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C J Archibald

Publications and source records attributed to C J Archibald.

10 recordsLinked to original sources
PubMed2001

Limitations of the Paced Auditory Serial Addition Test as a measure of working memory in patients with multiple sclerosis.

The Paced Auditory Serial Addition Test (PASAT) is a commonly used procedure that combines elements of both a working memory task and a test of information processing speed. Patients with multiple sclerosis (MS) have consistently been found to be impaired on this test and it has been recommended as a core outcome measure in clinical trials. The standard score for this task is the number of correct responses at each stimulus presentation rate but a concern has been raised that subjects may ignore some test items in order to chunk the information into manageable portions and avoid performing several cognitive tasks simultaneously. To account for this strategy, one can examine the proportion of correct responses that are consecutive (termed dyads), since such responses require that the task be performed according to the instructions. We compared a group of 35 mildly to moderately disabled MS patients and matched healthy controls on the PASAT. The MS patients made significantly fewer correct responses at the 2 slowest presentation rates (2.4, 2.0 s/digit) while their scores at faster rates (1.6, 1.2 s/digit) did not discriminate them from controls as well. Nevertheless, the MS patients' percentage of dyads was significantly lower than that of the control sample across all stimulus presentation rates. While our study supports the use of the PASAT as a test that distinguishes MS patients from healthy individuals, our results also illustrate problems that lie in the interpretation of this difference in performance. It appears that a chunking strategy may be common in the PASAT, particularly as task demands increase, and that this may mask actual performance differences. If so, the total correct response score alone is limited as a measure of working memory and information processing speed. More detailed analyses of PASAT performance, coupled with other measures of information processing, may help clarify the underlying cognitive deficits of MS patients.

Adult↗
PubMed2001

Improved detection of differential information-processing speed deficits between two disease-course types of multiple sclerosis.

Patients with multiple sclerosis (MS) frequently demonstrate impairments of information-processing speed (IPS) on measures such as the Paced Auditory Serial Addition Test (PASAT; D. M. A. Gronwall, 1977). The authors have previously shown that their new PASAT scoring method (mean dyad score) is better correlated in comparison with more traditional PASAT scoring method(s), with magnetic resonance imaging measurement of the total area (mm2) of white-matter sclerotic lesions (P. J. Snyder & J. C. Cappelleri, 2001). The present study reports that the mean dyad score discriminated 20 relapsing-remitting MS (RRMS) patients from 15 secondary-progressive MS (SPMS) patients noticeably better than did the standard scoring method(s). Mean dyad scores < 4.13 classified patients as having SPMS with 73% accuracy (sensitivity), whereas scores > or = 4.13 classified patients as having RRMS with 80% accuracy (specificity).

Adult↗
PubMed2000

Information processing efficiency in patients with multiple sclerosis.

Reduced information processing efficiency, consequent to impaired neural transmission, has been proposed as underlying various cognitive problems in patients with Multiple Sclerosis (MS). This study employed two measures developed from experimental psychology that control for the potential confound of perceptual-motor abnormalities (Salthouse, Babcock, & Shaw, 1991; Sternberg, 1966, 1969) to assess the speed of information processing and working memory capacity in patients with mild to moderate MS. Although patients had significantly more cognitive complaints than neurologically intact matched controls, their performance on standard tests of immediate memory span did not differ from control participants and their word list learning was within normal limits. On the experimental measures, both relapsing-remitting and secondary-progressive patients exhibited significantly slowed information processing speed relative to controls. However, only the secondary-progressive patients had an additional decrement in working memory capacity. Depression, fatigue, or neurologic disability did not account for performance differences on these measures. While speed of information processing may be slowed early in the disease process, deficits in working memory capacity may appear only as there is progression of MS. It is these latter deficits, however, that may underlie the impairment of new learning that patients with MS demonstrate.

Adult↗
PubMed1999

Outcome after pulmonary thromboendarterectomy.

Pulmonary thromboendarterectomy (PTE) surgery is an effective treatment for the majority of patients with chronic thromboembolic pulmonary hypertension (CTEPH), with an acceptable mortality rate. The immediate outcome after PTE has repeatedly shown a dramatic decline in pulmonary vascular resistance, echocardiographic evidence of reduced right heart pressure, and increased perfusion on lung scan. Prospective long-term follow-up studies (1 to 4 years post-PTE) have found most patients to be in New York Heart Association class I or II, with significantly improved quality of life and ability to walk, climb stairs, return to work, and perform household tasks. Disease-related symptoms and hospitalizations and/or emergency room visits have also been significantly reduced. These findings indicate an improved functional status and longer life expectancy can be achieved after PTE.

Endarterectomy↗
PubMed1999

Long-term outcome after pulmonary thromboendarterectomy.

