Formal assessment of cognition
Clinical neuropsychological assessment is the gold standard with respect to formally evaluating and documenting the nature and severity of cognitive impairment.
Clinical neuropsychological assessment is the gold standard with respect to formally evaluating and documenting the nature and severity of cognitive impairment, together with the relevant behavioural, emotional and psychosocial factors that may be contributing to a clinical profile.
Formal neuropsychological assessment is very time consuming, with the typical assessment lasting 3-4 hours. Included in the assessment is a detailed clinical interview with the person and often, additionally, with a family member, carer or care worker. The clinical history from the interview and any available case notes, medical records or previous medical and psychological reports may assist the clinician to generate hypotheses about the potential causes of cognitive impairment.
The remainder of the assessment time is spent administering standardised tests and questionnaires that comprehensively sample all domains of cognition. The skill of the neuropsychologist is in bringing together the history, test results and client presentation to formulate an opinion about the cause and nature of their cognitive impairments. From this platform, the neuropsychologist can make recommendations about prognosis, treatment and management.
Psychometric versus neuropsychological assessment
Psychometric assessment involves test administration. Neuropsychological assessment involves test administration, behavioural observation and integration of available history.
It's often thought that neuropsychologists only administer tests and arrive at their conclusions based purely on test results. This is an inaccurate perspective, as many tests have inherent sources of error, meaning test variability is the norm. There's no single test that can rule in or out a diagnosis of cognitive impairment, because of the various factors that contribute to a test score. Neuropsychologists are trained in test interpretation to derive the greatest meaning from test scores in an individual's psychosocial context.Back to top
A neuropsychologist is a psychologist who has completed specialist training in acquired brain injury. Neuropsychologists diagnose brain injury and can provide recommendations for ongoing care and rehabilitation needs (arbias 2011).
Contact the Brain Injury Association (BIA) NSW for information on how to access a neuropsychologist or assistance in accessing a neuropsychologist in NSW. BIA NSW also administers a brokerage program to support people to access neuropsychological services. Contact them on1800 802 840 or visit www.biansw.org.au.
What factors are assessed?
The average neuropsychological assessment involves administering a large number of separate tests (often over 20). Although most tests are multifactorial in what they assess, the following skills within each of the main domains are assessed in a standard neuropsychological assessment:
- Attention span
- Focused attention
- Sustained attention
- Divided attention
- Complex attention (e.g. working memory)
- Basic visual and sensory perception and integration
- Motor skills
- Constructional skills
- Immediate memory
- Delayed memory
- Verbal memory
- Visual memory
- Encoding, storage and retrieval
- Mental flexibility
- Abstract reasoning (verbal and visual)
- Impulse control/inhibition
Various programs and services have used a three-tiered pathway to identify cognitive impairment and/or diagnose neurocognitive disorders (e.g. Robben et al 2010). Such a process is cost effective because only people with self-reported cognitive difficulties proceed to cognitive screening tests, and only those identified as impaired on cognitive screening tests proceed to full neuropsychological assessment if required. The process is shown in the following figure.
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Case study: Sam
Sam was referred to ABC Drug and Alcohol Service. On intake he completed the Cognitive Failures Questionnaire, upon which he indicated difficulties such as losing his temper, forgetting where items are placed and becoming distracted with other things after starting a task; his total score was 80/100.
As such, the MoCA was administered and he scored 22/30. He experienced particular difficulty in the Visuo-spatial/Executive, Attention and Delayed Recall sections. There was a long waiting list for neuropsychological assessment but, based on phone consultation with a local neuropsychologist, a number of practical strategies were implemented at the service. These included minimisation of distractions, encouragement to work on only one thing at a time, establishing routine times for regular activities (e.g. shower, meals, and appointments), maintenance of a tidy and well-organised environment and the provision of prompts and cues to aid recall.
When Sam was seen for his neuropsychological assessment three months later, he was found to demonstrate a cognitive profile consistent with moderate traumatic brain injury, which he had sustained in an assault five years earlier. Following neuropsychological assessment, Sam was given psychoeducation about the effects of the brain injury, and a range of cognitive compensatory strategies were suggested, modelled and employed. His case worker from ABC Drug and Alcohol Service sat in on the feedback session and was able to implement these strategies in the treatment setting and afterward, when receiving follow-up in the community when working with Sam.
As a result, Sam was better able to consistently attend appointments, bring with him the required materials, understand the content of interventions (through assertively asking the speaker to repeat or re-explain new concepts in more concrete terms and with examples), and to complete the program. Sam was also given strategies to help manage escalations in anger. He and his case worker developed a non-verbal sign to indicate rising agitation, and Sam was able to walk away at these times and return when he felt more relaxed.Back to top
Find out more
arbias, Brain Foundation Victoria, Headway Victoria (2005) Your Guide to Neuropsychological Assessment, arbias, Brain Foundation Victoria, Headway Victoria.
NADA (Network of Alcohol and Drug Agencies) (2013b) Brief Guide to Cognitive Impairment Screening and Assessment Tools, NADA: Sydney.Back to top