An international study to assess reliability of the Migraine Disability Assessment (MIDAS) score

BACKGROUND

The Migraine Disability Assessment (MIDAS) instrument is a five-item questionnaire developed to measure headache-related disability and improve doctor-patient communication about the functional consequences of migraine.

OBJECTIVES

To examine the test-retest reliability and internal consistency of the five items and of the overall MIDAS score in population-based samples of migraine sufferers in two countries and to compare consistency across countries.

METHODS

Using a clinically validated telephone interview, population-based samples of migraine-headache sufferers were identified in the United States (Baltimore, MD) and the United Kingdom (Merton and Sutton, Surrey). Eligible individuals completed the MIDAS questionnaire on two occasions an average of 3 weeks apart. The MIDAS score is derived from five questions about missed time from work and household work (one question each about missed days and days with at least 50% reduced productivity) and missed days of nonwork activities.

RESULTS

A total of 97 migraine-headache sufferers from the United States and 100 from the United Kingdom completed the MIDAS questionnaire twice. Mean and median item values and overall MIDAS scores were similar between the United States and the United Kingdom. Test-retest Spearman correlations of individual items ranged from 0.46 to 0.78. No significant differences in item-specific correlations were observed between the United States and United Kingdom. The test-retest Pearson correlation of the MIDAS score (i.e., sum of lost days and reduced-effectiveness days in each domain) was 0.80 in the United States and 0.83 in the United Kingdom. The Cronbach alpha, a measure of internal consistency, was 0.76 in the United States and 0.73 in the United Kingdom.

CONCLUSIONS

This is the first international population-based study to assess the reliability of a disability-related illness severity score for migraine. The reliability and internal consistency of the Migraine Disability Assessment score are similar to that of a previous questionnaire (Headache Impact Questionnaire). However, the Migraine Disability Assessment score requires fewer questions, is easier to score, and provides intuitively meaningful information on lost days of activity in three domains.

Assessment of command-following in minimally conscious brain injured patients

OBJECTIVE

To develop a method for establishing the presence of command-following in individuals with traumatic brain injury, based on the principles of single-subject experimental design.

DESIGN

A series of single-subject experiments, individualized to the particular command-following question about a particular patient.

SETTING

An inpatient rehabilitation hospital with a specialized program for vegetative and minimally conscious brain injured patients.

PATIENTS

Eight individuals with serious brain injury of traumatic or nontraumatic origin, presenting in vegetative or minimally conscious states.

INTERVENTIONS

The frequency of performance of the behavior in question was assessed in response to commands and in relation to appropriate control conditions. Data were analyzed with chi2 or Fisher's exact test, as well as measures derived from signal detection theory.

MAIN OUTCOME MEASURES

The frequency of performance of a specific behavior in the presence of a command and in relevant contrasting conditions.

RESULTS

This method identified whether a specific behavior was being performed in response to command and whether the reliability of this behavior was changing over time either spontaneously or in response to treatment.

CONCLUSIONS

Quantitative assessment of command-following based on principles of single-subject experimental design can determine whether patients are capable of following commands and whether this ability changes over time or in response to treatment.

An overview of behaviour difficulties found in long-term elderly care settings

STUDY OBJECTIVE

To provide an understanding of the nature and prevalence of behaviour difficulties in long-term care facilities, to compare care settings and comment on the appropriateness of the need for specialist care.

DESIGN

Nurses or carers implemented two rating scales in randomly selected settings.

SETTING

Nursing homes, residential homes and NHS elderly long-stay wards.

SUBJECTS

Elderly long-stay patients.

MAIN RESULTS

NHS and nursing home long-term care facilities show similar behaviour difficulties, with nursing homes experiencing more behaviour manifestations in most cases. Residential facilities have behaviour difficulties to a lesser extent.

CONCLUSIONS

Nursing homes have limited formal psychiatric intervention compared to NHS settings. Behaviour difficulties result in increased work for general practitioners and increased hospital referrals. More prospective research is required into the antecedents, effects and treatments of patients with behaviour difficulties in nursing homes. For example, it may be appropriate that specialist input is provided for nursing homes in order to implement behaviour intentions and contribute to the reduction of GP callouts and pharmacological interventions.

