Dementia n Alzheimer's

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Dementia and amnestic disorders.
Dementia. 1. DEFINITION Dementia is defined as a progressive impairment of cognitive functions occurring in clear consciousness (that is, in the absence of delirium). Dementia consists of a variety of symptoms that suggest chronic and widespread dysfunction. Global impairment of intellect is the essential feature, manifested as difficulty with memory, attention, thinking, and comprehension. Other mental functions may often be affected, including mood, personality, and social behavior. Nevertheless, the diagnosis of dementia should not be made without evidence of memory deficits and at least one other cognitive deficit/Dementia must be distinguished from mental retardation and other cognitive disorders, such as amnestic disorder, that involve impairment of only one intellectual function, memory. Although there are specific diagnostic criteria for various dementias, such as Alzheimer's disease or vascular dementia, all dementias have certain common elements, as defined by the revised fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV): The symptoms result in significant impairment in social or occupational functioning, and they represent a, significant decline from a previous level of functioning. Epidemiology With the aging population, the prevalence of dementia is rising. The

prevalence of moderate to severe dementia in different population groups is approximately 5 percent in the general population older than 65 years of age, 20 to 40 percent in the general population older than 85 years of age, 15 to 20 percent in outpatient general medical practices, and 50 percent in chronic care facilities. By 2050, current predictions suggest that there will be 14 million Americans with AIzheimer's disease and, therefore, more than 18 million people with dementia. ETIOLOGY The most common causes of dementia in individuals older than 65 ears of age are: AIzheimer's disease (which accounts for approximately 60 percent), vascular dementia (15 percent), and mixed vascular and AIzheimer's dementia (15 percent). Other illnesses that account for approximately 10 percent include Lewy body dementia; Pick's disease; frontotemporal dementias; normal pressure hydrocephalus (NPH); alcoholic dementia; infectious dementia, such as human immunodeficiency virus (HTV) or syphilis; and Parkinson's disease. Some sources suggest that as much as 5 percent of dementias evaluated in clinical settings may be attributable to reversible causes, such as metabolic abnormalities (e.g., hypothyroidism, nutritional deficiencies (e.g., vitamin B12 or folate deficiencies), or dementia syndrome due to depression. Possible Etiologies of Dementia Degenerative dementias: Alzheimer's disease Frontotemporal dementias (e.g., Pick's disease) ; Parkinson's disease Lewy body dementia .

Idiopathic cerebral ferrocalcinosis (Fahr's disease) Progressive supranuclear palsy Miscellaneous Huntington's disease Wilson's disease Metachromatic leukodystrophy Neuroacanthocytosis Psychiatric Pseudodementia of depression Cognitive decline in late-life schizophrenia Physiologic Normal pressure hydrocephalus Metabolic Vitamin deficiencies (e.g., vitamin B12, folate) Endocrinopathies (e.g., hypothyroidism) Chronic metabolic disturbances (e.g., uremia) Tumor Primary or metastatic (e.g., meningioma or metastatic breast or Jung cancer) Traumatic Dementia pugilistica, posttrauniatic dementia Subdural hematoma Infection Prion diseases (e.g., Creutzfeldt-Jakob disease, bovine spongiform encephalitis, Gerstmann-Straussler syndrome) Acquired immune deficiency syndrome Syphilis Cardiac, vascular, and anoxia Infarction (single or multiple or strategic lacunar) Binswanger's disease (subcortical arteriosclerotic encephalopathy) Hemodynamic insufficiency (e.g., hypoperfusion or hypoxia) Demyelinating diseases Multiple sclerosis Drugs and toxins Alcohol Heavy metals Irradiation Pseudodementia due to medications(e.g.,anticholinergics) Carbon monoxide

