Family History Of Left-handedness Research Articles

Fifty Years of Handedness Research: A Neurological and Methodological Update.

Handedness, a complex human aspect that reflects the functional lateralization of the hemispheres, also interacts with the immune system. This study aimed to expand the knowledge of the lateralization of hand, foot, and eye activities in patients with immune-mediated (IM) or other (noIM) neurological diseases and to clarify the properties of the Edinburgh Handedness Inventory (EHI) in an Italian population. Three hundred thirty-four patients with IM or noIM diseases affecting the brain or spine and peripheral nervous system were interviewed about stressful events preceding the disease, subjective handedness, and familiarity for left-handedness or ambidexterity. The patients and 40 healthy subjects underwent EHI examination. In the whole group of participants, 24 items of the EHI were classified into five factors (Hand Transitive, Hand Refined, Hand Median, Foot, Eye), demonstrating good reliability and validity. Chronological age had a significant influence on hand and foot EHI factors and the laterality quotient (LQ), particularly on writing and painting. In the patient groups, EHI factors and the LQ were also predicted by age of disease onset, duration of disease, and family history of left-handedness or ambidexterity. No differences were found between patients and healthy subjects, but pencil use scored significantly lower in patients with IM diseases than in those with noIM brain diseases. These results demonstrate that the lateralization of hand and foot activities is not a fixed human aspect, but that it can change throughout life, especially for abstract and symbolic activities. Chronic neurological diseases can cause changes in handedness. This may explain why, unlike systemic immunological diseases, IM neurological diseases are not closely associated with left-handedness. In these patients, the long version of the EHI is appropriate for determining the lateralization of body activities to contextualize the neurological picture; therefore, these findings extend the Italian normative data sets.

Dynamics of functional MRI and speech function in patients after resection of frontal and temporal lobe tumors

There are no studies on application of functional MRI (fMRI) for long-term monitoring of the condition of patients after resection of frontal and temporal lobe tumors. The study purpose was to correlate, using fMRI, reorganization of the speech system and dynamics of speech disorders in patients with left hemisphere gliomas before surgery and in the early and late postoperative periods. A total of 20 patients with left hemisphere gliomas were dynamically monitored using fMRI and comprehensive neuropsychological testing. The tumor was located in the frontal lobe in 12 patients and in the temporal lobe in 8 patients. Fifteen patients underwent primary surgery; 5 patients had repeated surgery. Sixteen patients had WHO Grade II and Grade III gliomas; the others had WHO Grade IV gliomas. Nineteen patients were examined preoperatively; 20 patients were examined at different times after surgery. Speech functions were assessed by a Luria's test; the dominant hand was determined using the Annette questionnaire; a family history of left-handedness was investigated. Functional MRI was performed on an HDtx 3.0 T scanner using BrainWavePA 2.0, Z software for fMRI data processing program for all calculations >7, p<0.001. In patients with extensive tumors and recurrent tumors, activation of right-sided homologues of the speech areas cold be detected even before surgery; but in most patients, the activation was detected 3 months or more after surgery. Therefore, reorganization of the speech system took time. Activation of right-sided homologues of the speech areas remained in all patients for up to a year. Simultaneous activation of right-sided homologues of both speech areas, the Broca's and Wernicke's areas, was detected more often in patients with frontal lobe tumors than in those with temporal lobe tumors. No additional activation foci in the left hemisphere were found at the thresholds used to process fMRI data. Recovery of the speech function, to a certain degree, occurred in all patients, but no clear correlation with fMRI data was found. Complex fMRI and neuropsychological studies in 20 patients after resection of frontal and temporal lobe tumors revealed individual features of speech system reorganization within one year follow-up. Probably, activation of right-sided homologues of the speech areas in the presence of left hemisphere tumors depends not only on the severity of speech disorder but also reflects individual involvement of the right hemisphere in enabling speech function. This is confirmed by right-sided activation, according to the fMRI data, in right-sided patients without aphasia and, conversely, the lack of activation of right-sided homologues of the speech areas in several patients with severe postoperative speech disorders during the entire follow-up period.