[Effects of experimental vasectomy on testicular structure: ultrastructural study]

We have performed experimental vasectomies in dogs in order to study effects of vas deferens ligature with close technique, on the testicular ultrastructure. We point out the existence of alterations: structural changes of the seminiferous epithelium, great extracellular spaces which are generated for the premature exfoliation of germinal cells, degeneration of the germinal shock cells, the appearance of immature germinal cells and multinucleate spermatids in every stages of the spermatogenesis, the fall of mature spermatozoid number, thickening of basal membrane, relative increase in the Sertoli's cells size as well as their phagocytic function, and existence of spermaphagos unfasted into tubular lumen. The Leydig's interstitial islets show an absolutely normal cellular and vascular configuration.

Effects of hospital closure on mortality rates of the over-65 long-stay psychiatric population

The closure of this 100-year-old hospital has allowed us to look at the effect on mortality of moving the whole over-65 long-stay population to other settings. Our results confirm that there is a slight excess of deaths during and immediately after these moves, but that there is no longer-term effect on mortality rates.

[A morphological and morphometric study of the testicle in the rat vasectomized by electrocautery technics]

OBJECTIVE

To evaluate the influence of vasectomy by different fulguration methods on the rat testicular structure.

METHODS

Experimental vasectomy was performed in Wistar rats by means of the Shapiro and Silber, and the Schmidt cauterization techniques. The animals were orchidectomized between 7 days and 9 months following vasectomy. A morphological and morphometric study of the rat testes was performed.

RESULTS

We have observed that both cauterization techniques do not produce sequelae in the rat testicular structure and its morphology is compatible with the normal. The morphometric study showed that both techniques produced a significant decrease (p > 0.05) of the area occupied by seminiferous epithelium within one month post-vasectomy; however, these values returned to normal three months thereafter.

CONCLUSIONS

Vasectomy by different fulguration methods does not change the rat testicular structure.

Differential effect of a dopaminergic agonist on prefrontal function in traumatic brain injury patients

We examined the effects of low-dose bromocriptine, a D2 dopamine receptor agonist, on processes thought to be subserved by the prefrontal cortex, including working memory and executive function, in individuals with traumatic brain injury. A group of 24 subjects was tested using a double-blind, placebo-controlled crossover trial, counterbalanced for order. Bromocriptine was found to improve performance on some tasks thought to be subserved by prefrontal function, but not others. Specifically, there was improvement in performance on clinical measures of executive function and in dual-task performance, but not measures that tap the ability to maintain information in working memory without significant executive demands. Also, on control tasks not thought to be dependent on the prefrontal cortex, no improvement on bromocriptine was noted. These results demonstrate a selective effect of bromocriptine on cognitive processes which involve executive control, and provide a foundation for potential therapies for patients with prefrontal damage causing dysexecutive syndromes.

Morphometry of the human splenic artery: muscular columns, morphofunctional aspects and developmental implications

There is a paucity of studies in the literature concerning the structural characteristics of the arterial wall in the abdominal region using human material and specialized morphometric techniques. In the present study we carry out the morphometric study, describing a series of structural peculiarities in 12 segments of the human splenic artery. Among these the presence of length-wise or spiral-shaped muscular columns in the medial layer which mark and reduce the diameter of the arterial lumen is of major importance. In its underlying intima small localized thickenings appear which, with age may become generalized. We also analyze the different intimal thickenings and such indices as the Intimal Thickening Index, Lumen Reduction Index and Pathologic Thickening Index, with differences among the groups we have considered. The study of elastin in the various parietal structures help us to understand the possible pathogenesis of the thickenings, and to clarify the important morphological-functional correlation for the regulation of blood flow which exists in this arterial region.

[Experimental vasectomy: comparison of the testicular structure with various surgical techniques]

We have performed experimental vasectomies in dog in order to study different repercussions of various surgical techniques on the testicular structure. The closed technique, with ligature of both cut ends of the sectioned vas deferens caused a severe tubular atrophy, which finally destroyed the architecture of the testis with compensating hypertrophy of the intertubular connective tissue. The technique of the "open cut end", leaving the proximal end free and allowing the normal drainage of the vas deferens into the interstitial space of the spermatic cord, had not any influence on the testicular-structure, at least in the studied period of time, now one year. We can't reject any long-term immunological phenomena. The conclusion of this study is that the peculiarities of the surgical techniques of vasectomy have a decisive influence on the preservation of the testicular structure.

