Neurological post-acute sequelae of SARS-CoV-2 infection.

The novel coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can have two phases: acute (generally 4 weeks after onset) and chronic (>4 weeks after onset). Both phases include a wide variety of signs and symptoms including neurological and psychiatric symptoms. The signs and symptoms that are considered sequelae of COVID-19 are termed post-COVID condition, long COVID-19, and post-acute sequelae of SARS-CoV-2 infection (PASC). PASC symptoms include fatigue, dyspnea, palpitation, dysosmia, subfever, hypertension, alopecia, sleep problems, loss of concentration, amnesia, numbness, pain, gastrointestinal symptoms, depression, and anxiety. Because the specific pathophysiology of PASC has not yet been clarified, there are no definite criteria of the condition, hence the World Health Organization's definition is quite broad. Consequently, it is difficult to correctly diagnose PASC. Approximately 50% of patients may show at least one PASC symptom up to 12 months after COVID-19 infection; however, the exact prevalence of PASC has not been determined. Despite extensive research in progress worldwide, there are currently no clear diagnostic methodologies or treatments for PASC. In this review, we discuss the currently available information on PASC and highlight the neurological sequelae of COVID-19 infection. Furthermore, we provide clinical suggestions for diagnosing and caring for patients with PASC based on our outpatient clinic experience.

Clinical features of patients who visited the outpatient clinic for long COVID in Japan.

Background: The clinical course, comorbidity, and management of symptoms after the acute phase of coronavirus disease 2019 (COVID-19) remain controversial. Methods: This was a descriptive case series study, examining the characteristics of patients with longstanding symptoms related to COVID-19 who visited our outpatient clinic between 1 June and 31 December 2021. We analyzed patients' background, chief complaints, clinical course after COVID-19 onset, and clinical examination results. Results: A total of 90 patients with a mean age of 39.8 years were confirmed as having long COVID. The median time between diagnosis of COVID-19 and visiting our clinic was 66.8 days, and 89 patients (98.9%) were unvaccinated. Depression was the most common comorbidity (nine patients, 10.0%). The most common chief complaint was disturbance of smell and/or taste (35, 38.9%), followed by memory disturbance (22, 24.4%) and fatigue (29, 31.1%). Head MRI was performed for 42 (46.7%) patients, and the most common finding was sinusitis (four patients). Olfactory testing was conducted in 25 patients (27.8%) using a T&T olfactometer, and 14 patients (56%) had mild olfactory impairment. Of the five odors in the T&T, recognition of ß-phenylethyl alcohol was most impaired. Conclusions: This study describes the basic characteristics of long COVID in Japan. It suggests that long COVID is complex because it results in a wide range of symptoms.

[Outpatient Clinic for Long COVID].

We summarize the current status of outpatient clinics for patients with long-term coronavirus disease 2019-associated post-acute sequelae severe acute respiratory syndrome coronavirus 2 infection (PASC) at the National Center of Neurology and Psychiatry Hospital. The pathogenesis of PASC is not well understood and its symptoms vary. Recently, the number of patients with PASC has been increasing, meaning that many physicians will need to treat such patients occasionally. Although diagnostic, testing, and treatment methods have not been established, clinicians must apply a long-term management approach to patients based on the clinical evaluation of each individual. Furthermore, there is an urgent need to establish a system for analyzing PASC on a long-term basis.