The Dartmouth Memory Handbook
Section 2: Evaluation
GETTING A DIAGNOSIS
Robert B. Santulli, M.D.
(revised September, 2016)
Often, there have been many years of active symptoms before a person with a cognitive disorder finally gets a diagnosis. There are a number of reasons for this: the gradual onset of Alzheimer’s disease or other dementia; the subtlety of early symptoms; the reluctance of patients and their families to seek help; the time and expertise it takes for a busy physician to take the necessary history and perform the necessary office tests; the stigma associated with Alzheimer’s disease and other memory disorders; among others.
While it is never good news to get a diagnosis of Alzheimer’s disease or other serious cognitive disorder, it is often a relief to patients and families who have long suspected that something was wrong, but couldn’t identify exactly what the problem was.
The Importance of Getting a Diagnosis
Getting a diagnosis allows patients and families to begin to plan for the future, and for patients (while they are still reasonably cognitively intact) to play an active role in that planning. It also allows for steps to be taken to insure safety, and to lessen the chance for exploitation of the cognitively impaired individual. Getting a diagnosis of dementia should encourage individuals to begin the process of completing Advance Directives as soon as possible, if these have not already been done. Waiting may mean that the person with a cognitive disorder may have progressed to the point where he or she is no longer able to complete these documents legally (see page 223 for more information on Estate Planning, Durable Powers of Attorney, Advance Directives and Guardianship).
Getting a diagnosis of Alzheimer’s disease, or other dementia, also gives the patient and family an opportunity to learn all they can about the disease, which is important for being able to cope effectively with it. Finally, getting a diagnosis can lead to the initiation of medication treatment, which may slow the progression of Alzheimer’s disease, and possibly other dementias.
Beginning the Diagnostic Process
The diagnostic process must begin with the recognition on the part of an individual, and/or his family, that something is wrong that needs to be investigated. There needs to be a rejection of the notion that getting very forgetful is an inevitable part of the aging process. Individuals and families should not be led into thinking that it will “get better” with time; with time and without treatment memory disorders almost always get worse.
Getting a diagnosis usually begins with an evaluation by the primary physician. It is essential that a care partner be part of that evaluation, as it is unlikely that a person with a memory disorder will be able to tell the physician all that he or she needs to know to make a diagnosis, and it is unlikely that the person with the memory disorder will be able to recall enough of what went on during the visit with the doctor to be informative to the care partner. A physician who does not permit a care partner to be part of the diagnostic visit, or who dismisses the concerns of the individual, stating that “It’s normal to be forgetful when you get older” may be the wrong physician for the person with memory concerns, and another medical opinion should be sought. Fortunately, those attitudes are more and more uncommon (but not unheard of) these days.
The evaluation by the primary physician may be limited or extensive, depending on the usual practice of that physician. Some primary care physicians are very skilled at diagnosing and treating persons with Alzheimer’s disease or other memory disorders, while others prefer to refer most people with these concerns to a specialist. When symptoms are atypical, rapidly progressive, not responding to appropriate treatment, or causing a great deal of distress, a specialist should definitely be consulted. That specialist might be a geriatrician, a neurologist, or a geriatric psychiatrist. The nature of the individual’s symptoms may lead to a particular specialist referral.
The Detailed Evaluation
The detailed evaluation of someone with memory complaints involves taking a thorough history of the symptoms from both the person with cognitive difficulties and his or her primary care partner. It is common that the person with cognitive difficulties and the primary care partner see the presence or severity of the symptoms quite differently.
Typically, those suffering from the condition tend to see the symptoms as less severe than do their care partners, who are usually (but not always) more objectively accurate.
This can create a difficult state of “discordance” between the patient and caregiver, which has a number of negative effects, including increasing the degree of stress considerably. This issue is discussed in more detail on p.183.
Part of the evaluation involves determining what daily behaviors (instrumental activities of daily living such as driving, handling finances, and the like; and routine activities of daily living, such as dressing, bathing, eating, and toileting) are impaired; evaluating what if any mood, behavior or personality changes are present; assessing whether or not any blood relatives of the individual have had significant cognitive illness; and reviewing in detail his or her current and past medical history and current medications.
