To evaluate the impact of the COVID-19 pandemic on disruptions of neurological services and the implemented mitigation strategies, WHO commissioned this rapid review on the topic. The literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) . A standardized data extraction sheet was designed in line with the categories used in WHO’s COVID-19 Pulse Surveys as well as the Rapid Assessment of MNS disorders . The study was done in parallel with a Global Survey on disruptions and mitigation strategies coordinated by the European Federation of Neurological Associations (EFNA) in collaboration with 34 scientific and patient associations related to neurology in support of WHO’s Neurology and COVID-19 Global Forum working group on Essential Neurological Services. We used the same variables, to allow future comparability between the results of the survey and the present study.
Studies were included if they addressed the impact of the COVID-19 pandemic on the provision of neurological services, adopted or proposed mitigation strategies, or both. Studies were excluded in the following cases: (i) publication before November 2019; (ii) lacking original data; (iii) publication in a language other than English, Spanish, French, Italian, Portuguese or German; (iv) focus on basic science or preclinical aspects of the infection; and (v) focus on clinical aspects, diagnosis or therapeutics only.
Two databases were screened, PubMed and the WHO COVID-19 database, a curated database of all COVID-19 related published articles and pre-publications. The search was conducted on February 18, 2021 and updated on February 28, 2021. The search string was developed together with a WHO librarian combining terms on three axes: (1) COVID-19 related terms, (2) neurological categories and (3) outcomes related to service disruption and mitigation strategies . The full detail on the search is available in the supplementary appendix.
Study selection criteria
A single author (D GA) screened all search results to identify studies meeting inclusion criteria. The studies were ordered chronologically and included in a spreadsheet. Both the title and the abstract of the studies were reviewed. Whenever eligibility could not be determined by the title and abstract alone, the full articles were screened for eligibility. When the study did not fulfil eligibility criteria, the reason for exclusion was described in the database.
Data extraction process and extracted information
The method of data extraction was automatic from the PubMed database for the following variables: title, authors, citation, journal, digital object identifier (DOI) and date of creation in PubMed; the remaining variables were manually extracted. For the WHO database, all data were manually extracted using a standardized form. The extracted information included the publication date, the studied population (adult, children or both), the subspecialty of neurology, language of publication, country, where the study took place, study design, and study setting (inpatient, emergency care, outpatient, or a combination). The full list of subspecialties and study designs is available in the supplementary appendix.
The sample size was also described, and in those studies that accounted for patients from 2020 and historical controls, we only included patients studied in 2020. When the study analyzed specialties of medicine other than neurology, only the neurological patients were included in the sample size. If the study described the opinion of healthcare providers, caregivers or students, the number of participants interviewed was included as the sample size.
Specific variables evaluated for service disruption and mitigation strategies
Data extraction followed the same categories of services, causes for disruption, and mitigation strategies as used by WHO’s COVID-19 Pulse Surveys, the Rapid Assessment of MNS services as well as WHO’s operational guidelines on maintaining essential health services during COVID-19 (chapter on MNS disorders) [4, 9], with additional delineations as and when necessary.
First, we extracted whether the study described any degree of interruption of the following categories: (1) emergency and acute care for neurological disorders; (2) investigations (including neuroimaging, neurophysiology, lab diagnostics, and others); (3) treatment and care for neurological disorders (including interventions and therapies, such as planned surgeries and access to medicines); (4) neurorehabilitation, inclusive of physiotherapy, speech therapy, occupational therapy, cognitive rehabilitation, and psychology/counselling; (5) cross-sectoral service delivery for neurological disorders, including community-based services, residential long-term care, adult/child day care, special/inclusive school educational programmes for children, interventions for caregivers, and services/programmes delivered by non-governmental organizations; (6) promotion of brain health and prevention of neurological disorders, in addition to implementation activities of national prevention plan and neurology advocacy; (7) training of residents, PhD students or other educational activities; (8) research.
The causes of service disruptions were assessed and classified into: (1) closure of inpatient or outpatient services or consultations as per health authority directive; (2) decrease in outpatient volume due to patients not presenting for care; (3) decreased volume of patients due to cancellation of elective care; (4) inpatient services/hospital beds not available due to saturation; (5) insufficient staff to provide services (e.g., due to quarantine/self-isolation of health-care providers due to COVID-19); (6) clinical staff shifted to provide COVID-19 clinical management or emergency support; (7) insufficient Personal Protective Equipment (PPE) available for health care professionals to provide services; (8) disruption of supply chains resulting in unavailability or stock out of essential medicines, medical diagnostics or other health products at health facilities; (9) travel restrictions hindering access to the health facilities for patients.
The degree of service disruption was graded into no disruption, mild, moderate, or severe, based on the study findings as per the authors judgment. In case the level of disruption was not explicitly reported, the degree was approximated based on the change respective to the baseline period or with other similar studies, as mild (1–39%), moderate (40–69%) or severe (70% or higher).
Mitigation strategies were classified into the following categories: (1) triaging of neurological patients to identify priorities; (2) redirection of patients to alternate care sites (e.g., primary care), reorientation of referral pathways or integration of several services into a single visit; (3) telemedicine deployment to replace in-person consults or other teleconsultation formats; (4) self-care interventions, provision of home-based care, or helplines for patients and caregivers; (5) catch-up campaigns for missed appointments; (6) task-shifting or role delegation; (7) recruitment of additional staff, novel supply chain management and logistics approaches; (8) novel dispensing approaches for medicines, novel prescribing approaches (e.g., tele-prescription, extended drug prescriptions); (9) community communications (e.g., informing on changes to service delivery, addressing misinformation and community fears) to ensure that all citizens are aware and informed of continuity of services and that routine care can always be sought; and (10) government removal of user fees.
Risk of bias, summary measures and synthesis of results
Since this review was not focused on the results of a therapeutic or diagnostic intervention, whenever any information regarding service disruption or mitigation strategies was present, the study was included in the review. The results were summarized as numbers and percentage of studies per category, over the total of included studies. Traditional tools for the evaluation of bias were not appropriate for the purpose of the study, and, therefore, were not used. Although not necessarily considered a bias in itself, we analyzed whether studies were published in international journals versus national or regional journals for the most frequently studies countries.
We classified the represented countries according to the Gross National Income (GNI) per capita, according to the 2019 World Bank atlas  criteria, into low income, lower middle, upper middle and high income. The full criteria are available in the supplementary appendix.