- Email: [email protected]
Gender differences in navigation strategy, not performance
S22 P-043
Abstracts: Clinical Assessment / 1 (Suppl 1) (2005) FTD/ALS - A RARE CASE WITH COGNITIVE IMPAIRMENT AND VARIETY OF SPEECH DISORDERS
Katarzyna A. Gustaw1, Jolanta Panasiuk2; 1UMCS, IOAM, Lublin, Poland; 2UMCS, Lublin, Poland Background: Dementia rarely occurs in patients with ALS, although known associations include the Parkinson-ALS-dementia complex of Guam. In cases of sporadic forms of ALS-dementia complex, front temporal dementia is the most common clinical feature. We report a case of definite ALS with domination of progressive bulbar palsy and progressive cognitive impairment with variety of speech disorders. Methods: We studied 61 years old man with rapid progressive history of changes in mood and personality, and anxiety in the evening. One year later he developed attention loss, loss of verbal fluency leading to complete mutism, impairment of perceptual skills. Two years later he developed a full range of Motor Neuron Disease at the level of spinal cord and bulb as well as flaccid dysarthria manifested by breath, articulation, prosody and resonance disorders. We observed very rapid progression leading ultimately breath difficulties and respiratory failure. Patient underwent full general and neurological examination and neuropsychological assessment was carried out. Brain MRI and CT scans revealed cortical atrophy of frontal lobe. EEG was normal. Pattern in EMG was not different from that seen in ALS. El Escorial criteria were used to diagnose definite ALS. Patient was treated farmacologically as well as a bunch of rehabilitation methods were used. reported the sporadic case of MND and dementia with familial history of ALS and FTD. P-044
TRANSITION FROM NORMAL COGNITION TO AMNESTIC MCI TO DAT: A TEN-YEAR LONGITUDINAL CASE STUDY WITH ANNUAL COMPREHENSIVE COGNITIVE ASSESSMENTS
Ronald F. Zec, Nicole R. Burkett; SIU School of Medicine, Springfield, IL, USA Background: Although considerable research in recent years has focused on the transition from Mild Cognitive Impairment (MCI) to dementia, there is very little detailed study of the transition from normal cognition to MCI and dementia. Objective: We studied the transition from clearly intact memory and cognitive functioning to mild cognitive impairment of the amnestic type to very early dementia of the Alzheimer type (DAT) in a woman with a family history of DAT using annual evaluations with a comprehensive cognitive test battery over a 10-year period. Methods: The woman was 74 years old at the first evaluation and was 83 years old at the most recent evaluation. She has 18-years of education (master’s degree in education) and is a retired high school biology teacher. The 3.5 hour test battery used in this study included the extended Alzheimer Disease Assessment Scale and additional tests of mental status, attention, new learning and memory, language, visuospatial functioning, and problem solving ability. Conclusions: The patient displayed average or better memory and cognition on all test measures using age norms at her first assessment at age 74. She subsequently displayed a gradually progressive decline on measures of new learning and memory (i.e., episodic memory) over the next ten years beginning with small declines on sensitive memory measures (e.g., 30-minute delayed recall on the Rey Auditory Verbal Learning Test) and resulting in severe impairment in episodic memory by age 78. A severe amnestic amnesia preceded any measurable decline on the non-memory measures. This case demonstrates that the progressive memory decline in DAT can occur gradually over seven or more years before there is any measurable impairment in non-memory cognitive functions even when a comprehensive neuropsychological battery is used to chart the course of decline in both memory and non-memory cognitive functioning. Further research is needed to study the transition from normal cognition to MCI to early dementia to determine how common (i.e., representative) this course of memory and cognitive decline is among patients with DAT and to
describe other patterns and rates of memory and cognitive decline in other DAT patients. P-045
CHRONOLOGICAL EVENTS OF NEUROLOGICAL DISEASES
Harendra I. Joshi; Joshi Research Centre, Mumbai, India Principle: Dr Constantine Hering’s Law of cure: “The cure must always take place from above downward, from within outward, from organs of greater importance, to organs of lesser importance and in the reverse order of the appearance of the symptoms” GROUPING OF DISEASES: Number of In India Patients 918 934 437
