Brain Injury, March 2012; 26(3): 234–240

A comparison of two assessments of high level cognitivecommunication disorders in mild traumatic brain injury

TANYA BLYTH1, AMANDA SCOTT1, ANNABELLE BOND2, & ELDHO PAUL3

1Speech Pathology Department, 2Occupational Therapy Department, The Alfred, Melbourne, Australia, and3Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia

(Received 11 August 2010; revised 29 November 2011; accepted 8 December 2011)

AbstractPrimary objectives: Individuals with traumatic brain injury (TBI) frequently encounter cognitive communication disorders.Deficits can be subtle but can seriously influence an individual’s ability to achieve life goals. Feedback from rehabilitationfacilities indicated that high level cognitive communication disorders are not consistently identified in the acute setting. Thisstudy aimed to compare the cognitive communication results from two screening assessments, the Cognistat and theCognitive Linguistic Quick Test (CLQT), in participants with a mild traumatic brain injury and to relate these findings to arange of prognostic indicators.Methods: Eighty-three adults post-TBI (16–81 years; 79.5% males) were recruited at an acute trauma centre. The languagecomponents of the two tests were analysed.Main outcomes and results: The CLQT identified more participants with an impairment in language than the Cognistat,19.3% compared to 1.2% ( p< 0.001). No clinical variables relating to the participants’ brain injury were found to beassociated with language impairment.Conclusions: This study found that the CLQT identified more individuals with high level cognitive communication deficitsthan the Cognistat in the acute setting.

Keywords: Assessment, closed head injury, cognitive, language

Introduction

Traumatic brain injury (TBI) continues to be aleading cause of death and disability worldwide[1, 2], with adolescents and young adults, in theirmost productive years, being among the highest atrisk [3, 4]. Australian statistics show that theincidence of TBI is 100/100 000 of the residentpopulation [5]. Mild cases of TBI account for�80–85% of all head injuries [2, 6, 7] and thus isa major public health concern. In comparison tomoderate–severe brain injuries, mild TBI is oftenmore difficult to diagnose because symptoms such asloss of consciousness (LOC), Post TraumaticAmnesia (PTA), disorientation and confusion

rapidly resolve. There is also a frequent absence ofobjective radiological evidence [6]. It has beenshown that most symptoms post-mild TBI resolve3–6 months after injury, however there is a sub-group of patients, �25–35% [8], whose disabilitypersists for a further 3–6 months [8–10].

Individuals with TBI frequently encounter cogni-tive communication disorders, which arise fromimpairments in language as well as cognitive func-tions [11, 12]. Whelan and Murdoch [13] reportedthat mild TBI may produce lasting effects onlinguistic functions, particularly in relation to com-plex operations that demand cognitive flexibility.These include difficulties in comprehending

Correspondence: Tanya Blyth, Speech Pathologist, The Alfred, PO Box 315, Prahran, Victoria 3181Australia. Tel: þ6139076 3339. Fax: þ6139076 8540.E-mail: t.blyth@alfred.org.au

ISSN 0269–9052 print/ISSN 1362–301X online � 2012 Informa UK Ltd.DOI: 10.3109/02699052.2012.654587

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extended oral or written language, communicating indistracting or stressful environments, ineffective useof social cues and socially inappropriate language. Inaddition, difficulty understanding abstract language,inefficient verbal reasoning and verbal learning canalso be observed in individuals with cognitive com-munication disorders [14].

Anecdotal feedback from rehabilitation facilitiesindicated that high level cognitive communicationdisorders were not consistently identified at TheAlfred. The Alfred is an acute hospital located inVictoria, Australia. It has a large trauma centrewhich admits �5000 patients annually. Somepatients had been identified as having cognitivelanguage impairment at a rehabilitation facility, thisled to concerns about those who did not attendrehabilitation and returned home after their acuteadmission without any Speech Pathology assess-ment. Even the most subtle communication impair-ments can seriously influence the success of anindividual’s social, vocational, familial and academicreintegration [14]. Screening is important to provideearly and accurate identification of language andcognitive deficits in the acute setting to ensurepatients receive appropriate rehabilitation and com-pensatory strategies [8].

While cognitive communication problems arefrequently the focus of management in rehabilitationtherapy, language and communication impairmentin patients with TBI is seldom the focus ofSpeech Pathology in the acute setting. Typically,mild TBI patients perform within normal limits onstandard aphasia batteries which are designed toevaluate the effects of focal brain lesions associatedwith language [12, 15]. Consequently, high levelcognitive communication deficits may not be reliablyidentified in the TBI population. This populationmay have broader-based communication deficitsrather than impairment of specific linguistic pro-cesses [8, 11].

