Tag: cognitive effort

The maintained attention assessment in patients affected by Myalgic encephalomyelitis/chronic fatigue syndrome: a reliable biomarker?

Abstract:

The maintained attention is the cause of great functional limitations in CFS/ME, a disease that mainly affects women in the central period of life. Cognitive function is explored using the Montreal Cognitive Assessment, the maintained attention using the Toulouse-Piéron test with which the Global Index of Attention and Perception (GIAP) is obtained, the fatigue using the visual analog scale and the perception of effort using the modified Borg scale. The final sample were 84 patients (66 women/18 men) who met diagnostic criteria (Fukuda-1994, Carruthers-2011) and 22 healthy controls (14 women/8 men).

Most of patients maintain normal cognitive function, showing low or very low attention score in the 70% of patients with a marked cognitive fatigue compared to the control group (p < 0.05). There were no significant differences between genders in GIAP or fatigue for CFS/ME; however, sick women perceive cognitive effort higher than men.

Deficits in sustained attention and the perception of fatigue, so effort after performing the proposed test are a sensitive and reliable indicator that allows us to substantiate a clinical suspicion and refer patients for further studies in order to confirm or rule out CFS/ME.

Source: Murga I, Aranburu L, Gargiulo PA, Gómez-Esteban JC, Lafuente JV. The maintained attention assessment in patients affected by Myalgic encephalomyelitis/chronic fatigue syndrome: a reliable biomarker? J Transl Med. 2021 Dec 4;19(1):494. doi: 10.1186/s12967-021-03153-1. PMID: 34863209. https://pubmed.ncbi.nlm.nih.gov/34863209/

Resting-state functional connectivity, cognition, and fatigue in response to cognitive exertion: a novel study in adolescents with chronic fatigue syndrome

Abstract:

Emerging evidence suggests that central nervous system dysfunction may underlie the core symptoms of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in adults, such as cognitive disturbance, fatigue and post-exertional malaise. Research into brain dysfunction in the pediatric CFS/ME context, however, is severely lacking. It is unclear whether the adolescent CFS/ME brain functions differently compared with healthy peers, particularly in situations where significant mental effort is required. This study used resting-state functional MRI in a novel repeated-measures design to evaluate intrinsic connectivity, cognitive function, and subjective fatigue, before and after a period of cognitive exertion in 48 adolescents (25 CFS/ME, 23 healthy controls).

Results revealed little evidence for a differential effect of cognitive exertion in CFS/ME compared with controls. Both groups demonstrated a similar rate of reduced intrinsic functional connectivity within the default mode network (DMN), reduced sustained attentional performance, slower processing speed, and increased subjective fatigue as a result of cognitive exertion.

However, CFS/ME adolescents consistently displayed higher subjective fatigue, and controls outperformed the CFS/ME group overall on cognitive measures of processing speed, sustained attention and new learning. No brain-behavior relationships were observed between DMN connectivity, cognitive function, and fatigue over time.

These findings suggest that effortful cognitive tasks may elicit similar levels of energy expenditure across all individuals in the form of reduced brain functioning and associated fatigue. However, CFS/ME may confer a lower starting threshold from which to access energy reserves and cognitive resources when cognitive effort is required.

Source: Josev EK, Malpas CB, Seal ML, Scheinberg A6, Lubitz L, Rowe K, Knight SJ. Resting-state functional connectivity, cognition, and fatigue in response to cognitive exertion: a novel study in adolescents with chronic fatigue syndrome. Brain Imaging Behav. 2019 May 17. doi: 10.1007/s11682-019-00119-2. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31102168

A Concurrent Cognitive Task Does Not Perturb Quiet Standing in Fibromyalgia and Chronic Fatigue Syndrome

Abstract:

BACKGROUND AND OBJECTIVES: Cognitive complaints are common in fibromyalgia (FM) and chronic fatigue syndrome (CFS). Fatigue as well as pain may require greater effort to perform cognitive tasks, thereby increasing the load on processing in the central nervous system and interfering with motor control.

METHODS: The effect of a concurrent arithmetic cognitive task on postural control during quiet standing was investigated in 75 women (aged 19-49 years) and compared between FM, CFS, and matched controls (n=25/group). Quiet standing on a force plate was performed for 60 s/condition, with and without a concurrent cognitive task. The center of pressure data was decomposed into a slow component and a fast component representing postural sway and adjusting ankle torque.