右中心前回中下部梗塞により失文法を呈した１例

A right-handed 75-year-old man was admitted to our hospital complaining of sudden speech difficulty. Neurological examination showed slight left facial palsy of central origin. Although his spontaneous speech was fluent and contained no phonological or verbal paraphasia, it was like telegraphic speech, omitting or misusing postpositional particles. There was no history of changing handedness or family history of sinistrality or ambidexterity. Brain magnetic resonance imaging revealed fresh infarction of the middle-lower part of the right precentral gyrus. The WAIS-R VIQ, PIQ, and total IQ scores were 108, 100, and 117, respectively. In the explanation of a four-frame comic strip of the SLTA, there were misuses of postpositional particles in both speaking and writing. There was about 10% misuse on 249 questions for inserting postpositional particles in sentences. He had difficulty in changing from active- to passive-voice sentences and vice versa. In this patient, the lesion of the middle-lower part of the right precentral gyrus might be important for the expression of agrammatism in crossed aphasia.

Unexpected right hemisphere language representation identified by the intracarotid amobarbital procedure in right-handed epilepsy surgery candidates

The intracarotid amobarbital procedure (IAP) is used for language lateralization in the presurgical evaluation for intractable epilepsy. Some epilepsy surgical centers forgo IAP for right temporal lobectomies in right-handed patients with no personal/family history of left-handedness, implying that right hemisphere language representation does not occur in these patients. To test this hypothesis, a retrospective analysis was performed on 156 consecutive epilepsy surgery candidates who underwent IAP. Of the 156 candidates, 122 were right-handed, and 55 of the 122 demonstrated right hemisphere seizure focus. Right hemisphere language representation was found in 22 of 55 patients, with two demonstrating significant right hemisphere language despite a right hemisphere seizure focus and no family history of left-handedness. Only 1 of 156 patients undergoing IAP experienced permanent neurological complications. Although relatively uncommon, right hemisphere language representation may occur more frequently than complications from cerebral angiography and, therefore, presurgical IAP is recommended for all epilepsy surgery candidates regardless of handedness to minimize the risk of severe language decline.

Language lateralization in left-handed and ambidextrous people: fMRI data.

It is generally accepted that most people have left-hemispheric language dominance, though the actual incidence of atypical language distribution in non-right-handed subjects has not been extensively studied. The authors examined language distribution in these subjects and evaluated the relationships between personal handedness, family history of sinistrality, and a language laterality index (LI) measured with fMRI. The authors used whole-brain fMRI to examine 50 healthy, non-right-handed subjects (Edinburgh Handedness Inventory quotient between -100 and 52) while they performed language activation and nonlinguistic control tasks. Counts of active voxels (p < 0.001) were computed in 22 regions of interest (ROI) covering both hemispheres and the cerebellum. LI were calculated for each ROI and each entire hemisphere using the formula [L - R]/[L + R]. Activation was predominantly right hemispheric in 8% (4/50), symmetric in 14% (7/50), and predominantly left hemispheric in 78% (39/50) of the subjects. Lateralization patterns were similar for all hemispheric ROI. Associations were observed between personal handedness and LI (r = 0.28, p = 0.046), family history of sinistrality and LI (p = 0.031), and age and LI (r = -0.49, p < 0.001). The incidence of atypical language lateralization in normal left-handed and ambidextrous subjects is higher than in normal right-handed subjects (22% vs 4-6%). These whole-brain results confirm previous findings in a left-handed cohort studied with fMRI of the lateral frontal lobe. Associations observed between personal handedness and LI and family history of handedness and LI may indicate a common genetic factor underlying the inheritance of handedness and language lateralization.

Hemimegalencefalia y zurdería manual patológica. A propósito de un caso

Hemimegalencephaly is a disorder of neurone proliferation and migration, associated with excessive growth of all or part of one cerebral hemisphere, and variable degrees of pachygyria, polymicrogyria, neuronal heterotopy and gliosis of white matter. It is considered to be a rare malformation with severe encephalopathy, epilepsy resistant to treatment started early, contralateral hemiparesia and severe retardation of development. However, there may also be milder forms. The syndrome of pathological left handedness is associated with disorders of language, visuo-spatial changes and weakness and hypertrophy of the right limbs, with no family history of left handedness. It occurs in lesions predominantly of the left hemisphere which have occurred in the first six years of life. A 12 year old girl presented with a syndrome of pathological left-handedness and craniofacial asymmetry of the left hemisphere. MR showed the left ventricle and hemisphere to be of increased size and with focal hyperintensity in the white matter, and at the level of the left parietotemporoccipital region there was a thick cortex with little interdigitation of white and grey matter. Minor forms of hemimegalencephaly are probably more frequent than is generally believed. A high index of suspicion is necessary to identify them. They should be considered in cases of left handedness, craniofacial or bodily asymmetry, cutaneous hamartomas, persistent electroencephalographic asymmetry and asymmetry on neuroimaging with an enlarged ventricle and homolateral hemisphere. Study of this may give information which is useful for understanding plasticity and mechanisms of recovery and functional compensation of immature nerve tissue.

