Transcript DIAGNOSIS OF AZLHEIMER’S DISEASE
MILD COGNITIVE IMPAIRMENT
DIFFERENTIAL DIAGNOSIS
J. Wesson Ashford, M.D., Ph.D.
Stanford / VA Alzheimer’s Center VAMC, Palo Alto, California May 14, 2004
MILD COGNITIVE IMPAIRMENT CRITERIA
(Amer. Acad. Neurology)
(Petersen et al., 2001 – Neurology 56:1133) 1. Memory complaint, preferably corroborated by an informant 2. Objective memory impairment 3. Normal general cognitive function 4. Intact activities of daily living 5. Not demented - Earlier descriptions by: Jonker, Hooyer, 1990 Flicker, Ferris, Reisberg, 1991 Zaudig, 1992
Study Mayo Toronto Columbia MGH Seattle NYU
MILD COGNITIVE IMPAIRMENT ISSUES IN DEFINITION
(Petersen et al., 2001 – Neurology 56:1133) Mean Age Criteria 81 74 66 72 74 71 MCI Memory Impairment Questionable dementia CDR 0.5
Isolated memory loss GDS 3 Annual conversion rate to AD % 12 14 15 6 12 25
100% 90% 80% 70% 60% 50% 40% 30% 20% AD MCI Non-Affected 10% 0% 60 62 64 66 68 70 Markov Chain model 72
Age
74 76 78 80 82 84 Yesavavage et al., 2002
ALZHEIMER’S DISEASE
Estimate MMSE as a function of time
30 25 20 15 10 5 0 -10 -8 -6 -4 -2 0 2 4
Estimated years into illness
6 8 10 AAMI / MCI DEMENTIA Ashford et al., 1995
Age-Associated Memory Impairment vs Mild Cognitive Impairment
• Memory declines with age – need to consider relative to APOE genotype!
• Age - related memory decline corresponds with atrophy of the hippocampus • Older individuals remember more complex items and relationships • Older individuals are slower to respond • Memory problems predispose to development of Alzheimer’s disease • Thus --- screening for MCI / early AD must consider age!
– And should consider APOE genotype!
Early Recognition of AD: Consensus Statement (AAGP, AGS, Alzheimer’s Association)
• AD continues to be missed as diagnosis • AD is unrecognized and under-reported – patients do not realized – families tend to compensate • Effective treatment and management techniques are available – (AChEIs FDA approved) – Several other approaches are beneficial Small et al., JAMA, 1997
DIAGNOSTIC CRITERIA FOR DEMENTIA OF THE ALZHEIMER TYPE
(DSM-IV, APA, 1994) A. DEVELOPMENT OF MULTIPLE COGNITIVE DEFICITS 1. MEMORY IMPAIRMENT 2, OTHER COGNITIVE IMPAIRMENT B. THESE IMPAIRMENTS CAUSE DYSFUNCTION IN IN SOCIAL OR OCCUPATIONAL ACTIVITIES C. COURSE SHOWS GRADUAL ONSET AND DECLINE D. DEFICITS ARE NOT DUE TO: 1. OTHER CNS CONDITIONS 2. SUBSTANCE INDUCED CONDITIONS F. DO NOT OCCUR EXCLUSIVELY DURING DELIRIUM G. ARE NOT DUE TO OTHER PSYCHIATRIC DISORDER
Differential Diagnosis: Top Ten
(commonly used mnemonic device: AVDEMENTIA) 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Alzheimer Disease (pure ~40%, + mixed~70%) Vascular Disease, MID (5-20%) Drugs, Depression, Delirium Ethanol (5-15%) Medical / Metabolic Systems Endocrine (thyroid, diabetes), Ears, Eyes, Environ.
