Neurocognitive Disorders
Which of the following features characterizes alcohol-induced major or mild neurocognitive disorder, amnestic-confabulatory type? a. Amnesia for new information and confabulation. b. Seizures. c. Amnesia for previously learned information and downward gaze paralysis. d. Aphasia. e. Anosognosia and apraxia.
Amnesia for new information and confabulation. Explanation: Neurocognitive disorder induced by alcohol frequently manifests with a combination of impairments in executive function and memory and learning domains. Features of alcohol-induced amnestic-confabulatory (Korsakoff's) neurocognitive disorder include prominent amnesia (severe difficulty learning new information with rapid forgetting) and a tendency to confabulate. These manifestations may co-occur with signs of thiamine encephalopathy (Wernicke's encephalopathy) with associated features such as nystagmus and ataxia. Ophthalmoplegia of Wernicke's encephalopathy is typically characterized by a lateral gaze paralysis.
The diagnostic criteria for major or mild neurocognitive disorder with Lewy bodies (NCDLB) include fulfillment of criteria for major or mild neurocognitive disorder and presence of "a combination of core diagnostic features and suggested diagnostic features for either probable or possible neurocognitive disorder with Lewy bodies." Another feature necessary for the diagnosis is that "the disturbance is not better explained by cerebrovascular disease, another neurodegenerative disease, the effects of a substance, or another mental, neurological, or systemic disorder." Which of the following completes the list of features necessary for the diagnosis? A. An acute onset and rapid progression. B. An insidious onset and gradual progression. C. An insidious onset and rapid progression. D. A waxing and waning presentation. E. A characteristic finding on ultrasound of the neck.
An insidious onset and gradual progression. Explanation: NCDLB includes not only progressive cognitive impairment (with early changes in complex attention and executive function rather than learning and memory) but also recurrent complex visual hallucinations; concurrent symptoms of rapid eye movement sleep behavior disorder (which can be a very early manifestation); as well as hallucinations in other sensory modalities, depression, and delusions. The symptoms fluctuate in a pattern that can resemble a delirium, but no adequate underlying cause can be found. The variable presentation of NCDLB symptoms reduces the likelihood of all symptoms being observed in a brief clinic visit and necessitates a thorough assessment of caregiver observations. The use of assessment scales specifically designed to assess fluctuation may aid in diagnosis. Another core feature is spontaneous parkinsonism, which must begin after the onset of cognitive decline; by convention, major cognitive deficits are observed at least 1 year before the motor symptoms. NCDLB is a gradually progressive disorder with insidious onset. However, there is often a prodromal history of confusional episodes (delirium) of acute onset, often precipitated by illness or surgery.
Genetic testing is the primary laboratory test for the determination of Hunting- ton's disease. Which of the following best characterizes the genetic nature of Huntington's disease? A. X-linked recessive inheritance with incomplete penetrance. B. Autosomal recessive inheritance with complete penetrance. C. Autosomal dominant inheritance with complete penetrance. D. Random mutation. E. X-linked dominant inheritance.
Autosomal dominant inheritance with complete penetrance. Explanation: The genetic basis of Huntington's disease is a fully penetrant autosomal dominant expansion of the CAG trinucleotide, often called a CAG repeat, in the huntingtin gene. A CAG repeat length of 36 or more is invariably associated with Huntington's disease, with longer repeat lengths associated with early age at onset.
Major or mild neurocognitive disorder (NCD) due to prion disease encompasses NCDs associated with a group of subacute spongiform encephalopathies caused by transmissible agents known as prions. What is the most common prion disease? A. Creutzfeldt-Jakob disease. B. Wernicke-Korsakoffsyndrome. C. Bovine spongiform encephalopathy. D. Huntington's disease. E. Neurosyphilis.
Creutzfeldt-Jakob disease. Explanation: Prion diseases include Creutzfeldt-Jakob disease, variant Creutzfeldt-Jakob disease, kuru, Gerstmann-Sträussler-Scheinker syndrome, and fatal insomnia. The most common type is sporadic Creutzfeldt-Jakob disease, typically referred to as Creutzfeldt-Jakob disease (CJD). (Variant CJD is much rarer and is associated with transmission of bovine spongiform enceph- alopathy, also called "mad cow disease.") Typically, individuals with CJD present with neurocognitive deficits, ataxia, and abnormal movements such as myoclonus, chorea, or dystonia; a startle reflex is also common. Typically, the history reveals rapid progression to major NCD over as little as 6 months, and thus the disorder is typically seen only at the major level. However, many individuals with the disorder may have atypical presentations, and the disease can be confirmed only by biopsy or at autopsy. Wernicke-Korsakoff syndrome, neurosyphilis, and Huntington's disease are not prion diseases; rather, Wernicke-Korsakoff syndrome is secondary to thiamine deficiency, Huntington's disease is secondary to a genetic defect, and neurosyphilis is caused by a sexually transmitted infection.
