Assessment of lesion pathology in multiple sclerosis using quantitative MRI morphometry and magnetic resonance spectroscopy.

Quantitative measurement of MRI-defined brain lesions can provide an index of the extent and activity of disease in multiple sclerosis patients. However, the relationships between these indices and clinical features are not well-understood. Heterogeneity of the pathological changes underlying MRI lesions may be an important factor determining the correlation between MRI lesion volumes and clinical measures.

Validation of a French version of an informant-based questionnaire as a screening test for Alzheimer's disease.

Background: Development of informant-based screening tests for dementia is an emerging field. The reliability and validity of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), an instrument that screens for dementia in general, have been established. We conducted a study to validate a French version of the IQCODE as a screening test for Alzheimer's dementia in the elderly living in the community.

Use of proton magnetic resonance spectroscopy for monitoring disease progression in multiple sclerosis.

Decreases in brain N-acetylaspartate are associated with neuronal loss or dysfunction. We report a longitudinal study in which changes in the N-acetylaspartate to creatine resonance intensity ratio measured by brain proton magnetic resonance spectroscopy were used to follow the progression of brain pathology in 7 patients with multiple sclerosis over an 18-month period. Four of the patients had a history of recurrent relapses and 3 had a secondary progressive course.

Hemostatic markers in acute transient ischemic attacks.

Background And Purpose: Hemostatic abnormalities have been shown previously in stroke patients. The purpose of this study was to assess the activity of selected parameters of the coagulation system in acute reversible cerebral ischemia.

Methods: We measured fibrinopeptide A, thrombin-antithrombin III, and D-dimer in 36 patients in both the acute (< 7 days) and postacute stage (1 and 3 months) after a transient ischemic attack (TIA).

The latent period of multiple sclerosis: a critical review.

It is a widely held belief that multiple sclerosis is a disease with a long latent period that is preceded by heightened susceptibility before adolescence. There has, however, been little research focused on either the estimation of the latent period or determination of the susceptibility period. In this article, we present a critical assessment of the relevant literature on migrant studies, cluster studies, the Faroe Islands "epidemic," sibling study, and novel statistical approaches as they pertain to the pre-onset natural history of multiple sclerosis.

Adult children's perceptions of their responsibility to provide care for dependent elderly parents.

We examined how adult children in Canada whose parents were hospitalized in an acute care setting perceived responsibility for their parents' care. Using a visual analogue scale, adult children rated the amount of financial, emotional, and physical support families "should" and "could" give to elderly persons described in four vignettes. All scores were high, with "should" consistently higher than "could" for every vignette and for each of the three types of support.

Multiple sclerosis: a comparison of the latent periods of different populations.

While some research in multiple sclerosis has concentrated on the latent period of this disease in single population groups, none has attempted to carry out significance tests to compare the distributions of the latent periods of two distinct groups. Two comparisons are made here, between the populations attending the Multiple Sclerosis Clinic of the Montreal Neurological Institute and Hôpital Neurologique et Neuro-Chirurgical Pierre-Wertheimer, Lyon. We also compared the latent period separately in males and females.

Interobserver variability in the interpretation of contrast venography, technetium-99m red blood cell venography and impedance plethysmography for deep vein thrombosis.

Contrast venography (CV) is the standard technique for diagnosing deep vein thrombosis (DVT). Newer noninvasive tests have also proven efficacious. However, there is a lack of data on the level of agreement among observers in their interpretation of the results of the various tests.

Is multiple sclerosis an infectious disease? Inference about an input process based on the output.

The output process of an infinite-server queue with a Poisson process input is observed starting at time 0 with an empty queue. It is assumed that the service time distribution is known. This article discusses statistical inference about the input intensity.

[Quantitative scales for measuring neurological deficit in cerebrovascular diseases].

The development of quantitative scales for the measurement of neurological deficit is a complex process involving the assessment of both validity and reliability. The steps required in the validation and reliability assessment are outlined in this paper. Each component of the process is illustrated using the results of the validation of the Canadian Stroke Scale (CNS).