There are many medical conditions and medications that can have a significant impact on memory, thinking, concentration and other cognitive functions. It may be that a change in medication or treatment of an underlying medical condition may improve if not totally eliminate the cognitive difficulty. Depression, anxiety and other psychiatric conditions, especially if untreated, can cause significant cognitive difficulties, not to mention general distress.
It is also necessary for the physician to review any prior medical records in order to have a clear picture of the individual’s general health and medication history prior to the assessment. These should be obtained and sent to the evaluating physician for review prior to the appointment.
Testing
As part of the evaluation, a physical examination should be performed if this has not been done recently. Certain parts of the general physical or neurological examination may need to be repeated to determine if there are any conditions present that could contribute to the current cognitive symptoms.
Individuals being evaluated will generally undergo some form of cognitive testing during the assessment. There are several brief cognitive tests commonly used for this purpose.
These take only a few minutes and are generally well tolerated, unless the individual has considerable cognitive problems and/or significant defensiveness about his or her difficulties. A more extensive battery of neuropsychological testing can be useful in delineating the exact areas of cognitive difficulty, or can be helpful in obtaining a detailed measure of current cognitive abilities to compare to a previous or future point (see p.
37).
Several blood tests are typically performed as part of the evaluation, to rule out unexpected but generally readily treatable causes of cognitive difficulties, such as thyroid disease. Laboratory tests are also useful to provide information about other aspects of the individual’s general health.
Head imaging (CT, MRI, or PET scan of the brain) is commonly but not universally performed as part of the diagnostic assessment. No head imaging study in common use is able to make a definitive diagnosis of Alzheimer’s disease or any of the other common dementias, but can be very helpful in ruling out the presence of a brain tumor, stroke, blood clot, or other lesion that could be a cause of, or contributor to, the symptoms. A diagnosis of vascular dementia almost always requires head imaging evidence of small or large strokes or other vascular damage in the brain.
The diagnostic process may require more than one visit, and the second visit will often take place after the laboratory testing and/or neuroimaging has been performed and the results reviewed.
Accuracy of the Diagnosis
Given our current state of knowledge, it is not possible to make a diagnosis of a particular form of dementia with 100% accuracy no matter how much information is available, but experienced clinicians can be accurate up to 90% of the time, according to research. While it is critical to rule out conditions (such as brain tumors) which may be life threatening, or conditions such as underactive thyroid, which is generally reversible once diagnosed, it may be difficult, initially, to determine the exact nature of the dementing illness. However, following an individual over time will often help clarify the diagnosis, and soon, it is hoped, there will be more accurate diagnostic tools which will help make the diagnosis of a cognitive disorder earlier, and with greater accuracy.
Note: For information about the Dartmouth-Hitchcock Healthy Aging Brain Care Clinic, please see p. 279.
DIFFERENTIAL DIAGNOSIS
Aleksandra Stark, MD
Assistant Professor of Neurology, Geisel School of Medicine at Dartmouth; Attending Neurologist, Dartmouth-Hitchcock Medical Center
When an older individual presents to the neurologist with complaints of memory or personality changes, or both, the physician must consider a wide variety of different conditions. Is this some form of mild cognitive decline? Is it a condition brought on by a physical disorder or other condition? Or is it some form of dementia?
A frequently asked question is “what is the difference between Alzheimer’s disease and dementia?” Dementia is simply a term that means a person has had cognitive (memory) decline that has become severe enough that they may require help with their activities of daily living (paying bills, medication management, and so forth). Alzheimer’s disease is the most common cause of dementia. A person may have very mild Alzheimer’s disease, but not meet criteria for dementia if they can function completely independently and suffer only mild memory impairment. Another question asked is: “Well, we know he has dementia, so what kind is it?” Not all dementia and memory loss are due to Alzheimer’s disease. The causes of memory loss can be explained as falling into two categories: potentially treatable causes of memory loss (medical problems, medications, vitamin deficiencies) and irreversible or neurodegenerative causes of memory loss. This chapter will touch briefly on the medical/treatable causes of memory loss although a thorough review of these is beyond the scope of this chapter, which will focus more on the neurodegenerative causes of dementia.