308 311 208 79
Location of diseases
713 Ectoderm 717 344 217 466 Endoderm Respiratory system Urinary system G.I.Tract 307 150 54 131 Mesoderm Myotone- muscles, blood, lymph etc Dermotone- Dermis Osteotone- Joints, cartilages etc 223 Organs involvement- Heart, Liver, Kidneys etc, 213 Endocrinal involvement- Pancreas, thyroid, ovaries, adrenals, etc 74 Neural plate-A, Central Nervous system, B, Sympathetic Nervous System 54 Mind- Neurotic disorders Psychotic disorders
we could establish with substantial evendences at our research centre that diseases always travels in the REVERSE orders of Dr Constantine Hering’s Law of Ideal Cure. (Herring Law of Cure states; “ The cure must always take place from above downward, from within outward, from organs of greater importance, to organs of lesser importance and in the reverse order of the appearance of the symptoms”The representations of diseases follow the following stepladder events or complex events, Level: 1, Ectoderm-----Skin. The most outward layer of body, Level: 2, Endoderm----A Respiratory Tract, B Urinary Tract C Gastro intestinal Tract (Widely known fact that when skin eczema or atopic dermatitis is suppressed with steroids, asthma is bound to appear or Vice versa) Level: 3, Mesoderm------Connective tissues, A, Myotone_muscles, blood, lymph etc, B, Dermotone---Dermis C, Osteotone-----Joints, cartilages etc Level: 4, Organs--- Heart, Liver, Kidneys etc, Level: 5, Endocrinal---- Pancreas, thyroid, ovaries, adrenals, Level: 6, Neural plates------A, Central Nervous system, B, Sympathetic Nervous System, Level: 7 Mind-----------Psychotic disorders, Neurotic disorders, E.g. Schizophrenias, Insanity etc, Considering the same sequence and principle we could draw conclusions regarding body secretions, external and internal both. The most important and highest important secretions are produced by Level: 7. Secretions are Neurotransmitters (dopamine, serotonin, acetylecholine etc) whereas the secretions from Level: 1 is perspiration and sebum. Even at the functional level also the principle remains the same. (As if diseases travels from perspiration to neurotransmitters) Formations complex, Following factors have studied in detail, In all diseases, pathological or microscopic changes are not the causative factors for the formation of diseases but these are the end result of diseases. P-046
GENDER DIFFERENCES IN NAVIGATION STRATEGY, NOT PERFORMANCE
Laura A. Cushman, Charles J. Duffy, Teresa Stefenella, William K. Vaughn; University of Rochester, Rochester, NY, USA Background: Men and women are thought to use different approaches to finding their way but both genders show progressive impairments of navigational capacities in Alzheimer’s disease (AD). Objective: We previously found no differences between men and women in total (summed) navigation scores. However, further analyses showed significant gender differences among subtests. Methods: We conducted a variety of navigational tests, neuropsychological tests and psychophysical tests in men and
Abstracts: Clinical Assessment / 1 (Suppl 1) (2005) women with AD. We found the same overall degree of impairment but very different types of errors in men and women. There were small gender differences in psychophysical tests of visuospatial perception and neuropsychological tests of cognitive function. However, there were large differences in how these measures related to navigational impairment in men and women. Conclusions: Men showed strong links between visuospatial processing and navigational performance, whereas women showed strong links between verbal capacities and navigational performance. Our findings suggest that navigational impairment in AD forces greater reliance on perceptually mediated path cues in men and on verbally mediated landmark cues in women. P-047
THE APPLICABILITY OF CURRENT CONCEPTS OF MCI TO EARLY PRESENILIN-1 RELATED ALZHEIMER’S DISEASE
