Abstract: Journal of Neurology (2021) 268:2666–2670 https://doi.org/10.1007/s00415-020-10272-0 ORIGINAL COMMUNICATION COVID‑19 in Parkinson’s disease: what holds the key? R. Sainz‑Amo1 · B. Baena‑Álvarez1 · I. Pareés1 · G. Sánchez‑Díez1 · P. Pérez‑Torre1 · J. L. López‑Sendón1 · S. Fanjul‑Arbos1 · E. Monreal1 · I. Corral‑Corral1 · N. García‑Barragán1 · J. C. Martínez‑Castrillo1 · A. Fasano2,3 · A. Alonso‑Cánovas1 Received: 10 September 2020 / Revised: 4 October 2020 / Accepted: 10 October 2020 / Published online: 24 October 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Introduction Parkinson’s disease (PD) is more frequent in the elderly and increases the risk of respiratory infections. Previous data on PD and SARS-CoV-2 are scarce, suggesting a poor prognosis in advanced disease and second-line therapies. Methods A retrospective case–control study comparing patients with PD and COVID-19 and patients with PD without COVID-19 was conducted during the pandemic period in Spain (March 1st–July 31st 2020) in a tertiary university hospital. Results Thirty-nine (COVID-19 +) and 172 (COVID-19-) PD patients were included. Fifty-nine percent were males in both groups, with similar age (75.9 ± 9.0 COVID-19 + , 73.9 ± 10.0 COVID-19-), disease duration (8.9 ± 6.2 COVID-19 + , 8.5 ± 5.6 COVID-19-) and PD treatments. COVID-19 was mild in 10 (26%), required admission in 21 (54%) and caused death in 8 (21%) patients. Dementia was the only comorbidity more frequent in COVID-19 + patients (36% vs. 14%, p = 0.0013). However, in a multivariate analysis, institutionalization was the only variable associated with COVID-19 + (OR 17.0, 95% CI 5.0–60.0, p < 0.001). When considering severe COVID-19 (admission or death) vs. mild or absent COVID-19, institutionalization, neoplasm, dementia and a lower frequency of dopamine agonists were associated with severe COVID-19. In multivariate analysis, only institutionalization [OR 5.17, 95% CI 1.57–17, p = 0.004] and neoplasm [OR 8.0, 95%CI 1.27–49.8, p = 0.027] remained significantly associated. Conclusion In our experience, institutionalization and oncologic comorbidity, rather than PD-related variables, increased the risk of developing COVID-19, and impacted on its severity. These findings suggest that epidemiologic factors and frailty are key factors for COVID-19 morbidity/mortality in PD. Appropriate preventive strategies should be implemented in institutionalized patients to prevent infection and improve prognosis. Keywords SARS-CoV-2 · COVID-19 · Parkinson · Institutionalization · Comorbidity · Prognosis