Evaluation of subjective perceived rating for grip strength depending on handedness for various target force levels.

BACKGROUND: Measurement of hand exertion is very important to quantify the risk of Work-related Musculoskeletal Disorders (WMSDs) in manufacturing fields. Although a direct measurement is the most accurate way to quantify physical load, it is expensive and time consuming. To solve this limitation, a subjective self-report method has been proposed as a possible alternative. OBJECTIVE: The purpose of this study was to analyze the accuracy of subjective perception for grip force exertions associated with handedness (dominant and non-dominant hands). METHODS: A total of nine healthy adults participated in this study. All participants were asked to exert hand grip forces for randomly selected target force levels without any information about the actual target force levels. Then, participants were also asked to rate the subjective perception of their exertion level using % Maximum Voluntary Contraction (MVC) after each hand grip force exertion. RESULTS: The trend of subjective perception for various target force levels was different according to the handedness. In the case of the dominant hand, participants tend to rate less MVC levels (under-estimation) than the actual target force levels at lower than 50% MVC, whereas they tend to rate more MVC levels (over-estimation) than the actual target force levels at higher than 50% MVC, respectively. In case of non-dominant hand, generally participants showed over-estimate for all levels of MVCs in this study. CONCLUSIONS: According to the results of this study, subjective perception of exertion showed different patterns on the handedness (S-shape for dominant hand vs. over-estimation for non-dominant hand) for various target force levels. Therefore, it would be necessary to apply different criteria for each hand to evaluate subjective perception of hand grip exertion tasks.

On manual laterality (handedness) in humans and its forensic significance - a literature review.

Manual laterality (handedness) in humans has some significance for forensic practice where it is primarily employed in the form of handedness preference, based on a simplified three-stage classification (right-handed, left-handed and ambidextrous). In cases of homicide or suicide, the pattern of injuries, particularly cutting or stab injuries and gunshot wounds, may provide clues as to the perpetrator's handedness. In injuries inflicted by another person, the pattern of findings can in isolated cases allow to draw conclusions as to the handedness of the perpetrator. In self-inflicted injuries and suicide, the dominant hand is usually used either alone or as the lead hand. If it is found that fatal injuries were inflicted by the non-dominant hand, this gives rise to doubt that the manner of death is suicide. Evidence of handedness is of little value in distinguishing between suicide and homicide. Due to new developments in dentistry, imaging procedures and especially genetics, the utility of handedness in the identification of unknown persons or cadavers has significantly diminished. In living subjects, useful evidence of handedness can be obtained by observing the performance of specific gestures or activities. The subject should be asked to perform tasks involving one and two hands in a specific sequence. Standardised measurements of the morphology of the shoulders and upper extremities are able to make a statistical distinction between right and left. Since the accuracy of this process is, however, only,around 75 %, morphological determination of handedness should not be used in living subjects, but should be restricted to the identification of unknown cadavers or other post-mortem examinations.

Lateralisation abnormalities in obsessive-compulsive disorder: a line bisection study.

OBJECTIVE: Asymmetry in brain structure and function is implicated in the pathogenesis of psychiatric disorders. Although right hemisphere abnormality has been documented in obsessive-compulsive disorder (OCD), cerebral asymmetry is rarely examined. Therefore, in this study, we examined anomalous cerebral asymmetry in OCD patients using the line bisection task. METHODS: A total of 30 patients with OCD and 30 matched healthy controls were examined using a reliable and valid two-hand line bisection (LBS) task. The comparative profiles of LBS scores were analysed using analysis of covariance. RESULTS: Patients with OCD bisected significantly less number of lines to the left and had significant rightward deviation than controls, indicating right hemisphere dysfunction. The correlations observed in this study suggest that those with impaired laterality had more severe illness at baseline. CONCLUSIONS: The findings of this study indicate abnormal cerebral lateralisation and right hemisphere dysfunction in OCD patients.

Occupational ocular accidents amongst Greek endodontists: a national questionnaire survey.