Neurologic (other primary degenerations, etc.) Tumor, Toxin, Trauma Infection, Idiopathic, Immunologic Amnesia, Autoimmune, Apnea, AAMI VA – consider PTSD, Gulf War Syndrome
Dementia Definition
• Multiple Cognitive Deficits: – Memory dysfunction • especially new learning, a prominent early symptom – At least one additional cognitive deficit • aphasia, apraxia, agnosia, or executive dysfunction • Cognitive Disturbances: – Sufficiently severe to cause impairment of occupational or social functioning and – Must represent a decline from a previous level of functioning
Alzheimer’s Disease versus Dementia
– 50 - 70% of dementias are AD – Probable AD - 30% of cases, 90% correct – 20% have other contributing diagnoses – Possible AD - 40% of cases, 70% correct – 40% have other contributing diagnoses – Unlikely AD - 30% of cases, 30% are AD – 80% have other contributing diagnoses
Vascular Dementia
(DSM-IV - APA, 1994) A. Multiple Cogntive Impairments 1. Memory Impairment 2. Other Cognitive Disturbances B. Deficits Impair Social/Occupational C. Focal Neurological Signs and Symptoms or Laboratory Evidence Indicating Cerebrovascular Disease Etiologically Related to the Deficits D. Not Due to Delirium
Factors Associated with Multi-infarct Dementia • History of stroke (especially in Nursing Home) – Followed by onset of dementia within 3 months • Abrupt onset, Step-wise deterioration • Cardiovascular disease - HTD, ASCVD, & Atrial Fib • Depression (left anterior strokes), personality change • More gait problems than in AD • MRI evidence of T2 changes (?? Binswanger’s disease) – Basal ganglia, putamen – Periventricular white matter • SPECT / PET show focal areas of dysfunction • Neuropsychological dysfunctions are patchy
VASCULAR DEMENTIA CHANGE ON THE MINI-MENTAL STATE EXAM OVERTIME
30 20 10 0 -5 < event < event < event 0 5
AVERAGE TIME OF ILLNESS (years)
10
Post-Cardiac Surgery
• 53% post-surgical confusion at discharge (delirium) • 42% impaired 5 years later (dementia) • May be related to anoxic brain injury, apnea • May be related to narcotic/other medication • May occur in those patients who would have developed dementia anyway (? genetic risk) • Cardio-vascular disease and stress may start Alzheimer pathology • Any surgery may have a similar effect related to peri-op or post-op anoxia or vascular stress Newman et al., 2001, NEJM
Drug Interactions
• Anticholinergics: amitriptyline, atropine, benztropine, scopolamine, hyoscyamine, oxybutynin, diphenhydramine, chlorpheniramine, many anti-histaminics – May aggravate Alzheimer pathology • GABA agonists: benzodiazepines, barbiturates, ethanol, anti-convulsants • Beta-blockers: propranolol • Dopaminergics: l-dopa, alpha-methyl-dopa • Narcotics: may contribute to dementia
Drug Toxicity
• Anti-cholinergic – Peripheral: blurred vision, dry mouth, constipation, urinary obstruction – Central: confusion, memory encoding block • Gaba-agonist: – Muscle relaxant, anti-convulsant, sedative, anti-anxiety, amnesic, confusion • Medication induced electrolyte imbalance – Confusion (watch for in nursing home)
Depression
• Onset: rapid • Precipitants: psycho-social (not organic) • Duration: less than 3 months to presentation • Mood: depressed, anxious • Behavior: decreased activity or agitation • Cognition: unimpaired or poor responses • Somatic symptoms: fatigue, lethargy, sleep, appetite disruption • Course: rapid resolution with treatment, but may precede Alzheimer’s disease
Delirium Definition
(more often a problem in medical in-patients) Disturbance of consciousness i.e., reduced clarity of awareness of the environment with reduced ability to focus, sustain, or shift attention Change in cognition (memory, orientation, language, perception) Development over a short period (hours to days), tends to fluctuate Evidence of medical etiology
Delirium
Susceptibility may be symptom of early dementia, or delirium may predispose to later dementia Predisposing factors dementia Age, infections, Medical conditions Infections: G.U. - urinary Respiratory (URI, pneumonia) G.I.
