Abstract
BACKGROUND:
The utility of neuropsychology in the treatment and evaluation of neuropsychological disorders and neurodegenerative diseases is supported by scientific study. As a discipline, neuropsychology’s value and efficacy when applied to the dementia spectrum are rooted in its inherent adaptability as a practical, cost-effective, and scientifically based resource for differential diagnosis, treatment planning, and forensic decision making.
OBJECTIVES:
This article provides a framework for conceptualizing dementia as a spectrum of disorders and outlines a rationale for preferential reliance upon neuropsychological tenets. The function of neuropsychology in differential diagnosis, clinical management, integrative care, and forensic applications is delineated for use as a contemporary interdisciplinary reference.
METHODOLOGY:
An overview of the literature on dementia as a spectrum of disorders has been integrated with the science and practice of neuropsychology.
CONCLUSIONS:
The utility of neuropsychology emanates from its focus on brain functioning and the discipline’s appreciation for the relationship between brain functioning and cognition, mental state, and behavior. Early and routine referral for neuropsychological assessment allows for the objective determination of normal versus abnormal neurocognitive functioning, provides a baseline for serial reassessment, and leads to the more rapid deployment of effective treatments. Beyond the hospital and clinic, neuropsychological expertise is increasingly sought after as integral to the legal system when decisions regarding eligibility for long term care and questions about capacity require objective and reliable measurement.
Keywords
Introduction
The utility of neuropsychology in the treatment and evaluation of neuropsychological conditions and neurodegenerative diseases is supported by scientific study (APA, 2017; APA 2018; Smith 2018; Weintraub, Wicklund, & Salmon, 2012). As a subspecialty within the broader field of clinical psychology, neuropsychology embodies the integration of neuroscience with an intended clinical application. Neuropsychological tenets make it possible to quantify and qualify the effects of cerebral injury on cognitive, behavioral, emotional, occupational, and social functioning, thereby paving the way for effective interventions and treatment planning. These principles elucidate the nature of impairment and the recovery process. Moreover, these tenets facilitate explanation and understanding of the functional impact of progressive and non-progressive neurological disease on memory, attention, communication, and decision making (Schoenberg & Scott, 2011; Tuokko & Smart, 2018).
Neuropsychologists are trained to gather relevant information in a standardized manner and assess brain functioning by measuring cognitive performance, emotional states, and behavioral change. The examination data collected are used to hypothesize probabilities, diagnose, plan, and carry out treatments for individuals with neurological, physiological, and psychological disorders. Neuropsychological assessment can also provide an objective and standardized index of an individual’s capacity to understand risk and benefit and make reasoned medical, financial, and testamentary decisions. Eligibility for the release of long-term care benefits has become increasingly reliant upon independent medical and neuropsychological evaluations.
Features that characterize the utility of neuropsychology
Neuropsychologist as a specialist
A clinical neuropsychologist is a specialist with expertise in the applied science of brain and behavior relationships. Neuropsychologists undergo advanced training in the assessment of brain and behavioral relationships and in the treatment of a broad spectrum of mental health and neurological conditions that affect behavior, psychological well-being, cognitive functioning, and independence. Clinical neuropsychologists use this knowledge to assess, diagnose, and treat patients across the lifespan with neurological, medical, psychiatric, cognitive, and neurodegenerative conditions.
Training and board certification
Extensive doctoral-level training and licensure are required to provide neuropsychological and psychological assessment services. Specialization in neuropsychology requires additional proficiencies beyond clinical psychology (Hannay, Bieliauskas, Crosson, Hammeke, Hammsher, & Koffler, 1998). Although somewhat variable by country and for each state within the United States, the standard for independent practice as a clinical psychologist is a minimum of three to four years of graduate coursework in an accredited clinical psychology doctoral program, 1500 hours of practicum training, a one to two year, 40 hour per week internship with clinical supervision, a post-doctoral supervised residency of one to two years, and successful completion of the state licensing examination. Doctoral-level training in neuropsychology provides the foundation needed to administer and select the proper tests, interpret the performance of the examinee and measured change, assign meaning to the pattern and degree of change for a given individual, monitor changes, rule out other possible explanations for symptom complaints, and render a diagnosis. Board certification as a specialist or diplomate following licensure and residency is optional in neuropsychology as it is in medicine. Board Certification attests that the successful candidate completed the educational, training, and experiential requirements of the specialty; passed both a written and oral examination of competencies deemed necessary to provide quality services and has demonstrated the knowledge and skills deemed essential by a group of board-certified peers. The primary objective of the board certification process is to recognize, certify, and promote competence in the specialty and ensure the safeguarding of the consumer.
Neuropsychological assessment: Principles, methodology, and application
The tools and methodology used by neuropsychologists have broad scientific support (Ball, Stutts, Morgan, Peck & Sari, 2004; Miller, 2009). The combination of psychological, neurological, cognitive, behavioral, and neuroanatomical principles and techniques is used to evaluate neurocognitive status, specify strengths and liabilities, support diagnostic impressions, and formulate treatment recommendations. A neuropsychological assessment allows for improved accuracy and validity when coordinating patient care with primary care physicians, neurologists, interdisciplinary treatment teams, family, and residential caretakers.