The effects of visual distraction following traumatic brain injury

Clinical assessments of individuals with traumatic brain injury (TBI) typically report attentional difficulties, with distractibility prominent among these complaints. However, laboratory-based measures have often failed to find disproportionate distraction among patients with TBI, as compared to control participants. In this experiment, we tested 21 patients hospitalized for rehabilitation following recent TBI and 21 demographically comparable control subjects on a visual reaction time go-no-go task in which the target was preceded or followed by a brightly colored moving visual stimulus, appearing above the target location. Early distractors actually served as warning stimuli, improving accuracy and speed for both participant groups. Distractors occurring at or shortly after the time of target presentation had no significant impact on accuracy or response bias in either group, but did produce slowing of RT that was significantly greater for patients than for controls. The distractor that produced maximal slowing occurred 100 ms after the presentation of the target or foil. Repeated testing sessions led to reduction in the impact of the distractor and loss of the group difference in RT impact. The degree of RT slowing induced by distraction was modestly related to injury severity, as measured by the current score on the Disability Rating Scale, and the time until the patient first followed verbal commands. There was also a trend of greater RT slowing among individuals with focal orbitofrontal lesions, as assessed on neuroimaging studies. These results document a greater susceptibility to extraneous visual distraction among patients with TBI in comparison to controls. The fact that this difference appears only in the RT domain, and is greatest when the distractor follows the target, suggests that the primary impact of visual distractors is on response preparation and execution rather than target detection.

Effects of methylphenidate on attentional function after traumatic brain injury. A randomized, placebo-controlled trial

Attention deficits after traumatic brain injury (TBI) are common and disabling. Many pharmacologic agents have been used to ameliorate attention deficits, and considerable interest has focused on methylphenidate (MP) because of its documented efficacy in attention deficit disorder. However, clinical studies of MP in subjects with TBI have yielded mixed results. We examined the effects of MP on attentional function in individuals with TBI referred specifically for attentional assessment and treatment. Subjects were studied in a double-blind, placebo-controlled, repeated crossover design, using five different tasks designed to measure various facets of attentional function. MP produced a significant improvement in the speed of mental processing. Orienting to distractions, most aspects of sustained attention, and measures of motor speed were unaffected. These results suggest that MP may be a useful treatment in TBI but is primarily useful for symptoms that can be attributed to slowed mental processing.

Working memory impairments in traumatic brain injury: evidence from a dual-task paradigm

Although many individuals with traumatic brain injury (TBI) perform well on standard neuropsychological tests, they often exhibit marked functional difficulties. The functions which are impaired seem to be analogous to the role of the central executive system (CES) in Baddeley's [Working Memory, 1986, Oxford University Press, New York] widely accepted model of working memory. The purpose of this study was to investigate CES function in individuals with TBI with a dual-task paradigm. We studied 25 non-demented persons who were at various stages in their recovery from severe TBI and compared their performance on a dual-task paradigm to a group of age-matched controls. Our dual-task paradigm measured performance on a simple visual reaction time task both alone (baseline) and during concurrent tasks of articulation or digit span. Subjects were also assessed with other neuropsychological tests of executive function. TBI patients had slower reaction times on the primary task when performed alone (P < 0.05) and greater decrements in performance during dual-task conditions (P < 0.01). They also exhibited significantly greater deficits than control subjects on other measures of executive function. Although correlations between dual-task performance and other executive measures were quite low, principle components analysis suggested that a common factor does exist between these measures. These findings support the conclusion that TBI patients have a working memory impairment that is due to dysfunction of the CES and which may be related to executive function deficits as measured by standard neuropsychological testing.

[Contribution to the morphological knowledge of the articulations of the human tympanic ossicular chain]

The structure of human tympanic bones and their articulations was studied. Martin's trichrome stain of serial sections revealed the transmission paths of force lines based on bone lamellae density and acid fuchsin staining, which disclosed functional "critical points" (mechanical solicitation). This study contributed basic knowledge and a morphological and functional classification of the incudomalieotar and incudostapedial joints. The incudomalieolar joint was confirmed as a "riding saddle" but the incudostapedial joint as a "spheroid joint" was questioned. Information on capsule structure the meniscus and articular cartilage of the incudomalleolar joint is given.

