PLOS ONE Medicine&Health

Low frequency of N-methyl-D-aspartate receptor autoimmunity in tick-borne encephalitis

by Jakob Morén, Barbro Persson, Anna Sörman, Åke Lundkvist, Hanin Shihab, Marie Studahl, Malin Veje, Göran Günther, Gabriel Westman

Background

Tick-borne encephalitis is a viral infection of the central nervous system that may cause severe illness and long-term sequelae, to which underlying mechanisms are not completely understood. Autoantibodies against the N-methyl-D-aspartate receptor (anti-NMDAR) may be triggered by immunologic events, occur sporadically, and can cause autoimmune encephalitis. Following herpes simplex encephalitis and Japanese encephalitis, anti-NMDAR autoantibodies may develop and have been associated with relapse or impaired cognitive recovery. Tick-borne encephalitis has been shown to trigger anti-NMDAR encephalitis in sporadic cases, but the frequency of autoimmunization is unknown.

Objectives

The objective of this study was to assess the frequency of intrathecal anti-NMDAR antibody development following tick-borne encephalitis and to explore whether such antibodies could be relevant to cognitive complaints.

Methods

Adult patients with tick-borne encephalitis were included retrospectively from one cohort and prospectively from another. A stored post-acute cerebrospinal fluid sample was required for anti-NMDAR analysis. Two commercial kits (Euroimmun AG, Lübeck, Germany) were used to detect anti-NMDAR IgG antibodies in cerebrospinal fluid.

Results

A total of 71 cerebrospinal fluid samples from 53 patients were analyzed for anti-NMDAR antibodies. Samples were obtained at a median of 91 days (range 21–471) after onset of central nervous system symptoms. Anti-NMDAR antibodies were detected in two samples from a single tick-borne encephalitis patient, corresponding to 1.9% of patients (95% CI: 0.05–10.1%).

Conclusions

The development of intrathecal anti-NMDAR autoantibodies following tick-borne encephalitis is a rare event, and further studies are needed to clarify their potential relevance to cognitive outcomes in a minority of cases. Testing for anti-NMDAR antibodies in cerebrospinal fluid may be considered in patients who experience clinical deterioration following an initial recovery.

PLOS ONE Medicine&Health

Fatigue and cognitive dysfunction in previously hospitalized patients with COVID-19: A 1-year follow-up

by Ingrid Andreasson, Hanna C. Persson, Ann Björkdahl

Purpose

The aim was to longitudinally explore changes in fatigue- and cognition-related symptoms during the first year after hospital treatment for COVID-19.

Method

Patients hospitalized for COVID-19 in Gothenburg, Sweden, were consecutively included from 01-07-2020 to 28-02-2021. Patients were assessed at the hospital (acute) and at 3 and 12 months after hospital discharge. Cognition was assessed with the Montreal Cognitive Assessment (MoCA), the Trail Making Test B (TMTB), and the Cognitive Failure Questionnaire (CFQ). Fatigue was assessed using the Multidimensional Fatigue Inventory-20 (MFI-20) and the Mental Fatigue Scale (MFS). Data was analyzed with demographics and changes over time calculated with univariable mixed-effects models.

Result

In total, 122 participants were included. Analyzes of Z-scores for MoCA indicated improvement over the year, however the results were 1 SD below norm at all assessments. Alertness (TMTB scores) improved significantly from the acute assessment to the 12- month follow-up (p = Conclusion

In the first year after hospitalization for COVID-19, most patients experienced fatigue and cognitive impairment. Alertness improved, but improvements in other domains were limited.