At present there is no clear gold standard for ascreening assessment of cognitive communicationdisorders for the mild traumatic brain injuredpopulation. Prior to this study, practice at TheAlfred was to screen all patients for cognitive deficitspost-confirmed TBI. This entailed an OccupationalTherapist administering the Cognistat [16]. Patientswere referred to Speech Pathology for an assessmentonly if overt language or communication problemswere evident on the Cognistat. A failure to identifyhigh level cognitive communication disorders in thispatient population may result in them not receivingappropriate rehabilitation and lead to significantproblems in achieving life goals.

The Cognistat is a standardized assessment ofcognition developed in 1987 in the US [16].It assesses intellectual functioning in five major

ability areas: language, constructions, memory, cal-culations and reasoning. It was designed to discrim-inate disability from the average performance of thenormal population and was not designed as ameasure of full cognitive performance.

In 2005, benchmarking with clinicians in themajor trauma units of Australia indicated that theCognistat was the most widely used screeningassessment in the acute setting [17]. The Cognistathas been reported to be useful in detecting cognitiveimpairment in the adult TBI population [18]. It hasbeen deemed to be clinically useful in the acutesetting as a cognitive screen, as it is easily and quicklyadministered, as well as being sensitive to cognitivedysfunction [19]. Doninger et al. [20] found thatthere was a ceiling effect with the Cognistat forpeople with a TBI who are living in the community.This suggests that the Cognistat may be more usefulfor people with a more severe cognitive impairment.The Cognistat has a screening question for eachcognitive sub-test and if this is answered incorrectlythe patient completes the sub-test. Previous studieshave indicated that exclusive reliance on the screenportion of a sub-test may over-estimate cognitiveability [20].

A more recently developed assessment of cogni-tion is the Cognitive Linguistic Quick Test (CLQT)[21]. It was published in 2001 and developed in theUS. It has been described as having great potential asan initial screening tool for the evaluation ofneurocognitive effects post-TBI [22]. The CLQTwas designed to quickly assess the five cognitivedomains of; attention, memory, language, executivefunction and visuospatial skills.

In view of feedback from clinicians at rehabilita-tion facilities that cognitive communication prob-lems were being under-recognized the CLQT waschosen for this study because the sub-tests thatassess language on the CLQT are more complexthan those of the Cognistat. While both tests assess arange of cognitive domains, the focus of this studywas language. Although both tests assess language,there are major differences between the tasks con-tributing to this domain.

Identification of prognostic indicators for languageimpairment would be useful to define a sub-group ofpatients post-TBI who would benefit from a cogni-tive communication assessment. In previous studies,predictive factors for language impairment followinga TBI have been variable. The GCS score, educationlevel and to a lesser extent age were significantfactors in predicting language deficits in a study byLeBlanc et al. [11]. This study used a battery ofscreening tests to assess for language impairmentspost-TBI of all severity in the acute setting. A brainlesion on CT was not a strong predictor in this study.Lee et al. [7] also found that changes on CT and

Assessment of cognitive communication 235

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MRI brain scans did not account for cognitiveimpairment in the mild TBI population.Conversely, Borgaro et al. [23] indicated thatpatients in a rehabilitation setting with mild TBI,who had changes on CT brain, performed signifi-cantly worse on speech and language sub-tests of aneuropsychological battery.

The primary aim of this study was to compare thelanguage scores of two assessments used to screencognitive function in participants who have a mildTBI. A secondary aim was to examine the relation-ship between findings of cognitive communicationdisorders to a range of prognostic indicators includ-ing age, gender, mechanism of injury, education,evidence of LOC, new traumatic abnormalities onCT brain imaging, neurosurgical intervention andthe presence of PTA. A better understanding ofthese factors would improve clinical care and prac-tice in the acute setting.

Method

Participants

A total of 83 participants were included in the study.These were recruited from consecutive admissions toThe Alfred’s acute trauma centre and the neurosur-gery unit. Twelve weeks of prospective data werecollected between 1 March and 31 May 2009. Ethicsapproval was gained through The Alfred EthicsCommittee and all participants gave informedconsent.