AIM: To investigate amongst Greek endodontists, the incidence of ocular accidents during practice, the circumstances associated with them, the therapeutic measures taken after the accidents, their compliance with the use of eye protection and their eye care behaviour. METHODOLOGY: One hundred and forty-seven endodontists met the inclusion criteria and were invited to participate in the survey. Data were gathered through interviews based on a questionnaire. Participants were asked for personal/professional data, information on ocular accidents in the past 5 years, post-accident actions and the type of eye protection used. Their eyesight status and frequency of ocular examination were also recorded. Data were analysed using chi-square test, independent samples t-test and logistic regression. The level of significance was set at P = 0.05. RESULTS: The response rate was 84%. Ocular accidents were reported by 73% of the participants. Amalgam and NaOCl were the foreign bodies most frequently associated with ocular accidents. Medical assistance was sought in 16% of the most recent accidents. No permanent eye damage was reported. Regular use of magnification (OR:0.305, 95%CI:0.123-0.754) and years of clinical experience (OR:0.191, 95%CI:0.066-0.551) were significant predictors for the incidence of ocular accidents. Adequate eye protection was utilized by 82% of endodontists. Endodontists with eyesight deficiencies attended more frequently for ocular examination (P = 0.018). CONCLUSION: A high percentage of endodontists experienced ocular accidents. Regular use of magnification and increasing years in practice were associated with a reduced risk of ocular accidents. The majority of endodontists reported using adequate eye protection.

Lateral preference and schizotypy revisited: comparison of handedness measurement and classification methods.

A sample of 256 undergraduate students was administered five schizotypy scales and a lateral preference questionnaire consisting of 41 handedness items, in order to examine the effect of different approaches to the measurement and classification of handedness on the relationship between schizotypy and lateral preference. The extended handedness questionnaire included the 12 items of Annett's handedness questionnaire, the 10 items of Oldfield's (1971) Edinburgh Handedness Inventory, the 19 items of the lateral preference questionnaire used by Kelley and Coursey (1992a), and additional items from Steenhuis and Bryden's (1989) 32-item Waterloo Handedness Inventory, allowing the examination and comparison of a variety of handedness classification schemes and the computation of several continuous measures of handedness, and comparison of their relationships to schizotypy. Different approaches to the measurement and classification of handedness yielded somewhat different findings concerning the relationship to schizotypy, which also varied depending on gender and the schizotypy measure involved. Among males, higher schizotypy scores were associated with more dextral lateral preference, whereas among females higher schizotypy was associated with mixed right-handedness.

Hand dominance influences the processing of observed bodies.

In motor tasks, subgroups of lefthanders have been shown to differ in the distribution of attention about their own bodies. The present experiment examined whether similar attentional biases also apply when processing observed bodies. Sixteen right handers (RHs), 22 consistent left handers (CLHs) and 11 relatively ambidextrous inconsistent left handers (ILHs) performed an own body transformation task in which they were instructed to make speeded left-right judgements about a schematic human figure. Attentional biases associated with handedness were found to extend to observed bodies: CLHs' judgements were faster to the figure's left side, while ILHs, like RHs, showed facilitated performance to the figure's right side. These results demonstrate a novel embodiment effect whereby the processing of a static schematic human figure is modulated by an individual's personal motor capabilities. This finding suggests that motor simulation may contribute to whole body perception in the absence of actual or implied actions.

The relation between lateralisation, early start of training, and amount of practice in musicians: a contribution to the problem of handedness classification.

This study investigates the influence of extensive bimanual training in professional musicians on the incidence of handedness in the most basic form of right-handedness (RH) and non-right-handedness (NRH), according to Annett's "right shift theory". The lateralisation coefficients (LCs) of a total sample of 128 bimanually performing music students were calculated for speed, regularity, and fatigue of tapping by using the speed tapping paradigm. Additionally, the accumulated amount of practice was recorded by means of retrospective interviews. The proportion of designated right-handers (dRH) and non-right-handers (dNRH) in hand performance was identified by binary logistic regression from LCs. A proportion of 30.8% designated NRH in the group of musicians was found, while in the control group of non-musicians (matched for age range) a proportion of 21.7% designated NRH was observed. Incidence of dNRH was higher in string players (35.6%) than in pianists (27.1%). As an effect of the extensive training of the left hand, tapping regularity increased and tapping fatigue decreased among those participants who evidenced an increased amount of accumulated practice time on the instrument. However, speed difference between hands (as indicated by LCs) remained uninfluenced by bimanual training. This finding is in contrast to those of Jancke, Schlaug, and Steinmetz (1997). Finally, our study provides a more reliable (statistical) classification as an external criterion for future genetic analyses of handedness.

