Understanding the Experience and Impacts of Brain Fog in Chronic Pain: A Scoping Review

Figures & data

Figure 1. Working definition of brain fog and embedded constructs.

Figure 2. Prisma diagram.

Figure 3. Brainfog contributors model.

Table

Study	Country	Study design	Level of evidence	Sample size	Purpose	Brain fog defined (Y/N)
Eccleston^Citation54	England	Repeated measures between subjects	3	CP = 22	The experience of pain’s impact on attentional control tasks	N
Landrø et al.^Citation57	Norway	Cross-sectional	3	FM = 25 HC = 18	Compare the memory functioning of patients with FM to HC	N
Schnurr^Citation73	England	Cross-sectional	3	CP = 134	Investigate memory complaints in CP participants	N
Iezzi et al.^Citation81	England	Cross-sectional	3	CP = 73	Investigate the relationship between chronic pain and attention	N
Koutantji et al.^Citation56	England	Quasi-experimental mixed model	3	High pain = 18 Low pain = 18	Compare the processing of pain related words in participants with high vs. low pain	N
McCracken and Iverson^Citation65	United States	Cross-sectional	3	CP = 275	Examined predictors of cognitive complaints in participants with CP	N
Witty et al.^Citation84	United States	Cross-sectional	3	CP = 78	Examined problem solving ability and pain ratings in participants with CP	N
Dick et al.^Citation53	Canada	Cross-sectional	3	FM = 20 RA = 20 MSK = 20 HC = 20	Compare attentional functioning in FM vs. RA vs. MSK vs. HC	N
Sephton et al.^Citation72	United States	Cross-sectional	3	FM = 50	Explore relationship between memory function and biological/psychological factors in participants with FM	N
Apkarian et al.^Citation52	United States	Cross-sectional	3	CP = 26 HC = 26 CRPS = 12	Investigate emotional decision making in CP vs. HC vs. CRPS	N
Roth et al.^Citation83	United States	Cross-sectional	3	CP = 222	Explore relationship between external factors and cognitive dysfunction in participants with CP	N
Veldhuijzen et al.^Citation99	United States	Cross-sectional	3	CP = 14 HC = 14	Explore the effects of pain on driving performance	N
Ling et al.^Citation89	England	Independent group design	3	CP = 72	Experience memory deficits in participants with CP	N
Berg et al.^Citation80	United States	Quasi-experimental	2	CP = 60	Examine relationship between pain intensity and concentration	N
Dick et al.^Citation78	Canada	Cross-sectional	3	N/A	Examine mechanisms of cognitive disruption in FM	N
Lee et al.^Citation58	England	Cohort	3	HC = 1273 CWP = 266	Explore association between CWP and cognition	N
Glass et al.^Citation43	United States	Cross-sectional	3	FM = 18 HC = 14	Explored executive function in participants with FM	N
Reyes Del Paso et al.^Citation75	Spain	Cross-sectional	3	FM = 35	Evaluate cognitive performance in participants with FM	N
Pulles and Oosterman^Citation63	Netherlands	Cross-sectional	3	CP = 30	Explore the relationship between pain intensity and neuropsychological function in participants with CP	N
Williams et al.^Citation50	United States	Cross-sectional	3	FM = 72	Explore types of cognitive dysfunction in participants with FM	Y
Seo et al.^Citation59	Spain	Cross-sectional	2	FM = 19 HC = 22	Investigate differences in neural correlates of working memory in FM vs. HC	N
Landrø et al.^Citation79	Norway	Cross-sectional	3	CP = 72	Explore neuropsychological functioning in participants with pain	N
Isbir et al.^Citation74	Turkey	Cross-sectional	3	CP = 98	Explore relationship between chronic pain and cognitive function	N
Martinsen et al.^Citation46	Sweden	Cohort	2	FM = 29 HC = 31	Explore differences in cognitive function in FM vs. HC	Y
Shmygalev et al.^Citation76	Germany	Cross-sectional	3	FM = 43 HC = 129	Assess driving performance in FM vs. HC	N
Coppieters et al.^Citation62	Belgium	Case-control	3	CINP = 35 CWAD = 32 HC = 28	Examine differences in cognitive performance in CINP vs. CWAD vs. HC	N
Tamburin^Citation100	Italy	Cross-sectional	3	CLBP = 24 HC = 24	Explore cognitive performance of participants with CLBP	N
Grisart and Plaghki^Citation64	United States	Cross-sectional	3	CLBP = 17 FM = 16	Explore mechanisms contributing to cognitive impairment	N
Coppieters et al.^Citation61	Belgium	Case control	4	CP = 28 CIP = 35 CWAD = 32	Investigate cognitive impairment in CP vs. CIP vs. CWAD	N
Elvemo et al.^Citation77	Norway	Cross-sectional	3	CP = 20 HC = 20	Explore differences in working memory in participants with CP vs. HC	N
Kalfon et al.^Citation45	Israel	Cross-sectional	3	CP = 50	Explore cognitive impairment in participants with CP	Y
Ferreira et al.^Citation101	Brazil	Cross-sectional	3	CP = 45 HC = 45	Explore cognitive functioning in participants with CP vs. HC	N
Gunnarsson et al.^Citation102	Sweden	Cross-sectional	3	MSK = 214	Explore cognitive functioning in participants with MSK	N
Nadar et al.^Citation93	Kuwait	Cross-sectional	3	CP = 40 HC = 29	Explore cognitive functioning in participants with CP vs. HC	N
Ojeda et al.^Citation85	Spain	Cross-sectional	3	CP = 336	Investigate the validity of memory tool in participants with CP	N
Baker et al.^Citation68	Australia	Cross-sectional	3	N = 41	Explore relationship between self-report and objective pain measures	N
González-Villar et al.^Citation55	United States	Cross-sectional	3	FM = 35 HC = 35	Compare working memory in FM vs. HC	N