John M. Ringman1, Yaneth Rodriguez2, Claudia Diaz-Olavarrieta2, Mireya Chavez2, Lynn Fairbanks1, Miguel Angel Macias-Islas3, Jill Murrell4, Berndardino Ghetti4, Claudia H. Kawas5; 1University of California, Los Angeles, Los Angeles, CA, USA; 2National Institute of Neurology and Neurosurgery, Mexico City, Mexico; 3Neurosciences Department, University of Guadalajara, Guadalajara, Mexico; 4 Department of Pathology and Laboratory Medicine, University of Indiana School of Medicine, Indianapolis, IN, USA; 5University of California, Irvine, Irvine, CA, USA Background: Persons at risk for the inheritance of mutations in genes causing autosomal dominant Alzheimer’s Disease (AD) provide a unique opportunity to study clinical, imaging, and biochemical markers of the early stages of the illness. However, there are some phenotypic differences between this form of the illness and the more common late-onset AD. Current concepts of early AD focus on a clinically-defined state of mild cogntive impairment, or 佣MCI,” with an emphasis on the amnestic subtype. Objective(s): The objective of this study was to apply the Petersen criteria for MCI to persons at-risk for the inheritance of Presenilin-1 (PS1) mutations to ascertain the applicability of these categories to this population. Methods: Fifty-one non-demented Mexican persons at-risk for the inheritance of PS1 mutations (30 with PS1 mutations, 21 without) underwent genetic and Spanish-language neuropsychological testing. Z-scores were calculated for each subject on each test with reference to the means and standard deviations of those not carrying PS1 mutations. These were then averaged to create composite scores for Verbal Memory, Executive Function/Working Memory, Language, and Visuospatial domains. Depending on these scores and the presence or absence of a cognitive complaint, subjects were categorized into: 1) MCI, amnestic subtype 2) MCI, non-amnestic single domain subtype, and 3) MCI, multiple domains subtype. Two mutation carriers qualified for the non-amnestic single domain subtype and 5 qualified for the multiple domains subtype of MCI. In all subjects qualifying for MCI, Executive Function/Working Memory was one of the affected domains. No subjects qualified for the amnestic subtype of MCI. Conclusions: Though this study was limited by a relative lack of tests assessing delayed memory, it suggests that the category of amnestic MCI as a strong predictor of AD is less useful in persons at-risk for AD by virtue of PS1 mutations. This is at least partly explained by a larger decline in executive function occurring early in this form of AD. P-048
COMPARISON OF ERP SPECTRAL BANDS FOR EARLY DIAGNOSIS OF ALZHEIMER DISEASE USING MULTIRESOLUTION WAVELET ANALYSIS
Apostolos Topalis1, Nicholas Stepenosky1, Jennifer Frymiare2, John Kounios2, Christopher Clark3, Robi Polikar1; 1Rowan University, Glassboro, NJ, USA; 2Drexel University, Philadelphia, PA, USA; 3 University of Pennsylvania, Philadelphia, PA, USA Background: While the positive predictive value of clinical diagnosis of Alzheimer’s disease (AD) is around 93% with an overall performance of
S23
75% at university hospitals, most patients are evaluated at community clinics where the expertise and the accuracy of the disease specific dementia diagnosis remains uncertain. We describe a multiresolution wavelet and artificial neural network (ANN) based automated classification technique for early diagnosis of AD based on the analysis of event related potentials (ERP), obtained through the oddball paradigm. The ERPs are multi-component, spectrally non-stationary signals that can provide a sensitive physiologic measure of the integrity of the underlying neuronal circuitry in the temporal and parietal regions. The non-stationary and multi-component nature of the ERPs makes wavelet analysis a well suited approach. Objective: To determine which time-frequency components of the ERPs carry the most relevant information for distinguishing AD patients from normal controls, and whether such information is adequate to render the wavelet and neural network based automated classification a viable approach for AD diagnosis at community clinics. Methods: ERP data are obtained from a cohort of probable AD patients and normal individuals using the oddball paradigm with novel sounds. To date, data from 32 patients - 12 diagnosed with probable-AD, and 20 cognitively normal controls - have been analyzed. The average age of both cohorts was 76 with average MMS scores of 29.5 (⫽0.6) and 22.4 (⫽4.2), for controls and probable-AD patients, respectively. Seven-level wavelet decomposition using the Daubechies-4 wavelet was performed to divide the ERPs into following frequency bands: (0-1), (1-2), (2-4), (4-8), (8-16), and (16-32) Hz. A multilayered perceptron ANN has been trained and tested (using leave-one-out cross-validation) for each frequency band in order to determine which band is most informative in classifying ERP signals, and whether the approach can prove to be a useful diagnostic tool. Conclusions: This study shows that the most informative features are found in the (2-4 Hz, which includes P300) and the (0-1 Hz) frequency ranges. These ranges had an overall classification performance of 84% and 77.5%, respectively, making ERPs a potentially useful biomarker, and wavelet/ neural network analysis a promising approach. P-049