A 79-year-old woman with a history of depression is being evaluated at a nursing home for a suspected urinary tract infection. She is easily distracted, perseverates on answers to questions, asks the same question repeatedly, is unable to focus, and cannot answer questions regarding orientation. The mental status changes evolved over a single day. Her family reports that they thought she "wasn't herself" when they saw her the previous evening, but the nursing report this morning indicates that the patient was cordial and appropriate. What is the most likely diagnosis? A. Major depressive disorder, recurrent episode. B. Depressive disorder due to another medical condition. C. Delirium. D. Major depressive disorder, with anxious distress. E. Obsessive-compulsive disorder.
Delirium. Explanation: This patient's symptoms are proximally related to the urinary tract infection: her mental status changes had a temporal, fluctuating course with disturbance in attention and cognition. These are the diagnostic features of delirium.
In a patient with mild neurocognitive disorder (NCD), which of the following would distinguish probable from possible Alzheimer's disease? a. Evidence of a causative Alzheimer's disease genetic mutation from either genetic testing or family history. b. Clear evidence of decline in memory and learning. c. Steadily progressive, gradual decline in cognition, without extended plateaus. d. No evidence of mixed etiology. e. Onset after age 80.
Evidence of a causative Alzheimer's disease genetic mutation from either genetic testing or family history. Explanation: The only way that mild NCD due to probable Alzheimer's disease can be diagnosed is if there is evidence of a causative Alzheimer's disease genetic mutation from either genetic testing or family history. Mild NCD due to possible Alzheimer's disease is diagnosed on the basis of the presence of all of the clinical criteria described in options B-D above. Age at onset is not a diagnostic criterion.
Which of the following is a core feature of major or mild neurocognitive disorder with Lewy bodies? a. Fluctuating cognition with pronounced variations in attention and alertness. b. Recurrent auditory hallucinations. c. Spontaneous features of parkinsonism, with onset atleast 1 year prior to development of cognitive decline. d. Fulfillment of criteria for rapid eye movement (REM) sleep behavior disorder. e. Evidence of low striatal dopamine transporter uptake in basal ganglia as demonstrated by single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging.
Fluctuating cognition with pronounced variations in attention and alertness. Explanation: Recurrent well-formed visual hallucinations (not auditory hallucinations) and parkinsonism arising after (not earlier than) cognitive impairment are the other core features of major or mild neurocognitive disorder with Lewy bodies. REM sleep behavioral disorder and excessive sensitivity to neuroleptic agents are "suggestive diagnostic features"; low dopamine transporter uptake in basal ganglia is a diagnostic marker but is not included in the diagnostic criteria.
Both major and mild neurocognitive disorders can increase the risk of delirium and complicate its course. Traditionally, delirium is distinguished from dementia on the basis of the key features of acute onset, impairment in attention, and which of the following? A. Fluctuating course. B. Steady course. C. Presence of mania. D. Presence of depression. E. Cogwheeling movements.
Fluctuating course. Explanation: According to Criterion B for delirium, the disturbance develops over a short period of time, usually hours to a few days, and tends to fluctuate during the course of the day, often with worsening in the evening and night when external orienting stimuli decrease.
In major or mild frontotemporal neurocognitive disorder, which of the following is a diagnostic feature of the language variant? A. Severe semantic memory impairment. B. Severe deficits in perceptual-motor function. C. Receptive aphasia. D. Grammar, word-finding, or word-generation difficulty. E. Hyperorality.
Grammar, word-finding, or word-generation difficulty. Explanation: The language variant diagnosis specifically requires worsening in language function with at least relative sparing of learning and memory and perceptual-motor function. Hyperorality is a diagnostic feature of the behavioral deficit variant. Signs of either the language variant or behavior variant can also occur in patients in whom the other variant is predominant, but the diagnosis would be based on the predominant features.
