial and maintenance doses in neuromyelitis optica spectrum disorder: Experience from a national health institute in México.

BACKGROUND: NMOSD is an inflammatory disorder of the central nervous system that primarily affects the optic nerves and spinal cord. Rituximab (RTX) is a monoclonal antibody directed against CD20, an epitope expressed on pre-B and mature B cells. It has of wide use in several antibody-mediated autoimmune diseases. OBJECTIVES: To demonstrate RTX clinical efficacy at different initial and maintenance doses administered in patients with NMOSD. METHODS: In this retrospective/observational study we recruited subjects with NMOSD with at least one RTX infusion. Annual relapse rates (ARR) were compared in several induction and maintenance regimens with RTX in 66 patients with NMOSD. RESULTS: Fifty-four (81.8%) were female and two thirds (66.7%) had positive anti-AQP4 antibodies. The most prevalent induction and maintenance regimens were 1000 mg on days 1 and 15 (51.5%) and 1000 mg every 6 months (40.9%), respectively. Overall, the annual relapse rate (ARR) decreased from 1.15 to 0.46 with RTX (p < 0.001). In patients with persistent relapses, the ARR decreased from 1.66 to 1.22, representing a relative risk reduction of 24%. Treatment with RTX decreased the ARR from 1.36 to 0.4 in the 500 mg induction and maintenance dose subgroup, and from 0.7 to 0.4 in the 1000 mg induction and maintenance dose subgroup. CONCLUSION: RTX treatment in patients with NMOSD demonstrated a marked and sustained reduction in the ARR, regardless of induction and maintenance regimens. EDSS stability was observed, even in patients with active and severe NMOSD.

Severe fingolimod rebound syndrome after switching to cladribine treatment.

We present the clinical and imaging characteristics of a patient whom presented with rebound syndrome after switching from fingolimod to cladribine treatment due to hematologic toxicity. Previous imaging studies had shown a non-aggressive phenotype of the disease, however multiple active tumefactive lesions became evident after beginning treatment with cladribine. The patient responded well to plasmapheresis.