[Effects of vasectomy on the testicular structure of the dog]

Study of the effect on testis structure in the dog caused by a vasectomy. Emphasis is made on how in animals undergoing ligature of both ends of the ductus deferens, existence of structural changes, which are consistently present, are proportional to the time elapsed from performance of vasectomy. Such changes are revealed by: degeneration of germinal epithelium, thickening of basal membrane and hypertrophy of interstitial tissue at the expense of unspecific connective tissue. Changes were first seen as from the fourth month, but a full year has to elapse prior to noting a marked germinal hypoplasia. These experimental results cast doubts on the safety of such sterilization approach, although they cannot be entirely extrapolated to humans.

Modeling case mix adjustment of stroke rehabilitation outcomes

Case mix adjustment models for long-term stroke rehabilitation outcomes should be developed (1) to facilitate equitable comparisons of outcomes across treatment settings, thereby reducing disincentives for treating complex cases, (2) to improve triage into the most appropriate level of rehabilitative care after discharge from acute care, and (3) to confirm that case mix factors are equated in treatment effectiveness studies and by random assignment across conditions in clinical trials. Case mix adjustment is necessary for valid quality improvement processes. A conceptual model of case mix adjustment of long-term rehabilitation outcomes is presented that (1) is diagnosis-specific, (2) includes demographic variables as important case mix factors, (3) encompasses triage into rehabilitation as well as treatment processes as aspects of quality of rehabilitative care, (4) contains outcomes measuring functional status as well as mortality and morbidity, and (5) keys timing of outcomes to onset of conditions requiring rehabilitation rather than discharge from rehabilitation. The number of potential interactions among case mix indicators requires a sophisticated analytic framework. Random factors in the model illustrate that case mix adjustment can never be perfect. Nevertheless, it is essential. A brief review of the stroke literature on prediction of long-term outcomes suggests that additional work is needed to specify relevant case mix indicators.

Phasic arousal in response to auditory warnings after traumatic brain injury

Traumatic brain injury (TBI) is believed to have adverse effects on attention, but because of the multifaceted nature of the arousal and attentional network, the precise impact of TBI on various subcomponents of this network remains controversial. As part of a larger program of research on attention in TBI, we studied the effects of auditory warning signals on accuracy, reaction time, and response bias, as indices of phasic arousal in a visual go/no-go task. Warnings were presented randomly at various pre-stimulus intervals to a sample of recently injured patients and control subjects. For each subject and performance index, we examined the time interval required to reach maximal phasic arousal, the degree of performance change occurring at this maximal point, and the ability to maintain this state of increased arousal over longer warning intervals. After adjustment for baseline differences, there were no significant differences between patients and controls in any aspect of performance. Examination of effect sizes suggested that this was not due to limited statistical power, but that any differences between groups, if present, must have been small. In contrast, in our prior research on sustained attention and observable behaviors related to attention, large group differences have been found. These data suggest that mechanisms responsible for auditorily-induced phasic arousal responses are largely preserved in severe TBI.

Inattentive behavior after traumatic brain injury

Clinicians and families report that traumatic brain injury results in a variety of attention deficits. Numerous laboratory studies have documented slowing of information processing, alteration in event-related potentials, or difficulty attending to specific relevant task dimensions in the presence of redundant information. However, little is known about how these information processing abnormalities relate to observable behaviors in daily living or work environments, which presumably form the basis for clinicians' and families' reports. We developed a quantitative assessment of behavioral inattentiveness in both quiet and distracting environments, and demonstrated excellent interrater reliability. Using this assessment, we have studied 20 patients with recent traumatic brain injury and 20 demographically comparable control subjects. We have confirmed marked differences in behavioral attentiveness between patients and controls in both distracting and nondistracting environments.

Improved arousal and initiation following tricyclic antidepressant use in severe brain injury

Three patients with severe traumatic brain injury demonstrated significant improvement in arousal and initiation after administration of tricyclic antidepressants. The first patient showed improved motor and speech initiation in response to amitriptyline following several months of functional plateau. The second patient was minimally responsive 2 months after injury and demonstrated improved arousal following the use of desipramine. Both patients deteriorated when the medications were discontinued and improved again when they were restarted. These two cases provide strong evidence for a medication effect. The third patient began to verbalize following desipramine administration, despite being mute for more than a year after injury. Previous case reports describe cognitive-enhancing effects, such as improved arousal, attention, memory, and initiation, of dopaminergic agents, and in the case of tricyclic antidepressants, effects on agitation. The role of norepinephrine in promoting neurological recovery after brain lesions has been demonstrated in animals. The cases presented here provide some of the first data to show similar efficacy in humans and underscore the need for controlled trials to better determine which patients will benefit.