Which of the following is not a diagnostic criterion, feature, or marker of major or mild neurocognitive disorder with Lewy bodies (NCDLB)? a. Concurrent symptoms of rapid eye movement (REM) sleep behavior disorder. b. High striatal dopamine transporter uptake in basal ganglia demonstrated by single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. c. Low striatal dopamine transporter uptake in basal ganglia demonstrated by SPECT or PET imaging. d. Severe neuroleptic sensitivity. e. Insidious onset and gradual progression.
High striatal dopamine transporter uptake in basal ganglia demonstrated by SPECT or PET imaging. Explanation: The underlying neurodegenerative disease in NCDLB is primarily a synucleinopathy due to alpha-synuclein misfolding and aggregation. Cognitive testing beyond the use of a brief screening instrument may be necessary to define deficits clearly. Assessment scales developed to measure fluctuation can be useful. The associated condition REM sleep behavior disorder may be diagnosed through a formal sleep study or identified by questioning the patient or informant about relevant symptoms. Neuroleptic sensitivity (challenge) is not recommended as a diagnostic marker but raises suspicion of NCDLB if it occurs. A diagnostically suggestive feature is low striatal dopamine transporter uptake on SPECT or PET scan. Other clinically useful markers potentially include relative preservation of medial temporal structures on computed tomography/magnetic resonance imaging brain scan; reduced striatal dopamine trans- porter uptake on SPECT/PET scan; generalized low uptake on SPECT/PET perfusion scan with reduced occipital activity; abnormal (low uptake) [123I]metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy suggesting sympathetic denervation; and prominent slow-wave activity on the electroencephalogram with temporal lobe transient waves.
The diagnostic criteria for neurocognitive disorder (NCD) due to HIV infection include fulfillment of criteria for major or mild NCD and documented infection with human immunodeficiency virus (as confirmed by established laboratory methods). Which of the following is a prominent feature of NCD due to HIV infection? A. Impairment in executive functioning. B. Conspicuousaphasia. C. Significant delusions and hallucinations at onset of the disorder. D. Marked difficulty with recall of learned information. E. Rapid progression to profound neurocognitive impairment.
Impairment in executive functioning. Explanation: NCD associated with HIV infection generally shows a "subcortical pattern" with prominently impaired executive function, slowing of processing speed, problems with more demanding attentional tasks, and difficulty in learning new information, but fewer problems with recall of learned information. In major NCD, slowing may be prominent. Language difficulties, such as aphasia, are uncommon, although reductions in fluency may be observed. HIV pathogenic processes can affect any part of the brain; therefore, other patterns are possible. An NCD due to HIV infection can resolve, improve, slowly worsen, or have a fluctuating course. Rapid progression to profound neurocognitive impairment is uncommon in the context of currently available combination antiviral treatment; consequently, an abrupt change in mental status in an individual with HIV may prompt an evaluation of other medical sources for the cognitive change, including secondary infections.
In addition to documented infection with HIV and fulfillment of criteria for major or mild neurocognitive disorder (NCD), what other requirement must be met to qualify for a diagnosis of major or mild NCD due to HIV infection? a. Presence of HIV in the cerebrospinal fluid. b. A pattern of cognitive impairment characterized by early predominance of aphasia and impaired memory for previously learned information. c. Presence of progressive multifocal leukoencephalopathy. d. Inability to attribute the NCD to non-HIV conditions (including secondary brain diseases), another medical condition, or a mental disorder. e. Presence of Kayser-Fleisher rings.
Inability to attribute the NCD to non-HIV conditions (including secondary brain diseases), another medical condition, or a mental disorder. Explanation: In addition to requiring fulfillment of criteria for major or mild NCD and documented infection with HIV, the diagnostic criteria for NCD due to HIV infection stipulate that the NCD is not better explained by non-HIV conditions, including secondary brain diseases such as progressive multifocal leukoencephalopathy or cryptococcal meningitis; and that it is not attributable to another medical condition and is not better explained by a mental disorder. An NCD due to HIV infection generally shows a "subcortical pattern" with prominently impaired executive function, slowing of processing speed, problems with more demanding attentional tasks, and difficulty in learning new in- formation, but fewer problems with recall of learned information. In major NCD, slowing may be prominent. Language difficulties, such as aphasia, are uncommon, although reductions in fluency may be observed. HIV pathogenic processes can affect any part of the brain; therefore, other patterns are possible. NCD due to HIV is more prevalent in individuals with high viral loads in the cerebrospinal fluid, but this is not a diagnostic criterion. Kayser-Fleisher rings are observed in Wilson's disease, not HIV.
