Cognitive impairment in COVID-19 patients and its relation to laboratory data

Introduction:
Neuropsychological manifestations are increasingly reported in patients with COVID-19, but the subject is poorly understood and our knowledge about cognitive impairment is limited. This study aimed to investigate neuropsychological involvement of COVID-19 and its relation to laboratory data.

Material and methods:
This study was conducted among patients admitted to a tertiary medical center in Iran, in the period March 2020 to March 2021. Neuropsychiatric assessments were carried out by the Addenbrooke’s Cognitive Examination (ACE) test in all patients and interpreted by a specialist. It was performed using the Persian version of ACE in six domains consisting of attention, orientation, memory, language, visual perception and visuospatial skills. Laboratory data were assessed among all patients. Statistical analyses were performed using SPSS.

Results:
Among 114 patients with COVID-19, the mean age was 48.46 ±13.61 years, and the male/female ratio was 1.32. The mean values of some abnormal laboratory data were: erythrocyte sedimentation rate (ESR) 57.2 ±29.8, C-reactive protein (CRP) 81.7 ±59.8 and D-dimer 459.3 ±395.4. Cognitive impairment was detected in 41 patients (63%). The mean score of ACE was 80.68 ±19.29. Statistical analysis showed correlations between total result of the ACE test and laboratory findings that were not statistically significant.

Conclusions:
In our study, no relation was found between laboratory test results and the overall cognitive examination score but statistical analysis showed a correlation between CRP and verbal fluency, between hemoglobin level and language and visuospatial domains, and also between total level of bilirubin and memory. These relations may suggest that we should follow the neurocognitive features in COVID-19 patients earlier.