Some kinds of memory loss are normal as we age. In general, age-associated memory changes are characterized by some reduction in the ability to learn and remember new material (mild changes in recent or short-term memory), as well as difficulty coming up with names of people and places. These changes, although occasionally embarrassing, are generally not considered to be pathological, but rather part of the normal aging process. Memory deficits that are due to dementing disorders such as Alzheimer’s disease are not part of normal aging. Signs and symptoms of Alzheimer’s disease are discussed elsewhere in this handbook.
During a clinical evaluation, a doctor will determine whether the patient meets the criteria for dementia. As mentioned above, dementia is not a disease, but a term used to signify the loss of cognitive and functional abilities. Even if dementia is not present, it does not mean that the patient’s cognition is normal. A patient may have more memory loss than is normal for their age, but remain functionally independent, and this is called mild cognitive impairment, or MCI (see p.9).
What Is the Cause of MCI or Dementia?
Up to 75% of all dementing illnesses in the elderly (65 and over) are due in whole or in part to Alzheimer’s disease. Alzheimer’s disease is a neurodegenerative disease of the brain characterized by a clinical dementia with prominent memory impairment and specific microscopic pathology including senile plaques and neurofibrillary tangles.
Normal Aging, Dementia with Lewy Bodies, Vascular Dementia, Frontotemporal Dementia – Things to Look for in the History:
Alzheimer’s disease typically starts insidiously with either memory loss or word-finding difficulties. Other common signs and symptoms a clinician may ask about include geographical disorientation (getting lost) and impairments in reasoning, problem solving, and judgment. Apathy, depression, and anxiety are common in mild cognitive impairment due to Alzheimer’s disease and become more noticeable in very mild and mild Alzheimer’s disease dementia. Impairment in controlling one’s behavior increases as the disease progresses.
The most common disorders that may be confused with Alzheimer’s disease are other neurodegenerative dementias. If the patient showed behavioral problems and/or personality changes first and foremost, or has prominent problems with reasoning and judgment, then a behavioral variant frontotemporal dementia might be considered (see p. 97). A primary progressive aphasia may be considered if problems with language predominate (see p. 109).
If there is any evidence of visual hallucinations or illusions, or if there are signs of parkinsonism (rigidity, slowness of movement, a tremor), dementia with Lewy bodies (or other disorders that cause parkinsonism) may be considered (see p. 77).
Vascular dementia may be considered if strokes are seen on the structural imaging scan (CT or MRI). It is also possible for a patient to have a mixed dementia of Alzheimer’s disease plus vascular disease, depending upon the amount of vascular disease present on the structural imaging study, and whether a number of the symptoms are consistent with vascular dementia (see p. 75).
Dementia with Lewy bodies is a neurodegenerative disease of the brain characterized clinically by dementia, visual hallucinations, Parkinsonism, and a sleep behavior disorder known as a rapid eye movement (REM) sleep disorder (see p. 77).
Parkinsonism is a general term that refers to a group of neurological disorders that cause movement problems similar to those seen in Parkinson’s disease, such as tremors, slow movement and stiffness. Changes that may be noticed include decreased facial (emotional) expression, a stooped posture, decreased arm swing while walking, a “shuffling gait,” in which patients seem not to pick up their feet when walking, and postural instability.
A REM sleep behavior disorder may be present for years preceding the onset of memory impairment. In a person with REM sleep disorder, the paralysis that normally occurs during REM sleep is incomplete, allowing the individual to “act out” his or her dreams. He or she may yell out fearfully, accidentally kick or punch a wall or bed partner, or even fall out of bed. RBD is characterized by the acting out of dreams that are vivid, intense, and violent. Patients often do not remember having acted out their dreams when they wake up. Other sleep disturbances, such as nightmares, difficulty distinguishing dreams from being awake, and daytime drowsiness, may occur.
Another hallmark of dementia with Lewy Bodies is fluctuating attention or alertness. Brief episodes of poor attention and/or being poorly responsive may also be present early on.
Family members often notice that their loved ones are much more alert at some times during the day than other times, and that they may have “good days” and “bad days.” In addition to visual hallucinations, visual illusions or perceptual misperceptions may occur. Sometimes it may be as simple as problems with visual color and depth perception (one patient could not see the shower water against the backdrop of the shower wall) or complicated illusions (one patient believed his dresser to be a big friendly furry monster).