Which of the following neurocognitive disorders (NCDs) is especially characterized by deficits in domains such as speech production, word finding, object naming, or word comprehension, whereas episodic memory, perceptual-motor abilities, and executive function are relatively preserved? A. Major or mild NCD due to Alzheimer's disease. B. Major or mild NCD with Lewy bodies. C. Major or mild vascular NCD. D. Behavioral-variant major or mild frontotemporal NCD. E. Language-variant major or mild frontotemporal NCD.
Language-variant major or mild frontotemporal NCD. Explanation: Major or mild frontotemporal NCD comprises a number of syndromic variants characterized by the progressive development of behavioral and personality change and/or language impairment. The behavioral variant and three language variants (semantic, agrammatic/nonfluent, and logopenic) exhibit distinct patterns of brain atrophy and some distinctive neuropathology. The criteria must be met for either the behavioral or the language variant to make the diagnosis, but many individuals present with features of both. Individuals with language-variant major or mild frontotemporal NCD present with primary progressive aphasia with gradual onset, with three subtypes commonly described: semantic variant, agrammatic/nonfluent variant, and logopenic variant, and each variant has distinctive features and corresponding neuropathology. Individuals with behavioral-variant major or mild frontotemporal NCD present with varying degrees of apathy or disinhibition. They may lose interest in socialization, self-care, and personal responsibilities, or display socially inappropriate behaviors. Insight is usually impaired, and this often delays medical consultation. The first referral is often to a psychiatrist. Individuals may develop changes in social style, and in religious and political beliefs, with repetitive movements, hoarding, changes in eating behavior, and hyperorality. In later stages, loss of sphincter control may occur. Cognitive decline is less prominent, and formal testing may show relatively few deficits in the early stages. Common neurocognitive symptoms are lack of planning and organization, distractibility, and poor judgment. Deficits in executive function, such as poor performance on tests of mental flexibility, abstract reasoning, and response inhibition, are present, but learning and memory are relatively spared, and perceptual motor abilities are almost always preserved in the early stages.
A 69-year-old semiretired radiologist with responsibility for chest x-ray interpretation at his academic medical center has been referred by the hospital's Employee Assistance Program for clinical evaluation because of concerns expressed by other clinicians that he has been making many mistakes in his x-ray interpretations over the past few months. Evaluation discloses a remote history of alcohol dependence with sobriety for the past 20 years, and a depressive ep- isode following the death of his wife 9 years before the current problem, treated with cognitive-behavioral therapy with full resolution of symptoms after 6 months and no recurrence. He acknowledges some trouble concentrating but no other symptoms, and he minimizes the alleged x-ray interpretation problems. He cannot state the correct date or day of the week and cannot recall the previous day's news events, but he can describe highlights of his long career in medicine in great detail. Collateral history from his children reveals that on several occasions in the past year neighbors in his apartment building had complained that he forgot to turn off his stove while cooking, resulting in a smoke-filled apartment. He scores 21/30 on the Mini-Mental State Examination. What diagnosis best fits this clinical picture? A. Major neurocognitive disorder (NCD). B. Mild NCD. C. Adjustment disorder. D. Major depressive disorder. E. No diagnosis.
Major NCD. Explanation: Concern has been raised about cognitive decline affecting this patient's functioning, and his test performance is very abnormal, so he clearly meets Criterion A for major NCD. Forgetting to keep track of what is cooking on the stovetop, with the result that neighbors have to intervene because of a smoke condition, is a good example of inability to perform activities of daily living independently, so he meets Criterion B for major NCD, as opposed to mild NCD. He is not delirious, so he meets Criterion C. Neither his remote history of alcohol dependence nor his remote history of depression accounts for his cognitive problems, and there is no evidence of another mental disorder, so he probably also meets Criterion D.
A 68-year-old semiretired cardiologist with responsibility for electrocardiogram (ECG) interpretation at his community hospital is referred by the hospital's Employee Assistance Program for clinical evaluation because of concerns expressed by other clinicians that he has been making many mistakes in his ECG interpretations over the past few months. The patient discloses symptoms of persistent sadness since the death of his wife 6 months prior to the evaluation, with frequent thoughts of death, trouble sleeping, and escalating usage of sedative-hypnotics and alcohol. He has some trouble concentrating, but he has been able to maintain his household, pay his bills, shop, and prepare meals by himself without difficulty. He scores 28/30 on the Mini-Mental State Examination (MMSE). Which of the following would be the primary consideration in the differential diagnosis? A. Major neurocognitive disorder (NCD). B. Mild NCD. C. Adjustment disorder. D. Major depressive disorder. E. No diagnosis.