Mental rotation test performances and familial sinistrality in dextrals, with special reference to the bent twig theory

Recently, in this journal, Casey 1995 and McKeever (1996) noted that they have reached opposite conclusions regarding the effect of familial sinistrality on mental rotation ability in dextral females. Casey and colleagues concluded that those dextral women with a family history of left handedness (the FS+) are comparable to men in mental rotation ability and that the overall male superiority on such tasks is a function of the poor performances of dextral women who lack left handedness (the FS−) in their families. McKeever and colleagues had come to the exact opposite conclusion. We restudied this question and eliminated three possible methodological factors that might conceivably have accounted for the different outcomes. The results of the present study failed to find any relationship of FS status to mental rotation ability. These findings raise serious questions as to the replicability of any FS status/mental rotation ability relationships.

Crossed aphasia with alalia in Greek—a case study; Extent of a problem

The neuropsychological and neurolinguistic performance of an adult dextral Greek man with crossed aphasia (with alalia) after cerebrovascular accident were longitudinally examined. The patient was a 23 year-old, right-handed, monolingual Greek man without any family history of left-handedness. Initial neuropsychological testing revealed classic Broca's Aphasia with alalia, but without visuospatial disabilities, limb apraxia or memory deficits. Written language was intact. There was a dissociation between praxis and language. His mood was jovial, but within normal limits. Serial CT scan studies unequivocally localized the lesions to the right hemisphere (cortical and subcortical), involving the right temporoparietal and subcortical white matter and the thalamus. The recovery of linguistic abilities was rapid and complete after 6 months. The clinicoanatomic correlation is compatible with the view that crossed aphasia is a mirror representation of that seen in standard cases of uncrossed aphasia. The course of recovery suggests complete lateralization of language to the right hemisphere with bilateral or crossed representation of non-verbal skills.

Stability and ear advantage for dichotically presented environmental sound stimuli: development during early childhood.

55 right-handed children with no family history of left-handedness received two dichotic presentations of environmental sounds. The mean test-retest interval was 9 days. Raw accuracy scores yielded acceptable temporal stability (rs > .72). The expected consistent left-ear advantage for environmental sound stimuli was only evident in younger and less mature children. Five- and 6-yr.-old children, particularly those with strong right-hand preferences, had a right-ear advantage for the stimuli. Their computed laterality coefficients showed low and nonsignificant test-retest reliabilities, however. Three- and 4-yr.-old children, particularly those with weak hand preferences, had a left-ear advantage for the same stimuli. Of the 3- and 4-yr.-old children who did not have strong right-hand preferences, 92% demonstrated consistent ear advantages across testing sessions and their laterality coefficient test-retest correlations were significant. In contrast, only 47% of the strongly right-handed 3- and 4-yr.-old children and 71% of the strongly right-handed 5- and 6-yr.-old children had consistent ear advantages for the same stimuli. It is suggested that the 3- and 4-yr.-old children processed these stimuli according to endogenous, stimulus-specific brain mechanisms and that learned processing strategies overrode these mechanisms for the 5- and 6-yr.-old children.

Childhood hemiplegia: is the side of lesion influenced by a family history of left-handedness?

Family histories of left-handedness were obtained for 396 children with congenital or acquired hemiplegia. As in other studies, right-sided hemiplegia was substantially more common than left-sided hemiplegia. The excess of right hemiplegia was entirely accounted for by children with left-handed relatives. This is contrary to what would be expected if the preponderance of right hemiplegia reflected a greater vulnerability of the dominant hemisphere to early damage. Though the observed association between right hemiplegia and a family history of left-handedness may well have occurred by chance, it could potentially reflect some heritable aspect of cerebral asymmetry (such as slow development of the left hemisphere) that predisposes an individual both to left-handedness and to left-hemisphere injury.