All participants had a recent history of traumato the head and at least one of the followingindicators: (1) new traumatic changes on theinitial CT scan as reported by a radiologist, (2)a period of LOC (3) loss of memory for eventsimmediately before or after the injury and (4) analteration in mental state at the time of injury,such as feeling dazed, disorientated or confused.This was quantified by diminished GCS between13–14 on admission to the EmergencyDepartment. Those participants who had beenconsidered to be in PTA were included in thestudy only when they were no longer in PTA asmeasured by the daily Westmead PTA scale [24].Participants were not assessed until they were alertand, when applicable, had ceased intravenousopiate-based pain relief.

Participants were excluded from the study if theyhad a history of previous head injury, psychosis orneurological deficit, were chronic drug and alcoholabusers or were younger than 16 years of age.Participants with English as a second language wereexcluded from the study.

Measures

Relevant demographic information and history ofpresenting injuries were collected using the hospitalmedical record and self, family or significant otherreport on admission. This information includedGCS on admission, age, gender, mechanism ofinjury, education and report of LOC. Evidence ofnew traumatic abnormalities on CT brain imaging,neurosurgical intervention and emergence from PTAwas collected from the medical record at the time ofassessment.

The two standardized assessments, the Cognistatand the CLQT, were administered. Language func-tion was measured using language sub-tests of thetwo assessments. Anyone who did not score withinnormal limits on either test was considered to beimpaired.

Cognistat. The Cognistat has eight scored tasks thatcontribute five cognitive domains. Normative datawere collected on 119 participants without relevantmedical and neurological problems and on30 neurosurgical participants with documentedbrain lesions. The mean scores on all sub-tests forthe neurosurgical group were reported to fall belowthe scores of the non-clinical participants, althoughthe statistical significance of these differenceswas not reported. It is of interest to note that,although the average scores for the language domainwere lower than non-clinical participants, they werewithin normal limits according to the test’s scores.The score for the language domain is calculated bysumming the scores for the comprehension, repeti-tion and naming tasks. Although the Cognistat has ascreening question for each sub-test, the completeassessment was administered for the purpose of thisstudy. This enabled scores from the languagedomain to be compared across both assessments.

CLQT. The CLQT has 10 tasks that contribute tofive cognitive domains. In its development twomatched groups (28 clinical and 64 non clinicalparticipants) were compared. The clinical group hadthe following diagnoses: closed head injury, leftCVA, right CVA, bilateral CVA and Alzheimer’sdisease.

The CLQT underwent more extensive validationand reliability studies in comparison to the Cognistat.These studies established different functional levelsfor two age groups, severity ratings for each of thedomains and inter-scorer agreement. Although TBIparticipants were included in its development, nospecific studies evaluating its use within the mild TBIpopulation have been published. The score for thelanguage domain is calculated by summing the scores

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for; personal facts, confrontation naming, storyretelling and generative naming. Table I summarizesthe tasks involved in the language sub-tests of bothassessments.

Procedure

The Cognistat was administered by qualifiedOccupational Therapists and the CLQT by qualifiedSpeech Pathologists. All the clinicians were experi-enced in assessing patients within the Trauma andNeurosurgery Units at The Alfred. The standardizedmethods of administration and scoring for both testswere followed.

The two assessments were completed indepen-dently of each other and the scores and testresponses were not viewed by clinicians untilboth assessments were completed. The Cognistatand CLQT were administered to all participantswithin 48 hours of one another. Participantswere assessed on average 4.4 days post-injury;median 2 days, interquartile range 1–5. The orderof administration was alternated to reduce assess-ment bias. The assessments were completed at theparticipants’ bedside, replicating the usual clinicalsetting.

Statistical analysis

All data were analysed using SAS version 9.2 (SASInstitute, Cary, NC). Comparison of impairment onthe CLQT and the Cognistat language domains wasperformed using the McNemar’s test. A two-sidedp-value of 0.05 was considered statistically signifi-cant. Participant characteristics and clinical factorswere compared between impaired and non-impairedgroups using the Student’s t-test for normallydistributed data and Mann-Whitney U-test forskewed data. Differences in proportions betweengroups were compared using the chi-square test forequal proportion or Fisher’s exact test where num-bers were small.

Results

Participant characteristics

The language subtests were completed in 83 partic-ipants. The participant characteristics were col-lected. These are summarized in Table II.

Comparison of the Cognistat and CLQT

language results

There were significant differences in resultsobtained between the CLQT and Cognistat for the

Table I. Details of the language subtests of the Cognistat and the CLQT.