Major depressive disorder. Explanation: Not enough information has been provided to know for certain whether this patient meets criteria for a specific mood disorder diagnosis—or for a substance use disorder diagnosis—but a major NCD can be ruled out. Although the patient's test score on the MMSE is within the normal range, he does meet Criterion A for major NCD, in that concerns about a decline in cognitive function have been raised due to his increased error rate in interpreting ECGs. Regarding Criterion B for major NCD, the patient does not demonstrate loss of ability to perform activities of daily living independently and so does not qualify for a diagnosis of major NCD. He does meet Criterion C, in that he is not demonstrating signs of delirium. The fact that his problems have become evident only in the context of mood issues strongly suggests that a depressive disorder and/or substance use may account for his work performance deficits; therefore, he likely will not meet Criterion D for NCD. Although he could meet Criterion B for mild NCD, a mood disorder would be the most prominent consideration in the differential diagnosis.
Which of the following statements about the diagnosis of neurocognitive disorder due to Huntington's disease (NCDHD) is true? a. NCDHD is a laboratory-based diagnosis/disorder. b. NCDHD is a disorder that requires positive neuroimaging for diagnosis. c. NCDHD is a clinical diagnosis based on abnormal physical findings and family history/genetic findings. d. NCDHD is a diagnosis that is best defined as patients who have a pill-rolling tremor. e. NCDHD is a diagnosis mostly based on radiological examination.
NCDHD is a clinical diagnosis based on abnormal physical findings and family history/genetic findings. Explanation: Genetic testing is the primary laboratory test for the determination of Huntington's disease, which is an autosomal dominant disorder with complete penetrance. A diagnosis of definite Huntington's disease is given in the presence of unequivocal extrapyramidal motor abnormalities in an individual with either a family history of Huntington's disease or genetic testing showing a CAG trinucleotide repeat expansion in the HTT gene, located on chromosome 4.
Prion disease has been reported to occur in individuals of all ages, from the teenage years to late life. Which of the following best characterizes the time frame of disease progression? A. Over a few months. B. Over several days. C. Over several weeks. D. Over 5 years. E. Over 10 years.
Over a few months. Explanation: Prion disease may develop at any age in adults—the peak age for sporadic Creutzfeldt-Jakob disease is approximately 67 years, although it has been reported to occur in individuals spanning the teenage years to late life. Prodromal symptoms of prion disease may include fatigue, anxiety, problems with appetite or sleeping, or difficulties with concentration. After several weeks, these symptoms may be followed by incoordination, altered vision, or abnormal gait or other movements that may be myoclonic, choreoathetoid, or ballistic, along with a rapidly progressive dementia. The disease typically progresses very rapidly to the major level of impairment over several months. More rarely, it can progress over 2 years and appear similar in its course to other neurocognitive disorders.
A 72-year-old man with no history of alcohol or other substance use disorders and no psychiatric history is brought to the emergency department (ED) because of transient episodes of unexplained loss of consciousness. His wife reports that he has experienced repeated falls and syncope over the past year, as well as auditory and visual hallucinations. A thorough workup for cardiac disease has found no evidence of structural heart disease or arrhythmias. In the ED, he is found to have severe autonomic dysfunction, including orthostatic hypotension and urinary incontinence. What is the best provisional diagnosis for this patient? A. New-onset schizophrenia. B. New-onset schizoaffective disorder. C. Possible major or mild neurocognitive disorder with Lewy bodies. D. Possible major or mild neurocognitive disorder due to Alzheimer's disease. E. New-onset seizure disorder.
