Neuro-PASC is characterized by enhanced CD4+ and diminished CD8+ T cell responses to SARS-CoV-2 Nucleocapsid protein.

Introduction: Many people with long COVID symptoms suffer from debilitating neurologic post-acute sequelae of SARS-CoV-2 infection (Neuro-PASC). Although symptoms of Neuro-PASC are widely documented, it is still unclear whether PASC symptoms impact virus-specific immune responses. Therefore, we examined T cell and antibody responses to SARS-CoV-2 Nucleocapsid protein to identify activation signatures distinguishing Neuro-PASC patients from healthy COVID convalescents. Results: We report that Neuro-PASC patients exhibit distinct immunological signatures composed of elevated CD4+ T cell responses and diminished CD8+ memory T cell activation toward the C-terminal region of SARS-CoV-2 Nucleocapsid protein when examined both functionally and using TCR sequencing. CD8+ T cell production of IL-6 correlated with increased plasma IL-6 levels as well as heightened severity of neurologic symptoms, including pain. Elevated plasma immunoregulatory and reduced pro-inflammatory and antiviral response signatures were evident in Neuro-PASC patients compared with COVID convalescent controls without lasting symptoms, correlating with worse neurocognitive dysfunction. Discussion: We conclude that these data provide new insight into the impact of virus-specific cellular immunity on the pathogenesis of long COVID and pave the way for the rational design of predictive biomarkers and therapeutic interventions.

Neurologic Manifestations of Long COVID Differ Based on Acute COVID-19 Severity.

OBJECTIVE: To characterize neurologic manifestations in post-hospitalization Neuro-PASC (PNP) and non-hospitalized Neuro-PASC (NNP) patients. METHODS: Prospective study of the first 100 consecutive PNP and 500 NNP patients evaluated at a Neuro-COVID-19 clinic between 5/2020 and 8/2021. RESULTS: PNP were older than NNP patients (mean 53.9 vs 44.9 y; p < 0.0001) with a higher prevalence of pre-existing comorbidities. An average 6.8 months from onset, the main neurologic symptoms were "brain fog" (81.2%), headache (70.3%), and dizziness (49.5%) with only anosmia, dysgeusia and myalgias being more frequent in the NNP compared to the PNP group (59 vs 39%, 57.6 vs 39% and 50.4 vs 33%, all p < 0.003). Moreover, 85.8% of patients experienced fatigue. PNP more frequently had an abnormal neurologic exam than NNP patients (62.2 vs 37%, p < 0.0001). Both groups had impaired quality of life in cognitive, fatigue, sleep, anxiety, and depression domains. PNP patients performed worse on processing speed, attention, and working memory tasks than NNP patients (T-score 41.5 vs 55, 42.5 vs 47 and 45.5 vs 49, all p < 0.001) and a US normative population. NNP patients had lower results in attention task only. Subjective impression of cognitive ability correlated with cognitive test results in NNP but not in PNP patients. INTERPRETATION: PNP and NNP patients both experience persistent neurologic symptoms affecting their quality of life. However, they harbor significant differences in demographics, comorbidities, neurologic symptoms and findings, as well as pattern of cognitive dysfunction. Such differences suggest distinct etiologies of Neuro-PASC in these populations warranting targeted interventions. ANN NEUROL 2023;94:146-159.

Therapeutic Approaches to the Neurologic Manifestations of COVID-19.

As of May 2022, there have been more than 527 million infections with severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) and over 6.2 million deaths from Coronavirus Disease 2019 (COVID-19) worldwide. COVID-19 is a multisystem illness with important neurologic consequences that impact long-term morbidity and mortality. In the acutely ill, the neurologic manifestations of COVID-19 can include distressing but relatively benign symptoms such as headache, myalgias, and anosmia; however, entities such as encephalopathy, stroke, seizures, encephalitis, and Guillain-Barre Syndrome can cause neurologic injury and resulting disability that persists long after the acute pulmonary illness. Furthermore, as many as one-third of patients may experience persistent neurologic symptoms as part of a Post-Acute Sequelae of SARS-CoV-2 infection (Neuro-PASC) syndrome. This Neuro-PASC syndrome can affect patients who required hospitalization for COVID-19 or patients who did not require hospitalization and who may have had minor or no pulmonary symptoms. Given the large number of individuals affected and the ability of neurologic complications to impair quality of life and productivity, the neurologic manifestations of COVID-19 are likely to have major and long-lasting personal, public health, and economic consequences. While knowledge of disease mechanisms and therapies acquired prior to the pandemic can inform us on how to manage patients with the neurologic manifestations of COVID-19, there is a critical need for improved understanding of specific COVID-19 disease mechanisms and development of therapies that target the neurologic morbidities of COVID-19. This current perspective reviews evidence for proposed disease mechanisms as they inform the neurologic management of COVID-19 in adult patients while also identifying areas in need of further research.

Evolution of neurologic symptoms in non-hospitalized COVID-19 "long haulers".

