Bias from dependent misclassification.
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Bias↗
Biomedical subjects
G Dellatolas
Publications and source records attributed to G Dellatolas.
Upper limb injuries and handedness plasticity.
In a questionnaire survey of 9591 men between 17 and 27 years of age, there was an association between present handedness score and report of an earlier injury causing a temporary shift of hand use. The proportion of weak right-handers was higher among those who reported injuries. Overall, there was no association between left-handedness and injuries. Nevertheless, injuries occurring before the school attendance age, which concerned only a very small fraction of the respondents, were associated with an increased frequency of left-handedness. The data emphasize the plasticity of human handedness, and do not suggest that innate left- or non-right-handedness is a risk factor for accident occurrence.
Adolescent↗
Association between criminality and psychosis: a retrospective study of 3984 expert psychiatric evaluations.
This study reports on 3984 expert psychiatric evaluations in eastern Algeria over a period of 23 years. Factors associated with different types of crimes or misdemeanors, particularly those associated with a diagnosis of psychosis in the case of a homicide or attempted homicide committed by male subjects are described. Among the 1007 cases of homicide and attempted homicide, the diagnosis of psychosis was made 200 times (19.9%). Psychotic subjects were older, more likely to have a previous psychiatric history, less likely to come from very large families, and less likely to have been raised by both their parents.
Adult↗
Distributions of hand preference and hand skill asymmetry in preschool children: theoretical implications.
We describe the distributions of hand skill asymmetry for the Peg-moving task and the Graphic test among 765 preschool children. A single normal component was observed for the Peg-moving task, but two normal components for the Graphic test, which corresponded primarily to the right- and left-handed children. Hand Preference and Graphic test hand skill asymmetry were age-dependent, but there was no age effect on the PMT hand skill asymmetry. Results are discussed in relation to the Annett's Right Shift theory.
Child↗
Foot and eye preferences in adults: relationship with handedness, sex and age.
Age, sex, and handedness effects in foot and eye preferences were studied by questionnaire in large samples of normal adult populations from five different countries (total sample, n = 5064). Foot and eye preference were significantly associated with handedness category (right or left) in all the 10 sex by country samples for foot, and in 9/10 samples for eye. The overall frequencies of crossed preferences were 5% between hand and foot and 19.5% between hand and eye. In right-handers, a gradual shift toward the "right" with increasing age was systematically observed, both for footedness and eyedness. The proportion of crossed hand-foot preference was higher in men than women (7.4% vs 2.5%), and higher in left-handers than right-handers (16.3% vs 4.1%). Sex differences in the proportion of crossed hand-eye preference were variable from one country to the other.
Adolescent↗
Correlated nondifferential misclassifications of disease and exposure: application to a cross-sectional study of the relation between handedness and immune disorders.
In cross-sectional studies, misclassifications of exposure and of health status may be related. For instance some subjects may tend to overreport both exposure and disease. A misclassification is said to be nondifferential if the sensitivity and the specificity which characterize it do not depend on the true status of the subjects for the other variables. Nondifferential misclassifications of two dichotomic variables may be correlated if the probability of being misclassified for one of them depends on the presence of an error of classification for the second one. Models are presented to estimate the bias induced by correlated nondifferential misclassifications on an odds ratio whose true value is unity. For most usual situations, when the great majority of the subjects are healthy and nonexposed, the influence of overreporting is shown to be larger than that of underreporting. It appears to be relatively easy to find a spurious, but significant, relationship. Real data are analysed to show that the potential consequences of correlated nondifferential misclassifications are not purely theoretical. In a sample of 1676 subjects from the general population we observed significant relations between left-hand shift and various aspects of health status: reporting a history of eczema, experience of a serious health problem in the past, experience of a serious health problem presently, use during the last month of analgesics or of drugs for circulatory problems, or digestion, consultation with a physiotherapist or hospitalization during the last year. These results, as with many similar ones previously reported, are highly suggestive of an information bias. They are less easily explained by biological hypotheses, e.g. Geschwind's theory of cerebral lateralization, than by correlated misclassifications resulting from overreporting of both the use of the left hand and the existence of some health problems by healthy right-handers. The modelling used in this report supports this hypothesis.