Autonomic dysfunction may also occur, leading to low blood pressure upon standing (also called orthostatic hypotension), fluctuations in pulse and blood pressure, urinary incontinence, constipation, impotence, eating and swallowing difficulties, falls, and fainting. Lastly, depression and apathy may precede the onset of dementia with Lewy bodies.
The most common disorders that may be confused with Lewy Body Dementia are other neurodegenerative dementias. Vascular dementia should be considered if there are many large or small ischemic strokes on the structural imaging scan (CT or MRI).
Strokes in certain areas of the brain called the basal ganglia can produce Parkinsonism that may look similar to that the Parkinsonism seen in dementia with Lewy bodies.
Progressive supranuclear palsy is another atypical parkinsonian disorder that may be considered if there is an abnormality of vertical eye movements, rigidity of the neck and trunk, difficulty swallowing, and frequent falls. Corticobasal degeneration (another parkinsonian disorder) may be considered if there are strong asymmetric findings, such as one sided or asymmetric rigidity, inability to control the motor function of one limb.
Primary Progressive Aphasia
Three variants of language disorder will be discussed in this chapter, and they all fall under the rubric of primary progressive aphasia, or PPA (see also p.109).
Semantic dementia is a variant of PPA in which a patient loses memory for the meaning of words. The patient may first start to have problems with word finding, naming, and some problems with comprehension of words. Speech seems fluent, but he or she may substitute words or phrases with “things” or “stuff.” When presented with a word (for example, “microwave”), the patient may say “what is a microwave?” On cognitive testing, the patient may have problems with naming an object and describing its use. As the disorder progresses, in addition to problems with the expression and comprehension of language, these individuals may have problems with self-control of behaviors. There is also a loss of understanding of the meaning of things, such that they may now know what a toothbrush is for, for example, or that a tree has green leaves.
Semantic dementia is usually due to brain pathology that causes frontotemporal dementia, and is therefore usually considered a variant of frontotemporal dementia. Less often, semantic dementia may be caused by Alzheimer’s disease pathology.
Progressive non-fluent aphasia (also referred to as a non-fluent/agrammatic primary progressive aphasia) starts with problems with word finding and naming (similar to the early pattern in semantic dementia). Language may be agrammatic (“cow jumped over moon,” or “dog walk over bridge”), phonemic errors may be made (“efelant” instead of “elephant”). They may demonstrate stuttering, hesitancy, and slow, effortful speech.
Frustration is common due to preserved insight into the disabilities early on in the disorder. The difference between progressive non-fluent aphasia (PNFA) and semantic dementia is that patients with PNFA do not lose their understanding of the meaning of words. They have problems with word finding, naming, and fluency of language, but maintain their understanding of language until late in the disease process. PNFA is usually a variant of frontotemporal dementia, and less often, a variant of Alzheimer’s disease.
Logopenic aphasia is a variant of primary progressive aphasia that starts with word finding difficulties, problems with naming, and speech hesitancy. Comprehension of language and grammar are preserved. Logopenic aphasia is usually a variant of Alzheimer’s disease, and less often, a variant of frontotemporal dementia.
The most common disorders that may be confused with primary progressive aphasias include stroke, Alzheimer’s disease, or brain injury. A clinician seeing a patient with complaints of word finding and language problems will also inquire about and look for signs of other neurological disorders. In a stroke or brain injury, symptoms of aphasia start suddenly, and usually do not progressively worsen over time. The clinician may also ask about other signs and symptoms that may be associated with stroke, such as weakness or loss of function of one limb, sensory loss (numbness), or slurring of speech.
Frontotemporal dementia (FTD) is a progressive neurodegenerative disorder with three common clinical presentations (see p. 97). The three common clinical presentations are: behavioral (or frontal) variant frontotemporal dementia, semantic variant primary progressive aphasia (also called semantic dementia or temporal variant frontotemporal dementia), and non-fluent/agrammatic variant primary progressive aphasia (also called progressive non-fluent aphasia). As the latter two diagnoses were described in detail above, they will not be addressed further in this section. We will focus on behavioral variant FTD (bvFTD).
Behavioral variant frontotemporal dementia presents with gradual changes in personality and social conduct early on in the disease process (in fact, they are likely to be the very first changes noted by family, prior to cognitive changes). Patients may demonstrate apathy, early disinhibition, and loss of insight and empathy. Early disinhibition may present with inappropriate social remarks, improper sexual comments, and poorly concealed use of pornography. Patients may demonstrate unusual eating behaviors such as dramatic changes in food preferences (particularly sweets), poor manners, gluttonous behavior, and eating strange things (such as a jar of mayonnaise).
