[Post-COVID-19 condition-Clinical phenotyping in practice]

The high number and clinical heterogeneity of neurological impairments in patients with a post-COVID-19 condition (PCC) poses a challenge for outpatient care.

Our aim was to evaluate the applicability of the proposed subtypes according to the guidelines "Long/Post-COVID" (30 May 2024) and their phenotyping using clinical and neuropsychological findings from our post-COVID outpatient clinic.

The evaluation was based on cross-sectional neurological and psychological test examinations of the patients, which were carried out using standardized questionnaires and test batteries. In addition, a detailed anamnesis of the current symptoms and a retrospective survey of the acute symptoms up to 4 weeks after the confirmed infection was conducted. The subtypes were classified according to the abovementioned guidelines based on the medical history and selected patient questionnaires, to which we added a 5th subtype with reference to the previous guidelines "Long/Post-COVID" (as of 5 March 2023).

A total of 157 patients were included between August 2020 and March 2022. The presentation was at a median of 9.4 months (interquartile range, IQR = 5.3) after infection, with a mean age of 49.9 years (IQR = 17.2) and more women (68%) presenting, with a total hospitalization rate of 26%. Subtype 1 (postintensive care syndrome) showed the highest proportion of men, highest body mass index (BMI) scores and the highest rates of subjective complaints of word-finding difficulties (70%). Subtype 2 (secondary diseases) was dominated by cognitive impairment and had the highest depression scores. Subtype 3 (fatigue and exercise-induced insufficiency) was the most common, had the most symptoms and most severe subjective fatigue and the largest proportion of women. Subtype 4 (exacerbation) mainly showed affective symptoms. Subtype 5 (complaints without relevance to everyday life) had the lowest scores for depression, fatigue and BMI. Neurological and psychological conditions were frequently pre-existing in all groups.

The management of PCC can be improved at various levels. A standardized subtype classification enables early individually tailored treatment concepts. Patients at risk should be identified at the primary care level and informed about risk factors and prevention strategies. Regular monitoring of cardiovascular risk factors and physical activity are essential for PCC treatment. In the case of cognitive deficits and concurrent affective symptoms, psychotherapeutic support and drug treatment with selective serotonin reuptake inhibitors (SSRI) should be provided at an early stage.