DIAGNOSIS The diagnosis of dementia is made by careful history, clinical examination, and selected diagnostic tests. The clinical history is most valid if corroborated with a family member or other knowledgeable informant, as patients with memory disorders are often poor historians. A social history, including occupational exposures to toxins or heavy metals, substance use, and HIV risk factors, is important in the evaluation. The medical history should include current medical conditions and their trpaffnents, history of head trauma, cardiovascular illness, vascular risk factors, and history of transient ischemic attacks or cerebrovascular accidents (CVAs). A family history of dementia is particularly important in early-onset Alzheimer's disease or other known genetically transmitted diseases, such as Huntington's chorea. A physical and neurological examination should be performed to look for active medical problems, evidence of focal neurological signs, or movement disorders. Another important aspect to the evaluation of a patient for a dementia is a complete mental status examination. In addition to the usual components of a mental status examination (appearance, mood,thought form and content, etc.), the clinician should evaluate of level of alertness and should conduct a screening cognitive assessment that addresses language (comprehension, fluency, etc.) and cognition. To assess cognition, the clinician must evaluate memory (as observed on interview as well as tested, such as remembering a list of words), orientation, reading, writing, speech production, calculation, abstraction, executive functioning, and constructional ability. Depending on the history, other areas may be evaluated, such as fine sensory function (e.g., two-point discrimination or graphesthesia) and visuospatial skills. There are a variety of standardized assessments used to evaluate cognition. The clinical history should include the onset of symptoms, the quality of symptom progression (i.e., in a gradual and progressive manner, stepwise), a review of the cognitive domains defined in the DSM-IV (Table), and an assessment of how the cognitive changes have affected various areas of functioning. An evaluation for other psychiatric disorders is also crucial, as severe depression may present as dementia. In addition, schizophrenia is associated with a decrease in cognitive abilities, especially after 60 years of age.

Table Screening Laboratory Tests Assessments Rationale Labs: complete blood count, serum electroRule out correctable or lytes, renal and hepatic function, glucontributory causes of cose, albumin and protein, vitamin B 12 dementia and folate, rapid plasma reagin (syphilis), thyroid-stimulating hormone, urinalysis Imaging: computed tomography without Rule out infarcts, mass contrast or magnetic resonance imaging lesions, tumors, and hydrocephalus Neurological examination Correlate imaging findings with clinical examination Neuropsychological testing Mini-Mental State Examination : screening test of cognitive function Formal description of cognitive impairments CLINICAL FEATURES Although the core features are the same for all dementias, the onset and course may vary. For example, a stroke followed by a dementia is, by definition, rapid in onset. Alzheimer's disease is usually insidious in onset. The time from the onset of clinical features to presentation for evaluation varies considerably and depends on the etiology of the dementia, as well as personal and social factors, including

individual and cultural attitudes and beliefs about aging, premorbid personality, and intelligence. Studies show that, although physicians are aware of the prevalence and diagnostic criteria for dementia, they .often do not screen for cognitive impairment. Cognitive Impairment. The core symptoms of cognitive dysfunction in dementia, as defined in the DSM-IV, are described in the following sections. Memory.Loss of short-term memory is often the first clinical feature that comes to the notice of patients and their relatives. Typically, memory impairment is manifested by difficulty in learning new information. As dementia progresses, retrieval of highly learned information (long-term memory) also becomes impaired. Memory deficits may be reflected in repetitiveness, missing appointments, misplacing objects, and burning meals. Topographical memory is also commonly affected, and patients may get lost. In mild-stage dementia, disorientation is usually confined to unfamiliar places. As the disease progresses, this impairment can occur in familiar environments as well. Confabulation may also occur and may manifest itself as insertion of false memories. Language.Aphasia production of (impaired writing, or or absent signs) comprehension may present or as

speech,

impoverished speech and can eventually progress to mutism in the severe stage. Nominal aphasia, the difficulty in naming objects, is common in the mild stage. Typically, this presents as word-finding difficulty, initially for low-frequency words (such as harmonica) but