Standardized and statistically-based methods make it possible to 1) compare individual performance to a higher level of premorbid functioning; 2) differentiate between normal versus impaired performance; 3) compare performance profiles to demographically adjusted norms of the same age, gender, race, and educational level; 4) conduct serial reevaluations to monitor disease progression; and 5) use results to inform treatment planning (Lezak, Howieson, Bigler, & Tranel, 2012; Schoenberg & Scott, 2011). Neuropsychological evaluations incorporate background history (viz., developmental, legal, medical, educational, occupational, psychiatric), behavioral observation, collateral interviews, and objective measurement (Wilson, Rous & Sopena, 2008). The process of assessing cognitive, emotional, and behavioral functioning is based upon the science of deficit measurement to quantify the degree and pattern of deficits, followed by the art of relating deficit patterns to neuroanatomy and identifying possible methods of remediation or compensation. Patterns of neurocognitive strength and areas of below-expected functioning characterize the integrity of the central nervous system for improved differential diagnosis. The combination of clinical evidence when correlated with biomarkers (e.g., protein tracers, amyloid plaques, cerebrospinal fluid, vascular damage), results of neuroimaging, and risk factors (age, family history of dementia, genetic variables) provides useful baseline data for serial referencing and multifactorial means to improve diagnostic accuracy (Hessena, Kirsebomc, Errksona, Elliassena & Naklingf, 2019). Neuropsychological analysis allows for the identification of relatively well-preserved functions that may be relied upon to compensate for specific cognitive deficits; educate family and caregivers; identify preferred techniques for improving attention, concentration, and memory.
Differential diagnosis within the dementia spectrum
Dementia is a neurological condition characterized as an abnormal decline in cognitive functioning. The term implies a collection of symptoms related to memory, language, and decision-making. Dementia is determined based on clinical evidence of impairment in two or more cognitive domains, in addition to social cognition (Albert, 2018). The dementia spectrum includes both progressive and reversible subtypes, a broad range of symptom presentations and causes, as well as varying degrees of deficit ranging from prodromal (early signs or symptoms which may forecast the onset of a disease before more diagnostically specific signs and symptoms develop) to more severe and advanced stages of the disease. Dementia and Alzheimer’s disease (AD) are not the same.
Subtype prevalence
Alzheimer’s disease (AD) is the most common form of dementia (Global Health and Aging, 2010). It accounts for between two-fifths and four-fifths of all dementia cases (Organization for Economic Cooperation and Development, OECD, 2018). The OECD has estimated the worldwide number of people living with AD to be between 27 million and 36 million. This currently fatal disease affects more than 15000 individuals per million people. Global studies have estimated that by the time a person reaches age 65, there is a one in nine likelihood of receiving a diagnosis within the dementia spectrum. In the OECD review, dementia was found to affect fewer than 3 percent of those aged 65 to 69, with prevalence rates escalating to almost 30 percent for those aged 85 to 89. More than one-half of women aged 90 or older have been diagnosed with dementia in France and Germany compared to about 40 percent in the United States, and just under 30 percent in Spain (Global Health and Aging, 2012).
Roughly one half of the 5.4 million diagnosed with Alzheimer’s disease in the United States alone have pure AD, and the remaining have mixed dementias (OECD, 2018). The most common types of non-AD are vascular dementia (VaD), Lewy body dementia (LBD), and frontotemporal dementia (FTD) (Heilman & Valenstein, 2003; Tuokko & Smart, 2018). Different etiologies within the dementia spectrum produce different neuropsychological and behavioral profiles. Progressive dementias such as Alzheimer’s disease, Lewy body dementia, and frontotemporal dementia are known to gradually weaken an individual’s ability to perform activities of daily functioning and increase reliance upon others for assistance (Albert, 2018). Other progressive neurodegenerative diseases that impact cognitive functioning include Creutzfeldt-Jacob disease, Chronic Traumatic Encephalopathy, and Parkinsonian and non-parkinsonian motor disorders with dementia (e.g., Amyotrophic Lateral Sclerosis, Cortical ganglionic degeneration). These less prevalent causes of progressive neurocognitive decline are not explicitly addressed in this article to emphasize the more common subtypes but are noted because of their unique characteristics and to highlight the importance of considering alternate etiologies when formulating impressions and improving diagnostic precision.
Distinguishing normalcy, pathology and subtype
At its most basic level, differential diagnosis involves the determination of normal versus abnormal cognitive functioning and rules out psychiatric and behavioral etiologies that warrant further assessment or treatment. The type of dementia may be hypothesized or determined based on evidence of hallmark features such as the presence of visual hallucinations, movement disorder, pattern of memory decline, and prominent family history. Diagnostic determination can lead to better care, more precise treatment interventions, reality-driven family education, prioritization of clinical interventions, and earlier identification of potentially reversible causes of cognitive impairment (Heilman & Valenstein, 2003).
The Alzheimer’s Association (2019) distinguishes between healthy, age-related memory changes and those that warrant evaluation. A diagnostic evaluation is recommended when there is indication of 1) memory loss that disrupts daily life; 2) compromised planning and problem-solving; 3) difficulty with familiar tasks at home, work or leisure; 4) confusion with time or place; 5) trouble understanding visual images and spatial relationships; 6) new problems finding words in speaking or writing; 7) misplacing things and losing the ability to retrace steps; 8) decreased or poor judgment; 9) withdrawal from work or social activities; 10) changes in mood and personality (alz.org/10signs). Alzheimer’s pathology begins to develop before cognitive symptoms become apparent in daily living. Neuropathology becomes increasingly apparent when enough neuronal loss in selected brain regions amasses to disrupt critical brain networks (Albert 2018; Weintraub et al. 2012). Early identification of cognitive impairment makes it possible to identify individuals who are at higher risk for a decline and who are likely to benefit from preemptive treatments. Early intervention techniques such as diet, exercise, and medical treatments can be initiated and serve as potentially protective measures.