Lenoir et al.^Citation90	Belgium	Case-control	4	CWAD = 13 CIP = 18 FM = 33 HC = 33	Identify validity of tool in CWAD vs. participants with FM vs. HC	N
Ren et al.^Citation66	China	Cross-sectional	3	CP = 24 HC = 24	Explore cognitive functioning in participants with CP vs. HC	N
Schrier et al.^Citation103	Netherlands	Cross-sectional	3	CP = 287	Explore cognitive functioning in participants with CP	N
Verim et al.^Citation104	United States	Cross-sectional	3	CP = 55 HC = 40	Explore relationship between enolase levels and cognitive functioning in participants with CP vs. HC	N
Galvez Sánchez et al.^Citation42	Italy	Cross-sectional	3	FM = 42	Explored the relationship with cognition and affect in participants with FM	N
Gunendi et al.^Citation44	United States	Cross-sectional	3	FM = 15	Evaluate sensory processing in participants with FM	Y
Ojeda et al.^Citation82	Spain	Cross-sectional	3	MSK = 245 HC = 72	Assess cognitive performance in participants with MSK vs. HC	N
Taylor et al.^Citation51	England	Cross-sectional	3	CP = 941	Patient perspective of nonpharmacological vs. pharmacological treatments in participants with CP	N
Blanco et al.^Citation40	United States	Cross-sectional	3	FM = 146 HC = 122	Analyze cognitive and olfactory functioning in participants with FM vs. HC	N
Bothelius et al.^Citation41	Sweden	Cross-sectional	3	CP = 22	Assess neuropsychological function in participants with CP	N
Moore et al.^Citation39	United States	Cross-sectional	3	FM = 24 HC = 26	Assess cognitive functioning in participants with FM vs. HC	N
Whibley et al.^Citation48	United States	Cross-sectional	3	FM = 50 HC = 50	Investigate association between pain intensity and measures of cognitive function	N
Castel et al.^Citation60	Spain	Cross-sectional	3	FM = 70 CP = 74 HC = 40	Explore relationship of cognitive performance in FM vs. CP vs. HC	N
Moreira and Novak^Citation35	Czech Republic	RCT	2	CP = 40	Investigate whether pain affects cognition and mobility	N
Jacobsen et al.^Citation34	Norway	Randomized controlled crossover trial	2	CP = 73	Investigate the utility of MINDFlex	N
Samartin-Veiga et al.^Citation69	Spain	Cross-sectional	3	FM = 19 HC = 22	Identify relationship brain electrical activity and cognition in participants with FM vs. HC	N
Corti et al.^Citation36	Australia	Cross-sectional	3	FM = 34 HC = 30	Explore cognitive profile of participants with FM with cognitive impairments	N
Munoz and Esteve^Citation71	United States	Cross-sectional	3	CP = 149	Explore memory complaints in CP	N
Lupu et al.^Citation92	Israel	Cross-sectional	3	CP = 33 HC = 31	Use Cogstate Brief Battery to assess cognition in participants with CP	N
Pappolla et al.^Citation49	United States	Cross-sectional	3	FM = 13	Explore association between FM and insulin resistance	Y
Seward et al.^Citation38	United States	Cross-sectional	3	CLBP = 307	Characterize driving experience of participants with CLBP	N
Tiwari et al.^Citation105	India	Cross-sectional	3	FM = 34 HC = 30	Compare measures of cognition in FM vs. HC	N
Baker et al.^Citation33	United States	RCT	3	CP = 39	Examine the efficacy of computerized training for cognitive impairment in CP	N
Oosterman et al.^Citation106,Citation107	Netheralands	Cross-sectional	3	CP = 34 HC = 32	Examine differences in executive and attentional control in CP vs. HC	N
Zhang et al.^Citation29	United States	Cross-sectional	3	CP = 20 HC = 25	Quantify differences in decision making in CP vs. HC	N
Liu et al.^Citation91	United States	Cross-sectional	3	CP = 331 HC = 333	Explore working and autobiographical memory in CP	N
Jorge et al.^Citation70	United States	Cross-sectional	3	RA = 33 CP = 24	Analyze memory deficits in CP	N
Russell et al.^Citation24	Germany	Qualitative (focus group)	5	FM = 14	Explore perceptions of exercise, sleep, and cognition	N
Gubler et al.^Citation86	Switzerland	Report study	5	CP = 33 HC = 33	Compare involuntary and voluntary attention in CP vs. HC	N
Berryman et al.^Citation25	Australia	Meta-analysis	1	CP	Explored working memory deficits in CP	N
Berryman et al.^Citation26	Australia	Meta-analysis	1	CP	Explored executive function deficits in CP	N
Bell et al.^Citation27	United States	Meta-analysis	1	CP	Synthesis of cognitive performance across FM studies	N
Innes and Sambamoorthi^Citation28	United States	Systematic review	1	CP	Evaluate association between CP and cognitive functioning	N
Mendonca et al.^Citation47	United States	Systematic review	1	FM	Investigate executive function in FM	N
Liu et al.^Citation31	Australia	Review	5	CP	Review of memory impairment factors in CP	N
Mazza et al.^Citation32	France	Review	5	CP	Review of memory impairments in CP	N
Glass^Citation30	United States	Review	5	CP	Explanation of dyscognition in FM	N
Galvez Sánchez et al.^Citation67	Italy	Cross-sectional	3	FM = 42	Explored the relationship with cognition and affect in participants with FM	N

Level of evidence defined by the Centre for Evidence-Based Medicine.

HC = healthy control; FM = fibromyalgia; RA = rheumatoid arthritis; MSK = musculoskeletal pain; CRPS = complex regional pain syndrome; CIP = chronic idiopathic disorder; CWAD = chronic whiplash-associated disorder; CP = chronic pain.

