The MPDI site that hosts open source scientific journals, has an article covering Long Covid patients being mis-diagnosed with functional neurological disorder and then being denied appropriate care. The article suggests that research into underlying mechanisms and diagnostic methods should explore how to determine whether motor and balance symptoms currently diagnosed as FND should be considered one part of Long COVID symptoms.
Extracts
Long COVID, also known as post-COVID-19 syndrome or post-acute sequelae of SARS-CoV-2 infection (PASC), is becoming widely recognized as a distinct disease entity. The Office for National Statistics (ONS) in the UK estimates approximately 2.1 million individuals self-report the disease, with over half of them having had the condition for over one year [2], making Long COVID a major and persistent disease burden on healthcare systems worldwide.
FND, also known as conversion disorder in the DSM-5-TR, or as dissociative neurological symptom disorder in the ICD-11, is characterized by the presentation of motor or sensory symptoms that lack compatibility of the symptom with a neurological substrate.
Currently, there remains no clinically utilized confirmatory test for Long COVID. High-resolution MRI scans and PET scans, amongst others, are being explored, but do not yet feature in the clinical evaluation of patients presenting with symptoms of Long COVID, and this contributes to no explanations being found in Long COVID patients presenting with motor symptoms. Given the broad WHO criteria and the lack of conclusive diagnostic tests, it is difficult to correctly diagnose Long COVID, and there are currently no clear diagnostic methodologies or treatments for Long COVID. In addition, the diagnostic criteria for neurological complications of PASC, including ‘brain fog’, ‘memory deficits’ and ‘encephalopathy’ are not established, which makes PASC-associated neurological syndromes impossible to consistently classify [9,32].
Consequently, given that neither FND nor Long COVID has a definitive test, an FND diagnosis can lead to no access to Long COVID-related care and patients being dismissed despite some similarities in the presentation and ongoing symptoms. Other factors at play can be that dysautonomia, such as PoTS, which are very common in Long COVID [34], require expert knowledge to differentiate with FND.
In view of the diagnostic ambiguity, there seems to be an urgent clinical need to deal with the differential diagnostic and treatment issues that arise in patients with Long COVID experiencing motor and balance problems. What would be needed for that? Access to proper diagnosis and treatment by clinicians with knowledge of both conditions seems to be key.
Labelling neurological dysfunction such as walking, balance and other neurological dysfunctional problems in Long COVID as FND without proper testing of both conditions does not serve patients who are then erroneously diagnosed with FND and dismissed from Long COVID services. Research into underlying mechanisms and diagnostic methods should explore how to determine whether motor and balance symptoms currently diagnosed as FND should be considered one part of Long COVID symptoms, in other words, one component of symptomatology, and in which cases they actually correctly represent FND. Research into rehabilitation models, treatment and integrated care is needed, and should take into account biological underpinnings as well as possible psychological mechanisms and the patient perspective.