A neuropsychological evaluation measures neurocognitive functioning, establishes if brain dysfunction is present, quantifies the degree and pattern of the deficits, applies findings to established neuropsychological criteria, and uses this information to differentiate one dementia subtype from another (Weintraub, Wickland, & Salmon 2012). The emergent performance profiles are used to help distinguish between cortical versus subcortical cerebral dysfunction or mixed presentations and, more importantly, facilitate diagnostic accuracy and identify potentially reversible conditions in need of immediate treatment (APA 2019; Mendez & Cummings, 2003).
Careful clinical interview and record review combined with standardized neuropsychological tests can 1) lead to a determination of most likely etiology, 2) identify potentially reversible conditions, and 3) identify other possible explanations of diminished cognitive performance that merit further study and specific treatment. For example, potentially reversible causes or conditions that have cognitive effects can be identified for further evaluation and referred for corrective interventions. Treatable conditions that may be mistaken for early dementia include sleep disorder, vitamin deficiency, persistent pain, possible autoimmune disease, infection, alcohol abuse, mood disorder, or other psychiatric condition.
Specific causes of reversible dementia include, among others, an underactive thyroid gland (hypothyroidism); vitamin A, C, D, B12 deficiency; heavy-metal poisoning, such as lead; side effects from medicines or drug interactions; environmental toxic exposure (mold, carbon monoxide, household chemicals, certain brain tumors; normal-pressure hydrocephalus; some cases of chronic alcoholism and substance abuse; some cases of encephalitis; HIV/AIDS; and nutritional deficiencies. Identification of and attention to reversible causes of cognitive and behavioral impairment is necessary to discerning etiology. Potentially reversible dementias should be identified, and treatment considered, even if the symptoms are not sufficiently severe to meet the clinical criteria for dementia, and despite the fact that partial or full reversal of the cognitive symptoms cannot be guaranteed (Tripathi & Vibha (2009).
Recent data indicate that the three most frequently observed potentially reversible conditions in patients with cognitive impairment or dementia are depression, adverse medication effects, and drug or alcohol abuse. Depression is by far the most common of the potentially reversible conditions (Bello & Shultz, 2011). Neuropsychologists are clinical psychologists by training. Accordingly, the psychological treatment of depression, drug, and alcohol abuse is a familiar and logical extension of services and are amenable to psychological interventions such as 1) cognitive-behavioral therapy, 2) psychoeducation, 3) cognitive and behavioral modification of self-defeating, impulsive, and unhealthy habits, 4) specific environmental changes, 5) family education, 6) care coordination, and 7) referral for community-based resources. The systematic and routine assessment of psychological status should focus on confounding comorbidities such as anxiety, depression, other psychiatric or personality disorders (Kogan, Edelstein, & McKee, 2000), chronic pain, fears and phobias, sleep disturbance, psychotic disturbance or delirium. Any one of these problems can have a significant impact on daily functioning and treatment outcomes, and as such, warrant intervention.
Different types of dementia require different medications and treatment priorities making timely and accurate assessments essential. For example, drugs with anticholinergic properties can worsen cognition and increase hallucinations in patients with Lewy Body Dementia (HCFA Guidelines for Potentially Inappropriate Medications in the Elderly, 2019). The Beers’ criteria are an excellent reference for healthcare providers when assessing for potentially correctible or alternate reasons for symptom complaints and identifying medication side effects and contraindications. The Beers’ recommendations represent the consensus of an expert panel of geriatric specialists (Journal of the American Geriatric Society, 2019).
Determining diagnosis from deficit performance patterns
The most used criteria for diagnosing Alzheimer’s disease are those developed by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s disease and Related Disorders Association (NINCDS-ADRDA). The NINCDS-ADRDA criteria require neuropsychological testing to confirm impairment (Blacker, Albert, Bassett, Harrell. Folstein,1994; Cox, 2011). The specific neuropsychological hallmarks of AD and the typical order by which they emerge have been studied (Weintraub et al., 2012). In dementia of the Alzheimer’s type, memory impairment and dyssomnia are two of the earliest cognitive symptoms, and both lend themselves to repeated measurement (Welsh, Butters, Hughes, Mohs, Heyman, 1991).
Objective neuropsychological assessment can determine the degree and pattern of cognitive dysfunction. An examination can also identify the type of memory loss, such as generalized or specific, episodic or semantic, immediate versus delayed, visual or verbal, and anterograde versus retrograde amnesia. The neuropsychologist can correlate patterns of impairment with known or associated neuroanatomical networks and specific regions of the brain. There are clinical characteristics that distinguish various dementias because of their association with vulnerable areas of the brain such as episodic versus semantic memory, phonemic versus category dysfluency, lateralized motor deficits, impaired olfaction, rapid forgetting, intrusion errors, and executive dysfunction ((Henry, Crawford, Phillips, 2005; Fuld, Katzman, Davies, Terry, 1982; Weintraub, Wickland, Salmon, 2012). For example, visual-spatial deficits are more prominent in DLB. The presence of visual hallucinations is the best predictor of DLB. The lack of visuospatial impairment is the best negative predictor (Tiraboschi, Salmon, Hansen, Hofstetter, Thal, Corey-Bloom, 2006).