MEMTRAX COMPUTERIZED MEMORY TEST, A ONE-MINUTE DEMENTIA SCREEN
J. W. Ashford; Stanford / VA Alzheimer Center, Palo Alto, CA, USA Background: There is a need for a single, brief screening test for early dementia, mild cognitive impairment, and pre-symptomatic Alzheimer’s disease that can be administered in a wide variety of settings with great flexibility of modality, e.g., doctor’s office, on-line, kiosk in drug store, booth at community health center. Such a test can be developed with a computer language that is easy and fun to take and still provide high discrimination between normal and impaired function inexpensively in a very brief period of time. Objective: To present the development of a computerized screening test. Methods: The Memtrax test is based on short-term memory, perception of complex objects, recognition, and recognition reaction-time. The test presents a series of pictures and requires recall of the pictures for recognition later in the series. The only response required of the individual taking the test is to press the space bar when a picture is repeated. Conclusions: Indications from administration of the test to patients presenting for assessment in a Memory Disorders Clinic and controls are that the test clearly discriminates normal individuals from patients with mild cognitive impairment and both of these from mild dementia patients. Most normal individuals make fewer than 10% errors and have a recognition reaction time less than 1 second. Patients with mild cognitive impairment generally make 10-25% errors and have recognition reaction times of 1 to 1.3 seconds. Mild dementia patients make 25-40% errors and have recognition reaction times of 1.2 to 1.6 seconds, and patients with moderate dementia score about chance (around 50% errors) with recognition reaction times over 1.6 seconds. The test can be administered on-line and is flexible so that scoring can be monitored and the test continually improved to provide more precise and reliable characterization of patients’ levels of impairment. A test such as this can easily be administered in a variety of settings and provide an economical means to identify those individuals that should be further examined for significant memory impairment.
Abstracts: Clinical Assessment / 1 (Suppl 1) (2005) FTD/ALS - A RARE CASE WITH COGNITIVE IMPAIRMENT AND VARIETY OF SPEECH DISORDERS
Katarzyna A. Gustaw1, Jolanta Panasiuk2; 1UMCS, IOAM, Lublin, Poland; 2UMCS, Lublin, Poland Background: Dementia rarely occurs in patients with ALS, although known associations include the Parkinson-ALS-dementia complex of Guam. In cases of sporadic forms of ALS-dementia complex, front temporal dementia is the most common clinical feature. We report a case of definite ALS with domination of progressive bulbar palsy and progressive cognitive impairment with variety of speech disorders. Methods: We studied 61 years old man with rapid progressive history of changes in mood and personality, and anxiety in the evening. One year later he developed attention loss, loss of verbal fluency leading to complete mutism, impairment of perceptual skills. Two years later he developed a full range of Motor Neuron Disease at the level of spinal cord and bulb as well as flaccid dysarthria manifested by breath, articulation, prosody and resonance disorders. We observed very rapid progression leading ultimately breath difficulties and respiratory failure. Patient underwent full general and neurological examination and neuropsychological assessment was carried out. Brain MRI and CT scans revealed cortical atrophy of frontal lobe. EEG was normal. Pattern in EMG was not different from that seen in ALS. El Escorial criteria were used to diagnose definite ALS. Patient was treated farmacologically as well as a bunch of rehabilitation methods were used. reported the sporadic case of MND and dementia with familial history of ALS and FTD. P-044
TRANSITION FROM NORMAL COGNITION TO AMNESTIC MCI TO DAT: A TEN-YEAR LONGITUDINAL CASE STUDY WITH ANNUAL COMPREHENSIVE COGNITIVE ASSESSMENTS