Constipation Drug toxicity Fracture (especially related to hip fracture)
Ethanol
• Possibly Neuroprotective – May not kill neurons directly (?Dietary recommendation?) • Accidents, Head Injury • Dietary Deficiency – Thiamine – Wernicke-Korsakoff syndrome • Hepatic Encephalopathy • Withdrawal Damage (seizures) Delayed Alcohol Withdrawal – Watch for in hospitalized patients • Chronic Neurodegeneration – Cerebellum, gray matter nuclei
Medical / Endocrine
• Thyroid dysfunction – Hypothyoidism – elevated TSH • Compensated hypothyroidism may have normal T4, FTI – Hyperthyroidism • Apathetic, with anorexia, fatigue, weight loss, increased T4 • Diabetes • Hypoglycemia (loss of recent memory since episode) • Hyperglycemia • Hypercalcemia • Nephropathy, Uremia • Hepatic dysfunction (Wilson’s disease) • Vitamin Deficiency (B12, thiamine, niacin) – Pernicious anemia – B12 deficiency, ?homocysteine
Eyes, Ears, Environment
• Must consider sensory deficits might contribute to the appearance of the patient being demented • Central Auditory Processing Deficits (CAPD) • Hearing problems are socially isolating • Visual problems are difficult to accommodate by a demented patient, ?To do cataract op?
• Environmental stress factors can predispose to a variety of conditions • Nutritional deficiencies (tea & toast syndrome)
Neurological Conditions
• Primary Neurodegenerative Disease – Diffuse Lewy Body Dementia (? 7 - 50%) – Note relation to Parkinson’s disease, symptoms – Hallucinations, fluctuating course, neuroleptic hypersensitivity) – Fronto-temporal dementia (tau gene) – Impaired attention, behavioral dyscontrol – Decrease blood flow, hypometaboism on SPECT / PET – (Pick’s disease, Argyrophylic grain disease) • Focal cortical atrophy – Primary progressive aphasia (many causes) – Unilateral atrophy, hypofunction on EEG, SPECT, PET • Normal pressure hydrocephalus – Dementia with gait impairment, incontinence – Suggested on CT, MRI; need tap, ventriculography
Other Neurologic Conditions
– Subdural hematoma – Huntington’s disease – Creutzfeldt-Jakob disease • Rapid progression • Characteristic EEG changes – Multiple sclerosis – Corticobasal degeneraton – Cerebellar degeneration – Progressive supranuclear palsey
• Tumor
– Primary brain tumor • M eningioma (treatable) • Glioma (usually not responsive to therapy) – Metastatic brain tumor – Remote effects of carcinoma •
Toxins
– Heavy metal screen if considered
Trauma
– Concussion, Contusion • Occult head trauma if recent fall – Subdural hematoma – Hydrocephalus: • Normal pressure (late effect of bleed) – Dementia pugilistica – Possible contributor to Alzheimer’s disease initiation and progression (? 4% of cases) – Concern re: physical abuse by caretakers
Infectious Conditions Affecting the Brain
– HIV – Neurosyphilis – Viral encephalitis (herpes) – Bacterial meningitis – Fungal (cryptococcus) – Prion (Creutzfeldt-Jakob disease); (mad cow disease)
AMNESIC DISORDER
DSM-IV A. Memory impairment - inability to learn new information, or - Inability to recall previously learned information • Memory disturbance significantly impairs social, occupational function, deterioration from past • Memory not due to delirium, dementia • Physiological basis or substance induced - Distinguish from dissociative disorders, dissociative amnesia, dissociative identity disorders • Specify - Transient – less than 1 month - Chronic - more than 1 month
Causes of Amnesic Disorders
• Amnesia – Dissociative: localized, selective, generalized – Organic - damage to CA1 of hippocampus • thiamine deficiency (WKE), hypoglycemia, hypoxia • Epileptic events – Partial complex seizures • Specific brain diseases – Transient global amnesia – Multiple sclerosis
Etiology of Alzheimer’s Disease
• Age (initial genesis vs response to stress) – Bigger factor than for mortality – Design in a plastic (memory) system, energy demands – Stressor response (inadequate repair mechanisms) • Trauma (head injury), vascular (stroke), surgery, loss, grief, immunological response, etc.
