Decreased Incidence of Guillain-Barré Syndrome during the COVID-19 Pandemic: A Retrospective Population-Based Study.

BACKGROUND: Guillain-Barré syndrome is an immune-mediated acute inflammatory polyneuropathy that is associated with various triggers, including certain infections and vaccines. It has been suggested that both SARS-CoV-2 infection and vaccination may be triggering factors for Guillain-Barré syndrome, but evidence remains equivocal. Here, we conducted a population-based incidence study of Guillain-Barré syndrome spanning the 3 years immediately prior to and the 2 years during the pandemic. METHODS: Cases were identified by searching a regional diagnostic database for the ICD-10 code for Guillain-Barré syndrome. Individuals who fulfilled the Brighton criteria for Guillain-Barré syndrome were included. Information on clinical presentation, laboratory values, and vaccination status were retrieved from medical records. We calculated the incidence immediately prior to and during the pandemic. RESULTS: The Guillain-Barré syndrome incidence rate was 1.35/100,000 person-years for the pre-pandemic period and 0.66/100,000 person-years for the pandemic period (incidence rate ratio: 0.49; p = 0.003). Three cases were temporally associated with SARS-CoV-2 infection and 1 case each to the AstraZeneca and Pfizer-BioNTech COVID-19 vaccines. CONCLUSIONS: Our results show that the incidence of Guillain-Barré syndrome decreased during the pandemic. This is most likely due to decreased prevalence of triggering infections due to social restrictions. Our findings do not support a causal relationship between Guillain-Barré syndrome and COVID-19.

Perioperative stroke and survival in coronary artery bypass grafting patients: a SWEDEHEART study.

OBJECTIVES: Perioperative stroke is a severe complication of cardiac surgery. We assessed the incidence of stroke over time, the association between stroke and mortality and identified preoperative factors independently associated with perioperative stroke, in a large nationwide cardiac surgery population. METHODS: All patients who underwent coronary artery bypass grafting in Sweden 2006-2017 were included in a registry-based observational cohort study based on prospectively collected data. Multivariable logistic and Cox regression models were used to assess associations between perioperative stroke and mortality and to identify factors associated with stroke. The median follow-up was 6 years (range 0-12). RESULTS: There were 441 perioperative strokes in 36 898 patients. The mean incidence was 1.2% and decreased marginally over time [adjusted odds ratio (OR) 0.97 per year (95% confidence interval 0.94-1.00), P = 0.035]. Stroke patients had a higher overall mortality risk during follow-up [adjusted hazard ratio 2.30 (2.00-2.64), P < 0.001], with the highest risk during the first 30 postoperative days [adjusted hazard ratio (7.29 (5.58-9.54), P < 0.001]. The strongest independent preoperative factors associated with stroke were prior cardiac surgery [adjusted OR 2.89 (1.40-5.96)], critical preoperative condition [adjusted OR 2.55 (1.73-3.76)], previous stroke [adjusted OR 1.77 (1.35-2.33)], preoperative angina requiring intravenous nitrates [adjusted OR 1.67 (1.28-2.17)], peripheral vascular disease [OR 1.63 (1.25-2.13)] and advanced age [OR 1.05 (1.03-1.06) per year]. CONCLUSIONS: The incidence of perioperative stroke after coronary artery bypass grafting has remained stable. Patients with perioperative stroke had a markedly higher adjusted risk of death early after surgery. The risk declined over time but remained higher during the entire follow-up period.

Incidence and outcome of Guillain-Barré syndrome in Iceland: A population-based study.

OBJECTIVE: In this study, we determine the incidence and outcomes of Guillain-Barré syndrome (GBS) in Iceland over a 20-year period. METHOD: Cases were identified from the records of both referral hospitals in the country. All cases met the Brighton Criteria for GBS. Disability was assessed at diagnosis, peak of symptoms, discharge, and follow-up using the Guillain-Barré Disability Scale. RESULTS: Sixty-three individuals fulfilled the diagnostic criteria with an average age of onset of 46 years (range 1-89 years) and a male:female ratio of 1. The average annual incidence was 1.1 per 100 000 person-years. Nerve conduction studies were consistent with demyelinating polyneuropathy in 87% of cases, acute motor axonal neuropathy (AMAN) in 4%, and were normal in 9%. Treatment was received by 89% of patients and included IVIG (84%), plasmapheresis (8%), or both treatments (3%). Mechanical ventilation was required by 22% of patients. Long-term follow-up with an average length of 6.5 years was available for 98% of patients, and the average GBS disability score at follow-up was 0.9. Four deaths related to GBS (6%) were observed. CONCLUSION: We believe we have identified all patients diagnosed with GBS in Iceland during the study period, with an incidence comparable to recent studies from well-defined populations around the world. Our reported mortality is similar to or higher than other population-based studies. At follow-up, 13% of patients still required a walking aid, but most survivors (74%) had minor or no symptoms.

Incidence and Natural History of Idiopathic Chronic Inflammatory Demyelinating Polyneuropathy: A Population-Based Study in Iceland.

BACKGROUND AND AIM: We report a population-based study conducted in Iceland to determine the incidence, clinical characteristics and prognosis of idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) during a 21-year period. METHODS: Cases were identified from the records of all practicing neurologists in the country, the only neurology department in the country and both neurophysiology laboratories. All index cases met the 2010 European Federation of Neurological Societies/Peripheral Nerve Society criteria for CIDP. RESULTS: Nineteen individuals fulfilled the diagnostic criteria during the study period. The average annual incidence was 0.3/100,000 (95% CI 0.04-2.47). There were 14 men (74%) in a gender ratio of 1:2.8. The mean age at diagnosis was 57 (range 19-81 years): women, 36 years and men, 63 years; p = 0.0006. The disease course was remitting-relapsing in 21% and chronic progressive or monophasic in 79%. The average length of follow-up was 6.9 years. The standardized mortality ratio for the 21-year study period was 0.9 (95% CI 0.3-2.2). CONCLUSION: We believe we have identified all diagnosed with CIDP in Iceland during a 21-year period. Many had no or only limited disease progression over the years and mortality is not increased compared with the general population.