Possible major or mild neurocognitive disorder with Lewy bodies. Explanation: Further information on cognition, time frame, and other etiologies must be ascertained, but the best working diagnosis with the limited in- formation available is neurocognitive disorder with Lewy bodies (NCDLB). Individuals with NCDLB frequently experience repeated falls and syncope and transient episodes of unexplained loss of consciousness. Severe autonomic dysfunction, such as orthostatic hypotension and urinary incontinence, may also be observed. Auditory and other nonvisual hallucinations are common, as are systematized delusions, delusional misidentification, and depression. The patient has auditory and visual hallucinations but no other feature of schizophrenia or schizoaffective disorder, and the age at onset, along with the associated neurological symptoms, suggest a neurodegenerative disorder rather than schizophrenia or schizoaffective illness. Among neurocognitive disorders, the prominence of hallucinations, episodic loss of consciousness, and autonomic symptoms in the early course—rather than marked memory impairment—argue against a neurocognitive disorder due to Alzheimer's disease and in favor of NCDLB. The patient has one of the "core diagnostic features" of NCDLB, visual hallucinations, justifying a "possible" level of certainty for the diagnosis. A seizure disorder might cause episodic loss of consciousness but would not parsimoniously account for hallucinations and autonomic symptoms.
Depression, irritability, anxiety, obsessive-compulsive symptoms, and apathy are frequently associated with Huntington's disease and often precede the on-set of motor symptoms. Psychosis more rarely precedes the onset of motor symptoms. Which of the following is a core feature of major or mild neurocognitive disorder due to Huntington's disease? A. Progressive cognitive impairment with early changes in executive function. B. Prominent early memory impairment, mostly affecting short-term memory. C. Psychosis in the early stages, with marked olfactory hallucinations. D. Voluntary jerking movements. E. Diminished hearing and smell.
Progressive cognitive impairment with early changes in executive function. Explanation: A core feature of Huntington's disease is progressive cognitive impairment with early changes in executive function (i.e., processing speed, organization, and planning) rather than learning and memory. Cognitive and associated behavioral changes often precede the emergence of the typical motor abnormalities of bradykinesia (i.e., slowing of voluntary movement) and chorea (i.e., involuntary jerking movements).
The essential feature of the DSM-5 diagnosis of delirium is a disturbance in attention/awareness and in cognition that develops over a short period of time, represents a change from baseline, and tends to fluctuate in severity during the course of a day. Which of the following additional conditions must apply? a. There must be laboratory evidence of an evolving dementia. b. The disturbance must be associated with a disruption of the sleep-wake cycle. c. The disturbance must not occur in the context of a severely reduced level of arousal, such as coma. d. The disturbance must be a direct physiological consequence of a substance use disorder. e. The disturbance must not be super imposed on a preexisting neurocognitive disorder.
The disturbance must not occur in the context of a severely reduced level of arousal, such as coma. Explanation: The essential feature of delirium is a disturbance of attention or awareness (Criterion A) that is accompanied by a change in baseline cognition (Criterion C) that cannot be better explained by a preexisting or evolving neurocognitive disorder (Criterion D1). The ability to evaluate cognition to diag- nose delirium depends on there being a level of arousal sufficient for response to verbal stimulation; hence, delirium should not be diagnosed in the context of coma (Criterion D2). The disturbance develops over a short period of time, usually hours to a few days, and tends to fluctuate during the course of the day (Criterion B). There is evidence from the history, physical examination, or lab- oratory findings that the disturbance is a physiological consequence of an underlying medical condition, substance intoxication or withdrawal, use of a medication, or a toxin exposure, or a combination of these factors (Criterion E). Both major and mild neurocognitive disorders (NCDs) can increase the risk for delirium and complicate the course. The most common differential diagnostic issue when evaluating confusion in older adults is disentangling symptoms of delirium and dementia. The clinician must determine whether the individual has delirium; a delirium superimposed on a preexisting NCD, such as that due to Alzheimer's disease; or an NCD without delirium. The traditional distinction between delirium and dementia according to acuteness of onset and temporal course is particularly difficult in those elderly individuals who had a prior NCD that may not have been recognized, or who develop persistent cognitive impairment following an episode of delirium.
Expressed as a percentile, what is the typical performance on neuropsychological testing of individuals with major neurocognitive disorder (NCD)? A. Sixtieth percentile or below. B. Fiftieth percentile or below. C. Twenty-fifth percentile or below. D. Sixteenth percentile or below. E. Third percentile or below.
Third percentile or below. Explanation: Neuropsychological testing, with performance compared with norms appropriate to the patient's age, educational attainment, and cultural background, is part of the standard evaluation of NCDs. For major NCD, performance is typically 2 or more standard deviations below appropriate norms (3rd percentile or below). For mild NCD, performance typically lies in the 1-2 standard deviation range (between the 3rd and 16th percentiles).