Adult↗
Age and cohort effects in adult handedness.
A systematic increase with age of the strong right-handers/mixed right-handers ratio, in normal adults, was found in Algeria, Greece, Italy, France and Spain. This age effect on adult handedness is not easily explained by variations in the social pressure against left-hand use, differential mortality, or information bias. There was no systematic decrease in the frequency of left-handedness with age. Left-hand writing among left-handers was common in the youngest age group and rare after 40 years of age.
Adolescent↗
Birth order and month of birth are not related with handedness in a sample of 9370 young men.
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Adolescent↗
Spasmodic torticollis--review of 220 patients.
220 patients with isolated and idiopathic spasmodic torticollis were followed and treated over a 14 year period. Each patient was given a short questionnaire leading to the present retrospective data analysis. In most areas, including female preponderance and frequency of postural tremor, the findings confirmed previous studies and highlighted particular points: importance of psychopathological antecedents and association with stressful life-events. The discussion deals with some of the conflicting debates surrounding this unusual disorder. What is the role of psychopathological factors? What is the therapeutic prognosis? The best therapeutic results were obtained by combining anticholinergic drugs, local injections and rehabilitation.
Adolescent↗
[Asymmetries of human cerebral cortex assessed in vivo by stereotaxic-stereoscopic angiography. Anatomo-functional correlations].
Morphological brain asymmetries of the planum temporale, Sylvian fissure and insula were assessed by stereotactic-stereoscopic angiography in 70 epileptic patients without neuroradiological abnormalities, at angiography and CT in these regions. Fifty four patients were right-handers and 16 not right-handers. In 57 patients hemispheric speech dominance was evaluated by the Wada test and electroclinical correlations: in 8 patients, 4 men and 4 women, speech was located in right hemisphere or bilaterally. Lateral asymmetry was present in the regions examined. Correlations between the morphological measurements were not identical in the left and the right hemisphere. No significant relationship was found between anatomical asymmetries and handedness. In men, but not in women, significant differences were observed between the right-bilateral speech group (4 subjects) and the left speech group (31 subjects): right hemisphere regions, including the insula, were larger in the former than in the later whereas, left hemisphere regions were identical in both groups.
Adolescent↗
An epidemiological reconsideration of the Geschwind-Galaburda theory of cerebral lateralization.
To contribute to the Geschwind-Galaburda theory of cerebral lateralization, we examined the relationship of left-handedness to allergic disorders and stuttering, using epidemiological data of two French samples, one of which (N = 9591) is representative of the French male population between 17 and 24 years of age. Results showed a higher frequency of stuttering but not of allergic disorders in left-handers. Extreme right-handedness was observed to be significantly associated with a lower frequency of allergic disorders; response bias might explain such a relationship. Findings were confirmed after allowing for potential confounding factors, such as age and education. In both samples, stuttering and allergic disorders were significantly related.
Adolescent↗
Handedness, immune disorders and information bias.
In order to investigate the relations between handedness and migraine or immune disorders, we performed a case control study comparing the handedness of patients suffering from systemic lupus erythematosus (SLE), type I diabetes, Graves' disease, or migraine to that of a random sample of controls from the general population. A handedness index was measured from a 10-item questionnaire. No significant difference was observed. But when the controls who denied having ever suffered from migraine or any allergic disease were set apart from those who gave at least one positive answer to the same questions, the former were found more right-handed, i.e. with a lower handedness index than the latter (P less than 0.05) and than the SLE patients (P less than 0.05). More generally, the mean observed handedness index of controls giving a positive answer to any question about their health was found repeatedly higher than that of controls giving a negative answer: this was observed for 27 of the 32 questions. These results are highly suggestive of an information bias, the subjects saying they use the right hand for each of the 10 activities considered in the questionnaire being more likely to deny having suffered from a given disease or used, more or less recently, some drug or medical service. Our conviction is that previous observations dealing with the same topic are also more easily explained by the presence of an information bias than by Geschwind's theory. The implications for the design of further epidemiologic studies are discussed.
Adult↗
[Early right posterior cerebral hemispheric lesion and right speech dominance in 2 right-handed female patients].
