Drawing the Line Between Postacute Sequelae of COVID-19 and Functional Neurologic Disorders A Daunting Clinical Overlap or Irrelevant Conundrum?

Abstract:

Coronavirus disease 2019 (COVID-19) is an acute infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in its multiple variants that classically presents with cough, fatigue, fever, headache, myalgias, and diarrhea. As vaccination becomes widely available and infection rates facilitate herd immunity across the globe, more attention has been given to long-term symptoms that may persist after the index infection, which include impairments in concentration, executive dysfunction, sensory disturbances, depression, anxiety, fatigue, and cough, among other symptoms classified under the umbrella term of postacute sequelae of SARS-CoV-2 infection (PASC).

Functional neurologic disorder (FND), also known as conversion disorder and functional neurologic symptom disorder, refers to the presence of one or more symptoms of altered voluntary motor or sensory function that are incompatible with and not better explained by a known neurological or medical condition that causes significant distress and functional impairment. Although the diagnosis of FND may not require the identification of an underlying psychological stressor, being diagnosed with an FND can worsen stigma and shift attention and resources away from other medical concerns that should be concomitantly addressed.

This review summarizes the literature on the overlapping nature and discrimination of PASC from FND in COVID-19 survivors. Based on this, we develop a treatment framework that targets unique domains of these complex overlapping presentations, following a multidisciplinary approach with an individualized treatment plan inclusive of physical and psychological interventions focused on functional rehabilitation.

Source: Sales, Paulo M.G. MD, MS; Greenfield, Melissa J. PsyD; Pinkhasov, Aaron MD; Viswanathan, Ramaswamy MD, DrMedSc; Saunders, Ramotse MD§; Huremović, Damir MD, MPP. Drawing the Line Between Postacute Sequelae of COVID-19 and Functional Neurologic Disorders: A Daunting Clinical Overlap or Irrelevant Conundrum?. The Journal of Nervous and Mental Disease 211(12):p 882-889, December 2023. | DOI: 10.1097/NMD.0000000000001643 https://journals.lww.com/jonmd/abstract/2023/12000/drawing_the_line_between_postacute_sequelae_of.2.aspx

Unique genetic and environmental determinants of prolonged fatigue: a twin study

Abstract:

BACKGROUND: Prolonged fatigue syndromes have been proposed as prevalent and disabling forms of distress that occur independently of conventional notions of anxiety and depression.

METHODS: To investigate the genetic and environmental antecedents of common forms of psychological and somatic distress, we measured fatigue, anxiety, depression and psychological distress in 1004 normal adult twin pairs (533 monozygotic (MZ), 471 dizygotic (DZ)) over 50 years of age.

RESULTS: Familial aggregation of psychological distress, anxiety and fatigue appeared to be due largely to additive genetic factors (MZ:DZ ratios of 2.12-2.69). The phenotypic correlations between the psychological measures (distress, anxiety and depression) were moderate (0.67-0.79) and higher than that between fatigue and psychological distress (0.38). Multivariate genetic modelling revealed a common genetic factor contributing to the development of all the observed phenotypes (though most strongly for the psychological forms), a second independent genetic factor also influenced anxiety and depression and a third independent genetic factor made a major contribution to fatigue alone. In total, 44% (95% CI 25-60%) of the genetic variance for fatigue was not shared by the other forms of distress. Similarly, the environmental factor determining psychological distress made negligible contributions to fatigue, which was underpinned largely by its own independent environmental factor.

CONCLUSION: This study supports the aetiological independence of prolonged fatigue and, therefore, argues strongly for its inclusion in classification systems in psychiatry.

 

Source: Hickie I, Kirk K, Martin N. Unique genetic and environmental determinants of prolonged fatigue: a twin study. Psychol Med. 1999 Mar;29(2):259-68. http://www.ncbi.nlm.nih.gov/pubmed/10218917

 

Postviral fatigue syndrome

Comment on: Possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome. [BMJ. 1992]

 

EDITOR,-A M 0 Bakheit and colleagues report enhanced release of prolactin after administration of buspirone in patients with the postviral fatigue syndrome compared with controls and patients with depression. Their report would have been improved if they had described more fully the differences between the two groups of patients. As they point out, depression can be difficult to distinguish clinically from the postviral fatigue syndrome.

The authors used the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised to define depressive illness, but to qualify for this diagnosis a patient need complain of only four symptoms such as fatigue, hypersomnia, retardation, and loss of concentration in addition to depressed mood. The criteria they used for the postviral fatigue syndrome included depression, fatigue, reversed sleep pattern, and constipation alternating with diarrhoea. It would be surprising if there was not a substantial overlap between the two groups and if one of the main factors affecting diagnosis was not whether the patient presented first to a psychiatrist or a neurologist.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882437/pdf/bmj00077-0052e.pdf

 

Source: Curtis D, Bullock T. Postviral fatigue syndrome. BMJ. 1992 Jun 13;304(6841):1566-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882437/