This study evaluated long-term outcome of pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Survival, functional status, quality of life, health care utilization, and relationships between these parameters and postoperative pulmonary hemodynamics were assessed. Questionnaires were mailed to 420 patients who were more than 1 yr post-PTE; 308 responded (mean age, 56 yr [range, 19-89 yr]; mean years since PTE, 3.3 [range, 1- 16]). Survival after PTE was 75% at > 6 yr. After surgery, symptoms were markedly reduced. Median distance walked was 5,280 ft; 56 patients could walk "indefinitely." Of the working population, 62% of patients unemployed before PTE returned to work. Post-PTE patients scored several quality of life components of the Rand SF-36 slightly lower than reported normals but significantly higher than did pre-PTE patients. Ten percent of patients used oxygen. Ninety-three percent were in NYHA Class I or II. Disease-related hospitalizations/ER visits were minimal. A relationship was shown between 48 h postoperative pulmonary vascular resistance (PVR) and walking and stair-climbing ability, NYHA class, dyspnea scores, and the physical function and general health quality of life components. These data indicate that PTE offers most CTEPH patients substantial improvement in survival, function, and quality of life, with minimal disease-related health care utilization.

Activities of Daily Living↗
PubMed1996

Conceptual reasoning as a mediator of verbal recall in patients with multiple sclerosis.

A number of intercorrelated factors, including level of neurologic impairment, age, and conceptual reasoning, appear to be related to memory performance among patients with Multiple Sclerosis (MS). A battery of neuropsychological tests was administered to 131 patients with MS ranging in age from 19 to 76 years, with a mean symptom duration of 12.3 years and an overall mild level of MS-related neurologic impairment. Regression analyses indicated that neurologic impairment and age each contributed uniquely to the prediction of delayed free recall of a word list. Furthermore, when the effect of conceptual reasoning was accounted for, neither neurologic impairment nor age were significantly related to recall. Thus, a mediated relation was confirmed, supporting the idea that a significant portion of neurologic-impairment-related and age-related differences in recall are due to differences in conceptual reasoning that are important for optimal performance on tests of recall. Additional analyses failed to support a similar mediated relation using recognition rather than recall as the measure of memory performance.

Adult↗
PubMed1994

Pain prevalence, severity and impact in a clinic sample of multiple sclerosis patients.

Previous studies have reported variable prevalence of pain in multiple sclerosis (MS) and have not documented the impact of pain on daily living. In this consecutive series, we report on data collected from structured interviews with 85 patients seen within a 16-month period at a regional referral clinic. The prevalence of pain for the month preceding assessment was 53%. There were no significant differences between patients who did and those who did not report pain on the basis of patient demographics (age, gender) and disease characteristics (disease subtype, duration and neurologic symptom severity). Disease duration and neurologic symptom severity were significantly correlated with the number of hours of pain per week but were not correlated with pain severity, the number of pain sites or pain-related distress. There was wide variability in the number of pain hours/week reported with 17.6% of the sample reporting continuous pain for the month preceding assessment. Sixty-five percent of patients with pain reported taking medications for pain and 90% of these patients evaluated their medication(s) as 50% effective or better. Nevertheless, patients with pain reported poorer mental health and more social-role handicap. Discussion focuses on the need for routine assessment of pain and the comprehensive evaluation of the effectiveness of pain interventions in the therapeutic management of patients with MS.

Adult↗
PubMed1994

The impact of fatigue on patients with multiple sclerosis.

Although fatigue is recognized as a symptom of MS, there have been insufficient methods for evaluating this symptom. We administered the Fatigue Impact Scale to 85 MS patients and 20 hypertensive patients. Neurologic impairment, mental health, and general health status were also assessed. MS patients reported significantly higher fatigue impact than hypertensive patients. Most MS patients reported fatigue as either their worst (14%), or one of their worst (55%) symptoms. Disease classification and neurologic impairment had little bearing on Fatigue Impact Scale scores in the MS sample. The best predictive models for mental health and general health status in the MS sample both included the Fatigue Impact Scale as a significant factor. This study demonstrates that: 1) fatigue is a very prevalent and severe problem in MS, 2) fatigue impact cannot be predicted by clinical measures of neurologic impairment, 3) fatigue has a significant effect on the mental health and general health status of MS patients.

Adult↗
PubMed1980

Results of a comprehensive rehabilitation program. Physiologic and functional effects on patients with chronic obstructive pulmonary disease.

Forty-two patients with chronic obstructive pulmonary disease participated in a comprehensive inpatient rehabilitation program. Criteria for a safe, maximum treadmill exercise regimen were established; all patients pursued this regimen for six weeks, without complications, even though 31 of 39 patients showed a decline in PaO2 with exercise. Postprogram O2 consumption, minute ventilation, heart rate, and respiratory rate were significantly reduced during exercise when compared with preprogram values. Sixteen of 29 patients improved in terms of dyspnea class; an additional 11 of these 29 improved with regard to activities of daily living. Most patients who improved physiologically also improved functionally. Patients able to tolerate higher levels of treadmill exercise initially had the greatest improvement in postcourse exercise performance. The data suggest that precourse functional and exercise classification is useful in selecting candidates who will receive the greatest functional benefits from participation in rehabilitative programs.

Activities of Daily Living↗