later for higher-frequency words (such as telephone). Later, fluent and nonfluent aphasias and jargon aphasia (meaningless phrases) may occur. Receptive aphasia, the inability to understand, is alsocommon and is severely disabling. An important clinical point to note is that, even when language has disintegrated completely, patients may understand nonverbal communication, such as gestures and pictures. Praxis.Apraxia is the loss or diminished ability to perform coordinated motor tasks, assuming that there is no neurological or other damage to the peripheral motor apparatus. It reflects dominant parietal involvement in the dementia process. Apraxia is a major cause of loss of independence in patients, as it is reflected in the inability to cook, to dress, to wash, to go to the toilet, and to eat. Occasionally, and unwittingly, relatives add to the patient's distress by misinterpreting the inability to carry out these acts as laziness or as a lowering of standards. This is an area in which the education of relatives is important. Gnosis.Agnosia, derived from the Greek word gnosis, which means knowledge, is the failure to accurately recognize sensory stimuli in the absence of sensory (e.g., visual or olfactory) deficits. Visual agnosia may be reflected in the functional misuse of everyday objects (e.g., urinating in the sink). Prosopagnosia is the inability to recognize faces, even of friends and relatives. Agnosias can occur in all sensory modalities. Some demented patients may, for example, be unable to recognize familiar smells.

Executive Functioning. Executive functioning is defined as the ability to plan, to sequence, to abstract, and to carry through complex tasks. Deficits in executive functioning are seen particularly in disorders affecting the frontal lobes. Executive functioning can be assessed by reviewing the patient's ability to perform at work, to pay bills, and to plan activities. Neuropsychological tests directly address executive functioning by asking the person to have flexibility in how they approach an organizational task (i.e., the ability to shift sets) or to copy complex figures, drawing a clock. These latter tests are not specific to executive functioning but can demonstrate how the patient addresses a task that involves planning and organization. Personality and Behavioral Changes. Notwithstanding the

devastating effects of the cognitive deficits described previously, it is, not infrequently, the changes in personality and behavior that families find most distressing. In assessing personality changes, the clinician must rely on close family members or friends, because the patient often does not have insight into these symptoms. Relatives may vary in their description of personality and behavioral change. Some overemphasize unpleasant behaviors, whereas others deny any changes at all. initiative and Individuals with dementia may lose drive and become indecisive and introverted. The spectrum of

emotions displayed may be narrowed, with the loss of warmth and humor. As the illness progresses, patients may sit all day in the same place, apparently doing little. This constellation of symptoms, often called negative symptoms, is usually characterized by prominent apathy. It is important to differentiate these latter

symptoms from depression, which characteristically has prominent sadness, tearfulness, neurovegetative changes, suicidal tendency, and inappropriate guilt,among other characteristics. The negative symptoms do not respond to antidepressant medication. Abnormalities of mood are well described in; the early stages of dementia. In addition, severe depression may mimic or exacerbate dementia. Mania is,also occasionally seen. In other patients, changes in behavior are reflected in agitation or disinhibition. Social skills may be lost, and there may be sexual disinhibition, use of inappropriate language, or both. Agitation may include irritability, angry outbursts, and threatening or aggressive behavior, as well as pacing and purposeless behaviors (e.g., packing and unpacking). Patients may wander, including leaving their homes in the middle of the night. ALZHEIMER'S the disease. Alzheimer's disease is the most common cause of dementia in elderly. Alzheimer first described the illness in 1907 when he reported the case of a 51-year-old woman with memory loss, topographical disorientation, persecutory delusions, misidentifications, and behavioral disturbances. At her death, he examined her brain and documented the neuropathological hallmarks of amyloid neurofibrillary tangles. A definitive diagnosis of can only be made at autopsy, using specific that have been laid out by the Alzheimer's Disease evaluating the course dementia, as plaque and

Alzheimer's disease

histopathological criteria

Consortium to Establish a Registry for (CERAD). Clinical diagnoses are made by

and history and by ruling out other causes of

discussed previously. With an appropriate history and workup, Alzheimer's disease has becomea diagnosis of and the clinical accuracy in specialized centers is more percent.

laboratory inclusion, than 85

DSM-lV Diagnostic

Criteria

for

Dementia

of

the

Alzheimer's Type
A. The development
of multiple cognitive deficits manifested by both:

(1) Memory impairment (impaired ability to learn new information or to recall previously learned information) (2) One (or more) of the following cognitive disturbances: (a) Aphasia (language disturbance) (b) Apraxia (impaired ability to carry out motor activities, despite intact motor function) (c) Agnosia (failure to recognize or to identify objects, despite intact sensory function)

(d) Disturbance in executive functioning (i.e., planning, abstracting). organizing, sequencing, or

B. The cognitive deficits in Criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning. C. The course is characterized by gradual onset and continuing cognitive decline. D. The cognitive deficits in Criteria A1 and A2 are not due to any of the following: (1) Other central deficits nervous in system memory conditions and that cause (e.g., progressive cognition

cerebrovascular disease, Parkinson's disease, Huntington's disease, subdural hematoma, normal-pressure hydrocephalus, tumor). (2) Systemic conditions that are known to cause dementia (e.g., hypothyroidism, deficiency, vitamin B, or folic acid deficiency, or niacin human hypercalcemia, neurosyphilis, and brain

immunodeficiency virus infection) (3) Substance-induced conditions. E. The deficits do not occur exclusively during the course of a delirium. F. The disturbance is not better accounted for by another Axis I

disorder (e.g., major depressive disorder or schizophrenia).

Code based on presence or absence of a clinically significant behavioral disturbance: Without behavioral disturbance: if the cognitive disturbance is not accompanied by any clinically significant behavioral disturbance. With behavioral disturbance: if the cognitive disturbance is accompanied by a clinically significant behavioral disturbance (e.g., wandering or agitation). Specify subtype: With early onset: if onset is at 65 years of age or younger .With late onset: if onset is after 65 years of age. Coding note: Also code Alzheimer's disease on Axis III. Indicate other prominent clinical features related to the Atzheimer's disease on Axis I (e.g., mood disorder due to Alzheimer's disease, with depressive features, and personality change to Alzheimer's disease, aggressive type).

VASCULAR dementia. Vascular dementia is the second most common cause of dementia after Alzheimer's disease. There are several important conceptual changes that have occurred over the past decade with regard to vascular dementia, and specific criteria have been developed to aid in clinical and pathological diagnosis.

DSM-IV Diagnostic Criteria for Vascular Dementia. A; The development of multiple cognitive deficits manifested by both: (1) Memory impairment (impaired ability to learn new information or to recall previously learned information) (2) One (or more) of the following cognitive disturbances: (a) Aphasia (language disturbance) (b) Apraxia (impaired ability to carry out motor activities, despite intact motor function) (c) Agnosia (failure to recognize or to identify objects, despite intact sensory function) (d) Disturbance in executive functioning (i.e., planning, organizing, sequencing, or abstracting). B. The cognitive deficits in Criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning. C. Focal neurological signs and symptoms (e.g., exaggeration of deep tendon reflexes, extensor plantar response, pseudobulbar palsy, gait abnormalities, and weakness of an extremity) or laboratory evidence indicative of cerebrovascular disease (e.g., multiple infarctions involving cortex and underlying white matter) that are judged to be etiologically related to the disturbance. D. The deficits do not occur exclusively during the course of a delirium. Code based on predominant features: With delirium: if delirium is superimposed on the dementia. With delusions: if delusions are the predominant feature.

With depressed mood: if depressed mood (including presentations that meet full symptom criteria for a major depressive episode) is the predominant feature. A separate diagnosis of mood disorder due to a general medical condition is not given. Uncomplicated: if none of the previous conditions predominates in the current clinical presentation. Specify if: With behavioral disturbance/ Coding note: Also code cerebrovascular condition on Axis III.

