Submitted by Gerald Showalter, Psy.D, Valley MedPsych
According to CDC estimates, approximately 5 million Americans were living with Alzheimer’s disease in 2014. This number is projected to almost triple to approximately 14 million Americans by 2060. Although it is the most common form of dementia, Alzheimer’s is just one of an array of neurodegenerative diseases and conditions for which appropriate screening, evaluation and early and accurate diagnosis can be essential in helping clinicians respond effectively to the needs of the patients and families affected by these conditions.
There are several advantages to using screening tools for cognitive change or impairment, whether in primary care, neurology, or other specialty settings. Such tools typically require limited administration time, may help to facilitate early identification of patients at potentially high risk for a specific condition or disorder, and may serve as an impetus for more comprehensive examination or as a baseline measure to monitor for change in functioning over time. Screening tools such as the MMSE or MOCA can also be administered as part of a routine clinical visit and may help to satisfy requirements for cognitive screening as set forth under the 2010 ACA. However, screening measures are not definitively diagnostic or conclusive as to the presence of a specific condition or disorder. In fact, in a 2014 study, Chan and colleagues found that among a sample of stroke patients, 78% of those who were classified as cognitively intact by the MOCA actually demonstrated impaired cognitive functioning within one or more cognitive domains. It has also been observed that misclassification of cognitive functioning increases when relying on individual cognitive domains of the MOCA. Moafmashhadi and Koski found in a 2012 study that individual cognitive domain scores on the MOCA were poor predictors of actual impairment in corresponding functional skill areas on more comprehensive neuropsychological testing. Such limitations in classification accuracy were perceived as likely due to restricted range of scores, ceiling effects and the non-measurement of other relevant areas of cognitive functioning such as intellectual efficiency, processing speed and visual memory. It has been noted elsewhere that the sensitivity of screening measures is limited (Olson and colleagues, 2011), and that clinicians should, therefore, also consider other clinical findings and associated risk factors in determining the need for referral for more comprehensive neuropsychological assessment.
Just as there are various advantages to the use of cognitive screening measures, there are clear benefits to more comprehensive neuropsychological assessment for certain patients. Such assessments can provide a more comprehensive clinical picture of the patient, and may help to clarify the individuals functioning across multiple cognitive and functional domains. Such assessments can also help to identify psychological problems and conditions, clarify their severity, and provide recommendations for treatment. The comprehensive neuropsychological assessment also integrates results from multiple psychological measures with information gleaned from clinical interviews, behavioral observations, record reviews and other collateral information, and may cover multiple domains of functioning such as language, memory, visuospatial and verbal problem solving, executive functioning, adaptive functioning, psychological/emotional functioning, capacity for self-care, and other functional domains relevant to referral questions posed.
In 2017, the National Academy of Neuropsychology published a proposed integrative process for the use of cognitive screening tests and comprehensive neuropsychological assessments. This model was intended to illustrate how the routine use of cognitive screening tests might assist medical providers in determining which patients might benefit from more comprehensive neuropsychological assessment. Importantly, the authors of this model emphasize that the model should not be interpreted to mean that screening tests must always precede referral for comprehensive evaluations, as direct referral for neuropsychological evaluation may be more appropriate when the presence of cognitive impairment is already established or highly suspected, and when further medical decision-making might benefit from the diagnostic clarity and/or delineation of more specific performance levels and patterns provided by the more comprehensive evaluation. The proposed practice model is presented below.
Valley MedPsych (VMP) is a local practice affiliated with Augusta Medical Group and Augusta Care Partners offering clinical psychology and neuropsychology services with offices in Waynesboro and Harrisonburg. There are two clinical neuropsychologists as well as several other psychologists and counselors affiliated with this practice. Referrals can be made by fax at 540-932-8551 or by contacting the office by phone at 540-221-1846. Additional information is available on the VMP website.
Chan et al. (2014). Underestimation of cognitive impairments by the Montréal cognitive assessment (MOCA) in an acute stroke unit population. Journal of the Neurological Sciences, 343, 176-179.
Moafmashhadi, P., & Koski, L. (2012). Limitations for interpreting failure on individual subtests of the Montréal cognitive assessment. Journal of Geriatric Psychiatry, 26, 19-28.
Olson et al. (2011). Prospective comparison of two cognitive screening tests: Diagnostic accuracy and correlation with community integration and quality of life. Journal of Neurooncology, 105, the 37-344.
Roebuck-Spencer et al. (2017). Cognitive screening tests versus comprehensive neuropsychological test batteries: a National Academy of Neuropsychology education paper. Archives of Clinical Neuropsychology, 32, 491–498.