Table

Category	Test	Study
Driving	Driving Behavior Questionnaire	Seward et al.^Citation38
	Driving Habits Questionnaire	Seward et al.^Citation38
	Driving Test Battery	Shmygalev et al.^Citation76
Memory	Interference Memory Test	Tamburin^Citation100
	Memory Observation Questionnaire	Schnurr^Citation73
	Test Your Memory	Ojeda et al.^Citation82,Citation85
	Memory Task	Koutantji et al.^Citation56
	Everyday Memory Questionnaire	Baker et al.,^Citation33,Citation68 Landrø et al.^Citation79
	Prospective Memory Questionnaire	Ling et al.^Citation89
	Test of Memory Malingering	Kalfon et al.^Citation45
	Incidental Memory	Landrø et al.^Citation57
	Auto evaluation of memory	Munoz and Esteve^Citation71
	Weschler Memory Scale	Schiltenwolf et al.,^Citation37 Blanco et al.,^Citation40 Apkarian et al.,^Citation52 Landrø et al.,^Citation57,79 Jorge et al.,^Citation70 Sephton et al.,^Citation72 Elvemo et al.,^Citation77 Iezzi et al.^Citation81
	Autobiographical Memory	Liu et al.^Citation91
	Memory Failures of Everyday	Castel et al.,^Citation60 Samartin-Veiga et al.^Citation69
	Rey-Osterrieth Figure	Galvez-Sánchez et al.,^Citation42,Citation67 Lee et al.,^Citation58 Iezzi et al.,^Citation81 Lenoir et al.^Citation90
	Pattern Recognition Memory	Schiltenwolf et al.^Citation37
	Rivermead Behavioral Memory Test–Story Recall	Pulles and Oosterman^Citation63
	Dot Memory Test	Whibley et al.^Citation48
	Category fluency	Pulles and Oosterman^Citation63
	Paired associates learning	Jacobsen et al.^Citation34
	Stroop task	Baker et al.,^Citation33,Citation68 Apkarian et al.,^Citation52 Pulles and Oosterman,^Citation63 Coppieters et al.,^Citation61,Citation62 Iezzi et al.,^Citation81 Ferreira et al.^Citation101
		Castel et al.,^Citation60 Lenoir et al.^Citation90
	Reading Span task	Dick et al.^Citation78
	Working Memory Index	Liu et al.^Citation31,Citation91
	Number sequencing	Corti et al.,^Citation36 Elvemo et al.^Citation77
	Spatial Working Memory	Jacobsen et al.^Citation34
Language	Controlled Oral Word Association	Iezzi et al.^Citation81
	Language Boston Naming	Corti et al.^Citation36
	Multiple Choice Vocabulary	Corti et al.^Citation36
	Matrix reasoning and vocabulary	Landrø et al.^Citation79
	Verbal learning	Corti et al.,^Citation36 Galvez-Sánchez et al.,^Citation42,67 Castel et al.,^Citation60 Landrø et al.^Citation79
Executive Function	Card Sorting Task	Baker et al.,^Citation33,Citation68 Jacobsen et al.,^Citation34 Apkarian et al.,^Citation52 Iezzi et al.,^Citation81 Tamburin^Citation100
	Design Fluency	Iezzi et al.^Citation81
	Zoo Mapping Task	Coppieters et al.,^Citation62 Pulles and Oosterman,^Citation63 Galvez-Sánchez et al.^Citation67
	Revised Strategy Application	Galvez-Sánchez et al.^Citation67
	Behavior Rating Inventory of Executive Function	Baker et al.^Citation68
	Cambridge Neuropsychological Test	Corti et al.,^Citation36 Schiltenwolf et al.^Citation37
	Iowa Gambling	Zhang et al.,^Citation29 Apkarian et al.,^Citation52 Elvemo et al.,^Citation77 Tamburin^Citation100
	Paced Auditory Serial Addition	Iezzi et al.^Citation81
	Problem Solving Confidence	Witty et al.^Citation84
	Go/no go	Elvemo et al.^Citation77
	Stop signal task	Jacobsen et al.^Citation34
Attention	Trail Making	Baker et al.,^Citation33,68 Schiltenwolf et al.,^Citation37 Galvez-Sánchez et al.,^Citation42 Coppieters et al.,^Citation62 Pulles and Oosterman,^Citation63 Iezzi et al.,^Citation81 Tamburin,^Citation100 Nadar et al.^Citation93
	Spatial Span	Schiltenwolf et al.^Citation37
	Complex Concentration Task	Berg et al.^Citation80
	Bourdon Vos Test	Coppieters et al.,^Citation62 Pulles and Oosterman^Citation63
	Oddball Task	Gubler et al.^Citation86
	Toulouse-Piéron Perceptual and Attention Test	Castel et al.^Citation60
	Attention Switching Task	Jacobsen et al.^Citation34
	Symbol Digit Modalities Test	Baker et al.^Citation68
	Test of Everyday Attention	Dick et al.^Citation78
General Cognitive Functioning	Multiple Abilities Self Report	Williams et al.^Citation50
	Digital Span Task	Apkarian et al.,^Citation52 Landrø et al.,^Citation57 Pulles and Oosterman,^Citation63 Elvemo et al.,^Citation77 Dick et al.,^Citation78 Tamburin^Citation100
	Cognitive Failure Questionnaire	Baker et al.,^Citation33, Schier^Citation103
	Contextual Memory task	Nadar et al.^Citation93
	IQ tests	Schiltenwolf et al.,^Citation37 Apkarian et al.,^Citation52 Landrø et al.,^Citation57,79 Sephton et al.,^Citation72 Elvemo et al.,^Citation77 Iezzi et al.^Citation81
	National Adult Reading Test	Pulles and Oosterman^Citation63
Screening	Montreal Cognition Assessment	Isbir et al.,^Citation74 Ferreira et al.^Citation101
	Mini-Mental State	Pulles and Oosterman,^Citation63 Ojeda et al.,^Citation85 Tiwari et al.^Citation105
Other	Visuospatial Judgment of Line Orientation	Corti et al.^Citation36
	Motor Coordination	Shmygalev et al.^Citation76
	Vigilance	Coppieters et al.,^Citation61 Shmygalev et al.^Citation76
	CANTAB	Jacobsen et al.,^Citation34 Corti et al.,^Citation36 Schiltenwolf et al.^Citation37
	Symbol Search test	Whibley et al.^Citation48
	Perceived Deficits Questionnaire	Coppieters et al.^Citation62