OBJECTIVE: We characterized the evolution of neurologic symptoms and self-perceived recovery of non-hospitalized COVID-19 "long haulers" 6-9 months after their initial Neuro-COVID-19 clinic evaluation. METHODS: In this follow-up study on the first 100 patients, 50 SARS-CoV-2 laboratory-positive (SARS-CoV-2+ ), and 50 laboratory-negative (SARS-CoV-2- ), evaluated at our Neuro-COVID-19 clinic between May and November 2020, patients completed phone questionnaires on their neurologic symptoms, subjective impression of recovery and quality of life. RESULTS: Of 52 patients who completed the study (27 SARS-CoV-2+ , 25 SARS-CoV-2- ) a median 14.8 (range 11-18) months after symptom onset, mean age was 42.8 years, 73% were female, and 77% were vaccinated for SARS-CoV-2. Overall, there was no significant change in the frequency of most neurologic symptoms between first and follow-up evaluations, including "brain fog" (81 vs. 71%), numbness/tingling (69 vs. 65%), headache (67 vs. 54%), dizziness (50 vs. 54%), blurred vision (34 vs. 44%), tinnitus (33 vs. 42%), and fatigue (87 vs. 81%). However, dysgeusia and anosmia decreased overall (63 vs. 27%, 58 vs. 21%, both p < 0.001). Conversely, heart rate and blood pressure variation (35 vs. 56%, p = 0.01) and gastrointestinal symptoms (27 vs. 48%, p = 0.04) increased at follow-up. Patients reported improvements in their recovery, cognitive function, and fatigue, but quality of life measures remained lower than the US normative population (p < 0.001). SARS-CoV-2 vaccination did not have a positive or detrimental impact on cognitive function or fatigue. INTERPRETATION: Non-hospitalized COVID-19 "long haulers" continue to experience neurologic symptoms, fatigue, and compromised quality of life 14.8 months after initial infection.

Persistent viral RNA shedding of SARS-CoV-2 is associated with delirium incidence and six-month mortality in hospitalized COVID-19 patients.

BACKGROUND: Persistent viral RNA shedding of SARS-CoV-2 following COVID-19 has increasingly been recognized, with limited understanding of its implications on outcomes in hospitalized COVID-19 patients. METHODS: We retrospectively assessed for persistent viral shedding across Northwestern Medicine Healthcare (NMHC) patients between March and August 2020. We assessed for predictors of persistent viral shedding, in-hospital delirium, and six-month mortality using binary logistic regression. RESULTS: Of the 2,518 hospitalized patients with an RT-PCR-confirmed diagnosis of COVID-19, 959 underwent repeat SARS-CoV-2 RT-PCR at least fourteen days from initial positive testing. Of those, 405 (42.2%) patients were found to have persistent viral shedding. Persistent viral shedding was associated with male sex, increased BMI, diabetes mellitus, chronic kidney disease, and exposure to corticosteroids during initial COVID-19 hospitalization. Persistent viral shedding was independently associated with incidence of in-hospital delirium after adjusting for factors including severity of respiratory dysfunction (OR 2.45; 95% CI 1.75, 3.45). Even after adjusting for age, severity of respiratory dysfunction, and occurrence of in-hospital delirium, persistent viral shedding remained significantly associated with increased six-month mortality (OR 2.43; 95% CI 1.42, 4.29). CONCLUSIONS: Persistent viral shedding occurs frequently in hospitalized COVID-19 patients and is associated with in-hospital delirium and increased six-month mortality.

Persistent neurologic symptoms and cognitive dysfunction in non-hospitalized Covid-19 "long haulers".

OBJECTIVE: Most SARS-CoV-2-infected individuals never require hospitalization. However, some develop prolonged symptoms. We sought to characterize the spectrum of neurologic manifestations in non-hospitalized Covid-19 "long haulers". METHODS: This is a prospective study of the first 100 consecutive patients (50 SARS-CoV-2 laboratory-positive (SARS-CoV-2+ ) and 50 laboratory-negative (SARS-CoV-2- ) individuals) presenting to our Neuro-Covid-19 clinic between May and November 2020. Due to early pandemic testing limitations, patients were included if they met Infectious Diseases Society of America symptoms of Covid-19, were never hospitalized for pneumonia or hypoxemia, and had neurologic symptoms lasting over 6 weeks. We recorded the frequency of neurologic symptoms and analyzed patient-reported quality of life measures and standardized cognitive assessments. RESULTS: Mean age was 43.2 ± 11.3 years, 70% were female, and 48% were evaluated in televisits. The most frequent comorbidities were depression/anxiety (42%) and autoimmune disease (16%). The main neurologic manifestations were: "brain fog" (81%), headache (68%), numbness/tingling (60%), dysgeusia (59%), anosmia (55%), and myalgias (55%), with only anosmia being more frequent in SARS-CoV-2+ than SARS-CoV-2- patients (37/50 [74%] vs. 18/50 [36%]; p < 0.001). Moreover, 85% also experienced fatigue. There was no correlation between time from disease onset and subjective impression of recovery. Both groups exhibited impaired quality of life in cognitive and fatigue domains. SARS-CoV-2+ patients performed worse in attention and working memory cognitive tasks compared to a demographic-matched US population (T-score 41.5 [37, 48.25] and 43 [37.5, 48.75], respectively; both p < 0.01). INTERPRETATION: Non-hospitalized Covid-19 "long haulers" experience prominent and persistent "brain fog" and fatigue that affect their cognition and quality of life.