Below you can browse publications from our partners and providers.
Computerized Neurocognitive Test (CNT)
Differentiating Between MCI and Early Dementia with a New Computerized Neurocognitive Screening Battery.
Mild Cognitive Impairment (MCI) is an abnormal, state of cognitive impairment intermediate between normal ageing and very early dementia. The earliest descriptions of MCI focused on patients with memory impairment; more recent studies have established other forms of MCI, based on impairment in executive control functions, and deficits in other areas as well. Screening for MCI and early dementia, therefore, must include a range of neurocognitive tests, not just tests of memory. Computerized Neurocognitive Testing (CNT) has the potential to administer tests of multiple cognitive domains, inexpensively, and in a short time. CNT”s represent a new tradition in mental testing, based on the earlier traditions of psychophysics, educational testing, and neuropsychology, but different as well. CNT is designed to test large numbers of people who may have very mild cognitive impairments related to 21st century problems: sports injuries, the effects of drugs and medical procedures like CABG, and ageing.
To validate a CNT, CNS Vital Signs, that can differentiate normal ageassociated memory impairment (AAMI) from MCI and mild dementia (MD). SUBJECTS: Patients at the NC Neuropsychiatry Clinics clinically diagnosed, by standard criteria, with MCI (N=36) or mild dementia (N=53), and 89 normal controls, matched for age, race and gender. METHODS: “CNS Vital Signs” is a PC-based neurocognitive screening battery, comprised of seven familiar tests: Verbal and Visual Memory, Tapping, Coding, the Stroop test, Shifting Attention and the CPT. The test battery is self-administered on an ordinary PC, and takes 30 minutes. The tests in the “Vital Signs” battery are highly reliable (Figure 1). Normative data from 600 normal subjects, age 10-90, indicates typical performance differences by age and gender (Figure 2). During the fifth decade of life, patients with MCI begin to diverge from normals on tests in the Vital Signs battery (Figure 3).
Test performance on the Vital Signs battery differed significantly among the three groups (AAMI, MCI, MD) in tests of memory, psychomotor speed, reaction time, cognitive flexibility and complex attention (General Linear Model). ROC analysis indicate acceptable levels of sensitivity and specificity especially for tests of memory, executive control and information processing speed (Figures 4,5,6; Table 1).
These data validate the use of CNS Vital Signs to identify patients with MCI and early dementia. CNT is ideally suited to serve as a screening tool in primary care settings, to identify patients with the earliest manifestations of dementing illness. It is ironic, that of all the serious medical conditions, dementia is the one for which the importance of early diagnosis has never been deemed important. The public health would be well served if CNT were used routinely: by primary care physicians as part of their annual examinations; perhaps also to screen elderly drivers, or to evaluate workers who are engaged in potentially hazardous occupations.Download PDF
Computerized Neurocognitive Test Batteries for Dementia Screening.
AD, even in its earliest stages, is not just a disease of memory. Long before any clinical signs are apparent, there are signs of cognitive weakness in various cognitive areas. The earliest “detectable cognitive deficits” are not only tests of verbal and visual memory but also measures of complex attention, executive control and reaction time/information processing speed. The diversity of the dementias, and the diversity of the neuropsychological symptoms of dementia, means that no single test is sufficient for the purpose of diagnosis or screening. Rather, a battery of neurocognitive tests is necessary. The commonality shared by all forms of dementia, however, indicates that an appropriate battery can comprise only a few well-chosen tests. This is important, because the major issue in dementia diagnosis is not necessarily to sub-type the various forms of the condition, but, rather, to make the diagnosis as early as possible. In the past couple of years, highly precise and reliable instruments have come available to screen for mild cognitive dysfunction in general, and early, presymptomatic dementia in particular. They are computerized neurocognitive test batteries. They are derived from the PC-based neuropsychological batteries that have been used for 20 years in military and aerospace medicine, in the pharmaceutical industry, in industrial and in sports medicine. In those settings, they are used to detect mild cognitive dysfunction related to many different causes. Now, several computer-based test batteries have been introduced as clinical screening tools (Table 1).Download PDF
Neurocognitive Testing Supports a Broader Concept of Mild Cognitive Impairment.