Table

Category	Subcategory	Test	Paper
Emotional Functioning		Pain Catastrophizing Scale	Baker et al.,^Citation33 Seward et al.,^Citation38 Pulles and Oosterman,^Citation63 Grisart and Plaghki,^Citation64 Munoz and Esteve^Citation71
		Positive and Negative Affect Scale	Galvez-Sánchez et al.^Citation42
		Toronto Alexithymia Scale	Galvez-Sánchez et al.^Citation42
		Coping Strategies Questionnaire	Castel et al.,^Citation60 Jorge et al.,^Citation70 Roth et al.^Citation83
		Connor-Davidson Resilience Scale	Schier^Citation103
		Perceived Stress Scale	Sephton et al.^Citation72
Mental Health	Depression Anxiety Other	Beck Depression Inventory	Kalfon et al.,^Citation45 González-Villar et al.,^Citation55 Landrø et al.,^Citation57 Galvez Sanchez et al.,^Citation67 Baker et al.,^Citation68 Shmygalev et al.,^Citation76 Roth et al.^Citation83
		Hospital Anxiety and Depression Scale	Martinsen et al.,^Citation46 Eccleston,^Citation54 Castel et al.,^Citation60 Grisart and Plaghki,^Citation64 Jorge et al.,^Citation70 Munoz and Esteve,^Citation71 Dick et al.,^Citation78 Gubler et al.,^Citation86 Shrier^Citation103
		Zung Depression Scale	Ling et al.^Citation89
		State-Trait Anxiety Inventory	Galvez-Sanchez et al.,^Citation42 Martinsen et al.,^Citation46 Shmygalev et al.^Citation76
		PCPT Spell It Out	Roth et al.^Citation83
		Pain Anxiety Symptoms Scale	Grisart and Plaghki^Citation64
Pain experiences and impairment		Pain Experience Scale	Berg et al.^Citation80
		Pain Disability Index	Berg et al.^Citation80
		Visual Analogue Scale	Jorge et al.,^Citation70 Gubler et al.,^Citation86 Liu et al.^Citation91
		Neck Pain-Related Disability	Coppieters et al.^Citation61
		Numerical Pain Intensity Rating Scale	Castel et al.,^Citation60 Grisart and Plaghki^Citation64
		Brief Pain Inventory	Zhang et al.,^Citation29 Baker et al.,^Citation33,Citation68 Shmygalev et al.,^Citation76 Lupu et al.^Citation92
		Pain Rating Index	Kalfon et al.,^Citation45 Martinsen et al.,^Citation46 González-Villar et al.,^Citation55 Pulles and Oosterman,^Citation63 Shmygalev et al.,^Citation76 Nadar et al.^Citation93
			Schiltenwolf et al.,^Citation37 Whibley et al.,^Citation48 Baker et al.^Citation68
		Fibromyalgia Survey Questionnaire	González-Villar et al.,^Citation55 Samartin-Viega et al.^Citation69
		McGill Pain Questionnaire	Galvez-Sanchez et al.,^Citation42 Dick et al.,^Citation78 Roth et al.^Citation83
		Pain Self-Efficacy Questionnaire	Baker et al.^Citation33
General measures of QOL		Sickness Impact Profile	McCracken and Iverson,^65 Witty et al.^Citation84
		Roland Morris Disability Questionnaire	Corti et al.^Citation36
		Patient Health Questionnaire	Mackay^Citation7
		Disability Rating Index	Pulles and Oosterman^Citation63
		SF-36	Martinsen et al.,^Citation46 Coppieters et al.,^Citation61 Pulles and Oosterman,^Citation63 Dick et al.,^Citation78 Ojeda et al.^Citation85

Eccleston C. Chronic pain and distraction: an experimental investigation into the role of sustained and shifting attention in the processing of chronic persistent pain. Behav Res Ther. 1995;33(4):391–405. doi:10.1016/0005-7967(94)00057-Q.

 PubMed Web of Science ®Google Scholar

Landrø NI, Stiles TC, Sletvold H. Memory functioning in patients with primary fibromyalgia and major depression and healthy controls. J Psychosom Res. 1997;42(3):297–306. doi:10.1016/S0022-3999(96)00301-7.

 PubMed Web of Science ®Google Scholar

Schnurr MRM. Memory complaints in chronic pain. Clin J Pain. 1995;11(2):103–11. doi:10.1097/00002508-199506000-00004.

 PubMed Web of Science ®Google Scholar

Iezzi T, Archibald Y, Barnett P, Klinck A, Duckworth M. Neurocognitive performance and emotional status in chronic pain patients. J Behav Med. 1999;22(3):205–16. doi:10.1023/A:1018791622441.

 PubMed Web of Science ®Google Scholar

Koutantji M, David P, David O. Cognitive processing of pain‐related words and psychological adjustment in high and low pain frequency participants. Br J Health Psychol. 2000;5(3):275–88. doi:10.1348/135910700168919.