Neuropsychological signs and symptoms vary, depending upon the part of the brain affected (Mendez et al. 2003: Smith, 2018). Initially, AD pathology is selective for limbic regions that subserve episodic memory. Over time, pathology spreads to other cortical regions causing further cognitive symptoms until a full dementia syndrome becomes evident. Other clinical hallmarks of AD include rapid forgetting (retention rate <50%) (Schoenberg & Scott, 2011), impaired recognition memory, intrusion errors, or a high frequency of false positive or false negative errors. Semantic fluency in AD has been touted as typically worse than phonemic fluency (Schoenberg & Duff, 2011), although a recent meta-analysis suggests that this disparity may not be as reliable a predictor as once thought (Laws, Duncan & Gale, in press).
Frontotemporal dementia (frontotemporal lobar degeneration) is an umbrella term for a diverse group of sequelae that result from changes to the frontal and temporal lobes of the brain. These neuroanatomical regions are generally associated with personality, behavior, memory, and language (Miller & Boeve, 2011). In frontotemporal dementia, portions of the frontal lobes shrink or atrophy. Significant personality changes are the earliest features of frontal lobe dementia (FTLD) frequently associated with Pick’s disease. Further subtype classification includes frontotemporal dementia, progressive nonfluent aphasia, and semantic dementia depending upon the type, sequence, and degree of symptom presentation.
Neuropsychological studies show that patients with vascular dementia have distinct characteristics. Vascular dementia is a cumulative decline in cognitive functioning due to multiple infarctions, ischemic injury, or hemorrhagic lesions within days or months of a stroke. The onset is sudden, and the course of cognitive deterioration is typically fluctuating with a stepwise progression (Mathias & Burke, 2009; Schoenberg & Scott, 2011; Weintraub et al., 2012).
Treatment planning based upon diagnosis
The diagnostic process may be highly focused on answering specific questions or more comprehensive, allowing for a broader analysis of cognitive, emotional, motor, and behavioral functioning. The results of a neuropsychological assessment are used to determine residual abilities, provide treatment recommendations to family and caretakers, identify non-pharmacological means to potentially modify the patient’s condition, and serve as guidelines for developing specific behavioral and psychosocial intervention programs. Neuropsychological performance on objective and standardized methods allows for the serial comparison and correlation of mental status and evidence of change against medical markers such as brain neuroimaging and laboratory testing. Multiple diagnostic comparisons from multiple sources of data enhance clinical accuracy (Nishant & Beretvas, 2018). As dementia progresses, the neuropsychological assessment allows for repeated measurement of general cognitive functioning, mood and mental status, amnesia, and specific phenomena such as agnosia, apraxia, and aphasia. Objective and systematic assessment of cognitive, behavioral, and emotional status by neuropsychological evaluation makes it possible to measure change or, more precisely, its rate, pattern, and degree. Regular reassessment illuminates the evolution of progressive neurological disease leading to diagnostic refinement, dementia staging, and subtype determination (Alpert, 2018; Begali & Jennett, 2014).
At the time of this publication, only two primary types of FDA-approved medications are available to potentially lessen the symptoms of Alzheimer’s disease, namely, cholinesterase inhibitors and an NMDA receptor antagonist (O’Brien, Holmes, Jones, Jones, & Livingston, 2017; Padilla, 2017). There is no current evidence to support any drug intervention that can reliably prevent or reverse dementia. However, a considerable effort toward the development and testing of various drugs and methodologies has been ongoing. Anticholinergic drugs block acetylcholine, a neurotransmitter needed for cognition, designed to keep open as many channels of communication among brain cells as possible. The first type of cholinesterase inhibitors designed to maintain healthy levels of acetylcholine includes brand names Aricept, Exelon, and Razadyne. Common side effects include loss of appetite, diarrhea, nausea, headache, and lowered heart rate. The second type of treatment, NMDA, memantine with brand name Namenda, has been formulated to target the effects of excess glutamate, which can cause further brain damage. The combination of cholinesterase inhibitors and memantine has been active in cases of mild to moderate Alzheimer’s disease and severe dementia (O’Brien et al., 2017).
Evidence based upon high-quality randomized trials or prospective studies, serial testing on consecutive patients, multiple study values, and systematic review of randomized control trials have led to the conclusion that neither cholinesterase inhibitors nor memantine are appropriate for frontotemporal dementia (O’Brien et al., 2017). When Lewy bodies found in individuals with Parkinson’s disease have already depleted acetylcholine, anticholinergic drugs may cause or increase confusion. First-generation antipsychotic medications, such as haloperidol (Haldol), are not recommended to treat Lewy body dementia because they can cause severe confusion, severe parkinsonism, sedation, and even death (American Geriatric Society, 2012, 2019). When medication is contraindicated or when no medication is available or recommended for psychosis, the family or caretaker must rely upon alternative treatments such as education and behavioral strategies to redirect attention or nullify the stimuli that seem to trigger hallucinations. For example, families can be advised to reduce clutter, redirect attention to something other than the delusion, reassure rather than argue, confirm that the family member experiencing hallucinations is safe and not in danger, and create as much structure as possible to reduce the potential for distress and ambiguity (Mendez & Cummings, 2003).