Two female patients presented a severe partial epilepsy of early onset and an extended right posterior hemispheric lesion of prenatal or perinatal origin. They were right-handed and all their first degree relatives were right-handed. Nevertheless, evidence of right hemispheric speech was documented in both patients, on the basis of a bilateral sodium amytal test in one case, and of a persistent aphasia after neurosurgical treatment in the other. The possible consequences of an early cerebral pathology on cerebral lateralization are discussed, including pathological right-handedness.
Adolescent↗
Hemispheric lateralization of motor and speech functions after early brain lesion: study of 73 epileptic patients with intracarotid amytal test.
This study reports results of a bilateral intracarotid amytal test in 73 epileptic patients with medically intractable focal seizures. No right-handers but 50% of left-handers have a right dominance for speech in this particular population. Lateralization of cerebral speech functions, as well as manual preference, are dependent on the neurological disease and can shift conjointly or independently. We study the relationships of those shifts to different variables related to the cerebral pathology: age at onset and lateralization of epilepsy, extensive brain damage, neurological deficit.
Adolescent↗
Mood disorders in left and right brain-damaged patients: comparison between ratings and self-ratings on the same adjective mood scale. Some methodological problems.
In the context of recent developments of the lateralization model of emotions, this study investigates the intensity of depressive mood in left (LBD) and right (RBD) unilateral brain-damaged patients, comparing expression and experience of negative emotion through rating and self-rating scales. Seventeen BD inpatients (6 LBD, 8 RBD and 3 neurological patients without lesions) completed the Zerssen 28-item mood scale a few days after their admission to hospital. During the same period, 2 nurses, one working during the morning, the other during the afternoon and 1 clinician, a neuropsychiatrist, under the instruction of rating the patient mood state, completed independently the same mood scale. Results show that there is a strong agreement among the self-rating and the observers' total scores, which is high between the clinician and the patient but less strong between the 2 nurses and each nurse and the patient. Morever, self-rating scores are significantly different from those attributed by observers. The comparison between LBD and RBD showed that LBD rated themselves as more depressed than RBD, but the differences were statistically significant in the case of the clinician ratings only. These results have been interpreted with reference to methodological problems rather than in terms of a possible discrepancy between expression and experience of affect.
Affect↗
Infantile spasms in Down syndrome--effects of delayed anticonvulsive treatment.
To investigate the impact of treatment lag in infantile spasms (IS) on treatment response, occurrence of later epilepsy, and long-term cognition and behavior in patients with one single etiological entity, we examined 18 patients with Down syndrome (DS) and earlier IS retrospectively (follow-up period of 32-180 months with a mean of 85.1 months), and determined their history and present condition, in terms of previously mentioned items. There was a statistically significant correlation between treatment lag and lag to cessation of spasms (R=0.55, P=0.02), developmental quotient (DQ) (R=-0.75, P=0.003), and score of autistic features (AF) (R=0.57, P=0.04). Moreover we found that the later the response to treatment of IS, the lower was the DQ (R=-0.86, P=0.001) and the higher was the score of autistic features (R=0.5, P=0.06). A long duration of spasms also determined a low DQ (R=-0.93, P<0.0001) and a high score of autistic features (R=0.66, P<0.01). All patients with persistent epilepsy (n=5) had had a treatment lag of over 2 months. Conversely, for all children treated within 2 months (n=8) spasms ceased within 3 months of treatment and none of them had later epilepsy. This group of patients with a treatment lag of less than 2 months had earlier treatment response (P=0.002), higher DQ (P=0.004) and lower score of autistic features (P=0.006). The data stress the importance of a short treatment lag in view of mental development and prevention of later epilepsy and autistic features, and raise the question of antiepileptogenic effect in this specific condition.
Adolescent↗
[Study of hand preference in a Spanish population, by means of a questionnaire].
828 Spanish subjects answered a 12-item handedness questionnaire. Validity of the items was examined using a Principal Components Analysis. Relationship between handedness and age, sex and familial sinistrality were also examined. The results are compared with those obtained in other countries and discussed in terms of practical use and applications of the questionnaire.
Adolescent↗