Trouble finding words is common in those with long Covid

An estimated 10 to 20% of people who have been infected with the Covid-19 go on to develop long-term symptoms, such as post-exertional malaise, breathlessness, a cough, and muscle aches. Many long Covid sufferers also report problems with memory, and other cognitive difficulties.

These cognitive symptoms are not well understood, writes a team led by María González-Nosti and the University of Oveido, Spain, in a recent paper in the International Journal of Language and Communication Disorders. In a bid to help address this, the researchers conducted a comprehensive assessment of the language processing abilities of 195 people aged 26 to 64 with long Covid (also known as 'post-Covid-19 syndrome') as well as 50 healthy controls — and they found some clear differences between these groups.

Some of the tests assessed the participants' semantic processing — by asking them to come up with synonyms for words, and to match words to their definitions, for example. There were also naming tasks, in which they had to name common objects or actions, and four types of verbal fluency tasks. In one of these verbal fluency tasks, they had to come up with as many words starting with the letter 'p' as possible in a minute, for example. In another, they had to list as many verbs as they could in the same time limit.

The results of the verbal fluency tasks showed that while the patients' scores fell into the normal range, they did worse than the healthy participants. Overall, they generated fewer words. They also tended to choose more easily accessible words. For example, in the verb fluency task, the patients came up with verbs that were more frequent, concrete, visualisable, and familiar than those of the healthy participants — think 'run', rather than 'envisage'. "The fact that their scores are lower, albeit still normal, may indicate subtle yet clinically relevant cognitive impairment," the team writes.  

When it came to the naming tasks, the results showed that the people with long Covid were significantly more likely to fail to come up with an answer. They also made more errors. This indicates that they found it harder to retrieve words, the team notes.

On the semantic tasks, the patients did about as well as the healthy participants. However, when the team took a closer look at the patient data, they found what they call "very interesting" results. Strikingly, the younger patients did worse than middle aged and older patients. In fact, older patients tended to do better across the tasks, the team notes, a trend that has been observed in some earlier research. Though this study can't reveal the cause, it takes time and experience to build up a potentially protective 'cognitive reserve', and the authors believe this may help to explain the result. Research into long Covid, however, is still young, so we can't say for sure. 

Overall, the patients' difficulties, revealed in this study, suggest that "cognitive impairment related to language may be more pronounced than previously understood," the researchers conclude. They recommend that people with long Covid should undergo a thorough language assessment — and they call for the development of new targeted interventions to address language-related challenges.

Read the paper in full:
María González‐Nosti, Barrenechea, A., Romina San Miguel‐Abella, Carmen, del, Lucía Fernández‐Manzano, Ainhoa Ramírez‐Arjona, Rodríguez‐Pérez, N., & Herrera, E. (2024). Lexical retrieval difficulties in post‐COVID‐19 syndrome: Insights from verbal fluency and naming tasks. International Journal of Language & Communication Disorders. https://doi.org/10.1111/1460-6984.13118