The National Academy of Neuropsychology convened an interorganizational Summit in Denver, Colorado, on population health solutions and the assessment of cognitive impairment in geriatric patients (Perry, Lacritz, Roebuck-Spencer, et al., 2018). The summit highlighted the importance of 1) educating patients and healthcare providers about the value of assessing baseline cognition; 2) relying upon appropriately normalized and validated measures for the target population; 3) incorporating health records to augment cognitive screening and assessment, and 4) tracking change in cognitive health over time.
Alternative treatment interventions
Psychoeducation regarding prevention and compensatory strategies is a vital role that the neuropsychologist is equipped to coordinate and provide. For example, evidence-based research, while ever-evolving, provides a source of scientifically supported lifestyle changes that may be shared to reduce the chances of a mild cognitive impairment converting to AD. The Alzheimer’s Association advises on the importance of controlling cardiovascular risks by stopping smoking; regular exercise; a diet that includes fresh fruits and vegetables, whole grains, and lean proteins; participation in mentally and socially stimulating activities, and an early diagnosis that leads to treatment.
Maiken, Peterson, & Thuesen (2019) have adapted neuropsychological techniques for use with patients diagnosed with progressive diseases such as Parkinson’s disease and dementia of Alzheimer’s type. For those with progressive diseases, neurorehabilitation is likely to rely on tailor-made approaches to mediate the specific, individual problems encountered at different stages of dementia. Practical examples may include that of increasing the frequency of social participation, promoting skill development and motivation for email use to enable contact with family and friends, reducing social anxiety, regaining the confidence to go outside, or improving specific activities of daily living. Other non-pharmacologic interventions shown to delay functional decline include occupational therapies and exercise interventions such as walking, resistance training, balance and flexibility training (McLaren, LaMantia & Callahan, 2013). For people in the more advanced stages of dementia, behavioral approaches may focus on maintaining one or two aspects of self-care, engaging in pleasurable activities, or reestablishing a sense of productivity by performing essential, repetitive tasks.
Cost-effectiveness, improved precision, and practical applicability
Neuropsychological applications have proven to be adaptable, practical, cost-effective, and essential resources for clinical diagnosis, treatment planning and intervention, family education, and as a basis for disability determination and long-term planning. Normative comparisons of the individual’s neurocognitive performance, subtest comparisons that establish a pattern of performance, and intra and individual comparisons based on age, education/occupation, and prior cognitive functioning using standardized measures and administered by a clinical neuropsychologist distinguish neuropsychological assessment from a time-constrained, general office screening. Norm referencing and culturally sensitive neuropsychological evaluations are integral to improving diagnostic accuracy, predicting atrophy, and charting the rate of neurodegeneration and the progression of neurodegenerative disease (Vuokismaa, McEvoy, Holland, Franz, & Kremen, 2018). Test performance results are best compared to the appropriate normative reference such as age, gender, educational level, and race (Schoenberg & Scott, 2011). Diagnosis and clinical treatment planning are enhanced when these demographic factors, in addition to culture and language, are considered (Perry, Lacritz, Roebuck-Spencer, et al., 2018). Attention to the same cultural, racial, and language diversities across treatment settings have critical implications for the delivery of culturally sensitive care (Cooper & Roter, 2003).
Neuropsychological assessment compared to neuroimaging
When used as the outcome measure or “gold standard,” neuropsychological assessment was deemed instrumental in accelerating clinical drug trials and made it possible to reduce the number of patients required and shortened the duration of these studies (Korolevin, 2014). Salmon & Bondi (2009) concluded that in the hands of a trained neuropsychologist, data regarding cognitive, motor, behavioral, linguistic, and executive functioning resulted in a more efficient identification of clinical pathology for intervention, than neuroimaging. Neuropsychological assessment provides insight into overall neuropsychological functioning, specific areas of impairment, degree of impairment, and functional status for which modern imaging techniques have only limited ability (Schmand et al., 2014).
Dutch investigators at the University of Amsterdam have shown that the progression of disease in memory clinic patients could be efficiently tracked in 45 minutes using neuropsychological testing (Schmand et al., 2014). By comparison, MRI measures of brain atrophy were less reliable at picking up relevant changes in neurobehavioral functioning. Investigators at the University of Amsterdam compared MRI measures of brain atrophy in 62 patients without dementia, and at follow up two years later. At baseline and at follow up, all patients had a “state-of-the-art” MRI scan. The MRI measures focused on volumes of the left and right hippocampus due to its role in memory and the inherent vulnerability of the hippocampus in patients with Alzheimer’s disease. Hippocampal volume decreased less than 1% in the group judged to be average at follow up and more than 3% in the impaired group. Memory and other cognitive functions were measured using five neuropsychological tests. The MRIs showed less pronounced differences between groups at baseline than the neuropsychological tests and less noticeable differences in the rate of change (Schmand et al., 2014).
The importance of early referral for neuropsychological assessment
Without question, increased notoriety regarding the Alzheimer’s epidemic has heightened concerns about memory lapses, thinking irregularities, and behavioral changes. This phenomenon is seen in general practice, neurology, and neuropsychology practices. Subjective complaints may or may not be indicative of the prodromal or early stages of progressive neurodegenerative disease. Nevertheless, worries about memory among the aging population have become a mounting concern, and neuropsychologists are playing an increasing role in early diagnosis and treatment planning (Cox, 2011). Many cases of dementia will remain undiagnosed when meaningful cognitive or behavioral changes go unattended, or reported symptoms are misattributed to “normal aging,” personality traits, or lifestyle changes (e.g., retirement, death of a spouse) (Kelley & Peterson, 2009).