RESULTS: Compared to controls, CFS and FM displayed lower frequency in the slow component (p < 0.001), and CFS displayed greater amplitude in the slow (p=0.038 and p=0.018) and fast (p=0.045) components. There were no interactions indicating different responses to the added cognitive task between any of the three groups.

CONCLUSION: Patients displayed insufficient postural control across both conditions, while the concurrent cognitive task did not perturb quiet standing. Fatigue but not pain correlated with postural control variables.

Source: Rasouli O, Fors EA, Vasseljen O, Stensdotter AK. A Concurrent Cognitive Task Does Not Perturb Quiet Standing in Fibromyalgia and Chronic Fatigue Syndrome. Pain Res Manag. 2018 Aug 7;2018:9014232. doi: 10.1155/2018/9014232. eCollection 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6109464/ (Full article)

Task related cerebral blood flow changes of patients with chronic fatigue syndrome: an arterial spin labeling study

Abstract:

Purpose: One hallmark of chronic fatigue syndrome (ME/CFS) is task related worsening of fatigue. Global brain hypoperfusion, abnormal regional activation, and altered functional connectivity of brain areas associated with cognition and memory have been reported but remain controversial.

Methods: We enrolled 17 female participants fulfilling the CDC Criteria for ME/CFS and 16 matched healthy controls (HC). Using a 3T-Phillips Achieva MRI-scanner, pseudo-continuous arterial spin-labeling (pCASL), was used to study the dynamics of regional cerebral blood flow (rCBF) and their relationship to mental fatigue in ME/CFS patients and HC during a demanding cognitive task, i.e. modified Paced-Auditory-Serial-Addition-Testing (PASAT).

Results: ME/CFS subjects reported more fatigue than HC at baseline (p < .01). Global brain perfusion of ME/CFS and HC subjects was similar at rest. The PASAT resulted in significantly increased fatigue in ME/CFS participants and HC. Although not different between groups, overall CBF significantly increased over the first 3 min of the PASAT and then decreased thereafter. Regional CBF (rCBF) changes were significantly different between groups during the post-task recovery period. Whereas improvement of fatigue of ME/CFS subjects was associated with decreased rCBF in both superior temporal gyri (STG), precuneus, and fusiform gyrus, it was associated with increased rCBF in the same areas in HC.

Conclusions: Our results suggest that ME/CFS is associated with normal global CBF at rest and during a strenuous task (PASAT); however rCBF of several brain regions associated with memory, goal-oriented attention, and visual function was differentially associated with recovery from fatigue in ME/CFS patients and HC.

Source: Roland Staud, Jeff Boissoneault, Jason G. Craggs, Song Lai & Michael E. Robinson (2018) Task related cerebral blood flow changes of patients with chronic fatigue syndrome: an arterial spin labeling study, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2018.1453919

Test effort in persons with Chronic Fatigue Syndrome when assessed using the Validity Indicator Profile

Abstract:

The current study examined the potential contribution of suboptimal effort to the cognitive deficits that are associated with Chronic Fatigue Syndrome (CFS) using the Validity Indicator Profile (VIP). Unlike most tests of effort, the VIP distinguishes between intentional and unintentional poor performance and does not assess cognitive functions that are affected by CFS, thereby reducing the risk of mistakenly attributing genuinely poor performance to reduced effort.

The VIP was administered to 54 persons with CFS and 54 matched healthy community controls, and performance categorized into 1 of 4 response styles (valid: compliant; invalid: suppressed, irrelevant, inconsistent), based on the level of effort expended (high or low) and the intention to perform well or not. VIP performance was classified as valid for the majority of participants (CFS and controls), indicating high levels of effort and an intention to perform well.

Three participants in the CFS group and four in the control group showed low levels of effort but an intention to do well (invalid: inconsistent). No participant performed in a manner indicative of an intent to perform poorly (invalid: suppressed, inconsistent). These findings suggest that poor effort is unlikely to contribute to cognitive test performance of persons with CFS.

