Computerised neuropsychological screening

To address the limitations of paper and pencil tests, computerised neuropsychological tests specific to sports concussion were developed (Patel, Shivdasani, & Baker, 2005). There are many advantages of computerised testing. They do not require a neuropsychologist to administer them, thus they are cost effective as they can be administered to a large group at the same time (Patel et al., 2005). Computerised testing ensures standardised administration, which increases reliability. Furthermore, they provide a more accurate measure of reaction time, measuring up to 0.01 of a second. They can randomise test items and generate alternative forms of the same test, minimising practice effects in

Test Areas assessed

HVLT-R Verbal memory (learning, delayed,

recognition)

BVMT-R Visual memory (learning, delayed,

recognition)

TMT-A Visual scanning & processing

speed

TMT-B Visual scanning, processing speed, &

cognitive flexibility

COWA Verbal fluency

WAIS;

Symbol Search

Visual processing speed, perceptual organisation, & planning

Digit Symbol Coding Psychomotor processing speed

repeat administrations. Lastly, most computerised tests automatically process raw scores into standardised scores (Lovell & Collins, 2002), removing the need for manual test scoring. Although the benefits over paper and pencil testing are vast, a disadvantage of computerised testing is that it does not allow for the administrator to observe the idiosyncratic behaviours during testing that often provide valuable information.

Several computerised neuropsychological assessment programmes exist. The most commonly used are the Automated Neuropsychological Assessment (ANAM; Cernich, Reeves, Sun, & Bleiberg, 2007), Cogstate Sport (Makdissi et al., 2001), Headminders Concussion Resolution Index (CRI; Erlanger et al., 1999), and Immediate Post-concussion Assessment and Cognitive Testing (ImPACT; ImPACTonline, 2013). The ANAM was initially developed by the US Department of Defence to assess the effects of chemical exposure and environmental stressors on military personal (Cernich et al., 2007). The ANAM Sports Medicine Battery (ASMB) is a subtest within the ANAM that is sensitive to the cognitive effects of concussion and has been used by the US military academy in their concussion management programme since 1999 (Reeves, Winter, Bleiberg, & Kane, 2007). The ASMB has demonstrated adequate test- retest reliability and internal consistency in addition to validity when compared to traditional paper and pencil neuropsychological tests (Cernich et al., 2007).

The Concussion Resolution Index (CRI; Erlanger et al., 1999) was developed by a company named HeadMinder, to be used specifically in the sports arena. It has a three-factor structure, measuring processing speed, simple reaction time, and complex reaction time. It too has demonstrated adequate reliability and validity and is currently used by many athletic organisations at different levels (Schatz & Zillmer, 2003).

Cogstate was developed in Australia, originally validated on 300 professional Australian Rules football players and hundreds of control participants (Makdissi et al., 2001). It too has demonstrated adequate reliability and validity (Schatz & Zillmer, 2003), but there is, however, a paucity of normative data (Collie, Darby, & Maruff, 2001).

ImPACT was created in the US by Mark Lovell and Joseph Marron (ImPACT online, 2013). It was the first computerised test battery developed to assess sport concussion and appears to be the most widely-used battery. The developers of ImPACT claim it to be the most scientifically validated neuropsychological computerised assessment for sport concussion (ImPACTonline, 2013). ImPACT has been used with high school, college, and professional level athletes (Lovell et al., 2006). It was developed to address limitations of the traditional paper-and- pencil NFL battery. It was initially developed as a desktop program in 2000, with an online version released in 2008 (Elbin, Schatz, & Covassin, 2011a). ImPACT follows a baseline model in which athletes act as their own controls, which individualises concussion assessment. Athletes complete the ImPACT battery pre- season and this acts as a baseline measure to which post-concussion testing is compared. This model has been evaluated and supported as an effective method of assessing cognitive impairment following a concussion (Barth et al., 1989; Iverson, Brooks, Collins, & Lovell, 2006; Schatz & Zillmer, 2003).

ImPACT consists of three main sections; demographic and health history information, a symptom inventory, and the neuropsychological test modules (ImPACTonline, 2013). The symptom inventory is the PCS mentioned previously in which athletes indicate on a 7-point Likert scale the severity of any symptoms they have experienced in the past 72 hours. From this a total symptom score is calculated. There are six different test modules (Word-memory, Design-memory, X’s and O’s, Symbol Match, Colour Match, and Three Letters) which were derived from traditional neuropsychological tests included in the NFL battery (ImPACTonline, 2013). Scores from the six test modules combine to produce five composite scores; Verbal Memory, Visual Memory, Visual Motor Speed, Reaction Time, and Impulse Control. A total score is not produced as test developers believe it would most likely be insensitive to concussive symptoms as not all concussed athletes will show decline in all cognitive areas assessed (ImPACTonline, 2013). The content of the ImPACT battery is discussed in more detail in the methodology section.

2.4 Summary

The way in which sport concussion is assessed and managed has changed over the years due to gains in our knowledge regarding its presentation and course of recovery. Assessment has shifted away from a simple, generalised approach toward a more individualised, multi-method assessment (McCrory et al., 2005; McCrory et al., 2009). The Concussion in Sport Consensus group have suggested that assessment should include both a self-report of symptoms in addition to neuropsychological testing (McCrory et al., 2009). To increase efficiency of administration, neuropsychological testing is now computerised and can be completed online. The ImPACT battery includes both neuropsychological tests and a self-report symptom scale. It appears to be the most widely used sport concussion battery. Notwithstanding, it is not without its own limitations, particularly regarding the lack of theoretical foundations and empirical research supporting its accuracy and reliability in detecting the cognitive effects of concussion. Hence the following two chapters focus on potential theoretical underpinnings and psychometric properties of the ImPACT battery.

Chapter 3: The Theoretical and Empirical Underpinnings of Concussion