Ronald F. Zec, Nicole R. Burkett; SIU School of Medicine, Springfield, IL, USA Background: Although considerable research in recent years has focused on the transition from Mild Cognitive Impairment (MCI) to dementia, there is very little detailed study of the transition from normal cognition to MCI and dementia. Objective: We studied the transition from clearly intact memory and cognitive functioning to mild cognitive impairment of the amnestic type to very early dementia of the Alzheimer type (DAT) in a woman with a family history of DAT using annual evaluations with a comprehensive cognitive test battery over a 10-year period. Methods: The woman was 74 years old at the first evaluation and was 83 years old at the most recent evaluation. She has 18-years of education (master’s degree in education) and is a retired high school biology teacher. The 3.5 hour test battery used in this study included the extended Alzheimer Disease Assessment Scale and additional tests of mental status, attention, new learning and memory, language, visuospatial functioning, and problem solving ability. Conclusions: The patient displayed average or better memory and cognition on all test measures using age norms at her first assessment at age 74. She subsequently displayed a gradually progressive decline on measures of new learning and memory (i.e., episodic memory) over the next ten years beginning with small declines on sensitive memory measures (e.g., 30-minute delayed recall on the Rey Auditory Verbal Learning Test) and resulting in severe impairment in episodic memory by age 78. A severe amnestic amnesia preceded any measurable decline on the non-memory measures. This case demonstrates that the progressive memory decline in DAT can occur gradually over seven or more years before there is any measurable impairment in non-memory cognitive functions even when a comprehensive neuropsychological battery is used to chart the course of decline in both memory and non-memory cognitive functioning. Further research is needed to study the transition from normal cognition to MCI to early dementia to determine how common (i.e., representative) this course of memory and cognitive decline is among patients with DAT and to
describe other patterns and rates of memory and cognitive decline in other DAT patients. P-045
CHRONOLOGICAL EVENTS OF NEUROLOGICAL DISEASES
Harendra I. Joshi; Joshi Research Centre, Mumbai, India Principle: Dr Constantine Hering’s Law of cure: “The cure must always take place from above downward, from within outward, from organs of greater importance, to organs of lesser importance and in the reverse order of the appearance of the symptoms” GROUPING OF DISEASES: Number of In India Patients 918 934 437
308 311 208 79
Location of diseases
713 Ectoderm 717 344 217 466 Endoderm Respiratory system Urinary system G.I.Tract 307 150 54 131 Mesoderm Myotone- muscles, blood, lymph etc Dermotone- Dermis Osteotone- Joints, cartilages etc 223 Organs involvement- Heart, Liver, Kidneys etc, 213 Endocrinal involvement- Pancreas, thyroid, ovaries, adrenals, etc 74 Neural plate-A, Central Nervous system, B, Sympathetic Nervous System 54 Mind- Neurotic disorders Psychotic disorders
we could establish with substantial evendences at our research centre that diseases always travels in the REVERSE orders of Dr Constantine Hering’s Law of Ideal Cure. (Herring Law of Cure states; “ The cure must always take place from above downward, from within outward, from organs of greater importance, to organs of lesser importance and in the reverse order of the appearance of the symptoms”The representations of diseases follow the following stepladder events or complex events, Level: 1, Ectoderm-----Skin. The most outward layer of body, Level: 2, Endoderm----A Respiratory Tract, B Urinary Tract C Gastro intestinal Tract (Widely known fact that when skin eczema or atopic dermatitis is suppressed with steroids, asthma is bound to appear or Vice versa) Level: 3, Mesoderm------Connective tissues, A, Myotone_muscles, blood, lymph etc, B, Dermotone---Dermis C, Osteotone-----Joints, cartilages etc Level: 4, Organs--- Heart, Liver, Kidneys etc, Level: 5, Endocrinal---- Pancreas, thyroid, ovaries, adrenals, Level: 6, Neural plates------A, Central Nervous system, B, Sympathetic Nervous System, Level: 7 Mind-----------Psychotic disorders, Neurotic disorders, E.g. Schizophrenias, Insanity etc, Considering the same sequence and principle we could draw conclusions regarding body secretions, external and internal both. The most important and highest important secretions are produced by Level: 7. Secretions are Neurotransmitters (dopamine, serotonin, acetylecholine etc) whereas the secretions from Level: 1 is perspiration and sebum. Even at the functional level also the principle remains the same. (As if diseases travels from perspiration to neurotransmitters) Formations complex, Following factors have studied in detail, In all diseases, pathological or microscopic changes are not the causative factors for the formation of diseases but these are the end result of diseases. P-046