Schroeder, Martin, & Walling (2019) recommend that family physicians refer patients for neuropsychological assessment when there are questions about 1) diagnostic decision making, 2) individualized management strategies, and 3) possible mild cognitive impairment, dementia, traumatic brain injury, or other clinical conditions that affect cognitive functioning. A neuropsychological evaluation can help identify and address concerns about functional capacities and provide an objective assessment of a patient’s ability to make decisions about health care or finances. Neuropsychological assessment can differentiate Alzheimer’s dementia from nondementia with nearly 90% accuracy (Schroeder, et al. 2019). Neuropsychological testing that measures severity increases the accuracy of functional outcome predictions.
Mild cognitive impairment (MCI) warrants monitoring by serial reexamination as statistics indicate that an estimated 15% of those diagnosed with MCI will convert to early-stage Alzheimer’s disease within one year (Mendez & Cummings, 2003, Smith 2018). Factors that predict a higher likelihood of conversion from MCI to AD include the presence of an APOE4 allele, increased hippocampal atrophy or asymmetry on magnetic resonance imaging (MRI), and decreased baseline metabolism of the entorhinal cortex on PET scan (Mendez et al., 2003). Peterson et al. (1999) first applied the term mild cognitive impairment to characterize those whose overall cognitive function is normal but who are showing progressive cognitive change as judged by subjective and informant report and cognitive scores (viz., performance on tests of episodic memory and new learning) that fall approximately 1.5 standard deviations below the means of their demographically comparable peers.
The American Academy of Neurology (AAN, 1996) and American Family Physicians (AFP, 2019) recommend a referral for neuropsychological assessment when 1) mental status screening reveals mild or questionable cognitive deficits, 2) a cognitive disorder is either in recovery or decline, 3) cognitive strengths or weaknesses need qualification for rehabilitation or therapeutic services, 4) a comprehensive profile together with clinical, laboratory, and imaging data assist with diagnosis, 5) pre-surgical data in preparation for epilepsy surgery is needed, and 7) when legal issues are dependent upon cognitive status. Likewise, the American Psychological Association (APA) has attested to the value of neuropsychological and psychological testing methods to 1) determine current functioning; 2) confirm or refute clinical impressions; 3) aid in differential diagnosis; 4) identify treatment needs and assign appropriate treatments; 5) predict treatment outcome; 6) monitor treatment effects over time; 7) assess treatment outcome; 8) reduce legal liabilities involved in providing healthcare services; and 9) tailor treatment in response to objective assessment results (APA, 2019; Ball, Stutts, Morgan, Peck & Sari, 2004).
The utility of neuropsychology in medico-legal and forensic arenas
Specialized services provided by the clinical neuropsychologist such as consultation, assessment, and expert opinion have become increasingly sought after as integral to matters of the court (Demakis, 2012; Larrabee, 2012). Neuropsychological assessment as the focus of Independent Medical Examinations (IMEs) is logical and justified when qualification of neuropsychological status and expert opinion are required from a non-treating (independent) doctor to release long term care (LTC) or disability benefits (Greiffenstein & Kaufman, 2012).
Forensic neuropsychological assessment has become increasingly sought after when questions regarding an individual’s capacity to make decisions for medical care, financial management, or testamentary matters are in question and warrant objective measurement (Grisso 1986; 2003). Capacity evaluations are based upon a thorough examination of all cognitive domains to include intellectual functioning, attention/concentration, executive functioning, language skills, visuospatial functioning, learning and memory, motor skills, psychiatric status and performance validity.
Disability Determination and Long-Term Care (LTC)
LTC insurance is coverage for the costs associated with assisted living, nursing home care or home health in the event the individual is unable to care for him or herself because of a chronic condition or disability. Long-term care insurance is an insurance product sold in the United States, the United Kingdom, and Canada that helps pay for the projected costs associated with long-term care and services not generally covered by health insurance, Medicare, or Medicaid. In 1990, the US Bipartisan Commission on Comprehensive Health Care (1991), also known as the Pepper Commission, recommended the creation of a new LTC program that would provide nursing home and community-based services for people who need hands-on or supervisory assistance with three out of five ADLs. Eligibility requires 1) a documented need for constant supervision due to cognitive impairment that impedes a person’s ability to function, or 2) behaviors that are dangerous, disruptive, or difficult to manage.
In recent years and increasingly, eligibility for the release of long-term care insurance benefits for persons suspected of cognitive disability has become contingent upon an independent medical evaluation by an MD or board-certified neuropsychologist. The examiner is to document the insured’s level of functional dependence, need for “substantial supervision,” and determine if the need is due to severe cognitive impairment. To qualify for Home and Community Based Care and Facility Services such as a nursing facility or assisted living facility, most LTC policies require that policy-driven conditions of eligibility are met and documented before monetary benefits are dispersed. Entitlement is determined based on evidence of chronic illness within a pre-established period (e.g., 12–24 months) and defined as being “unable to perform, without substantial assistance” at least two activities of daily living due to loss of functional capacity or severe cognitive impairment. Severe cognitive impairment must be determined by medical evidence and performance on standardized measures that reliably show significant dysfunction in 1) short- or long-term memory; 2) orientation to person, place, and time; 3) deductive or abstract reasoning; or 4) judgment as it relates to safety awareness 1 .