Experimental vasectomy and testicular structure

We have performed an experimental study on rats and dogs to evaluate the long term effects (from 1 to 12 months) of vasectomy on the structure of the testis. From four months after vasectomy onwards, the specimens showed very important changes in the seminiferous epithelium and Sertoli cells, with an obvious thickening of the basement membrane that supports the epithelium. The deterioration depended on the time passed and, over six months after vasectomy, the alterations were very clear and the seminiferous tubules became atrophic and shrunk, sometimes without any remains of seminiferous epithelium and with an important hypertrophy of the interlobular interstitial tissue, although we did not see an increase in the number of Leydig cells. Alterations due to vasectomy depend on the animal species, the peculiarities of techniques and, of course, the time passed after surgery.

Segregation of autoantibodies with disease in monozygotic twin pairs discordant for systemic sclerosis. Three further cases

OBJECTIVE

To study the serologic status of 3 previously unreported monozygotic twin pairs discordant for systemic sclerosis (SSc).

METHODS

Autoantibodies were measured by indirect immunofluorescence, immunodiffusion, and immunoprecipitation of 35S-labeled cell lines. Major histocompatibility complex (MHC) class II allele typing and DNA fingerprinting were used to confirm monozygosity.

RESULTS

Anti-PM-Scl, anti-threonyl transfer RNA synthetase, and anti-topoisomerase I antibodies, respectively, were found in each of the twins with SSc. None of the unaffected twin siblings had an identifiable autoantibody, although serum from 1 unaffected twin precipitated several unknown proteins. The MHC class II genotype in each twin was the genotype expected for the autoantibody that was present.

CONCLUSION

Autoantibodies of certain defined specificities are intimately linked with the development of SSc, because they segregate with SSc in individuals who start life with identical germline genes.

Assessment of vision and visual attention in minimally responsive brain injured patients

Sensory, motor, and cognitive assessment is a critical priority in the care of minimally responsive brain-injured patients. However, their inconsistent pattern of responding may interfere with the use of traditional forms of assessment such as the mental status or neurological examinations. In this article we describe a quantitative method, based on single-subject experimental design, for evaluating vision and visual attention in this patient population. In a series of randomized trials, combinations of a blank card, a colorful photograph, and no stimulus are presented to either or both visual fields while horizontal eye movements are observed. The relationship between the side and nature of the visual stimulus and the frequency of eye movements is analyzed to determine visual function in one or both eyes. We report six cases of minimally responsive patients assessed with this method. In case A, we show evidence of functional vision in both visual fields. Case B also shows functional fields, but with a monocular visual deficit. Cases C and D show a homonymous hemianopsia which, in case D, is further complicated by a monocular visual deficit. Finally, cases E and F show patterns of left and right visual extinction. Thus, this objective and quantitative method leads to conclusions about patients' visual function that are not readily apparent by clinical observation and that allow appropriate modifications in further assessment or treatment.

Sustained arousal and attention after traumatic brain injury

Clinicians report that patients with traumatic brain injury (TBI) often have difficulty with tasks requiring sustained attention, and there are neuroanatomical and neurophysiological reasons to expect such deficits. Nevertheless, laboratory measures of sustained attention or vigilance in TBI have produced conflicting results. These inconsistencies may be due to patient heterogeneity as well as the fact that vigilance performance is dependent on highly specific features of the task design. We developed a visual vigilance task in which the influence of non-attentional factors was minimized and task difficulty for patients and controls made comparable. Performance was characterized with respect to vigilance level as well as vigilance decrement, using measures of perceptual discrimination, response bias, reaction time and reaction time variability. Twenty-six patients with recent TBI and 18 control subjects were tested on this task. A MANOVA of ranked scores revealed significantly different patient and control performance overall. Initial level of performance (vigilance level) was slower and more variable for patients than controls, and patients showed more conservative response biases. Deterioration over time (vigilance decrement) was steeper for patients than controls for reaction time, reaction time variability, and response bias. Deterioration in accuracy (D') did not differ significantly between patients and controls. Performance was not related to available measures of injury severity. Hypotheses relating arousal mechanisms to vigilance performance are discussed.