GENDER DIFFERENCES IN NAVIGATION STRATEGY, NOT PERFORMANCE
Laura A. Cushman, Charles J. Duffy, Teresa Stefenella, William K. Vaughn; University of Rochester, Rochester, NY, USA Background: Men and women are thought to use different approaches to finding their way but both genders show progressive impairments of navigational capacities in Alzheimer’s disease (AD). Objective: We previously found no differences between men and women in total (summed) navigation scores. However, further analyses showed significant gender differences among subtests. Methods: We conducted a variety of navigational tests, neuropsychological tests and psychophysical tests in men and
Abstracts: Clinical Assessment / 1 (Suppl 1) (2005) women with AD. We found the same overall degree of impairment but very different types of errors in men and women. There were small gender differences in psychophysical tests of visuospatial perception and neuropsychological tests of cognitive function. However, there were large differences in how these measures related to navigational impairment in men and women. Conclusions: Men showed strong links between visuospatial processing and navigational performance, whereas women showed strong links between verbal capacities and navigational performance. Our findings suggest that navigational impairment in AD forces greater reliance on perceptually mediated path cues in men and on verbally mediated landmark cues in women. P-047
THE APPLICABILITY OF CURRENT CONCEPTS OF MCI TO EARLY PRESENILIN-1 RELATED ALZHEIMER’S DISEASE
John M. Ringman1, Yaneth Rodriguez2, Claudia Diaz-Olavarrieta2, Mireya Chavez2, Lynn Fairbanks1, Miguel Angel Macias-Islas3, Jill Murrell4, Berndardino Ghetti4, Claudia H. Kawas5; 1University of California, Los Angeles, Los Angeles, CA, USA; 2National Institute of Neurology and Neurosurgery, Mexico City, Mexico; 3Neurosciences Department, University of Guadalajara, Guadalajara, Mexico; 4 Department of Pathology and Laboratory Medicine, University of Indiana School of Medicine, Indianapolis, IN, USA; 5University of California, Irvine, Irvine, CA, USA Background: Persons at risk for the inheritance of mutations in genes causing autosomal dominant Alzheimer’s Disease (AD) provide a unique opportunity to study clinical, imaging, and biochemical markers of the early stages of the illness. However, there are some phenotypic differences between this form of the illness and the more common late-onset AD. Current concepts of early AD focus on a clinically-defined state of mild cogntive impairment, or 佣MCI,” with an emphasis on the amnestic subtype. Objective(s): The objective of this study was to apply the Petersen criteria for MCI to persons at-risk for the inheritance of Presenilin-1 (PS1) mutations to ascertain the applicability of these categories to this population. Methods: Fifty-one non-demented Mexican persons at-risk for the inheritance of PS1 mutations (30 with PS1 mutations, 21 without) underwent genetic and Spanish-language neuropsychological testing. Z-scores were calculated for each subject on each test with reference to the means and standard deviations of those not carrying PS1 mutations. These were then averaged to create composite scores for Verbal Memory, Executive Function/Working Memory, Language, and Visuospatial domains. Depending on these scores and the presence or absence of a cognitive complaint, subjects were categorized into: 1) MCI, amnestic subtype 2) MCI, non-amnestic single domain subtype, and 3) MCI, multiple domains subtype. Two mutation carriers qualified for the non-amnestic single domain subtype and 5 qualified for the multiple domains subtype of MCI. In all subjects qualifying for MCI, Executive Function/Working Memory was one of the affected domains. No subjects qualified for the amnestic subtype of MCI. Conclusions: Though this study was limited by a relative lack of tests assessing delayed memory, it suggests that the category of amnestic MCI as a strong predictor of AD is less useful in persons at-risk for AD by virtue of PS1 mutations. This is at least partly explained by a larger decline in executive function occurring early in this form of AD. P-048
COMPARISON OF ERP SPECTRAL BANDS FOR EARLY DIAGNOSIS OF ALZHEIMER DISEASE USING MULTIRESOLUTION WAVELET ANALYSIS
Apostolos Topalis1, Nicholas Stepenosky1, Jennifer Frymiare2, John Kounios2, Christopher Clark3, Robi Polikar1; 1Rowan University, Glassboro, NJ, USA; 2Drexel University, Philadelphia, PA, USA; 3 University of Pennsylvania, Philadelphia, PA, USA Background: While the positive predictive value of clinical diagnosis of Alzheimer’s disease (AD) is around 93% with an overall performance of