 Google Scholar

McCracken LM, Iverson GL. Predicting complaints of impaired cognitive functioning in patients with chronic pain. J Pain Symptom Manage. 2001;21(5):392–96. doi:10.1016/S0885-3924(01)00267-6.

 PubMed Web of Science ®Google Scholar

Witty TE, Heppner PP, Bernard CB, Thoreson RW. Problem-solving appraisal and psychological adjustment of persons with chronic low-back pain. J Clin Psychol Med Setting. 2001;8(3):149–60. doi:10.1023/A:1011361418436.

 Web of Science ®Google Scholar

Dick B, Eccleston C, Crombez G. Attentional functioning in fibromyalgia, rheumatoid arthritis, and musculoskeletal pain patients. Arthritis Rheum. 2002;47(6):639–44. doi:10.1002/art.10800.

 PubMed Web of Science ®Google Scholar

Sephton SE, Studts JL, Hoover K, Weissbecker I, Lynch G, Ho I, McGuffin S, Salmon P. Biological and psychological factors associated with memory function in fibromyalgia syndrome. Health Psychol. 2003;22(6):592–97. doi:10.1037/0278-6133.22.6.592.

 PubMed Web of Science ®Google Scholar

Apkarian AV, Sosa Y, Krauss BR, Thomas SP, Fredrickson BE, Levy RE, Harden NR, Chialvo DR. Chronic pain patients are impaired on an emotional decision-making task. Pain. 2004;108(1–2):129–36. doi:10.1016/j.pain.2003.12.015.

 PubMed Web of Science ®Google Scholar

Roth RS, Geisser ME, Theisen-Goodvich M, Dixon PJ. Cognitive complaints are associated with depression, fatigue, female sex, and pain catastrophizing in patients with chronic pain. Arch Phys Med Rehabil. 2005;86(6):1147–54. doi:10.1016/j.apmr.2004.10.041.

 PubMed Web of Science ®Google Scholar

Veldhuijzen DS, van Wijck AJM, Wille F, Verster JC, Kenemans JL, Kalkman CJ, Olivier B, Volkerts ER. Effect of chronic nonmalignant pain on highway driving performance. Pain. 2006;122(1–2):28–35. doi:10.1016/j.pain.2005.12.019.

 PubMed Web of Science ®Google Scholar

Ling J, Campbell C, Heffernan TM, Greenough CG. Short-term prospective memory deficits in chronic back pain patients. Psychosom Med. 2007;69(2):144–48. doi:10.1097/PSY.0b013e31802e0f22.

 PubMed Web of Science ®Google Scholar

Berg A, Oster K, Janig H, Likar R, Pipam W, Scholz A, Westhoff K. Objective measurement of chronic pain by a complex concentration test. Rev Psychol. 2009;16(1):37–46.

 Google Scholar

Dick BD, Verrier MJ, Harker T, Rashiq S. Disruption of cognitive function in Fibromyalgia syndrome. Pain. 2008;139(2008):610–16. doi:10.1016/j.pain.2008.06.017.

 PubMedGoogle Scholar

Lee DM, Pendleton N, Tajar A, O’Neill TW, O’Connor DB, Bartfai G, Boonen S, Casanueva FF, Finn JD, Forti G, et al. Chronic widespread pain is associated with slower cognitive processing speed in middle-aged and older european men. Pain. 2010;151(1):30–36. doi:10.1016/j.pain.2010.04.024.

 PubMed Web of Science ®Google Scholar

Glass JM, Williams DA, Fernandez-Sanchez M-L, Kairys A, Barjola P, Heitzeg MM, Clauw DJ, Schmidt-Wilcke T. Executive function in chronic pain patients and healthy controls: different cortical activation during response inhibition in fibromyalgia. J Pain. 2011;12(12):1219–29. doi:10.1016/j.jpain.2011.06.007.

 PubMed Web of Science ®Google Scholar

Reyes Del Paso GA, Pulgar A, Duschek S, Garrido S. Cognitive impairment in fibromyalgia syndrome: the impact of cardiovascular regulation, pain, emotional disorders and medication. Eur J Pain. 2012;16(3):421–29. doi:10.1002/j.1532-2149.2011.00032.x.

 PubMed Web of Science ®Google Scholar

Pulles WLJA, Oosterman JM. The role of neuropsychological performance in the relationship between chronic pain and functional physical impairment. Pain Med. 2011;12:1769–76. doi:10.1111/j.1526-4637.2011.01266.x.

 PubMed Web of Science ®Google Scholar

Williams DA, Clauw DJ, Glass JM. Perceived cognitive dysfunction in fibromyalgia syndrome. J Musculoskelet Pain. 2011;19(2):66–75. doi:10.3109/10582452.2011.558989.

 Web of Science ®Google Scholar

Seo J, Kim S-H, Kim Y-T, Song H-J, Lee -J-J, Kim S-H, Han SW, Nam EJ, Kim S-K, Lee HJ, et al. Working memory impairment in fibromyalgia patients associated with altered frontoparietal memory network. PLoS One. 2012;7(6):e37808. doi:10.1371/journal.pone.0037808.

 PubMed Web of Science ®Google Scholar

Landrø NI, Fors EA, Våpenstad LL, Holthe Ø, Stiles TC, Borchgrevink PC. The extent of neurocognitive dysfunction in a multidisciplinary pain centre population. Is there a relation between reported and tested neuropsychological functioning? Pain. 2013;154(7):972–77. doi:10.1016/j.pain.2013.01.013.

 PubMed Web of Science ®Google Scholar

Isbir A, Duger C, Mimaroglu C, Kol IO, Kaygusuz K, Gursoy S. Effect of chronic knee pain on cognitive function: clinical study. Musculoskelet Pain. 2014;22(2):187–92. doi:10.3109/10582452.2014.883030.