Amnestic disorders
Perhaps no other psychiatric disorder has so captured the imagination of the public as the amnestic disorder. The notion of losing the ability to identify one's self, to recognize friends and family or even one's own life has been incorporated into countless novels, plays, and movies. The amnestic is a central literary device that allows the author to then detail the search for self and the ramifications and repercussions of such a search. Often, the

rediscovery of self depends on unearthing an unspeakable trauma, the liberating force of a powerful kiss or other such manifestation of love, or simply a second head injury that mysteriously corrects the impact of the original. Unfortunately, these fanciful dramatizations bear little resemblance to the clinical picture of amnestic disorders, 'neither in their clinical presentations nor in the natural course or response to treatment. Amnesia for person is rare if not unheard of. The picture of a highly intelligent, fully functional, introspective and articulate subject experiencing amnesia is also rare; more often, the amnestic has associ ated impairments in personality and function. The amnestic nonetheless experiences an existential predicament, the loss of a personal history and one's place in that history. Every day, if not every moment, is isolated and independent of its predecessor. The only comfort for such an existential limbo is that the subject often cannot retain awareness of his or her condition beyond fleeting and evanescent insights. The amnestic disorders are a broad category that includes a variety of diseases and conditions that present with an amnestic syndrome. The syndrome is defined primarily by impairment in the ability to create new memories. More details regarding the syndrome and its signs, symptoms, course, and treatment are presented in the following sections. DIAGNOSIS AND CLINICAL FEATURES Symptoms and Signs. Amnestic disorders of a nonhysterical nature always involve anterograde amnesia, meaning impaired ability to leam and to retain new information, and a lesser degree of

retrograde amnesia, meaning impaired ability to recall previously learned information. The retrograde amnesia typically follows Ribot's law, as it is most prominent for recently learned information, with older memories being the best protected. The following, then, are the core features of all amnestic disorders: - There are severe deficits in new learning (anterograde amnesia). -Attention span (roughly the same as working memory, short-term memory, immediate memory, and registration) is intact -General intelligence is intact. -Retrograde amnesia is present but temporally graded, with more remote memories preserved. -Procedural memory or the ability to leam new tasks as opposed to new ideas, events, or words is intact. Amnestic subjects can also learn with priming and conditioning in laboratory circumstances. The practical usefulness of such preserved learning skills appears limited however; without the ability to consciously recall the new information, the learning accomplished is not pragmatically useful. Korsakoff's syndrome was the test amnestic syndrome described, and it is a good clinical model for the amnestic sydrome. As noted by Korsakoff, the memory deficit involves new learning but not older established memories and knowledge. Korsakovian patients typically demonstrate a change in personality as well, such that they display a lack of initiative, diminished spontaneity, and a lack of interest or concern. These changes appear frontal lobe-like, similar to the personality change ascribed to patients with frontal lobe lesions or degeneration. Indeed, Korsakov an patients often

demonstrate executive function deficits on neuropsychological tasks involving attention, planning, set shifting, and inferential reasoning consistent with frontal pattern injuries. For this reason, Korsakoff's syndrome is not a pure memory disorder, although it certainly is a good paradigm of the more common clinical presentations for the amnestic syndrome. Much of what is known about memory derives from the study of patients with pure lesions of memory and discretely localized brain damage. The patient H. M., studied over several decades by a series of distinguished neuropsychologists, developed amnesia after surgical extirpation of significant portions of the medial temporal lobe bilaterally to alleviate intractable epilepsy. These well-defined lesions allowed the delineation of differential aspects of memory through descriptions of what memory capacities H. M. had lost and which were retained. H. M., although providing an invaluable lesion model for memory function, is not a typical example of a patient with an amnestic disorder. The more common etiologies of nutritional deficiency, cerebrovascular disease, tumor, and cerebral infection tend to have more widespread cerebral involvement and, therefore, at least subtle deficits in domains other than memory. The DSM-IV offers subtypes of amnestic disorders: amnestic disorder due to general medical condition, substance-induced (specifying alcohol, sedative-hypnotic, anxiolytic, or unknown substances) persisting amnestic disorder, and amnestic disorder not otherwise specified. These subtypes do not differ in clinical signs and symptoms but only in the putative etiology. Associated Signs and Symptoms. Confabulation refers to the fabrication of information

spontaneously or in response to questions. Confabulation can be distinguished from conscious dissimulation or lying, as the patient believes his or her utterances and has no intent to mislead. Confabulations are not delusions per se either: They lack the systematic and fixed quality of a delusion. Two types of confabulation are noted: the more common momentary

confabulations and the more fill in the gap quality:

rare, fantastic confabulations.