S23
75% at university hospitals, most patients are evaluated at community clinics where the expertise and the accuracy of the disease specific dementia diagnosis remains uncertain. We describe a multiresolution wavelet and artificial neural network (ANN) based automated classification technique for early diagnosis of AD based on the analysis of event related potentials (ERP), obtained through the oddball paradigm. The ERPs are multi-component, spectrally non-stationary signals that can provide a sensitive physiologic measure of the integrity of the underlying neuronal circuitry in the temporal and parietal regions. The non-stationary and multi-component nature of the ERPs makes wavelet analysis a well suited approach. Objective: To determine which time-frequency components of the ERPs carry the most relevant information for distinguishing AD patients from normal controls, and whether such information is adequate to render the wavelet and neural network based automated classification a viable approach for AD diagnosis at community clinics. Methods: ERP data are obtained from a cohort of probable AD patients and normal individuals using the oddball paradigm with novel sounds. To date, data from 32 patients - 12 diagnosed with probable-AD, and 20 cognitively normal controls - have been analyzed. The average age of both cohorts was 76 with average MMS scores of 29.5 (⫽0.6) and 22.4 (⫽4.2), for controls and probable-AD patients, respectively. Seven-level wavelet decomposition using the Daubechies-4 wavelet was performed to divide the ERPs into following frequency bands: (0-1), (1-2), (2-4), (4-8), (8-16), and (16-32) Hz. A multilayered perceptron ANN has been trained and tested (using leave-one-out cross-validation) for each frequency band in order to determine which band is most informative in classifying ERP signals, and whether the approach can prove to be a useful diagnostic tool. Conclusions: This study shows that the most informative features are found in the (2-4 Hz, which includes P300) and the (0-1 Hz) frequency ranges. These ranges had an overall classification performance of 84% and 77.5%, respectively, making ERPs a potentially useful biomarker, and wavelet/ neural network analysis a promising approach. P-049
MEMTRAX COMPUTERIZED MEMORY TEST, A ONE-MINUTE DEMENTIA SCREEN
J. W. Ashford; Stanford / VA Alzheimer Center, Palo Alto, CA, USA Background: There is a need for a single, brief screening test for early dementia, mild cognitive impairment, and pre-symptomatic Alzheimer’s disease that can be administered in a wide variety of settings with great flexibility of modality, e.g., doctor’s office, on-line, kiosk in drug store, booth at community health center. Such a test can be developed with a computer language that is easy and fun to take and still provide high discrimination between normal and impaired function inexpensively in a very brief period of time. Objective: To present the development of a computerized screening test. Methods: The Memtrax test is based on short-term memory, perception of complex objects, recognition, and recognition reaction-time. The test presents a series of pictures and requires recall of the pictures for recognition later in the series. The only response required of the individual taking the test is to press the space bar when a picture is repeated. Conclusions: Indications from administration of the test to patients presenting for assessment in a Memory Disorders Clinic and controls are that the test clearly discriminates normal individuals from patients with mild cognitive impairment and both of these from mild dementia patients. Most normal individuals make fewer than 10% errors and have a recognition reaction time less than 1 second. Patients with mild cognitive impairment generally make 10-25% errors and have recognition reaction times of 1 to 1.3 seconds. Mild dementia patients make 25-40% errors and have recognition reaction times of 1.2 to 1.6 seconds, and patients with moderate dementia score about chance (around 50% errors) with recognition reaction times over 1.6 seconds. The test can be administered on-line and is flexible so that scoring can be monitored and the test continually improved to provide more precise and reliable characterization of patients’ levels of impairment. A test such as this can easily be administered in a variety of settings and provide an economical means to identify those individuals that should be further examined for significant memory impairment.