The narrow concept of Mild Cognitive Impairment (MCI) as an early form of Alzheimer’s disease (AD) has been broadened by research that established the existence of alternative forms of the condition that may presage other forms of dementia. METHOD: This was a naturalistic, cross-sectional study of patients in a community refrral clinic: patients with MCI and mild dementia (MD), compared to normal controls. A comprehensive computerized neurocognitive screening battery (CNS Vital Signs) was administered to all of the subjects. SUBJECTS: Thirty-six patients with MCI and 53 patients with mild dementia, diagnosed by standard criteria, compared to 89 matched normal controls. RESULTS: Multivariate analysis indicated significant differences among the three groups for all 15 primary test variables and for all five domain scores. Tests of memory, processing speed and cognitive flexibility were the most cogent discriminators between normals and MCI patients, and between MCI patients and patients with mild dementia. Tests of memory, processing speed and cognitive flexibility had the greatest sensitivity and specificity. CONCLUSIONS: Computerized testing can differentiate among normals, MCI patients and patients with mild dementia. In a diverse group of MCI and MD patients, impairments in memory, processing speed and cognitive flexibility were the most prominent deficits.Download PDF
A Computerized Neurocognitive Test Battery To Detect Malingering: A Study of True and Directed Malingerers
In order for a cognitive test to be reliable and clinically useful, it ought to have validity parameters that will detect subjects who are exaggerating their deficits. This is the first study of which we are aware to systematically evaluate the problem of invalid response patterns in a computerized test battery (CNT) that is widely used in research and clinical practice.
A cross-sectional, naturalistic study of suspected malingerers (SM), directed malingerers (DMAL) and patients who had severe traumatic brain injuries (TBI), evaluated in a Neuropsychiatric clinic, using the CNT battery of neurocognitive tests.
2861 participants, age 20-65 including 2172 normal participants, 589 TBI patients who had severe traumatic brain injuries, 40 suspected malingerers and 60 normal participants who were directed to feign malingering.
Normal Ss performed best on all the neurocognitive measures, followed by the TBI patients. The two malingering groups performed worst. There were no significant differences between the suspected malingerers (SM) and the directed malingerers (DMAL) when demographic differences were controlled. Twelve validity indicators (VI’s) were developed for the CNT test battery, based on the summary standard score (Index), eight test standard scores, and eight raw scores derived from the seven tests. The average sensitivity of the twelve VI’s in a comparison of TBI patients to the SM group was 0.568 and the specificity was 0.833. Probability estimates were generated for each VI (validity indicator) employing ROC analysis and chained probability. In addition, the added value of the verbal and visual memory tests as forced-choice tests was appraised.
Validity indicators embedded in the CNT computerized test battery can identify “non-credible responders,” i.e., malingerers. Used in conjunction with other tests, the CNT test battery is a quick and efficient way to identify patients who may be malingering cognitive dysfunction. The validity indicators can also be used to exclude invalid test data when the test battery is used in research.Download PDF
A Computerized Neurocognitive Test Battery Sensitive to Mild and Severe Brain Injury
Computerized neurocognitive testing (CNT) appears to be suited to measure relatively mild degrees of neurocognitive impairment in circumstances where speed, efficiency and low cost are important. Computerized tests are used in the evaluation and management of patients who have had mild brain injuries; the objective is to determine if computerized testing is equally reliable and valid in the evaluation of patients who have had more severe brain injuries.
A cross-sectional, naturalistic study of brain injury patients compared to normal controls.
An outpatient neuropsychiatry clinic.
141 patients, age 18-65, who had sustained traumatic brain injuries: 13 patients with post-concussion syndrome; 15 who had recovered from mild brain injuries; 85 patients who had had severe brain injuries, but who had recovered, and were living independently; and 28 severe brain injury patients who were unable to live without assistance; compared to 145 normal controls.
MAIN OUTCOME MEASURES:
The CNS Vital Signs (CNS VS) battery is a PC-based system that includes tests of verbal and visual memory, psychomotor speed, complex attention, reaction time and cognitive flexibility.
Performance on the CNS VS battery was related to severity of brain injury and degree of recovery. Tests of psychomotor speed and cognitive flexibility were the most relevant to TBI status. Patients who had recovered from mild brain injuries scored almost as well as normal controls. The Neurocognition Index (NCI), a summary score based on performance on all the tests in the battery, was 100 for normal controls and 98 for recovered mild brain injury patients. Post-concussive patients scored 82 on the MCI, and severe brain injury patients scored 66 on the NCI if they were living independently and 47 if they were not.