 

Source: Cockshell SJ, Mathias JL. Test effort in persons with Chronic Fatigue Syndrome when assessed using the Validity Indicator Profile. J Clin Exp Neuropsychol. 2012;34(7):679-87. doi: 10.1080/13803395.2012.668176. Epub 2012 Mar 23. https://www.ncbi.nlm.nih.gov/pubmed/22440059

 

Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise

Abstract:

OBJECTIVE: The purpose of this study was to compare the cardiovascular responses of patients with chronic fatigue syndrome (CFS) to healthy control subjects when performing stressful cognitive tasks before and after strenuous exercise.

METHOD: Beat-by-beat blood pressure and electrocardiogram were recorded on 19 women with CFS and 20 healthy nonexercising (ie, sedentary) women while they performed cognitive tests before, immediately after, and 24 hours after incremental exercise to exhaustion.

RESULTS: Diminished heart rate (p <.01) and systolic (p <.01) and diastolic (p <.01) blood pressure responses to stressful cognitive testing were seen in patients with CFS when compared with healthy, sedentary controls. This diminished stress response was seen consistently in patients with CFS across three separate cognitive testing sessions. Also, significant negative correlations between self-ratings of CFS symptom severity and cardiovascular responses were seen (r = -0.62, p <.01).

CONCLUSIONS: Women with CFS have a diminished cardiovascular response to cognitive stress; however, exercise did not magnify this effect. Also, the data showed that the patients with the lowest cardiovascular reactivity had the highest ratings of CFS symptom severity, which suggests that the individual response of the patient with CFS to stress plays a role in the common complaint of symptoms worsening after stress.

 

Source: LaManca JJ, Peckerman A, Sisto SA, DeLuca J, Cook S, Natelson BH. Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise. Psychosom Med. 2001 Sep-Oct;63(5):756-64. http://www.ncbi.nlm.nih.gov/pubmed/11573024

 

Memory, attention, and executive function in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine cognitive function in chronic fatigue syndrome.

METHODS: Twenty patients with chronic fatigue syndrome recruited from primary care and 20 matched normal controls were given CANTAB computerised tests of visuospatial memory, attention, and executive function, and verbal tests of letter and category fluency and word association learning.

RESULTS: Patients with chronic fatigue syndrome were impaired, predominantly in the domain of memory but their pattern of performance was unlike that of patients with amnesic syndrome or dementia. They were normal on tests of spatial pattern recognition memory, simultaneous and delayed matching to sample, and pattern-location association learning. They were impaired on tests of spatial span, spatial working memory, and a selective reminding condition of the pattern-location association learning test. An executive test of planning was normal. In an attentional test, eight subjects with chronic fatigue syndrome were unable to learn a response set; the remainder exhibited no impairment in the executive set shifting phase of the test. Patients with chronic fatigue syndrome were also impaired on verbal tests of unrelated word association learning and letter fluency.

CONCLUSION: Patients with chronic fatigue syndrome have reduced attentional capacity resulting in impaired performance on effortful tasks requiring planned or self ordered generation of responses from memory.

Source: Joyce E, Blumenthal S, Wessely S. Memory, attention, and executive function in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1996 May;60(5):495-503. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486360/ (Full article)

Cognitive impairment in patients with chronic fatigue: a preliminary study

Erratum in: J Neurol Neurosurg Psychiatry 1993 Oct;56(10):1142

Abstract:

Subjective impairment of memory and concentration is a frequent complaint in sufferers from chronic fatigue. To study this, 65 general practice attenders identified as having chronic fatigue were administered a structured psychiatric interview and a brief screening battery of cognitive tests.

Subjective cognitive impairment was strongly related to psychiatric disorder, especially depressed mood, but not fatigue, anxiety, or objective performance. Simple tests of attention and concentration showed some impairment but this was influenced by both fatigue and depression.

Subjects with high levels of fatigue performed less well on a memory task requiring cognitive effort, even in the absence of depression. There was no evidence for mental fatiguability. The relationship between depression, fatigue, and cognitive function requires further research.

 

Source: McDonald E, Cope H, David A. Cognitive impairment in patients with chronic fatigue: a preliminary study. J Neurol Neurosurg Psychiatry. 1993 Jul;56(7):812-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1015065/ (Full article)