When conducting this type of forensic neuropsychological evaluation, the neuropsychologist is to complete a thorough review of all available clinical and claim records; conduct a comprehensive interview of the insured regarding history and current functional activities; administer neuropsychological tests, symptom validity measures (at least two empirically-supported, stand-alone measures of cognitive symptom validity); and complete an analysis of embedded measures of symptom validity (Marson, 1996, 2012; Slick, Sherman, & Iverson, 1999; Young, 2014). Symptom and performance validity testing (SVT, PVT) is an essential component of all neuropsychological examinations. The American Academy of Clinical Neuropsychology recommends performance validity measures for all neuropsychological evaluations, particularly forensic evaluations (Heilbronner, Sweet, Morgan, Larrabee, & Mills, 2009), National Academy of Neuropsychology (Bush et al., 2005), and American Psychological Association (APA, 2017). There are a multitude of options such as stand-alone tests of validity, separate test validity scales, embedded indices designed to determine the probability that the examinee has given full effort, and that results are valid and not obscured by a tendency to exaggerate, minimize or malinger (Bigler E., 2014; Slick, et al., 1999).
Symptom and performance validity testing within the dementia spectrum
Individuals with dementia warrant special consideration when selecting tests and interpreting performance consistency and credibility. Standard and acceptable measures of performance validity (e.g., Test of Memory and Malingering), while appropriate for testing effort in older adults with mild cognitive impairment, may result in false positives for those with moderate to severe dementia. Individuals with moderate-to-severe cognitive impairment often fail stand-alone performance validity tests (PVTs), not because of deliberate symptom dissimulation, but because the test inadvertently measures vulnerable and impaired neurocognitive abilities (Walter, Morris, Swier-Vosnos, & Pliskin, 2014). Modification to the standards and methodology for performance and symptom validity testing is justified when dementia is evident (Larrabee, 2012).
Civil and forensic capacity evaluations
Within the context of legal decision-making, the terms capacity and competence are often used interchangeably. There are, however, important legal distinctions between these terms, each with specific implications (Demakis, 2012; Grisso 1986; Moye, Marson, Edelsteine, 2013). Competency is a legal term that refers to an individuals’ ability to make decisions independently and is ultimately determined by a judge.
US law identifies four core abilities as necessary to confirm decision-making capacity. Other types of capacity include financial, independent living, medical consent, and testamentary. Evaluations typically address predetermined questions regarding the individual’s ability to accept and refuse treatment (medical decision-making capacity), ability to make a will, and understand its value and consequences (testamentary), and the ability to understand and make reasonable decisions about money and finances (financial capacity). These abilities lend themselves to formal evaluation using specific neuropsychological tests and informal means to determine the individual’s ability to express a choice, understand the choice, appreciate the consequences of the choice, and reason (Appelbaum & Grisso, 1998, 2001). Within the context of medical decision-making, capacity refers to the cognitive ability to make informed treatment decisions, appreciate risk versus benefit, and to understand the consequences of a choice. Age-related changes in cognitive functioning and disease such as dementia affect these abilities. The impact of the disease on cognitive function is measurable (Grisso, 1986; Qualls & Smyer, 2007).
On the matter of testamentary capacity, a person who has reached the age of majority can by law, make a will, and a person who has a mental disorder can make a will provided she or he has the required capacity (Spar & Garb, 1992). Persons with sensory impairments can make a will if they are of sound mind. Ordinarily, legally insane persons may make a will during an interval when deemed to be of sound mind. No person can make a will if impaired mental status prevents normal perception, behavior, or social interaction; or if severely impaired whether arising from intoxication or an illness or any other cause since in these circumstances, the person does not know or appreciate what he or she is doing (Demakis, 2012; Qualls & Smyer, 2007). For financial and testamentary capacity, it is necessary to assess whether the will or monetary transaction is a voluntary decision, made without external pressure, coercion, or compulsion (Edelstein, Nygren, Northrop, Staats, & Pool, 1993; Marson et al., 2012). The person making the transaction should be aware of the activity to be undertaken, should not have a mental disorder, and should not be under the influence of drugs to the extent that judgment is impaired. There should be no evidence of undue influence or coercion (Singer, 1993). The testator should have enough capacity to know the extent of his/her property and be aware of the potential beneficiaries. The testator must understand the consequences of the will and know the content.
Neuropsychologists may conduct either contemporaneous or retrospective (sometimes posthumous) assessments of capacity and render an opinion as to whether the individual is or was sufficiently mentally capable of understanding the conditions, and the nature and impact of the legal decision. In these instances, the neuropsychologist must depend upon a comprehensive records review, collateral interviews, and contemporaneous or retrospective assessment of the individual’s capacity and mental status. Regardless of the assessment’s temporality, a capacity assessment must include an estimate of the patient’s premorbid ability to draw meaningful conclusions regarding the degree of deficit and its impact on the ability to make a choice, understand, appreciate, and reason (Marson, Triebel & Knight, 2012).
