The Impact of Long COVID on Cognitive Performance and Sleep Quality: An Analysis of the Rancagua Chilean Study (RACHIS).

Background Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to prolonged symptoms post-recovery, commonly known as long-term coronavirus disease 2019 (COVID-19) or "long COVID." Neuropsychiatric consequences of long COVID include cognitive dysfunction and sleep disturbances, which significantly impair daily living. This study aimed to explore the impact of long COVID on cognitive performance and sleep quality in patients receiving outpatient care. Material and methods This study involved a random sample of 138 of 363 patients, corresponding to 38% of the cohort, who tested positive for SARS-CoV-2 via polymerase chain reaction (PCR) between May 2020 and April 2021. These unvaccinated, non-hospitalized individuals, predominantly exhibiting mild disease symptoms, were prospectively assessed 11 months post-positive PCR test. After informed consent, demographic data, memory, and concentration impairment levels were collected through interviews. Participants reporting cognitive symptoms underwent the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MOCA), and the Pittsburgh Sleep Quality Index. Statistical analyses were conducted, including Student's t-test, Chi-square, Fisher's test, Kruskal-Wallis test, and Pearson correlation coefficient, with a significance threshold set at p<0.05. Results Of the 138 participants, 76 (55.1%) were female and 62 (44.9%) were male. The mean age was 45.9 years (± 13.0), with an average educational attainment of 10.4 years (± 3.7). Roughly 50% of the patients reported significant memory and concentration issues (p<0.001). Thirty-three participants underwent detailed cognitive assessments, revealing a 2:1 female-to-male ratio and a significantly higher prevalence of depression in female participants. Cognitive deficits were diagnosed in five (15.2%) participants via the MMSE and in 26 (78.8%) via the MOCA test, with notable deficits in visuospatial/executive functions, language repeat, and deferred recall (p<0.001). A lower educational level was correlated with higher cognitive deficits (p=0.03). Conclusion The study findings reveal that cognitive impairments, as a consequence of COVID-19, can persist up to 11 months post-infection. The MOCA test proved more effective in diagnosing these deficits and requires adjustments based on educational background. Sleep parameters remained largely unaffected in this cohort, likely attributed to the mild nature of the initial symptoms and the outpatient management of the disease.

Long-lasting brain fog is related with severity clusters of symptoms in COVID-19 patients

BACKGROUND: COVID-19 patients may experience Long-lasting symptoms from weeks to even months. AIM: To evaluate long-term cognitive impairment based on the severity of symptoms of COVID-19 infection in a primary health system setting. Material and Methods: From a database of 363 patients, 83 cases aged 47 ± 15 years, (58% females) were selected from June to August 2020. In patients who survived the virus, 24 infection-related symptoms were collected to create three severity clusters (mild, moderate, and severe). The follow-up time was at least seven months. Comparing the first two clusters with the severe cluster, the existence of brain fog and risk factors (obesity, hypertension, diabetes, chronic lung disease, and hypothyroidism) were analyzed. RESULTS: Thirty-one patients (37%) had persistent symptoms lasting up to 240 days. Fifty-one patients (61%) experienced brain fog. Concentration was affected by symptom severity (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.26-10.46, p = 0.02). Short- or long-term memory loss was not affected. Moreover, symptom severity was related to brain fog (OR 3.16, 95% CI 1.05-9.51, p = 0.04). Patients with persistent symptoms had a concentration impairment associated with severity patterns (OR 24.3, 95% CI 1.73-340.11, p = 0.03). Conclusions: Brain fog is associated with symptom severity in COVID-19 survivors and lasts for more than eight months.

ANTECEDENTES: Los pacientes que han tenido COVID-19 pueden experimentar síntomas persistentes que duran semanas a meses. OBJETIVO: Evaluar el deterioro cognitivo a largo plazo en función de la severidad de los síntomas de la infección por COVID-19, en un escenario de sistema primario de salud. Material y Métodos: De una base de datos de 363 pacientes se seleccionaron 83 casos de 47 ± 15 años (58% mujeres), de junio-agosto de 2020. Se recopilaron 24 síntomas relacionados con la infección, creando tres grupos (leve, moderado y severo), en pacientes que padecieron y sobreviven al virus. El tiempo de seguimiento fue de al menos siete meses. La existencia de niebla cerebral y de factores de riesgo (obesidad, hipertensión, diabetes, enfermedad pulmonar crónica e hipotiroidismo) se comparó los dos grupos de severidad más bajos con el nivel superior. RESULTADOS: Treinta y un pacientes (37%) tuvieron síntomas prolongados con una duración de hasta 240 días. Cincuenta y un pacientes (61%) mostraron niebla cerebral. El deterioro de la concentración fue afectado por la severidad (Razón de riesgo (RR) = 3,63, Intervalos de confianza (IC) 95%: 1,26-10,46, p = 0,02). La pérdida de memoria a corto o largo plazo no fue afectada. El grupo con mayor severidad se asoció a niebla cerebral (RR = 3,16, IC95%: 1,05-9,51, p = 0,04). Los portadores de síntomas prolongados tuvieron una alteración de la concentración asociado a severidad (RR: 3,16, IC95%: 1,05-9,51, p= 0,04). Conclusiones: La niebla cerebral está relacionada con la severidad de los síntomas en supervivientes de COVID-19 permaneciendo por más de ocho meses.

Long-lasting brain fog is related with severity clusters of symptoms in COVID-19 patients.

BACKGROUND: COVID-19 patients may experience Long-lasting symptoms from weeks to even months. AIM: To evaluate long-term cognitive impairment based on the severity of symptoms of COVID-19 infection in a primary health system setting. MATERIAL AND METHODS: From a database of 363 patients, 83 cases aged 47 ± 15 years, (58% females) were selected from June to August 2020. In patients who survived the virus, 24 infection-related symptoms were collected to create three severity clusters (mild, moderate, and severe). The follow-up time was at least seven months. Comparing the first two clusters with the severe cluster, the existence of brain fog and risk factors (obesity, hypertension, diabetes, chronic lung disease, and hypothyroidism) were analyzed. RESULTS: Thirty-one patients (37%) had persistent symptoms lasting up to 240 days. Fifty-one patients (61%) experienced brain fog. Concentration was affected by symptom severity (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.26-10.46, p = 0.02). Short- or long-term memory loss was not affected. Moreover, symptom severity was related to brain fog (OR 3.16, 95% CI 1.05-9.51, p = 0.04). Patients with persistent symptoms had a concentration impairment associated with severity patterns (OR 24.3, 95% CI 1.73-340.11, p = 0.03). CONCLUSIONS: Brain fog is associated with symptom severity in COVID-19 survivors and lasts for more than eight months.