Typically, confabulations arise in response to a question and have a "Did you have your breakfast?" is met with the confabulatory response of "I certainly did, let's see ... a good breakfast at that: orange juice, eggs, bacon, and a blueberry muffin." The confabulations may not be noted until the patient is asked openended questions that challenge his or her recall of details. The content is mundane and related to the question at hand. Fantastic confabulations, on the other hand, are often offered spontaneously and are striking for their dramatic content. The fill-in-the-gaps quality of the confabulation has led many to associate confabulations with memory disorders. However, confabulations may relate more to a failure of executive function than memory dysfunction. This is clearly the case with fantastic confabulations as presented in the previous case. The notion of "little Indians" or Nazis populating the closets is striking more for its patent absurdity than for how it solves the riddle of what the noises are that are emanating from the closet. There is obviously a failure of the frontal lobe executive function responsible for inhibiting absurd interpretations and responses. This executive function has the role of censoring the hypotheses that other regions of the brain

develop as explanations for sensory stimuli. Confabulation and personality change are more common in diencephalic amnesia (e.g., Korsakoff's syndrome) than in pure hippocampal amnesia, perhaps reflecting a concomitant involvement of frontal lobe structures or connections. Personality Change. The personality change seen in amnestic disorders may involve apathy or irritability, or a combination of the two. The following case illustrates the inactivity and constriction of interests that can be seen, as well as the persistent irritability and agitation that can accompany the amnesia. Motor and Sensory Symptoms. Motor and sensory symptoms may variably accompany an amnestic disorder, depending on the etiology. Some amnestic syndromes, such as transient global amnesia, are striking for the preservation of motor and sensory function. In contrast, the vitamin deficiencies are often accompanied by motor and sensory symptoms that persist beyond the initial recovery from acute Wernicke's encephalopathy. Patients with amnestic disorders deriving from Wemicke-Korsakoff syndrome may have gait abnormalities due to peripheral neurop athies, muscle weakness, or gait instability related to the comorbid cerebellar degeneration of chronic alcoholism. The latter may also account for the frequently seen fine motor dyscoordination. Although the more striking ocular abnormalities related to an acute Wernicke's encephalopathy often resolve with vitamin replenishment, patients might still manifest residual restriction in gaze, as well as subtle lateral nystagmus. Anosmia can accompany some amnestic disorders, such as that due to herpes simplex

encephalitis and certain strokes. As described previously, the signs and symptoms of the amnestic disorder are not restricted to the domain of memory. The foltowing case exemplifies the more common real-life presentation of a patient with amnestic disorder. Although the primary and most obvious deficit is in memory, this patient also has obvious impairments in comportment and judgment. The latter appear as an exaggeration of premorbid traits. This case illustrates the devastating impact of memory impairment on daily functioning and the capacity to live independently. Assessment. The assessment of a memory disorder begins even before the patient is seen. Is it the patient calling with subjective worries regarding his or her memory function or is it a friend or relative calling with concerns that the patient seems unaware of? How the patient arrives for evaluation is pertinent. Did he or she travel alone and maneuver public transportation or was he or she driven? Many patients with severe amnestic disorders are evaluated on inpatient medical or psychiatric services, where they are held out of concern for their ability to manage on their own. The typical office or bedside examination can provide many clues. The Folstein MMSE is the most widely used cognitive screen and is available in a multitude of languages. Poor performance on the ten orientation items provides a general estimate of overall cognitive function. Although the overall score may not be reflective of severe impairment, specific answers can be informative. For example, responding "1968" to the year is far more suggestive of memory impairment, perhaps a retrograde amnesia of decades, than missing

the-year by 1 or 2 years. Asking the patient to repeat three items assesses registration or immediate recall. Patients with amnestic disorders ought to be able to repeat these items accurately.

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