Degree versus direction: a comparison of four handedness classification schemes through the investigation of lateralised semantic priming.

Four classification systems were examined using lateralised semantic priming in order to investigate whether degree or direction of handedness better captures the pattern of lateralised semantic priming. A total of 85 participants completed a lateralised semantic priming task and three handedness questionnaires. The classification systems tested were: (1) the traditional right- vs left-handed (RHs vs LHs); (2) a four-factor model of strong and weak right- and left-handers (SRHs, WRHs, SLHs, WLHs); (3) strong- vs mixed-handed (SHs vs MHs); and (4) a three-factor model of consistent left- (CLHs), inconsistent left- (ILHs), and consistent right-handers (CRHs). Mixed-factorial ANOVAs demonstrated significant visual field (VF) by handedness interactions for all but the third model. Results show that LHs, SLHs, CLHs, and ILHs responded faster to LVF targets, whereas RHs, SRHs, and CRHs responded faster to RVF targets; no significant VF by handedness interaction was found between SHs and MHs. The three-factor model better captures handedness group divergence on lateralised semantic priming by incorporating the direction of handedness as well as the degree. These findings help explain some of the variance in language lateralisation, demonstrating that direction of handedness is as important as degree. The need for greater consideration of handedness subgroups in laterality research is highlighted.

Increased frequency of left-handedness in patients with unilateral coronal synostosis.

OBJECTIVE: Left-handedness reportedly has been more common in persons with neurological afflictions (e.g., stroke) and malformations (e.g., cleft lip with or without cleft palate) that demonstrate marked unilateral involvement. Coronal synostosis is also more frequently unilateral, affecting the right side more commonly than the left. We sought to compare left-handedness in patients with unilateral coronal synostosis versus healthy controls. SUBJECTS: All patients aged 3 years or older with nonsyndromic unilateral coronal synostosis and healthy controls recruited by pediatricians blinded to the study. MAIN OUTCOME MEASURES: Prospective data obtained for all participants included age, gender, and handedness. In patients with unilateral coronal synostosis, the side of synostosis and age at surgery were documented. Left-handedness in the study and control groups was compared using chi-square analysis. Left-handedness also was analyzed in the study group according to side of fusion. RESULTS: Eighty-six patients with nonsyndromic unilateral coronal synostosis comprised the study group; there were 96 controls. The mean ages of the study (8.8 years) and control groups (9.8 years) were not statistically different (p > .05). There were more girls in the study group (67%) than in the control group (56%), but this difference was not statistically significant (p > .05). Left-handedness was documented in 30.2% of the study group and 11.4% of the control group (p < .005). Left-handedness was twice as common in patients with left versus right unilateral coronal synostosis (44.4% versus 20.4%; p < .05). CONCLUSIONS: Left-handedness is nearly three times more common in patients with unilateral coronal synostosis than in controls and four times more likely in patients with left-sided fusion.

Patterns of hand preference for pairs of actions and the classification of handedness.

Pairs of actions such as write x throw and throw x racquet were examined for items of the Annett hand preference questionnaire (AHPQ). Right (R) and left (L) responses were described for frequencies of RR, RL, LR, and LL pairings (write x throw etc.) in a large representative combined sample with the aim of discovering the distribution over the population as a whole. The frequencies of RL pairings varied significantly over the different item pairs but the frequencies of LR pairings were fairly constant. An important difference was found between primary actions (originally write, throw, racquet, match, toothbrush, hammer with the later addition of scissors for right-handers) and non-primary actions (needle and thread, broom, spade, dealing playing cards, and unscrewing the lid of a jar). For primary actions, there were similar numbers of right and left writers using the 'other' hand. For non-primary actions more right-handers used the left hand than for primary actions but more left-handers did not use the right hand. That is, different frequencies of response to primary versus non-primary actions were found for right-handers but not for left-handers. The pattern of findings was repeated for a corresponding analysis of left-handed throwing x AHPQ actions. The findings have implications for the classification of hand preferences and for analyses of the nature of hand skill.