Sub-test Cognistat CLQT

Confrontation Naming

CLQT–‘Confrontation naming’Cognistat–‘Naming’

The patient is required to name simpleblack and white drawings of eightpictures.

The patient is required to name simpleblack and white drawings of 10pictures.

Generative Naming

CLQT–‘Generative Naming’ Not included in assessment The patient is required to retrieve andname as many animals and wordsbeginning with the letter ‘M’ as theycan in 1 minute.

Personal Facts

CLQT–‘Personal Facts’Cognistat–‘Orientation’

Included in assessment but does notcontribute to the language score.

The patient is required to answer fourquestions relating to date and place ofbirth, current age and address.

Repetition

Cognistat–‘Repetition’ The patient repeats phrases and sen-tences after oral presentation by theexaminer.

Not included in assessment.

Comprehension

CLQT–‘Story Retelling’Cognistat–‘Comprehension’

The patient is required to follow sixdifferent commands, involving one,two and three steps, using objectsplaced in front of them.

The patient is initially required to recall ashort story after it has been read aloudby the examiner. The patient is thenrequired to answer yes/no questionsabout the story.

Spontaneous Speech Sample

Cognistat–‘Speech Sample’ Examination of qualitative aspects ofspeech in response to a black andwhite line drawing is included but noscore is given.

Not included in assessment.

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language domain. The CLQT mean score was 31.1(SD¼ 2.8, median¼31, range¼ 25–37). A scorebelow or equal to 28 is considered impaired for the18–69 years age group or 27 for the 70–89 years agegroup. The Cognistat mean score was 25.2(SD¼ 1.6, median¼26, range¼ 15–26). A languagescore below or equal to 20 is considered impaired.One participant was identified as impaired on bothassessments, whilst a further 15 participants wereidentified as having an impairment on the CLQT.All 16 were mildly impaired according to the CLQTseverity ratings. This difference was statisticallysignificant (McNemar test statistic¼15.0;p< 0.001). This is presented in Table III.

Identification of language impairment on the CLQT

The CLQT identified 19.3% of participants (n¼16)as having impaired language. The generative namingand story retelling sub-tests of the CLQT were the

tasks more likely to detect impairment. These resultsare presented in Table IV.

Prognostic indicators

An analysis, comparing impaired and non-impairedgroups to determine if any of the factors wereassociated with participant performance on theCLQT assessments, was completed. This foundthat age, gender, mechanism of injury, education,evidence of LOC, diminished GCS, new traumaticabnormalities on CT brain imaging, neurosurgicalintervention and PTA were not predictive of theresults of language sub-tests. There were insufficientnumbers with impairment to complete this analysison the Cognistat.

Discussion

The goal of this project was to compare the rate ofdetection of high level cognitive communicationdeficits in the TBI population in the acute setting.Two standardized assessments were used. Thisstudy determined that more participants were iden-tified as having language impairment on the CLQT(19.3%) in comparison to the Cognistat (1.2%).These results supported the anecdotal reports of theunder-identification of cognitive communicationimpairments when only the Cognistat was used asa screening tool. This is of particular relevance toclinicians because the Cognistat is often used inclinical practice to identify those with languageimpairment. Prior to this study, Speech Pathology

Table II. Characteristics of participants (n¼83).

Characteristics M SD n %

Age (years) 35.3 16.7Gender

Male 67 80.7Female 16 19.3

Education level achievedSecondary school level 41 50.0Tertiary level 15 18.3Trade qualification 26 31.7

Vocational status/Employment statusFull time 45 54.2Part time 9 10.9Students 7 8.4Other (home duties,

retired,unemployed,receivingDepartmentof HumanServicesbenefits (welfare))

22 26.5

Mechanism of injuryMotor vehicle accident 27 32.5Assault 15 18.1Motor bike accident 17 20.5Fall 13 15.7Cyclist accident 7 8.4Falling objects 4 4.8

Known LOC 70 84.3New traumatic

abnormalities onCT brain imaging

28 33.7

Presence of PTAbeforeparticipation in study

4 4.8

Neurosurgery ‘yes’ 3 3.6

Table III. A comparison of impairment on the languagedomains of the Cognistat and CLQT (n¼ 83).

CLQT

Cognistat

TotalImpaired Within normal limits

Impaired 1 15 16Within normal limits 0 67 67

Total 1 82 83

Table IV. Individual language sub-test results of the CLQT.

Sub-test

Withinnormallimits Impaired

Confrontation naming 82 1Generative naming 72 11Personal facts 82 1Story retelling 65 18

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assessment at The Alfred was dependent on referralfollowing the Cognistat assessment.