Computerized tests like CNS VS allow clinicians the advantage of precise neurocognitive measurement in the service of diagnosis and appropriate treatment. CNT’s are never going to replace the flexibility or comprehensiveness of conventional neuropsychological testing, but they have a role to play in circumstances where a full test battery is not feasible, for example, screening and serial assessment.Download PDF
Neuropsych Questionnaire (NPQ)
An Internet-Based Symptom Questionnaire That is Reliable, Valid, and Available to Psychiatrists, Neurologists, and Psychologists
The Neuropsych Questionnaire (NPQ) addresses two important clinical issues: how to screen patients for a wide range of neuropsychiatric disorders, quickly and efficiently; and how to acquire independent verification of a patient’s complaints. The NPQ is available over the Internet in adult and pediatric versions. The adult version of the NPQ consists of 207 simple questions about common symptoms of neuropsychiatric disorders. The NPQ reports scores patient and/or observer responses in terms of 20 symptom clusters: inattention, hyperactivity-impulsivity, learning problems, memory, anxiety, panic, agoraphobia, obsessions and compulsions, social anxiety, depression, mood instability, mania, aggression, psychosis, somatization, fatigue, sleep, suicide, pain and substance abuse. The NPQ is reliable (patients tested twice, patient-observer pairs, two observers) and discriminates patients with different diagnoses. Scores generated by the NPQ correlate reasonably well with commonly used rating scales, and the test is sensitive to the effects of treatment. The NPQ is suitable for initial patient evaluations, and a short form is appropriate for follow-up assessment. The availability of a comprehensive computerized symptom checklist can help to make the day-to-day practice of psychiatry, neurology and neuropsychology more objective.Download PDF
Symptom Report and Diagnostic Properties of the Neuropsychiatric Questionnaire
A problem in psychiatry is the reliance on subjective data, especially self-reported symptoms. In this paper, we investigate the diagnostic validity of the Neuropsychiatric Questionnaire (NPQ) in a large group of patients from a private neuropsychiatric practice.
Patients over age 18 with generalized anxiety disorder (GAD), major depressive disorder (MDD), attention deficit disorder (ADHD), bipolar disorder (BPAD), and normal subjects were included in the analysis (N=1127). Inter-group comparisons were made by MANOVA, controlling for age, gender, education and computer familiarity with the criterion for significance at P < 0.01. Analysis of pairwise group differences was by one-way ANOVA with Bonferroni correction. Effect sizes were measured by Cohen’s d. The NPQ consists of 20 symptoms scale and four factors: cognitive, mania, somatic and anxiety-depression, which combine to make up a symptom load scale (SLS).
Patient groups differed in the makeup of relative contribution of the four factors to the SLS. When compared to normal subjects (N=45), those in the with (GAD, MDD, ADHD, BPAD), When the four diagnostic groups were compared in pairwise fashion to normal subjects (N=45), patient-reported symptoms occurred in the expected directions, but the effect sizes for the cited differences were, on average, small to moderate. In the discriminant validity analysis, the lowest Wilks’ Lambda was 0.622 and patients were correctly classified by the NPQ ranging from 65-79% of the time.
The NPQ, while being a useful tool for the clinician, deserves a diagnostic weight no higher than 24%. The clinical history, family history and examination deserve more weight. This tool may be more appropriate for tracking symptoms over time than for initial diagnosis. The average lambda score in Table 4 is 0.76. If that metric is at all meaningful, then what it means is that patient self-report contributes 24% to diagnostic discrimination and 76% comes from other sources.Download PDF
Factor Structure of an Internet-Based Symptom Checklist and Correlation with Conventional Rating Scales
The Neuropsych Questionnaire (NPQ) addresses two important clinical issues: how to screen patients for a wide range of neuropsychiatric disorders, quickly and efficiently; and how to acquire independent verification of a patient’s complaints. The NPQ is available over the Internet in both adult and pediatric versions. The adult version of the NPQ consists of 207 simple questions about common symptoms of neuropsychiatric disorders. The NPQ reports scores patient and/or observer responses in terms of 20 symptom clusters: inattention, hyperactivity-impulsivity, learning problems, memory, anxiety, panic, agoraphobia, obsessions and compulsions, social anxiety, depression, mood instability, mania, aggression, psychosis, somatization, fatigue, sleep, suicide, pain and substance abuse.
In this report, the factor analysis with a larger set of patients to investigate the factor structure of the NPQ and report the correspondence between the NPQ and other clinical RSs in common use. This analysis generated three distinct factors: cognitive, somatic and manic – and anxiety-depression. The symptoms scales that comprise the anxiety-depression factor load equally with the mania and somatic factors but not with the cognitive factor.
In summary, the NPQ is a useful tool in neuropsychiatric practice. It also generates interesting data about the nature of symptom self-report and its relationship to specific psychiatric diagnoses.Download PDF