Finger dermatoglyphics and their asymmetry in Bulgarian right-, mixed- and left-handers.

Since Bulgarians have never been investigated concerning the relationship between handedness and dermatoglyphics, the present study was aimed to investigate the aforementioned relationship in a Bulgarian sample. Digital dermatoglyphics and their asymmetries have been studied in 870 apparently healthy students from randomly selected Bulgarian secondary schools: 264 right-handers (RH), 246 mixed-handers (MH) and 360 left-handers (LH). The whorls were significantly less frequent and the ulnar loops more frequent in RH than in the other two handedness categories. Right-handers exceeded significantly MH and LH in the ulnar fluctuating asymmetries of the first and the fourth finger pairs. As compared to the number of investigated variables and especially to the important psychological and behavioral differences between handedness categories reported earlier in the same sample, the presented significant findings are rather scarce. Nevertheless they could contribute to the accumulation of data concerning the investigated relationship and to its better understanding.

The distribution of hand preference is discrete: a taxometric examination.

The dominant genetic models of human handedness (Annett, 1985; McManus, 1985a) have contrasting views on its nature. Whereas Annett's model proposes that handedness is distributed continuously (following the distribution of performance asymmetries of the hands), McManus's model proposes that handedness is distributed dichotomously. The aim of this study was to investigate the nature of the underlying distribution. The taxonomy of hand preference was analysed by two independent taxometric procedures, 'mean-above-mean-below-a-cut' and 'maximum-eigenvalue', separately in two geographically, demographically, and culturally distinct samples; one of Australian adults (N=787), and the other of Serbian high school students (N=1,224). The analyses revealed a latent categorical structure in both samples, with estimated mean base-rates of a right-handed taxon of 0.80 and 0.94 from the two analyses of the adult sample and of 0.79 and 0.93 from the two analyses of the high school sample. Subsequent analyses showed that the initial right-handed class could be subdivided into consistent and inconsistent right-handed subclasses in both samples. A supplementary analysis, including a measure of hand proficiency in a subset of the sample of Australian adults (N=596), also revealed a latent categorical structure, showing evidence for a categorical latent structure from a continuous measure of hand performance. We conclude that the distribution of hand preferences in humans is discrete and not continuous.

Epidemiologia da incapacidade funcional em idosos na comunidade: Inquérito de Saúde de Belo Horizonte e tradução e confiabilidade do instrumento de avaliação funcional SMAF no Projeto Bambuí / Epidemiology of disability in the elderly: Belo Horizonte Health Survey and translation and reliability of the Functional autonomy Measurement System SMAF, The Bambuí Health and Aging Study

Em um contexto de envelhecimento populacional, prevenir a incapacidade é um dos papéis cardinais da saúde pública. O objetivo geral desta tese foi investigar este fenômeno entre idosos residentes na comunidade em duas pesquisas. Os objetivos do primeiro estudo foram determinar a prevalência e os fatores associados à incapacidade funcional entre idosos na Região Metropolitana de Belo Horizonte, MG, Brasil. O modelo teórico adotado foi baseado em características predisponentes (sócio-demográficas), fatores extra-individuais (apoio social, uso de serviços de saúde) e intra-individuais (condições de saúde). Participaram do estudo 1.786 idosos (≥ 60 anos) selecionados por meio de amostra probabilística. A variável dependente foi a incapacidade funcional, definida como leve ou moderada (alguma dificuldade) e grave (total dependência) para realizar atividades da vida diária. A prevalência da incapacidade foi de 16% (8% leve e 8% grave).