The Canadian Neurological Scale: validation and reliability assessment.

The Canadian Neurological Scale (CNS) was designed to monitor mentation and motor functions in stroke patients. We assessed its validity and reliability on a group of 157 patients with a diagnosis of acute cerebrovascular accident. We determined validity by (1) correlating scale items and total score with the standard neurologic examination; (2) exploring the scale's predictive power with different end points at 6 months--the initial CNS was a significant predictor of outcome; (3) showing that the CNS had higher correlation coefficients with the initial neurologic examination than the Glasgow Coma Scale; and (4) assessing the responsiveness of the scale to change in the neurologic status of stroke patients.

On the estimation of the distribution of the latent period of multiple sclerosis.

A widely accepted hypothesis is that the initiation of multiple sclerosis occurs many years before the clinical onset of disease. Thus far, attempts to describe the characteristics of the latent period have depended entirely on ad hoc methods relying heavily on the results of migrant studies. Here, by introducing a stochastic model to describe the initiation-onset process, the distribution of the latent period is estimated, and several important consequences for multiple sclerosis discussed.

Mathematical models and individualized outcome estimates in multiple sclerosis.

There is an urgent need for individualized outcome estimates in multiple sclerosis (MS). This is a prerequisite for selecting appropriate therapies in a disease the outcome of which may vary between malignant and benign forms. This question was addressed by using probabilistic mathematical models.

Technetium-99m red blood cell venography in patients with clinically suspected deep vein thrombosis: a prospective study.

We have compared technetium-99m (99mTc) red blood cell (RBC) venography to serial impedance plethysmography (IPG) in 110 consecutive patients with a first episode of clinically suspected deep vein thrombosis (DVT). IPG was performed at Day 0 and, if abnormal, contrast venography was also performed to rule out a falsely positive result. Patients with an initially normal IPG had the test repeated at Days 1, 3, 5 to 7, and 10 to 14.

Stroke assessment scales: guidelines for development, validation, and reliability assessment.

The validity and reliability of clinical instruments, including clinical scales, need to be determined. This paper presents guidelines for development, validation, and reliability assessment of stroke assessment scales.

Methylmercury and the health of autochthons in northwest Quebec.

We conducted a cross-sectional epidemiologic and clinical study to evaluate the nature, magnitude, and frequency of unfavourable health states among residents of northwest Quebec. Of particular interest were the possible occurrence of Minamata disease and any other neurological abnormalities. We also sought to determine whether industrial or naturally-occurring mercury in the region's environment were causally associated with any disorders that might be detected.

Improvements to a simple Markov model of the natural history of multiple sclerosis. I. Short-term prognosis.

Follow-up data from a prognostic study done at L'Hôpital Neurologique de Lyon have been reanalyzed using a new methodologic approach. A stochastic survival model which allows the course of the disease to be described through the movement of patients from one disease state to another is presented. This approach extends previous modelling work by enabling the risk of transition between pairs of states to be written as a function of any number of discrete or continuous prognostic variables.

The Canadian Neurological Scale: a preliminary study in acute stroke.

Acute central nervous system dysfunction resulting in coma can be measured simply and reliably by the Glasgow scale. However, when the injury does not impair consciousness and the patient has aphasia, no comparable scale exists. A complementary scale to assess conscious and aphasic patients is proposed.

Observer variation in the classification of mammographic parenchymal patterns.

Wolfe has described different cancer risks associated with a classification of four patterns of the breast parenchyma on mammography, but there is however little information available on the ability of radiologists to agree on the classification of the different patterns. We have assessed inter-rater agreement on the assignment of films to one of the four mammographic patterns described by Wolfe. One hundred xeromammograms were selected, copied and distributed to 10 radiologists who were experts in mammography.

A Markov model of the natural history of multiple sclerosis.

Prior research into multiple sclerosis prognosis has produced conflicting results. This paper presents an original approach in which the disease course is described by the movements of patients through well-defined disease states. A Markov model is proposed to describe these movements and to evaluate the effect of prognostic factors on transitions from state to state.