• Genetics (amyloid related) – Familial, early onset: APP (21), PS (14, 1) (less than 5%) – Late onset: APOE e4 (ch19) (40% to 90% of AD) • relation to brain cholesterol metabolism?
• APOE e2 may be most protective – many other candidate genes • Relation to vascular factors, cholesterol, BP • Education (? design vs protection) • Environment - diet, exercise, toxin, smoking, infectious agent
AD Is Often Misdiagnosed
Patient initially diagnosed with AD Patient’s first diagnosis other than AD
35% 14% 14% No 72% 9% 7% Yes 28% 21% Dementia (not AD) Depression Normal aging Stroke No diagnosis Other Source: Consumer Health Sciences, LLC. Alzheimer’s Caregiver Project. 1999.
AD is Underdiagnosed
• Early Alzheimer’s disease is subtle – it is easy for family members and physicians to miss the initial signs and symptoms • Less than half of AD patients are diagnosed – Estimates are that 25% to 50% of cases remain undiagnosed • Undiagnosed AD patients often face avoidable social, financial, and medical problems • Early diagnosis and appropriate intervention may lessen disease burden • No definitive laboratory test for diagnosing AD exists Evans DA. Milbank Quarterly. 1990; 68:267-289
AD Can Be Readily Diagnosed
McKhann G et al. Neurology. 1984;34:939-944. Kazee AM et al. Alzheimer Dis Assoc Disord. 1993;7:152-164.
• A diagnosis of Alzheimer’s disease can be made with a high degree of certainty • Using NINCDS-ADRDA criteria, accuracy in autopsy-verified cases is approximately 90% • Diagnosis is a 2-step process: – Detection through screening – Confirmation through patient history and physical, caregiver interview, brain imaging, and appropriate laboratory studies
Assessment
History Of The Development Of The Dementia – Ask the Patient What Problem Has Brought Him to See You – Ask the Family, Companion about the Problem – Specifically Ask about Memory Problems – Ask about the First Symptoms – Enquire about Time of Onset – Ask about Any Unusual Events Around the Time of Onset, e.g., stress, trauma, surgery – Ask about Nature and Rate of Progression • Physical Examination • Neurological Examination
RELATIVE RISK FACTORS FOR ALZHEIMER’S DISEASE
• Family history of dementia • Family history – Downs • Family history - Parkinson’s • Maternal age > 40 years • Head trauma (with LOC) • History of depression • History of hypothyroidism • History of severe headache • NSAID use or statin use 3.5 (2.6 - 4.6) 2.7 (1.2 - 5.7) 2.4 (1.0 - 5.8) 1.7 (1.0 - 2.9) 1.8 (1.3 - 2.7) 1.8 (1.3 - 2.7) 2.3 (1.0 - 5.4) 0.7 (0.5 - 1.0) 0.2 (0.05 – 0.83) Roca, 1994, t’Veldt, 2002
FACTORS INFLUENCING ALZHEIMER’S DISEASE (age at onset, rate of progression)
• age • sex • genotype (presenilin, APO-E) • education • environment (head injury) • surgery • psychological problems: depression, agitation, anxiety, sleep disturbance • medication
PHYSICAL/NEUROLOGICAL EXAMINATION