Independent medical/neuropsychological examinations
Forensic and medico-legal assessments such as independent medical examinations (IMEs) are evaluations requested within the context of personal injury litigation, disability determination, or to justify the release of benefits. The neuropsychologist may be involved with any or all of the following assignments: 1) reviewing available clinical and claim records, 2) conducting an objective assessment of cognitive impairment; 3) providing a reliable and valid estimate of the claimant’s current cognitive capacity; 4) determining the etiology of any cognitive or emotional dysfunction; 5) rendering an opinion regarding the nature and severity of identified impairments (Bush, 2017). The neuropsychologist is also expected to render a professional opinion regarding the most likely etiology/etiologies for any identified cognitive impairment; the degree to which supervision is necessary because of cognitive impairment; any inconsistencies between the examinee’s functional activities and measured capacity; whether the results are reliable and valid; and the degree to which psychiatric and cognitive impairment impacts daily functional activities and demonstrates a need for substantial supervision.
Summary
Neuropsychology has made substantial contributions to the body of knowledge that has amassed on progressive neurological diseases, the neuropsychological and functional consequences of mild versus severe neurodegenerative decline, neurocognitive variations among dementia subtypes, and the efficacy of diagnosis-driven treatments. Neuropsychological principles make it possible to measure and explain the effects of cerebral injury on cognitive, behavioral, emotional, occupational, and social functioning. More specifically, these principles become the basis for qualifying the recovery process, the impact of progressive and non-progressive neurological disease on memory, attention, communication, and decision making; and the relevance of these variables at various stages of disease progression.
The utility of neuropsychology in the treatment and evaluation of neurological and psychological conditions and neurodegenerative diseases is well supported (APA, 2017; Demakis, 2012; Smith 2018; Weintraub, Wicklund, & Salmon, 2012). Compared to neuropsychological testing, MRIs have been shown less reliable at picking up early or clinically relevant changes in neurobehavioral functioning. Neuropsychological assessment, when used as the outcome measure or “gold standard,” has been instrumental in streamlining clinical drug trials by reducing the number of patients required and shortening the duration of these studies. The routine use of neuropsychological assessment makes it possible to efficiently deploy effective treatments to patients whose cognitive functioning is in progressive decline and for whom timeliness of intervention is crucial.
Within the dementia spectrum, neuropsychological assessment provides (a) an understanding of the degree and nature of neurocognitive decline, (b) a baseline for monitoring change, (c) objective cognitive and behavioral data that improves diagnostic accuracy, (d) basis for treatment recommendations, caregiver education, guidance, and long–term planning, and (e) repeatability for progress monitoring, diagnostic confirmation, and treatment efficacy. Test reliability and validity, sensitivity and specificity ratios in test selection, appropriate normative references for cultural, racial, gender, age, and language preference are critical for achieving diagnostic accuracy and recommending and implementing meaningful compensatory techniques with methods.
As a subspecialty within the broader field of clinical psychology, neuropsychology embodies the integration of neuroscience with an intended clinical application. Neuropsychology is framed around the study of how brain functioning influences behavior and cognition, and the use of that information to assess, diagnose, and treat individuals with neurological and psychological disorders (Barth, Pliskin, Axelrod, Faust, & Fisher, 2003). The utility of neuropsychology in the treatment and evaluation of neurological and psychological conditions and neurodegenerative diseases is rooted in its adaptability as a practical, cost-effective, and meaningful resource for clinical diagnosis, treatment, and basis for long term planning and forensic decision making.
In recent years, more scientific evidence supporting the role of neuropsychology in the modern-day care of older adults has amassed due to the demands for a practical, less expensive, and meaningful measurement methodology (Cox, 2011) and the increasing demand for neuropsychological assessment and consultation on legal matters associated with cognitive functioning (Demakis, 2012; Grisso, 2003). Neuropsychological expertise has become ever more sought after as integral to matters of the court. This demand for professional acumen and opinion is particularly important when the determination of an individual’s capacity to make decisions for medical care, financial management, and testamentary actions are required (Qualls & Smyer, 2007). Neuropsychology as a practice has specific advantages and has shown exponential growth as a viable resource within medicine, psychiatry, general healthcare, neurorehabilitation, and legal arenas. The examination data collected are used to hypothesize probabilities, diagnose, plan, and carry out treatments for individuals with neurological, physiological, and psychological disorders. The results and conclusions help prioritize treatment goals and coordinate a basis for care among primary care physicians, neurologists, interdisciplinary treatment teams, family, and residential caretakers.
Recent data indicate that the three most frequently observed potentially reversible conditions in patients with cognitive impairment or dementia are depression and drug or alcohol abuse. Depression is by far the most common of the potentially reversible conditions (Bello & Shultz, 2011). Neuropsychologists are clinical psychologists, which makes the psychological treatment of depression, drug, and alcohol abuse a straightforward endeavor and a logical extension to diagnostic care. Specific applications of directed care will often include 1) evidence-based treatments to alleviate symptoms of depression, 2) behavioral interventions to alter self-defeating and unhealthy behaviors, 3) recommendations for environmental modifications, 4) family education, and 5) care coordination.
Fifteen percent of persons 70 and older have dementia, indicating that the total cost of this disease in the United States alone is expected to reach an astounding $157 billion to $215 billion per year. The global cost of dementia will double by 2030 and is expected to reach $2 trillion (OECD, 2018). Unless earlier diagnoses, new strategies for prevention, and more effective treatments are developed, dementia care will place unprecedented and exponential demands on health and treatment facilitators.
Conflict of interest
None to report.