A previously healthy 67-year-old man, who is experiencing an acute change in mental status, is brought to the emergency department by his family. There is no evidence in the initial history, physical examination, and laboratory studies to indicate substance intoxication or withdrawal, or to suggest another medical problem as the cause of his altered mental state. Over the course of 1 hour of observation, his level of alertness varies from alert but distractible, with apparent auditory and visual hallucinations, to somnolent; he has difficulty sustaining attention to an examiner, and he cannot perform simple tasks such as serial subtractions or spelling words backwards. What is the most appropriate diagnosis? A. Delirium. B. Delirium due to another medical condition. C. Delirium due to substance intoxication. D. Delirium due to multiple etiologies. E. Unspecified delirium.
Unspecified delirium. Explanation: This man meets criteria for some sort of delirium, but at this point in the course of his illness it cannot be determined what the cause is. The "unspecified delirium" category can be used when the clinician chooses not to specify a specific cause, when the diagnostic criteria for delirium are not entirely fulfilled, or when the specific diagnostic subtype of delirium cannot be ascertained.
A 35-year-old man brings his 60-year-old father for evaluation of cognitive and functional decline, stating that he thinks his father has dementia; the son is also worried about the possibility of a hereditary illness. The physician notes to herself that the patient has substantial cognitive impairment and features suggestive of the diagnosis of major neurocognitive disorder due to Huntington's disease, but she is not sure about the cause of the neurocognitive disorder. She also notes that the patient's son appears extremely anxious. She has a tight schedule and cannot provide a counseling session for the patient's son until the next day. What is the most appropriate diagnosis to record on the insurance claim form that the patient's son will submit on his father's behalf? a. Unspecified central nervous system (CNS) disorder. b. Unspecified neurocognitive disorder. c. Unspecified mild neurocognitive disorder. d. Huntington's disease. e. Problem related to living alone (V code category reflecting other problems related to the social environment).
Unspecified neurocognitive disorder. Explanation: The category unspecified neurocognitive disorder applies to presentations in which symptoms characteristic of a neurocognitive disorder that cause clinically significant distress or impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the neurocognitive disorders diagnostic class. The unspecified neurocognitive disorder category is also used in situations in which the precise etiology cannot be determined with sufficient certainty to make an etiological attribution. In this case, Huntington's disease is suspected but not established. "Unspecified CNS disorder" is not a DSM-5 diagnosis and would be inadequately specific to the patient's condition. The apparent severity of the deficits precludes a diagnosis of mild neurocognitive disorder or a V code designation of problem related to living alone.
Major and mild neurocognitive disorders (NCDs) exist on a spectrum of cognitive and functional impairment. Which of the following constitutes an important threshold differentiating the two diagnoses? a. Whether or not the individual is concerned about the decline in cognitive function. b. Whether or not there is impairment in cognitive performance as measured by standardized testing or clinical assessment. c. Whether or not the cognitive impairment is sufficient to interfere with independent completion of activities of daily living. d. Whether or not the cognitive deficits occur exclusively in the context of a delirium. e. Whether or not the cognitive deficits are better explained by another mental disorder.
Whether or not the cognitive impairment is sufficient to interfere with independent completion of activities of daily living. Explanation: Criterion B for major or mild NCD relates to the individual's level of independence in everyday functioning. Individuals with major NCD will have impairment of sufficient severity to interfere with independence, such that others will have to take over tasks that the individuals were previously able to complete on their own. Individuals with mild NCD will have preserved independence, although there may be subtle interference with function or a report that tasks require more effort or take more time than previously. The distinction between major and mild NCD is inherently arbitrary, and the disorders exist along a continuum. Precise thresholds are therefore difficult to determine. Careful history taking, observation, and integration with other findings are required, and the implications of diagnosis should be considered when an individual's clinical manifestations lie at a boundary. For both mild and major NCD, Criterion A requires evidence of a cognitive decline based on 1) concern on the part of the patient, a knowledgeable informant, or a clinician that there has been such a decline; and 2) impairment in cognitive performance as documented by standardized testing or other objective assessment. For major NCD, significant decline and substantial impairment are specified; for mild NCD, the words modest and mild are used. Both disorders can occur with comorbid delirium, but they cannot be diagnosed if the cognitive impairment occurs only in the context of delirium (Criterion C). Both disorders can occur in patients with other significant disorders, but in order to make the diagnosis, the cognitive deficits must not be primarily attributable to another disorder (Criterion D).
