Post-acute sequelae of SARS-CoV-2 infection (PASC) or Long COVID is a condition that is estimated to affect 14 million people in the United States and over 400 million people globally. Some of the most disabling neurologic symptoms of PASC (Neuro-PASC) include chronic symptoms of brain fog and fatigue, headache, dizziness, and sleep issues, which significantly impact the quality of life and cognitive performance with a severe negative impact.
Despite the significant burden of this condition, data describing temporal variability in Neuro-PASC symptoms and determinants of recovery are limited. This research aimed to describe symptom patterns in Neuro-PASC with the aid of a mobile health application and pinpoint characteristics related to the improvement or ongoing symptoms.
Between July 2022 and May 2024, researchers recruited 128 patients who were referred to the Neuro-COVID-19 Clinic at Northwestern Memorial Hospital. Participants had neurologic symptoms more than 6 weeks after SARS-CoV-2 infection. Out of these, 63 patients provided sufficient information for analysis. The median time span between the symptom onset and clinic examination was 12.7 months.
The participants were asked to use the Neuro-COVID Recovery Care Companion (NCRCC), an app available to all users on the Epic MyChart platform. The patients were asked to document the presence or absence of 12 frequent Neuro-PASC symptoms every day and subjectively estimate the percent recovery compared to a pre-COVID baseline of 100%. The quality of life was measured at the baseline and 3 months using PROMIS measures of cognition, fatigue, sleep disturbance, anxiety, and depression.
The NIH Toolbox was used to measure objective performance in cognition. Retrospectively, patients who had better perceived recovery in the 3 months were classified as improvers and non-improvers. Out of the 63 respondents, 27 (42.9%) were improvers and 36 (57.1%)Â non-improvers. The average age of participants was 45.6 years. The proportion of women was significantly higher among non-improvers than among improvers (75.7% vs 50.0%; p = 0.04). The majority of participants (93.7%) were not hospitalized during their acute COVID-19 illness.
Improvers had more perceived time-varying recovery than non-improvers, with greater mean variance (7.01 vs 3.79; p = 0.0004) and a significant positive slope of recovery (5.84 vs 0; p < 0.0001). Several correspondence analysis models revealed a symptom group with the traits ofanosmia, dysgeusia, and lack of insomnia to be linked with reduced probability of improvement (p = 0.023). Improvers and non-improvers exhibited variations in their prevalence of anosmia, where the former was lower in proportion than the latter (11.1% vs 35.1%; p = 0.04).
Group variations at baseline had no significant differences in terms of quality-of-life scores or cognitive performance. In the 3-month follow-up, Improvers exhibited a tendency towards better processing speed and lesser sleep disturbance compared to non-improvers, but this was not significant. Both sets of respondents found the NCRCC application easy to use, satisfactory, and moderately useful.
This study provides new insight into the fluctuating nature of recovery in Neuro-PASC and identifies factors associated with poorer outcomes. Female patients with persistent symptoms of anosmia and dysgeusia were less likely to report improvement more than a year after the onset of COVID-19.
The findings suggest that variability in perceived recovery rather than overall symptom burden may be a defining characteristic distinguishing patients who improve from those who do not. Notably, sleep disturbance emerged as a potentially modifiable factor, highlighting insomnia treatment as a promising clinical target. Additionally, the successful use of a mobile application underscores the value of digital tools for capturing real-time symptom trajectories in chronic and poorly understood conditions such as Neuro-PASC.
Reference: Lank GK, Budhiraja S, Gaelen JI, et al. Characterizing Neuro-PASC outcome with the mobile Neuro-COVID recovery care companion application. BMC Neurol. 2026;26:24. doi:10.1186/s12883-025-04577-8