• CHECK BLOOD PRESSURE • IDENTIFY SYSTEMIC DISORDERS • CRANIAL NERVES – Olfactory dysfunction, poor eye tracking – Check for hearing, vision deficits • SENSORY DEFICITS – Proprioception, vibration • DEEP TENDON REFLEXES – Brisk, check for focal reflexes • PATHOLOGIC REFLEXES – Hyperactive snout reflex, Gegenhalten
NEUROPSYCHOLOGICAL TESTING (WAIS, WECHSLER)
• MEMORY: SHORT-TERM, REMOTE • VERBAL FUNCTION, FLUENCY • VISUO-SPATIAL FUNCTION • ATTENTION • EXECUTIVE FUNCTION • ABSTRACT THINKING • ACCOUNT FOR EDUCATION • ACCOUNT FOR PRIOR DISFUNCTIONS
CURRENT APPROACHES TO SEVERITY ASSESSMENT
• MINI-MENTAL STATE EXAM • CLOCK DRAWING • ANIMAL NAMING (1 minute) • MATTIS DEMENTIA RATING SCALE • ALZHEIMER’S DISEASE ASSESSEMENT SCALE (ADAS) • ACTIVITIES OF DAILY LIVING • GLOBAL CLINICAL SCALE • CLINICAL DEMENTIA RATING SCALE • GLOBAL DETERIORATION SCALE / FAST
LABORATORY TESTS (routine)
• BLOOD TESTS – electrolytes, liver, kidney function tests, glucose – thyroid function tests (T3, T4, FTI, TSH) – vitamin B12, folate – complete blood count, ESR – VDRL, HIV (if indicated) • EKG (if indicated) • CHEST X-RAY (if indicated) • URINALYSIS • ANATOMICAL BRAIN SCAN – CT (cheapest), MRI
SPECIAL LABORATORY TESTS
• FUNCTIONAL BRAIN IMAGING (SPECT, PET) • EEG, Evoked Potentials (P300) • REACTION TIMES (slowed in the elderly, especially when complex response is required • CSF ANALYSIS - ROUTINE STUDIES – ELEVATED TAU (future possible) – DECREASED AMYLOID (future possible) • HEAVY METAL SCREEN (24 hr urine) • GENOTYPING – APO-LIPOPROTEIN-E (for supporting diagnosis) – AUTOSOMAL DOMINANT (young onset)
Justification for Brain Scan in Dementia Diagnosis
• Differential Diagnosis: Tumor, Stroke, Subdural Hematoma, Normal Pressure Hydrocephalus, Encephalomalacia • Confirmation of atrophy pattern • Estimation of severity of brain atrophy • MRI shows T2 white matter changes – Periventricular, basal ganglia, focal vs confluent – These may indicate vascular pathology • SPECT, PET - estimation of regions of physiologic dysfunction, areas of infarction • Helps family to visualize problem
UCLA compound Shoghi-Jadid et al., 2002
67-year-old control Alzheimer patient PET brain images 2-(4’-methylamino-phenyl)-6-hydroxybenzothiazole (Pittsburgh Compound)
Genes and Alzheimer’s disease
(60% - 80 % of causation) (all known genes relate to b amyloid) • Familial AD (onset < 60 y/o) (<5%) – Presenilin I, II (ch 14, 1) – APP (ch 21) • Non-familial (late onset) – APOE • Clinical studies suggest 40 – 50% due to e 4 • If e2 is considered, may be 95% of causation • Population studies suggest 10 – 20% cause • Evolution over last 300,000 to 200,000 years – At least 20 other genes
APO-E genotype and AD risk
46 Million in US > 60 y/o //// 4 Million have AD (data from Saunders et al., 1993; Farrer et al., 1997) GenT %pop %AD #pop #AD risk If all US E2/2 1% 0.1% 0.5M .004M 0.8% .4 M E2/3 12 % 4% 5.5M .18M 3.2% 1.5 M E3/3 E3/4 60% 35% 27.6M 1.4M 5.1% 21% 42% 9.6M 1.7M 18% 2.3 M 8.2 M E4/4 2% 16% JW Ashford, MD PhD, 2003 .9M .6M 67% 30.7M
Are we ready to do genetic testing to predict AD?