Other abnormal behaviors include repetitive and/or ritualistic behaviors such as repeatedly buying items they do not need (buying cases of coca cola to stock the pantry), invasion of spaces not their own (stepping behind a check-out counter or peering into a neighbor’s windows). Neglect of self-care and poor hygiene are common.
All of the aforementioned signs and symptoms could be present in other dementias, such as Alzheimer’s disease; however, these symptoms are prominent early in behavioral variant frontotemporal dementia, but late and less prominent presentations of Alzheimer’s disease.
Other problems that may manifest in FTD are problems with executive function and language (as these are functions of the frontal and temporal lobes, consecutively).
Sequencing problems are common in FTD, making it difficult for patients to perform tasks such as preparing a snack or dressing (clothes may be put on backwards, in the wrong order, or three or four pairs of socks may be put on). Patients with FTD may experience delusions. For example, when watching TV, they may believe that a character is talking directly to them. Patients with FTD may also have memory problems, although they present a bit differently than memory problems in Alzheimer’s disease. In FTD the memory problems tend to be related to problems with sustained attention and decreased cognitive flexibility (the ability to hold onto information in ones mind and manipulate it, such as in calculations). Unlike patients with Alzheimer’s disease, patients with FTD may learn information with repeated exposure or practice. Once learned, information is generally retained in memory, although there is often difficulty accessing it.
Because Alzheimer’s disease is so common, when suspecting a frontotemporal dementia one must always consider the possibility that it is an atypical case of Alzheimer’s disease. Alzheimer’s disease should be especially considered when the patient is over the age of 65, as only one-quarter of cases of frontotemporal dementia— but most cases of Alzheimer’s disease—present over age 65. Other disorders to consider are dementia with lewy bodies (and other parkinsonian disorders) and vascular dementia.
Usefulness of Neuropsychological Assessment
In the Evaluation of Dementia
Nadia Pare, Ph.D.
Clinical Neuropsychologist, Geriatric Evaluation and Management Clinic, Omaha, NE
Dementia is an umbrella term that includes a wide set of neurodegenerative disorders.
Specifying the etiology and severity of the dementia is imperative to establishing a treatment plan and determining the current and future needs of the patient, including need for medical treatment, for change in residential arrangement and/or introducing home health care, for assistance with financial planning, for alternative transportation, to name a few. An interdisciplinary approach to evaluation is invaluable in establishing a clear diagnosis and prognosis. As such, neuropsychological assessment plays an key role not only by assessing which cognitive functions are affected by the dementia and the extent of the impairment, as well as ruling out the contribution of personality and mood factor but also by allowing to make recommendations regarding capacity to make sound medical and financial decisions, safety to live independently at home or modification needed to promote safety, safety to operate a motor vehicle, as well as ways to compensate for cognitive loss, to keep the patient socially engaged in an appropriate setting for their level of dementia, and to provide information that will help the family and caregiver(s) cope with the burden of care.
Referring for a Neuropsychological Evaluation
Who refers to a neuropsychologist and when should such a referral be made? Referrals can come from different sources. At times, family calls to request a neuropsychological evaluation due to concerns with their loved one’s memory. Patients themselves can also contact a neuropsychologist for such concerns. More frequently, physicians, especially primary care physicians, but also geriatricians, neurologists, psychiatrists, and physiatrists will call to refer a patient. Examples of referral questions include: determining diagnosis (including ruling out depression as possible explanation for cognitive symptoms), severity of dementia, safety of current living situation and need for assistance at home, ability to continue or to resume driving, ability to return to work, as well as capacity to make medical and financial decisions. Referral sources also often request recommendations on techniques or resources to manage behavioral and emotional issues.
