For the comprehensive list of articles on today’s post, please see the PubMed search, Neuropsychological Assessment for Dementia.
In this post, I link to and excerpt from Practical Neurology‘s A Primer in Neuropsychological Assessment for Dementia, JULY/AUGUST 2016.
All that follows is from the above resource.
Neuropsychological assessments are designed to identify the extent and severity of a patient’s cognitive and behavioral impairments. They allow us to determine a pattern of relative cognitive strengths and weaknesses, which indirectly yields information about the structural and functional integrity of a patient’s brain. Neuropsychologists use standardized tests to evaluate cognitive abilities such as attention, memory, language, processing speed, visuospatial, and executive functions.1 These types of comprehensive assessments are time-consuming and not always feasible or necessary in routine clinical practice. For neurologists, brief cognitive screening tasks can provide a quick estimate of a patient’s cognitive function and identify those who would benefit from a more detailed cognitive evaluation.
Commonly used cognitive screening tools include the Mini-Mental Status Examination (MMSE)2 and the Montreal Cognitive Assessment (MoCA).3 The MMSE is heavily weighed towards orientation and memory, and, as such, may be insensitive to cognitive deficits encountered in non-Alzheimer’s disease dementias. The MoCA evaluates a broader range of cognitive abilities, thereby providing higher sensitivity to detect mild cognitive impairment.4 Slightly longer and more comprehensive screening tools such as the Addenbrooke’s Cognitive Examination,5 Dementia Rating Scale,6 and the Philadelphia Brief Assessment of Cognition7 can be particularly helpful in differential diagnosis given their inclusion of additional cognitive and behavioral domains.
Despite the utility of general cognitive screening instruments, these may not be adequate for all patients. In fact, common cognitive screening tools may have poor sensitivity in highly educated individuals, or classify healthy subjects as impaired given their low educational attainment, primary language, or cultural background.
Best Uses for Neuropsychological Evaluations
Neuropsychological evaluations can be used to address or clarify a wide range of issues related to dementia. These include:
- Differential diagnosis: A patient’s cognitive profile can help differentiate normal aging from MCI, neurodegenerative disorders from reversible causes of cognitive complaints (e.g. depression), and can aid in the differential diagnosis of dementia due to different etiologies (e.g. Alzheimer’s disease (AD) versus Frontotemporal dementia (FTD)).8,9
- Longitudinal progression: Cognitive assessments can provide a baseline to track progression of disease or to document the effects of medications or behavioral interventions.
- Prediction of conversion to dementia: Impairments in neuropsychological tests can be predictive biomarkers of progression to AD and other dementias.10,11
- Function: A thorough cognitive and functional assessment can reveal areas of daily functioning where the patient may need assistance (e.g., remembering appointments, medications, etc.).12 These results can guide intervention strategies to ameliorate cognitive deficits and maximize independence (e.g., referral to speech therapy, use of day planners, assistive technologies).
- Competence: Performance on neuropsychological tests can aid clinicians and families determine a patient’s competence in areas such as driving, medical, financial and legal decision-making.
- Research: Quantifying behavior and cognition allows us to correlate patient scores to structural and functional images of the brain, thereby providing insights into the brain networks involved in particular functions. Cognitive tests are also used as sensitive outcome measures in clinical trials for disease modifying agents.
Formal Neuropsychological Assessments
A formal neuropsychological assessment for dementia will usually evaluate the following domains: [In the article, review each section below for details.]
Attention and Processing Speed.
Memory.
Visuospatial and constructional abilities.
Language.
Executive functions.
Mood and Behavior.
Conclusion
Neuropsychological assessments can be extremely useful in the detection, diagnosis, and management of dementia syndromes. A patient’s cognitive profile can help differentiate normal aging from MCI and can aid in the differential diagnosis of dementia due to different etiologies. Cognitive assessments can also provide a baseline to track progression of disease or to document the effects of medications or behavioral interventions. Finally, performance on neuropsychological tests can reveal areas of daily functioning where the patient may need assistance, thus guiding intervention strategies to ameliorate cognitive deficits and maximize independence. n
Katya Rascovsky, PhD is a Research Assistant Professor in the Department of Neurology and Frontotemporal Degeneration Center at the University of Pennsylvania School of Medicine in Philadelphia, PA.
