Cognitive Functions Cognitive impairment is frequent, affecting up - PDF document

6/18/2015 A SSESSING P ROCESSING S PEED IN M ULTIPLE S CLEROSIS : past and future Silvana L Costa, Ph.D., Helen Genova, Ph.D., John DeLuca, Ph.D. & Nancy D Chiaravalloti, Ph.D. CMSC May 2015 Indianapolis, Indiana Disclosures The authors have no financial disclosures or conflict of interest pertaining to this study 1

6/18/2015 Cognitive Functions • Cognitive impairment is frequent, affecting up to 70% of individuals with MS (Chiaravalloti et al, 2008) • Information processing speed (IPS) – One of the most prevalent cognitive difficulties ( Rosti-Otajärvi et al , 2013) – And is hypothesized, by some authors, as the key deficit underlying cognitive dysfunction in MS (DeLuca et al, 2004; Demaree et al., 1999; Forn et al 2008) Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS 2

6/18/2015 Review: Methods PubMed search Records identified Identification 1.January 1, 2004 and thorough database December 31, 2013. searching (n=233) 2. “ Processing Speed ” AND Records excluded (n=55) “ Multiple Sclerosis ” -Not Multiple Sclerosis (n=15) Screening -Other language then English (n=16) Records screened -Review article (n=23) (n=233) -Animal studies (n=1) Records excluded (n=21) Eligibility Full-text articles -Children (n=7) assessed for eligibility -No processing speed measure (n=178) (n=10) -Case study (n=2) -Opinion article (n=2) Included Articles included (n=157) The evolution of IPS study in MS: Frequency of articles by year 45 66% 39 40 35 34% 30 Number of articles 25 19 18 20 17 14 13 15 12 10 9 10 6 5 0 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Year Frequency 3

6/18/2015 Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS Samples Characteristics • What do we know about IPS and disease courses? • Articles included were divided into 3 categories 1) heterogeneous MS course, in which the study sample(s) is (are) composed of a combination of different disease courses. 2) one MS course, with the focus on understanding one disease course; 3) comparing multiple MS course, with the focus on comparing more than one disease course; 4

6/18/2015 Samples Characteristics Samples Characteristics Results summary • HC > MS Heterogeneous courses (more 53% • RR > SP then one course) • RR = CIS one MS course 34% • SP < CIS • PP < RR / PP = RR comparning MS 10% courses • PP > SP / PP = SP no information 3% regardinng Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS 5

6/18/2015 Frequency of reporting confounding variables No other neurological or psychiatric disease 61% Age 59% Education 52% at least 1 month after last exarcerbation 50% No drugs abuse 49% No alchool abuse 48% Steroids/corticosteroids free 39% Physical Impairment 31% Visual disturbances 29% Development Disorders 19% No psychoactive drugs 16% Depression 14% Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS 6

6/18/2015 Tests used to assess IPS in MS • We grouped assessments into 8 cognitive task categories based on their methodological approach: 1) symbol/digit substitution (e.g. SDMT); 2) working memory (e.g. PASAT); 3) reaction time (e.g. visual reaction time or choice reaction time); 3) executive functions (e.g. STROOP); 4) attention (e.g. Test of Attentional Performance); 5) other (e.g. Picture Naming Test ); 6) verbal fluency (e.g. Word List Generation Test ); 7) self-reported questionnaires (e.g. Processing Speed Difficulties Scale). Tests used to assess IPS in MS Symbol/Digit substitution test 132 Working memory 111 Reaction Time 45 Executive Functions 42 Attention 13 Other 10 Verbal Fluency 6 Self-reported Questionnaire 1 0 20 40 60 80 100 120 140 Number of times used 7

6/18/2015 Tests used more then 5 times Executive Functions Trail Making Test % of articles where IPS was assessed with PASAT and/or Stroop SDMT Memory Reaction Time semantic RT Choice RT 100 Simple RT Working 80 n-back % of articles PASAT 60 substitution Tests Digit Symbol Substitution Test 40 Symbols/Digit Symbol Search 20 Coding 0 PASAT SDMT SDMT Test 0 100 2004-2008 2009-2013 Total number of times used Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS 8

6/18/2015 IPS: defining the construct - Only 9.6% of the articles under review define IPS. Physiologically, information processing speed refers to the speed with which 4 one can process information in the Brain Processing speed is not a unitary construct, it is complex and it is a result 5 of the interaction of multiple factors Processing speed can be defined as the amount of time a person needs to 8 execute a cognitive task Number of times cited Study aims: understand HOW IPS has been assessed during 10 years of research – The methods applied to assess information processing speed (IPS) in individuals with MS • Sample characteristics • Frequency of reporting confounding variables • Behavior measures used to assess IPS – The theories applied to study information processing speed in individuals with MS • IPS definitions of the construct • Theories about IPS 9

6/18/2015 Theories about IPS - Only 21% of the articles under review discuss theories of IPS . Relative consequence model (DeLuca et al., 10 2004). Salthouse Theory (Salthouse, 1996). 6 Neural noise hypothesis (Kail, 1998). 5 Independent consequence model (DeLuca et 4 al., 2004). Subcortical dementia (Cummings & Benson, 4 1984). Cognitive reserve (Stern, 2002). 4 Posner model of attention (Posner & Petersen, 2 1990) Total times cited Assessing IPS in Multiple Sclerosis Past Future Mostly cross-sectional/prospective studies (only 10% of articles included were Longitudinal studies are in need longitudinal studies) Heterogeneous samples (more then one Studies design to assess IPS between disease course) disease courses Studies often don’t report • time since last exacerbation, Detail inclusion and exclusion criteria are • sensorial disturbances (e.g. vision) strongly encouraged • history of developmental disorders Use of diverse measures to assess IPS A clear definition and theoretical model of Construct rarely defined IPS in MS would be of great importance for Focus on hypothesis driven research and assessment and further understanding IPS not theory driven deficits in MS 10

6/18/2015 Acknowledgements • Nancy D Chiaravalloti, Ph.D. • John DeLuca, Ph.D. • Helen Genova, Ph.D. • Hearst Foundation • Kessler Foundation • Neuropsychology and Neuroscience Research • Rutgers New Jersey Medical School THANK YOU! 11