Idade e pior auto-avaliação da saúde apresentaram associações positivas e independentes com ambos os níveis de incapacidade. Hipertensão e artrite apresentaram associações com incapacidade leve ou moderada, enquanto diabetes e derrame apresentaram associações com incapacidade grave. Associação negativa com incapacidade grave foi observada para visita de amigos nos últimos trinta dias. Esses resultados mostram que as condições crônicas associadas à incapacidade na população estudada são passíveis de prevenção e que o apoio social externo à família é menor em idosos com incapacidade grave. A segunda pesquisa teve por finalidade apresentar a tradução para o português e a adaptação cultural de um instrumento de medida da avaliação funcional – o SMAF - elaborado para uso clínico e em populações idosas; bem como avaliar a confiabilidade intra e inter-observador desta versão, entre idosos participantes da nona onda de seguimento da coorte de Bambuí. Foram feitas a tradução e retro-tradução e adaptação transcultural por tradutores bilíngües, cujo resultado foi analisado por um grupo de especialistas e pelos autores do instrumento. Antes da aplicação do instrumento a equipe de pesquisadores brasileiros e os entrevistadores foram treinados com o apoio de pesquisadores canadenses. Foi conduzido um pré-teste com 10 idosos da comunidade, com diferentes graus de incapacidade.

Na fase de teste, participaram 89 idosos sorteados aleatoriamente para serem submetidos à aplicação integral do SMAF por quatro entrevistadores. Os idosos foram avaliados, nos seus domicílios, pelo mesmo entrevistador (teste-reteste; n=46), uma semana depois, ou por entrevistadores diferentes (inter-avaliadores; n=43), com intervalo de 24 horas. O coeficiente de correlação intra-classe (ICC) e o alfa de Cronbach foram usados para a análise estatística. Globalmente, os ICC foram 0,94 (IC 95% 0,90 - 0,97) para dois avaliadores diferentes e 0,99 (IC 95% 0,98-0,99) quando o mesmo entrevistador reavaliou o idoso com intervalo de 1 semana. A análise da consistência interna dessa versão do SMAF resultou em um alfa de Cronbach de 0,95. No presente estudo, o desempenho da versão em português do SMAF foi excelente em todas as dimensões consideradas, quando aplicado pelo mesmo ou por avaliadores diferentes. A versão traduzida do SMAF acrescenta à saúde pública brasileira um instrumento válido e confiável para avaliar a incapacidade na população idosa

Epidemiologia da incapacidade funcional em idosos na comunidade: Inquérito de Saúde de Belo Horizonte e tradução e confiabilidade do instrumento de avaliação funcional SMAF no Projeto Bambuí

Em um contexto de envelhecimento populacional, prevenir a incapacidade é um dos papéis cardinais da saúde pública. O objetivo geral desta tese foi investigar este fenômeno entre idosos residentes na comunidade em duas pesquisas. Os objetivos do primeiro estudo foram determinar a prevalência e os fatores associados à incapacidade funcional entre idosos na Região Metropolitana de Belo Horizonte, MG, Brasil. O modelo teórico adotado foi baseado em características predisponentes (sócio-demográficas), fatores extra-individuais (apoio social, uso de serviços de saúde) e intra-individuais (condições de saúde). Participaram do estudo 1.786 idosos (≥ 60 anos) selecionados por meio de amostra probabilística. A variável dependente foi a incapacidade funcional, definida como leve ou moderada (alguma dificuldade) e grave (total dependência) para realizar atividades da vida diária. A prevalência da incapacidade foi de 16% (8% leve e 8% grave).

Idade e pior auto-avaliação da saúde apresentaram associações positivas e independentes com ambos os níveis de incapacidade. Hipertensão e artrite apresentaram associações com incapacidade leve ou moderada, enquanto diabetes e derrame apresentaram associações com incapacidade grave. Associação negativa com incapacidade grave foi observada para visita de amigos nos últimos trinta dias. Esses resultados mostram que as condições crônicas associadas à incapacidade na população estudada são passíveis de prevenção e que o apoio social externo à família é menor em idosos com incapacidade grave. A segunda pesquisa teve por finalidade apresentar a tradução para o português e a adaptação cultural de um instrumento de medida da avaliação funcional – o SMAF - elaborado para uso clínico e em populações idosas; bem como avaliar a confiabilidade intra e inter-observador desta versão, entre idosos participantes da nona onda de seguimento da coorte de Bambuí. Foram feitas a tradução e retro-tradução e adaptação transcultural por tradutores bilíngües, cujo resultado foi analisado por um grupo de especialistas e pelos autores do instrumento. Antes da aplicação do instrumento a equipe de pesquisadores brasileiros e os entrevistadores foram treinados com o apoio de pesquisadores canadenses. Foi conduzido um pré-teste com 10 idosos da comunidade, com diferentes graus de incapacidade.