 Web of Science ®Google Scholar

Martinsen S, Flodin P, Berrebi J, Löfgren M, Bileviciute-Ljungar I, Ingvar M, Fransson P. Fibromyalgia patients had normal distraction related pain inhibition but cognitive impairment reflected in caudate nucleus and hippocampus during the stroop color word test. PLoS One. 2014;9(9):1–9. doi:10.1371/journal.pone.0108637.

 Google Scholar

Shmygalev S, Dagtekin O, Gerbershagen HJ, Marcus H, Jübner M, Sabatowski R, Petzke F. Assessing cognitive and psychomotor performance in patients with fibromyalgia syndrome. Pain Ther. 2014;3(2):85–101. doi:10.1007/s40122-014-0028-0.

 PubMedGoogle Scholar

Coppieters I, De Pauw R, Kregel J, Malfliet A, Goubert D, Lenoir D, Cagnie B, Meeus M. Differences between women with traumatic and idiopathic chronic neck pain and women without neck pain: interrelationships among disability, cognitive deficits, and central sensitization. Phys Ther. 2017;97(3):338–53. doi:10.2522/ptj.20160259.

 PubMed Web of Science ®Google Scholar

Tamburin S. Cognition and emotional decision-making in chronic low back pain: an ERPs study during Iowa gambling task. Front Psychol. 2014;5(1350):1–11. doi:10.3389/fpsyg.2014.01350.

 PubMedGoogle Scholar

Grisart J, Plaghki L. Impaired selective attention in chronic pain patients. Eur J Pain. 2002;3(4):325–33. doi:10.1016/S1090-3801(99)90014-9.

 Google Scholar

Coppieters I, Ickmans K, Cagnie B, Nijs J, De Pauw R, Noten S, Meeus M. Cognitive performance is related to central sensitization and health-related quality of life in patients with chronic whiplash-associated disorders and fibromyalgia. Pain Physician. 2015;18(3):289–401.

 Web of Science ®Google Scholar

Elvemo NA, Landrø NI, Borchgrevink PC, Håberg AK. A particular effect of sleep, but not pain or depression, on the blood-oxygen-level dependent response during working memory tasks in patients with chronic pain. J Pain Res. 2015;7:335–46.

 Google Scholar

Kalfon TB-O, Gal G, Shorer R, Ablin JN. Cognitive functioning in fibromyalgia: the central role of effort. J Psychosom Res. 2016;87:30–36. doi:10.1016/j.jpsychores.2016.06.004.

 PubMed Web of Science ®Google Scholar

Ferreira KDS, Oliver GZ, Thomaz DC, Teixeira CT. 1 MPF. Cognitive deficits in chronic pain patients, in a brief screening test, are independent of comorbidities and medication use. Arq Neuropsiquiatr. 2016;74(5):361–66. doi:10.1590/0004-282X20160071.

 PubMed Web of Science ®Google Scholar

Gunnarson H, Grahn B, Agerstorm J. Impaired psychomotor ability and attention in patients with persistent pain: a cross-sectional comparative study. J Pain Res. 2016;9:825–35. doi:10.2147/JPR.S114915.

 PubMed Web of Science ®Google Scholar

Nadar MS, Jasem Z, Manee FS. The cognitive functions in adults with chronic pain: a comparative study. Pain Res Manage. Published online 2016.

 Web of Science ®Google Scholar

Ojeda B, Salazar A, Dueñas M, Torres LM, Mico JA, Failde I. Assessing the construct validity and internal reliability of the screening tool test your memory in patients with chronic pain. PLoS One. 2016;11(4):1–16. doi:10.1371/journal.pone.0154240.

 Web of Science ®Google Scholar

Baker KS, Gibson SJ, Georgiou-Karistianis N, Giummarra MJ. Relationship between self-reported cognitive difficulties, objective neuropsychological test performance and psychological distress in chronic pain. Eur J Pain. 2018;22(3):601–13. doi:10.1002/ejp.1151.

 PubMed Web of Science ®Google Scholar

González-Villar AJ, Pidal-Miranda M, Arias M, Rodríguez-Salgado D, Carrillo-de-la-Peña MT. Electroencephalographic evidence of altered top-down attentional modulation in fibromyalgia patients during a working memory task. Brain Topogr. 2017;30(4):539–47. doi:10.1007/s10548-017-0561-3.

 PubMed Web of Science ®Google Scholar

Lenoir D, De Pauw R, Ickmans K, Schumacher C, Timmers I, Kregel J, Coppieters I. Validity and test-retest reliability of the Dutch modified perceived deficits questionnaire to examine cognitive symptoms in women with chronic whiplash, chronic idiopathic neck pain, and fibromyalgia. Pain Pract. 2018;18(7):850–63. doi:10.1111/papr.12683.

 PubMed Web of Science ®Google Scholar

Ren X, Lu J, Liu X, Shen C, Zhang X, Ma X, Sun J, Sun G, Feng K, Xu B, et al. Decreased prefrontal brain activation during verbal fluency task in patients with somatoform pain disorder: an exploratory multi-channel near-infrared spectroscopy study. Prog Neuropsychopharmacol Biol Psychiatry. 2017;78:153–60. doi:10.1016/j.pnpbp.2017.05.006.

 PubMed Web of Science ®Google Scholar

Schrier E, Geertzen JH, Dijkstra PU. Subjective cognitive dysfunction in rehabilitation outpatients with musculoskeletal disorders or chronic pain. Eur J Phys Rehabil Med . 2017;53(4):582–89. doi:10.23736/S1973-9087.16.04470-1.

 PubMed Web of Science ®Google Scholar

Verim S, Batmaz İ, Yazmalar L, Çavaş H, Nas K, Çevik R. Serum levels of neuron-specific enolase in patients with fibromyalgia syndrome: correlation with cognitive functions, quality of life and psychological state. J Back Musculoskelet Rehabil. 2018;77:2039–43.