• The family members want it – They consider recommendations against genetic testing to be “paternalistic” • Family members can make more powerful financial decisions based on this knowledge than the relevance of insurance companies implementing changes in actuarial calculations • Those at risk can seek more frequent testing – This is the best opportunity for early recognition • Those at risk will be better advocates for research • Specific preventive treatments can be developed for each genetic factor
2,500,000 2,250,000 2,000,000 1,750,000 1,500,000 1,250,000 1,000,000 750,000 500,000 250,000 0
U.S. Census 2000 by age
www.census.gov
Males, 138,053,563 Females, 143,368,343 Total = 281,421,906 >60 = 45,809,291 >65 = 35,003,844 >85 = 4,251,678 >100= 62,545 0 10 20 30 40 50 60 70 80 90 100
Age
JW Ashford, MD PhD, 2003
45,000 40,000 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0 0
U.S. mortality by age - 1999
www.cdc.gov
Males, 1,175,460 Females, 1,215,939 10 20 30 40 50
Age
60 70 80 90 100 JW Ashford, MD PhD, 2003
1.0000
0.1000
0.0100
U.S. mortality rate by age 1999 CDC / 2000 census
Males, 2t = 8.2yrs
Females, 2t = 7.5 yrs Alzheimer incidence 0.0010
0.0001
0 10 20 30 40
Age
50 60 70 80 90 100 JW Ashford, MD PhD, 2003
1 0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0 50
Probability Not Demented
60 70
Age
80 90 JW Ashford, MD PhD, 2003 100
16000 14000 12000 10000 8000 6000 4000 2000 0 50
U.S. Alzheimer Incidence (4 million / 8yr)
male=170,603 female=329,115 60 70 80
Age
JW Ashford, MD PhD, 2003 90 100
JW Ashford, MD PhD, 2003 (Incidence for a to a + 1 year)
1 0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0 50
Probability Not Demented
mean rate APOE 4/4 APOE 3/4 APOE 3/3 60 70
Age
80 90 JW Ashford, MD PhD, 2003 100
1 0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0 50
U.S. AD Incidence by APOE (proportion of cases)
4/4 3/4 3/3 60 70
Age
80 90 JW Ashford, MD PhD, 2000 100
Probability of Dementia Onset
0.04
0.03
APOE 4/4-M APOE 4/4-F APOE 3/4-M APOE 3/4-F APOE 3/3-M APOE 3/3-F 0.02
0.01
0 50 60 70 80 90
Age (single mortality correction)
100 JW Ashford, MD PhD, 2003
Cache County, probability of incident dementia Circles – females Squares - males Open – ApoE-e44 Gray – ApoE-e4/x Black – ApoE-ex/x Miech et al., 2002
Why Diagnose AD Early?
