Neurocognitive Difficulties Among Youth with POTS within an Intensive Pain Rehabilitation Program

Defining brain fog across medical conditions

'Brain fog' is commonly reported in more than a dozen chronic diseases, but what is it? We review research across conditions which has characterised brain fog and evaluate its definitions and objective correlates. Brain fog has been used to refer to a variable set of overlapping symptoms implicating cognition, fatigue, and affect. It has been defined as a distinct symptom, a syndrome, or a nonspecific term. We consider the evidence that brain fog is a transdiagnostic entity with a common phenomenology and profile of objective cognitive deficits. We discuss where these commonalities arise and argue that linguistic ambiguity, shared cognitive impairments, and noncognitive factors are more likely than shared neurobiology. We suggest how future research might apply existing tools to disambiguate the phenomena that brain fog conflates.

Long-COVID and postural orthostatic tachycardia syndrome: a preliminary comparison of neuropsychological performance

PURPOSE

The aim of the study is to analyze and compare the cognitive profile between 59 patients with long-COVID [LC; 30 of them with and 29 without a positive coronavirus disease 2019 (COVID-19) confirmatory test] and 31 patients with postural orthostatic tachycardia syndrome (POTS) and a matched group of 39 healthy control participants.

METHODS

Participants were examined on a battery of neuropsychological tests, including verbal memory, visuospatial abilities, attention, processing speed, verbal fluency, working memory, and visual memory. Anxious-depressive symptomatology was also analyzed and then controlled for possible influence on cognitive performance.

RESULTS

Patients with LC and POTS showed significantly lower performance compared with healthy peers. Differences on anxious and depressive symptoms were also found between the clinical and control groups, resulting in LC without a positive confirmatory test group exhibiting the highest rates of anxious symptoms. After controlling the effects of anxious-depressive symptomatology, the differences were eliminated for some of the cognitive variables, but additional differences were found between patients with LC and POTS after post hoc analysis.

CONCLUSIONS

Findings from the present study contribute toward the reinforcement of the evidence on cognitive alterations associated with LC and POTS. Anxious-depressive symptomatology has to be considered in both clinical groups since it could be affecting cognitive performance.

The Goals and Outcomes of Adolescent and Young Adults with POTS Attending an Intensive Interdisciplinary Treatment Program

Postural Orthostatic Tachycardia Syndrome (POTS) affects approximately 1% of adolescents, however, little research has been done in this area. This retrospective chart review describes the treatment goals and perceived progress as measured by the Canadian Occupational Performance Measure (COPM) of 111 adolescents and young adults (AYAs) aged 12-22 (M = 15.8, SD = 1.8) diagnosed with POTS who were admitted to an interdisciplinary intensive pain treatment program (IIPT). This study also examined the change in progress and satisfaction in goals over a 3-week intensive pain treatment program, as well as the utility and validity of the COPM as an outcome measure for AYAs attending an IIPT. Results indicated adolescents and young adults endorsed treatment goals focused on self-care, school, and leisure and found that performance and satisfaction scores significantly improved from admission to discharge. The findings also suggest that the COPM is a useful and valid outcome measure for this population.

The Contribution of Psychological Symptoms to Cognitive Difficulties in Youth With Postural Orthostatic Tachycardia Syndrome and Chronic Pain

INTRODUCTION

Subjectively experienced cognitive difficulties are common in youth with postural orthostatic tachycardia syndrome. The pathophysiological and psychological contributions of these cognitive impairments remain unclear.

METHOD

Participants were 96 adolescents and young adults diagnosed with postural orthostatic tachycardia syndrome and admitted to an intensive pain treatment program. Participants completed cognitive assessment and measures of postural orthostatic tachycardia syndrome symptoms, pain intensity, pain catastrophizing, anxiety, depression, and functional disability.

RESULTS

Self-reported autonomic symptom intensity, but not severity of heart rate change, was associated with cognitive performance. Symptoms of depression were associated with decreases in most measures of cognitive functioning. Pain intensity, pain catastrophizing, and depression but not cognitive scores and physiological measures, were significant predictors of disability.