 Google Scholar

Galvez-Sánchez CM, Paso Gar Del R, Duschek S. Cognitive impairments in fibromyalgia syndrome: associations with positive and negative affect, alexithymia, pain catastrophizing and self-esteem. Front Psychol. 2018;9(377):1–14. doi:10.3389/fpsyg.2018.00377.

 PubMedGoogle Scholar

Gunendi Z, Polat M, Vuralli D, Cengiz B. Somatosensory temporal discrimination is impaired in fibromyalgia. J Clin Neurosci. 2019;60:44–48. doi:10.1016/j.jocn.2018.10.067.

 PubMed Web of Science ®Google Scholar

Ojeda B, Dueñas M, Salazar A, Mico JA, Torres LM, Failde I. Factors influencing cognitive impairment in neuropathic and musculoskeletal pain and fibromyalgia. Pain Med. 2018;19(3):449–510. doi:10.1093/pm/pnx024.

 PubMed Web of Science ®Google Scholar

Taylor SJ, Steer M, Ashe SC, Furness PJ, Haywood-Small S, Lawson K. Patients’ perspective of the effectiveness and acceptability of pharmacological and non- pharmacological treatments of fibromyalgia. Scand J Pain. 2019;19(1):167–81. doi:10.1515/sjpain-2018-0116.

 PubMed Web of Science ®Google Scholar

Blanco S, Sanromán L, Pérez-Calvo S, Velasco L, Peñacoba C. Olfactory and cognitive functioning in patients with fibromyalgia. Psychol Health Med. 2019;24(5):530–41. doi:10.1080/13548506.2018.1549741.

 PubMed Web of Science ®Google Scholar

Bothelius K, Hysing E-B, Filén T, Lundeborg L, Gordh T. Insomnia-related memory impairment in individuals with very complex chronic pain. Cogn Behav Neurol. 2019;32(3):164–71. doi:10.1097/WNN.0000000000000196.

 PubMed Web of Science ®Google Scholar

Moore DJ, Meints SM, Lazaridou A, Johnson D, Franceschelli O, Cornelius M, Schreiber K, Edwards RR. The effect of induced and chronic pain on attention. J Pain. 2019;20(11):1353–61. doi:10.1016/j.jpain.2019.05.004.

 PubMed Web of Science ®Google Scholar

Whibley D, Williams DA, Clauw DJ, Sliwinski MJ, Kratz AL. Within-day rhythms of pain and cognitive function in people with and without fibromyalgia: synchronous or syncopated? Pain. 2022;163(3):464–82. doi:10.1097/j.pain.0000000000002370.

 Web of Science ®Google Scholar

Castel A, Cascp N-Pererira R, Boadai 1S. Memory complaints and cognitive performance in fibromyalgia and chronic pain: the key role of depression. Scand J Psychol. 2021;62:328–38. doi:10.1111/sjop.12706.

 PubMed Web of Science ®Google Scholar

Moreira S, Novak P. Effects of pain on cognitive function and mobility. Open Access J Clin Trials. 2019;11:1–10. doi:10.2147/OAJCT.S182502.

 Web of Science ®Google Scholar

Jacobsen HB, Klungsoyr O, Landrø NI, Stiles TC, Roche BT. MINDflex training for cognitive flexibility in chronic pain: a randomized, controlled cross-over trial. Front Psychol. 2020;11(604832):1–16. doi:10.3389/fpsyg.2020.604832.

 PubMedGoogle Scholar

Samartin-Veiga N, González-Villar AJ, Carrillo-de-la-Peña M. Neural correlates of cognitive dysfunction in fibromyalgia patients: reduced brain electrical activity during the execution of a cognitive control task. NeuroImage Clin. 2019;23(101817):1–7. doi:10.1016/j.nicl.2019.101817.

 Google Scholar

Corti EJ, Gasson N, Loftus AM. Cognitive profile and mild cognitive impairment in people with chronic lower back pain. Brain Cogn. 2021;151(2021):1–9. doi:10.1016/j.bandc.2021.105737.

 Google Scholar

Munoz M, Esteve R. Reports of memory functioning by patients with chronic pain. Clin J Pain. 2005;21(4):287–91. doi:10.1097/01.ajp.0000173993.53733.2e.

 PubMed Web of Science ®Google Scholar

Lupu T, Braw Y, Sacher Y, Ratmansky M. Cogstate brief battery: cognition and the feigning of cognitive impairment in chronic pain. Appl Neuropsychol Adult. 2021;29(6):1–12.

 Web of Science ®Google Scholar

Pappolla MA, Manchikanti L, Candido KD, Grieg N, Seffinger M, Ahmed F, Fang X, Andersen C, Trescot AM. Insulin resistance is associated with central pain in patients with fibromyalgia. Pain Physician. 2021;24:175–84.

 PubMed Web of Science ®Google Scholar

Seward J, Stavrinos D, Moore D, Attridge N, Trost Z. When driving hurts: characterizing the experience and impact of driving with back pain. Scand J Pain. 2021;21(3):445–56. doi:10.1515/sjpain-2020-0108.

 PubMed Web of Science ®Google Scholar

Tiwari VK, Nanda S, Arya S, Kumar U, Sharma R, Kumaran SS, Bhatia R. Correlating cognition and cortical excitability with pain in fibromyalgia: a case control study. Adv Rheumatol. 2021;61(10). doi:10.1186/s42358-021-00163-x.

 Google Scholar

Baker KS, Georgiou-Karistianis N, Lampit A, Valenzuela M, Gibson SJ, Giummarra MJ. Computerised training improves cognitive performance in chronic pain: a participant-blinded randomised active-controlled trial with remote supervision. Pain. 2018;159(2018):644–55. doi:10.1097/j.pain.0000000000001150.