• Safety (driving, compliance, cooking, etc.) • Family stress and misunderstanding (blame, denial) • Early education of caregivers of how to handle patient (choices, getting started) • Advance planning while patient is competent (will, proxy, power of attorney, advance directives) • Patient’s and Family’s right to know • Specific treatments now available – May slow underlying disease process – May delay nursing home placement longer if started earlier
Need for Better Screening and Early Assessment Tools
• Genetic vulnerability testing (trait risk) • Vulnerability factors (education, occupation, head injury) • Early recognition (10 warning signs) • Screening tools (6th vital sign in elderly) • Positive diagnostic tests – CSF – tau levels elevated, amyloid levels low – Brain scan – PET – DDNP, Congo-red derivatives • Mild Dementia severity assessments • Detecting early change over time – predicting progression, measuring rate
Need for a Brief Screening Test for Alzheimer’s Disease
• Recent evidence of benefits of anti cholinesterase agents in the treatment of mild Alzheimer’s disease – Improvement of cognition – Slowing of progression
Alzheimer Warning Signs Top Ten
Alzheimer Association 1. Recent memory loss affecting job 2. Difficulty performing familiar tasks 3. Problems with language 4. Disorientation to time or place 5. Poor or decreased judgment 6. Problems with abstract thinking 7. Misplacing things 8. Changes in mood or behavior 9. Changes in personality 10. Loss of initiative
Available Screening Tests
• MMSE • Too long • 7-Minute Screen • Too complex • Clock Drawing Test • Not sensitive • Mini-cog • Complex scoring, unclear adequacy • Memory Impairment Screen • Need for slightly shorter, easier test 10 -- 15 min 7 – 10 min 2 – 4 min 3 – 5 min 4 min • (a suitably accurate test that takes less than 2 minutes is not available)
12 10 8 6 4 2 0 0
Anim als nam ed in 1 m in (m m s>19) - CERAD data set
10 20
num ber of anim als nam ed
30 Normal Controls, CS = 1, n = 386 Alzheimer patients, CS = 0, n = 380 40
Animals name d in 30 se conds (mms>19)
16 14 12 10 8 6 4 2 0 0 JW Ashford, MD PhD, 2001 5 10 15
number of animals named
20 Normal Controls, n=386 Mild Alzheimer Patients, n=380 25
Animal naming ROCs (AUC 15: 0.74; 30: 0.83; 45: 0.86; 60: 0.87)
100 90 80 13 70 60 50 10 11 40 7 12 30 5 8 20 10 0 0 10 14 9 20 6 15 10 30 16 7 11 17 8 40 50 60
False Positive Rate (% )
70 .
animals in 15 secs animals in 30 secs animals in 45 secs animals in 60 secs 80 90 100
Brief Alzheimer Screen (BAS)
• Repeat these three words: “apple, table, penny”.
• So you will remember these words, repeat them again.
• What is today’s date? • D = 1 if within 2 days.
• Spell the word “WORLD” backwards • S = 1 point for each word in correct order • “Name as many animals as you can in 30 seconds, GO!” • A = number of animals • “What were the 3 words I asked you to repeat?” (no prompts) • R = 1 point for each word recalled BAS = 3 x
R
+ 2/3 x
A
+ 5 x
D
+ 2 x
S
90 80 70 20 10 0 60 50 40 30 3-22 JW Ashford, MD PhD, 2001 23 Mild AD Control 24 25
BAS Score
26 27-39 Mendiondo et al., 2004
BRIEF ALZHEIMER SCREEN (Normal vs Mild AD, MMS>19)
20 100 90 26 25 27 14 10 11 12 13 80 70 60 50 8 9 animals 1 m AUC = 0.868
40 9 7 animals 30 s AUC = 0.828
30 20 6 MMSE AUC = 0.965
Date+3 Rec AUC = 0.875 10 BAS AUC = 0.983
0 0 10 20 30 40 50 60 70 80
False Positive Rate (%) (1-Specificity)
90 JW Ashford, MD PhD, 2003 100
CONCLUSIONS on the BAS
• A single cut-off score provides reasonable sensitivity and specificity for the diagnosis of AD within 2 – 3 minutes • Two cut-off points divide the population into 3 tiers – the first cut-off indicates a low likelihood of dementia – the second indicates a high likelihood of dementia – the remaining group falls into a ‘gray area’ in need of closer scrutiny, follow-up, and more extensive testing • A suitably short screen can be administered yearly to individuals over 60 y/o as a 6 th vital sign • Next direction – use of IRT to locate level of impairment
BLT/Ashford Memory Test (to detect AD onset)
• New test to screen patients for AD: – World-Wide Web – based testing, – CD-distribution – KIOSK administration • Determine level of ability / impairment • Test takes about 1-minute • Test can be repeated often (e.g., quarterly) • Any change over time can be detected • Test is at: www.ibaglobal.com/BLT • For info, new tests, see: www.medafile.com
, www.brainlane.net