The significant difference in the detection ofcognitive communication problems found in thisstudy appears to be related in the level of complexityof the language sub-tests. The CLQT is moredemanding in terms of language comprehensionand verbal production skills. The comprehensionscore of the Cognistat is based on the ability tofollow 1–3 stage commands. Whilst the comprehen-sion task in the CLQT requires the participant torecall a short story and to then answer a series of yes/no questions about the story. The main difference inthe naming tasks between the two tests is theaddition of a generative naming sub-test in theCLQT. This task draws on verbal language skills,relating to semantic and phonological knowledge.

In the absence of a gold standard screeningassessment in the acute setting, clinicians need toremain aware that there may be an over- or under-identification of problems with these brief assess-ments. The Cognistat sub-tests were completed intheir entirety during the study, rather than relying ona single screening item to reduce the probability ofoverlooking cognitive deficits. It is possible thateither assessment may identify false positives. Thevalidity of the assessment results needs to beestablished. A longitudinal study examining theresolution of high level cognitive communicationdifficulties from the acute phase to 1 year post-injuryis recommended to evaluate the impact of impair-ments identified in the acute phase over time. Thiswould involve an examination of the actual impair-ment experienced by a participant including theirrestrictions in daily activity.

There were three discharge outcomes for theparticipants in this study. The largest group ofparticipants (60.4%) returned home without follow-up. A further 21.6% went home and receivedcommunity-based Speech Pathology and 18.0%were discharged to rehabilitation.

Although an objective of this study was to identifyfactors related to language impairment in order toreduce the need for extensive screening of patients,no associated factors were found. The results of thisstudy were consistent with the variable nature ofassociated factors with language function reported inthe literature [9]. This study differs from Le Blancet al.’s [11] study, which used a battery of screeningtests to assess for language impairments post-TBI inthe acute setting. They found that GCS score, ageand education level were significant factors inpredicting language deficits. However, Le Blancet al.’s study included a range of TBI severity asmeasured by GCS, possibly indicating that thosewith a more severe brain injury are more likely tohave language impairment. Borgaro et al. [23]

reported that patients who had changes on CTbrain performed significantly worse on speech andlanguage sub-tests when assessed using a neuropsy-chological battery. In contrast, Lee et al. [7] foundthat changes on the CT and MRI brain did notaccount for performance on verbal learning andmemory tasks in the mild TBI population. Thefindings of this research are consistent with Leeet al.’s study. This may be because a mild TBIpopulation was used in both studies.

It is important to acknowledge that there are somelimitations of the study. These include small samplesizes for some variables (CT brain changes n¼28,neurosurgical intervention n¼3, PTA n¼ 4) and theinclusion of participants aged 16–17 years (n¼ 7).Whilst this represents current clinical practice thetests were not standardized for use in thispopulation.

The participants in this study were comparable tothose in other studies in terms of gender, mean ageand mechanism of injury [2, 6, 7]. Most of themwere living independently and actively involved inthe workforce and/or study. This provides supportfor the need for further assessment and, whereappropriate, rehabilitation post-mild TBI.

Speech Pathologists and Occupational Therapistsin the acute setting are required to efficiently andeffectively identify high level cognitive and commu-nication deficits in order to facilitate dischargeplanning and appropriate referrals to rehabilitationfacilities. The CLQT was quick to administer andthe language tasks were appropriate for this clinicalpopulation. Language and communication impair-ments can cause significant problems in the short-and long-term, so the identification of these and theprovision of appropriate rehabilitation will enablepatients to benefit from early intervention and willassist patients to achieve their potential.

This study supported the contention that currentpractice was unreliable in identifying high levelcognitive communication problems in the acuteTBI population and highlights a need to furtherinvestigate the results of this study; in particular howthese results relate to long-term outcomes. Theclinical practice at this facility was typical of otheracute settings. Therefore, in the absence of associ-ated predictive factors, the need for screening forlanguage impairments by a Speech Pathologistshould be considered, with the aim of improvingdetection of high level cognitive communicationdeficits in the acute setting.

Acknowledgements

The authors thank the participants who participatedin the study and staff of the Speech Pathology and

Assessment of cognitive communication 239

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Occupational Therapy Departments at The Alfred,particularly Michelle Farquhar and RebeccaTwigley.

Declaration of Interest: This research was fundedby the Royal Automobile Club of Victoria with theSir Edmund Herring Scholarship.

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