CONCLUSION

Depression appears to be a significant contributor to the cognitive difficulties in youth with postural orthostatic tachycardia syndrome. These findings highlight the importance of assessing and treating affective symptoms in this population along with medical and lifestyle approaches to treating postural orthostatic tachycardia syndrome symptoms.

Neurocognitive Profiles in Adolescents With Postural Tachycardia Syndrome and Perceived Brain Fog: A Preliminary Report

BACKGROUND

Postural tachycardia syndrome (POTS) is associated with complaints of cognitive and emotional difficulties that may contribute to severe functional disability. For high-achieving adolescents, these symptoms can result in decreased participation in school and extracurricular activities. There are very limited data comparing subjective symptom reports to neurocognitive profiles in adolescents presenting with POTS, "brain fog," and cognitive difficulties.

METHODS

A review of medical records and neuropsychological data was conducted for six adolescents diagnosed with POTS at a pediatric neurology clinic. All patients had frequent symptoms of orthostatic intolerance for more than three months. There was heart rate increase of ≥40 beats per minute (bpm) within 10 minutes of active standing or head-up tilt test in five patients and 36 bpm in one patient, who was diagnosed with probable POTS. All were referred for neuropsychological evaluations due to reported debilitating cognitive problems and an inability to function in a regular academic setting. Patients underwent a six-hour neuropsychological evaluation utilizing standardized measures of cognitive and emotional functioning. Clinically reported symptoms included fatigue, poor concentration, and memory impairment as well as "brain fog."

RESULTS

Subjective complaints differed from patients' performance on standardized neuropsychological measures. Patients performed in the average to superior range across measures of general intelligence, verbal and working memory, processing speed, and sustained attention.

CONCLUSIONS

Further research is needed to elucidate the basis for perceived "brain fog" and cognitive impairment in POTS, such as better understanding of patient and parental perceptions of initial medical symptoms and diagnosis as well as symptom amplification due to biopsychosocial processes.

Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study)

PURPOSE

Approximately 96% of patients with postural orthostatic tachycardia syndrome (PoTS) report cognitive complaints. We investigated whether cognitive function is impaired during sitting and active standing in 30 patients with PoTS compared with 30 healthy controls (HCs) and whether it will improve with the counter manoeuvre of leg crossing.

METHODS

In this prospective pilot study, patients with PoTS were compared to HCs matched for age, sex, and educational level. Baseline data included norepinephrine plasma levels, autonomic testing and baseline cognitive function in a seated position [the Montreal Cognitive Assessment, the Leistungsprüfsystem (LPS) subtests 1 and 2, and the Test of Attentional Performance (TAP)]. Cognitive functioning was examined in a randomized order in supine, upright and upright legs crossed position. The primary outcomes were the cognitive test scores between HCs and patients with PoTS at baseline testing, and among the different body positions.

RESULTS

Patients with PoTS had impaired attention (TAP median reaction time) in the seated position and impaired executive functioning (Stroop) while standing compared with HC. Stroop was influenced by position (supine versus upright versus upright legs crossed) only in the PoTS group. Leg crossing did not result in an improvement in executive function. In patients with PoTS, there was a negative correlation of Stroop with norepinephrine plasma levels while standing.

CONCLUSION

Compared with HCs, PoTS participants showed impaired cognitive attention and executive function in the upright position that did not improve in the legs crossed position. Data provide further evidence for orthostatic cognitive deterioration in patients with PoTS.

TRIAL REGISTRATION INFORMATION

The study was registered at ClinicalTrials.gov (NCT03681080).

Attention and executive function are impaired during active standing in postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with cognitive dysfunction. We hypothesized executive function and attention is impaired in POTS during active standing. Eighty-seven POTS participants and 39 healthy controls of similar age, sex, and education level completed executive function (Stroop word-color) and attention (CogState Identification) tests in supine and standing postures in a cross-sectional study. POTS participants had lower executive function (t-score: 48 ± 11 vs. 55 ± 10 control; p = 0.009) and worse attention (reaction speed: 2.78 ± 0.11 vs. 2.69 ± 0.06 control; p < 0.001) during standing. These data provide new evidence that active standing impairs attention and executive functioning in POTS.