Na fase de teste, participaram 89 idosos sorteados aleatoriamente para serem submetidos à aplicação integral do SMAF por quatro entrevistadores. Os idosos foram avaliados, nos seus domicílios, pelo mesmo entrevistador (teste-reteste; n=46), uma semana depois, ou por entrevistadores diferentes (inter-avaliadores; n=43), com intervalo de 24 horas. O coeficiente de correlação intra-classe (ICC) e o alfa de Cronbach foram usados para a análise estatística. Globalmente, os ICC foram 0,94 (IC 95% 0,90 - 0,97) para dois avaliadores diferentes e 0,99 (IC 95% 0,98-0,99) quando o mesmo entrevistador reavaliou o idoso com intervalo de 1 semana. A análise da consistência interna dessa versão do SMAF resultou em um alfa de Cronbach de 0,95. No presente estudo, o desempenho da versão em português do SMAF foi excelente em todas as dimensões consideradas, quando aplicado pelo mesmo ou por avaliadores diferentes. A versão traduzida do SMAF acrescenta à saúde pública brasileira um instrumento válido e confiável para avaliar a incapacidade na população idosa

Multivariate neuropsychological prediction of seizure lateralization in temporal epilepsy surgical cases.

PURPOSE: Neuropsychological assessment can be of assistance in determining seizure lateralization in cases where EEG and MRI findings do not provide clear lateralizing data. While several studies have examined the lateralizing value of individual neuropsychological measures, clinicians are still in need of a statistically sound method that permits the incorporation of multiple neuropsychological variables to predict seizure lateralization in the individual patient. METHOD: The present study investigated the lateralizing value of several commonly used neuropsychological measures in a large sample of patients (n = 217) who eventually underwent surgical resection to treat their epilepsy. Side of surgery was used to operationally define seizure lateralization. A comparison of the relative utility of a multivariate versus univariate approach to predict seizure lateralization was conducted in temporal epilepsy cases. RESULTS: The results provide evidence for the incremental validity of neuropsychological measures, other than memory and IQ tests, in the prediction of seizure lateralization in patients with medically intractable epilepsy. These data indicate that a multivariate approach increases the accuracy of prediction of seizure lateralization for temporal lobe epilepsy cases. CONCLUSION: This study supports the use of a multivariate approach using neuropsychological measures to predict seizure lateralization in temporal epilepsy surgical candidates. Regression formulas are provided to enhance the clinical utility of these findings.

Axonal bias at a representational border in adult rat somatosensory cortex (S1).

The cortex is a highly organized structure and this organization is integral to cortical function. However, the circuitry underlying cortical organization is only partially understood, thus limiting our understanding of cortical function. Within the somatosensory cortex, organization is manifest as a map of the body surface. At the level of the cortical circuitry the horizontal connections of Layer 2/3 express a physiological bias that reflects discontinuities within the somatosensory map. Both excitation and inhibition are smaller when evoked from across a representational border, as compared to when they are evoked from within the representation. This physiological bias may be due to a bias in either the strength or number of synapses and/or the number of axons that cross this border and the extent of their arborization. In this study we used both an anterograde (Phaseolus vulgaris leucoagglutinin) and a retrograde (cholera toxin B) tracer to examine Layer 2/3 horizontal projections in rat S1. We determined that there is a bias in the amount of horizontal axonal projections that cross the forepaw/lower jaw border as compared to projections remaining within an individual representation. This bias in axonal projection and the correlated bias in excitation and inhibition may underlie the expression of the representational border.

Intellectual prognosis of status epilepticus in adult epilepsy patients: analysis with Wechsler Adult Intelligence Scale-revised.