Overview of the Evaluation Process
As opposed to cognitive screening performed in a primary care setting, a neuropsychological evaluation allows for an in-depth evaluation of cognitive functions. In fact, cognitive screens, while helpful to identify possible cognitive decline, tend to miss subtle cognitive decline or to minimize the actual extent of the deficits. This is especially true in individuals with a higher baseline of intellectual functioning and/or high level of education. Neuropsychological evaluation includes a thorough review of the medical records, interview with the patient and an informant (e.g. spouse, child, close friend), assessment of cognitive functions, and feedback to the patient and family. Different dementias can present with decline in different domains of cognitive functions. Typically, specific types of dementia will have different profiles of cognitive impairments, hence the importance of assessing all domains of cognitive functioning. Domains of cognitive functions assessed usually include: orientation, speed of information processing, attention, working memory, visual and verbal memory functions, language functions, visuo-spatial functions, and executive functions. A more in-depth description of each of these domains is provided below.
Review of Medical Records
A thorough review of medical records is essential when a patient is referred for a neuropsychological evaluation. In fact, review of medical records will inform the neuropsychologist of medical conditions that can affect the patient’s cognition, such as poorly controlled diabetes, hypothyroidism, history of traumatic brain injury, stroke, delirium, or seizure, among many others. Also, review of the medical record allows the neuropsychologist to be aware of medication(s) taken by the patient that may have an impact on cognitive functions and possibly explain or contribute to the cognitive decline.
For instance, anticholinergic medications, such as many of the prescribed medications for urinary incontinence or over-the-counter sleeping pills, can have a significant effect on memory. Finally, this review can reveal that the patient or his family expressed concerns with memory several months or even years prior to the actual referral to neuropsychology. The type of concerns expressed at the time can be useful in determining diagnosis.
Interview with the Informant
An important part of the neuropsychological evaluation is the interview with an objective informant, usually a family member who lives with the patient or has frequent contact with him. That is because in most types of dementia, as the severity of the deficits increase, the insight or awareness into these deficits declines. This decline in awareness of deficits is part of the dementia process. The informant provides an objective view of the patient’s cognitive impairment but most importantly, they provide a description of changes in functional status and document safety in the home environment. For instance, the informant can report changes in hygiene routine, presence of falls, ability to safely use appliances, difficulty with medication management, suspicion of financial abuse, issues with driving, among others. Having an objective informant is especially important when there is a discrepancy between functional impairment in daily life and performance on testing, as individuals with a higher baseline level of intellectual functioning tend to be able to compensate better on tests of cognitive abilities than in their activities of daily living.
Interview with the Patient
Interviewing the patient provides valuable information about the severity of the cognitive deficits and level of awareness that he has into his deficits. Asking the patient about autobiographical information (name, age, and location of his children, number of grandchildren, number of years he has been married, etc.), as well as educational, occupational, and medical history, is a very helpful way of assessing memory functions.
In addition, the interview provides information about the patient’s level of awareness into his functional status, as it allows the clinician to assess whether the patient has noticed decline in his ability to manage his finances, cook his meals, safely drive his car, etc.
The interview process also allows gathering of information regarding mood and personality, information that is useful in interpretation of the results. In fact, dementia occurs in the context of a baseline personality and no two patients have the exact same clinical presentation, despite having the same diagnosis. Finally, the interview process allows establishing rapport and making the evaluation process less threatening to the patient.
Evaluation of Cognitive Functions
The process of neuropsychological evaluation can last anywhere from a couple of hours to a full day, depending on the approach of the clinician. In a geriatric population, a clinician should in most cases keep the evaluation process, including interview and testing, to less than 3 hours, to avoid fatigue. Cognitive domains assessed in the evaluation process are described below.
Orientation is divided into orientation to self, time, and place. Orientation to self refers to the ability to provide autobiographical information (one’s age, date of birth, address, children’s names, and so forth). Orientation to time refers to ability to state the current year, season, month, date, day of the week, and time of day. Orientation to place refers to ability to identify one’s current location (including state, county, city/town, and building).
Speed of information processing refers to the time it takes to take in information (either visually or verbally) and react to it (either verbally or with a motor response). An example of this in a daily life situation would be the time it takes to find the “quick cook” button on a microwave oven.
Simple attention or “attention span” is the ability to attend to visual or verbal material for a short period of time. This would be for instance the ability to repeat a phone number immediately after it is presented.
Working memory refers to the ability to manipulate information in mind for a short period of time. Working memory is the ability required when calculating the amount of tip one wants to leave on a check or when trying to retain a telephone number until written on a piece of paper.