 PubMedGoogle Scholar

Oosterman JM, Derksen LC, van Wijck AJ, Kessels RP, Veldhuijzen DS. Executive and attentional functions in chronic pain: does performance decrease with increasing task load? Pain Res Manage. 2012;17(3):159–65. doi:10.1155/2012/962786.

 PubMed Web of Science ®Google Scholar

Oosterman JM, Derksen LC, van Wijck AJM, Veldhuijzen DS, Kessels RPC. Memory functions in chronic pain: examining contributions of attention and age to test performance. Clin J Pain. 2011;27(1):70–75. doi:10.1097/AJP.0b013e3181f15cf5.

 PubMed Web of Science ®Google Scholar

Zhang X, Gao R, Zhang C, Chen H, Wang R, Zhao Q, Zhu T, Chen C. Evidence for cognitive decline in chronic pain: a systematic review and meta-analysis. Front Neurosci. 2021;15(737874):1–15.

 Google Scholar

Liu X, Yang H, Li S, Wan D, Deng Y, Fu Y, Qu Q, Zhong L, Hu Y. Mediating effects of working memory on the relationship between chronic pain and overgeneral autobiographical memory. Memory. 2021;29(1):3298–304. doi:10.1080/09658211.2021.1889606.

 Google Scholar

Jorge L, Gerad C, Revel M. Evidences of memory dysfunction and maladaptive coping in chronic low back pain and rheumatoid arthritis patients: challenges for rehabilitation. Eur J Phys Rehabil Med. 2009;45:469–77.

 PubMed Web of Science ®Google Scholar

Russell D, Gallardo CÁ, W I, Hughes CM, Davison GW, Sañudo B, McVeigh JG. Exercise to me is a scary word: perceptions of fatigue, sleep dysfunction, and exercise in people with fibromyalgia syndrome—A focus group study. Rheumatol Int. 2017;38(3):507–15. doi:10.1007/s00296-018-3932-5.

 Web of Science ®Google Scholar

Gubler DA, Zei S, Egloff K, Frickmann F, Goetze B, Grosse Holtforth M, Harnik M, Streitberger K, Troche SJ. The effect of chronic pain on voluntary and involuntary capture of attention: an event-related potential study. Behav Neurosci. 2022;136(2):195–205. doi:10.1037/bne0000375.

 PubMed Web of Science ®Google Scholar

Berryman C, Stanton TR, Bowering KJ, Tabor A, McFarlane A, Moseley GL. Do people with chronic pain have impaired executive function? A meta-analytical review. Clin Psychol Rev. 2014;34(7):563–79. doi:10.1016/j.cpr.2014.08.003.

 PubMed Web of Science ®Google Scholar

Berryman C, Stanton TR, Bowering KJ, Tabor A, McFarlane A, Moseley GL. Evidence for working memory deficits in chronic pain: a systematic review and meta-analysis. Pain. 2013;154(8):1181–96. doi:10.1016/j.pain.2013.03.002.

 PubMed Web of Science ®Google Scholar

Bell T, Trost Z, Buelow MT, Clay O, Younger J, Moore D, Crowe M. Meta-analysis of cognitive performance in fibromyalgia. J Clin Exp Neuropsychol. 2018;40(7):698–714. doi:10.1080/13803395.2017.1422699.

 PubMed Web of Science ®Google Scholar

Innes KE, Sambamoorthi U. The potential contribution of chronic pain and common chronic pain conditions to subsequent cognitive decline, new onset cognitive impairment, and incident dementia: a systematic review and conceptual model for future research. J Alzheimers Dis. 2020;78(3):1177–95. doi:10.3233/JAD-200960.

 PubMed Web of Science ®Google Scholar

Mendonça B, Silva GG, Busatto LM, Dias NM. Executive functions in fibromyalgia: a systematic review. Psychol Neurosci. 2021;14(4):413–37. doi:10.1037/pne0000270.

 Google Scholar

Liu X, Li L, Tang F, Wu S, Hu Y. Memory impairment in chronic pain patients and the related neuropsychological mechanisms: a review. Acta Neuropsyc. 2014;26(4):195–201. doi:10.1017/neu.2013.47.

 PubMed Web of Science ®Google Scholar

Mazza S, Frotb M, Reya AE. A comprehensive literature review of chronic pain and memory. Prog Neuropsychopharmacol Biol Psychiatry. 2018;87:183–92. doi:10.1016/j.pnpbp.2017.08.006.

 PubMed Web of Science ®Google Scholar

Glass J. Cognitive dysfunction in fibromyalgia syndrome. J Musculoskelet Pain. 2010;18(4):367–72. doi:10.3109/10582452.2010.502626.

 Web of Science ®Google Scholar

Galvez-Sánchez CM, de Guevara CML, Montoro CI, Fernández-Serrano MJ, Duschek S, Paso Gar Del R. Cognitive deficits in fibromyalgia syndrome are associated with pain responses to low intensity pressure stimulation. PLoS One. 2018;13(8):1–9. doi:10.1371/journal.pone.0201488.

 Web of Science ®Google Scholar

Schiltenwolf M, Akbar M, Neubauer E, Gantz S, Flor H, Hug A, Wang H. The cognitive impact of chronic low back pain: positive effect of multidisciplinary pain therapy. Scand J Pain. 2017;17:273–78. doi:10.1016/j.sjpain.2017.07.019.

 PubMedGoogle Scholar

Mackay M. Lupus brain fog: a biologic perspective on cognitive impairment, depression, and fatigue in systemic lupus erythematosus. Immunol Res. 2015;63(1–3):26–37. doi:10.1007/s12026-015-8716-3.

 PubMed Web of Science ®Google Scholar