PURPOSE: Status epilepticus (SE) appears to cause cognitive dysfunction as well as other serious neurologic sequelae. To confirm whether SE produces a subsequent intellectual decline, we evaluated intellectual function prospectively in adult epilepsy patients with and without SE. METHODS: Of 1,685 patients with epilepsy who underwent comprehensive neuropsychological testing in two national hospitals in Japan, 15 patients experienced an episode of SE afterward and underwent the second neuropsychological examination after the SE episode. Forty clinically matched patients with epilepsy, but without an episode of SE since their initial neuropsychological examination, were also reevaluated. We compared IQs and subscores from the Wechsler Adult Intelligence Scale-Revised between the two groups by repeated measures analysis of variance. In the patients who experienced an SE episode, SE-related variables (i.e., age at the SE episode and type and duration of SE) and epilepsy-related variables such as epilepsy type, lateralization of EEG abnormalities, the presence of mesial temporal sclerosis, and previous history of SE, were evaluated in relation to intellectual outcome. RESULTS: Patients with SE, in comparison to those without SE, failed to show any significant post-SE intellectual decline. Furthermore, neither the SE-related variables nor the clinical characteristics were correlated with intellectual outcome. CONCLUSIONS: Our findings suggest that SE does not lead to a significant intellectual decline in adult patients receiving treatment for epilepsy.

Characterizing magnetoencephalographic spike sources in children with tuberous sclerosis complex.

PURPOSE: Tuberous sclerosis complex (TSC) often causes medically intractable seizures. Magnetoencephalography (MEG) localizes epileptiform discharges. To evaluate the use of MEG spike sources (MEGSSs) for localizing epileptic zones in TSC patients, we characterized MEGSSs and correlated them to EEG and magnetic resonance imaging (MRI) results. METHODS: We analyzed data from seven children who underwent prolonged video-EEG, MEG, and MRI. We classified MEGSSs as clusters (six or more spike sources, 1 cm between sources regardless of number of sources). RESULTS: A single, unilateral cluster with additional scatters occurred in two patients; these predominantly lateralized dipoles correlated to prominent tubers on MRI and ictal/interictal EEG zones. Bilateral clusters with scatters existed in two patients; cluster locations partly overlapped multiple prominent tubers. These patients also had bilateral or diffuse interictal discharges, bilateral or generalized seizures, and changing seizure types and EEG findings. Only bilateral scatters occurred in three patients; scatters partly overlapped EEG interictal/ictal-onset regions; one patient had coexisting generalized seizures. In one patient with equally bilateral scatters, scatters overlapped a prominent tuber and interictal/ictal-onset zones in the right frontal region. CONCLUSIONS: MEG contributes to information from EEG and MRI for localizing epileptogenic zones in children with TSC. A single cluster with scatters in a unilateral hemisphere predicts a primary epileptogenic zone or hemisphere; bilateral or multiple clusters indicate bilateral primary or potential epileptogenic zones; and bilateral scatters without clusters may indicate epileptogenic zones that are hidden within extensive areas of scattered MEGSSs.

Measuring familial sinistrality: problems with dichotomous classification.

Familial sinistrality (FS), or familial left-handedness, is usually measured as a presence/absence dichotomy (FS+/FS-). Measuring FS as a dichotomy is problematic in at least two ways: (1) magnitude data are discarded and (2) there is an increased risk of violating statistical assumptions. We hypothesised that using a non-dichotomised FS measure would allow more sensitive statistical tests than using a dichotomised measure. The non-dichotomised measure examined was proportion of family that is left-handed, or Proportional FS (FSP). FS measures of 60 healthy adults were consistent with our hypothesis: (1) The effect size was 2.3 times larger when FSP was used than when Dichotomised FS (FSD) was used; (2) the observed relationship was statistically significant when FSP was used but not when FSD was used; and (3) statistical assumptions were violated when FSD was used but not when FSP was used. When cases were weighted to account for an increased likelihood of FS in large families, results were similar. Next, bootstrapping methods were used to estimate empirically the long-term differences in power between analyses incorporating FSP and those incorporating FSD. Using FSP was associated with long-term increases in both power and effect size of over 50% relative to using FSD. We conclude that using a proportional rather than a dichotomous measure of FS will enhance the accuracy of observed effect sizes, increase the sensitivity of statistical tests, and reduce the likelihood of violating statistical assumptions.