Verbal and visual memory refers to the ability to learn new information. This is for instance the ability to retain news heard on television and that one wants to share with their spouse a few hours later. It could also be the ability to remember where a pair of glasses where last put down or to remember the location of your new doctor’s office.
Several aspects of language functions can be assessed during a neuropsychological evaluation, including receptive (what one hears or reads) and expressive language (what one verbally states or writes).. Expressive language usually refers to the ability to rapidly come up with words or to access one’s “internal dictionary”. Receptive language refers to the ability to understand verbal or written information.
Visuospatial function is the ability to perceive and analyze visual information, such as scanning visual information, judging distances, distinguishing shapes, foreground, and background, perceiving details, copying or reproducing shapes and forms, and organizing visual information to perceive a global figure.
Executive functions refer to metacognition or the group of cognitive processes that regulates, controls, and manages the other cognitive processes. This includes planning, organizing/classifying, strategizing, judgment and problem solving, reasoning, deductive thinking, abstracting, inhibiting irrelevant information or behaviors, self-regulating and monitoring, initiating an action and disengaging from a task, self-awareness, and multitasking or switching between tasks.
In addition to cognitive functions, a neuropsychologist assesses mood and personality.
This could be done during the interview with the patient and/or by use of psychometric measures such as questionnaires filled out by the patient. However, these rating scales cannot replace clinical judgment and behavioral observations.
Several tests or tools are used to assess each of the cognitive domains mentioned above. The amount of time spent assessing each domain depends on the referral question and suspected diagnosis. For instance, more time could be spent assessing memory functions when a dementia of Alzheimer’s disease etiology is suspected, while executive functions would be assessed more thoroughly when a fronto-temporal dementia is suspected. Tests are administered following standardized procedures that follow a specific set of instructions and demonstration. These procedures are important to make sure that results of the evaluation cannot be attributed to testing variables (such as poor understanding of instructions or distraction from the testing environment).
Interpretation of results is made by comparing the results to a set of norms, which consists of average scores for a sample of healthy individual belonging to the same age group and with a similar level of education as the patient. Norms also often control for gender and at times control for ethnicity.
In establishing a diagnosis of dementia, the clinician looks for patterns of results that are typical of a dementia. For instance, dementia of Alzheimer’s disease etiology will tend to affect orientation, memory functions (especially ability to retain information over time), as well as language functions (especially confrontation naming or ability to come up with the name of images, and semantic fluency or ability to rapidly name words that belong to a category, such as musical instruments). However, vascular dementia (or dementia due to cerebrovascular disease in the brain) will tend to affect speed of processing, visuospatial functions, and phonemic fluency (naming words starting with a specific letter).
Obviously, this is a gross generalization of how the concept of “patterns of results” works and clinical judgment plays a major role in recognizing such patterns.
Providing Feedback and Beyond
Once the evaluation has been completed and a diagnosis has been made, a feedback session will be scheduled to share the results of the evaluation and ensuing recommendations. During this session, the patient and family should be encouraged to ask questions to better understand the diagnosis and how it concretely affects daily life and future plans and needs. Planning for future needs should be addressed during the feedback session. This may include discussing power of attorney and living will, residential preference, safety at home, among others. Patient or family may ask for information that can be better provided by a social worker and it is imperative for the neuropsychologist to recognize their limitation and to refer to the appropriate professional (medical social workers and home health agency staff can help with this).
When referred by a physician, the physician will receive a copy of the report, as this may allow him to adapt his treatment plan, such as prescribing appropriate medications (such as donepezil or memantine), discontinuing medications (such as pills that can affect cognition or increase risk of falls), ordering brain imaging or other medical tests, or referring the patient to a specialist, such as a neurologist, as needed. Some patients and physicians will request a follow-up evaluation, which is typically not done before a year or two after the original evaluation, as significant decline is not expected to happen before then. Results can also be shared with other professionals, such as speech therapists, social workers, psychotherapists, or others, again with the goal of better adapting their treatment plan to the needs of the patient.
Conclusion
A neuropsychology evaluation is an important tool to assess cognitive changes and assist with the diagnosis of dementia. Using an interdisciplinary approach to dementia care and knowing when to refer to other professionals is the most beneficial and effective strategy for accurately diagnose a dementia and promote comprehensive care of older adults.