The Prevalence and Origins of Left Hand Preference in High Risk Infants, and its Implications for Intellectual, Motor and Behavioural Performance at Four and Six Years

This study investigates the origins of hand preference at 4 years in a cohort of 115 high risk and premature infants; the relationship between patterns of hand preference and intellectual, motor, temperament and behavioural status at 4 and 6 years; and evidence for brain injury in mediating the relationship between hand preference and development disorder. Increased left hand preference was independently associated with extreme prematurity, high neonatal risk, increased numbers of minor physical anomalies, lowered itellectual and motor abilities, and more difficult temperament. These findings supported the presence of intrauterine and neonatal pathological mechanismis leading to left hand preference in a small number of children. Neither poor function of the non dominant hand nor absence of a family history of left handedness could further define this pathological subgroup. Support for pathological mechanisms producing left handedness was found predominately in the infants of high birth weight, whereas prevalence of left handedness was increased mainly among the extremely low birth weight infants. In this latter group the prevalence of left handedness was also increased among children of normal intelligence, suggesting that mechanisms other than brain damage lead to left hand preference in very premature infants.

Japanese crossed Wernicke's aphasia

A right-handed Japanese man with no personal or family history of left-handedness developed severe Wernicke's aphasia, a mild constructional disorder, and slight left hemiparesis. MRI revealed infarction in the territory of the righ middle cerebral artery, including areas homologous to Broca's and Wernicke's areas. The cerebral blood flow in these areas remained diminished even after language activation. The most likely explanation is that language production occurred in the left Broca's area, while language comprehension occurred in the right Wernicke's area (a dissociated aphasia).

Selective activation effects of concurrent verbal and spatial memory loads in left-handed and right-handed adults

Thirty-two left-handed subjects, divided into four groups according to sex and familial sinistrality, and 16 right-handed subjects without familial sinistrality (8 male, 8 female) participated in a tachistoscopic unilateral letter-identification task with concurrent verbal- and spatial-memory loads. Across groups, a significant right visual field advantage for letter-identification was found. In the majority of both left-handed and right-handed subjects, the concurrent verbal-memory load resulted in a selective activation, with the right visual field performance showing improvement. However, the group of left-handed males with a positive family history of sinistrality gave less evidence of selective left-hemispheric activation as a consequence of the verbal-memory load. The concurrent spatial-memory load did not result in a consistent pattern of selective activation.

Interhemispheric Processing in Left- and Right-Handers

Inter- and intrahemispheric processing for left- and right-handers were compared in two experiments. In one, subjects performed a digit-matching task and in the other they decided if two letters were part of a previously presented word. On some trials the matching items were presented initially only to one hemisphere (within-hemisphere trials), and hence the match decision could be reached by a hemisphere in isolation. On other trials, one item of the match pair was presented to each hemisphere (across-hemisphere trials), requiring interhemispheric interaction for the match decision. Patterns of performance on within-as compared to across-hemisphere trials were identical for the two handedness groups in both experiments. Furthermore, individual characteristics of subjects such as their hand posture, sex and family history of left-handedness did not affect the pattern of performance. These results suggest that interhemispheric processing may not differ between right- and left-handers.

Absence of aphasia in a dextral with a left hemisphere lesion: A case report

Abstract Right-handed patients with aphasia due to a right hemisphere lesion, or sinistral aphasics with a left hemisphere lesion, are referred to as crossed aphasics (Bramwell 1899). Since left damaged sinistrals with aphasia are the rule (Brown and Hecaen 1976), it is the dextral with a right hemisphere lesion that has received most of the attention. When we reviewed the topic of crossed aphasia in dextrals some years ago in relation to a case report (Brown and Wilson 1973). only seven other cases could be found that satisfied the minimal criteria of a clearcut aphasia dextrality and a negative family history ofleft handedness, but since this paper there have been many additional observations (e.g. Assal, Perentes and Dervaz 1981, Donoso, Santander and Pavez 1984, Pillon, Desi and Lhermitte 1979, Wechsler 1976; see Joanette, Puel, Nespoulos, Rascol and Lecours [1982] and Castro-Caldas and Confraria [1984] for review).

Buccofacial apraxia without aphasia due to a right parietal lesion

Buccofacial praxis in right-handers is thought to be mediated by the left hemisphere. We present the case of a right-handed man without family history of sinistrality who exhibited a buccofacial apraxia following a unilateral right parietal infarction. Other findings such as intact language, visuospatial impairment, and hemi-inattention are more characteristic of right posterior lesions.

The effects of handedness on event-related potentials in a rhyme-matching task

Event-related potentials (ERPs) were recorded from one midline and three pairs of homotopic lateral sites while subjects determined whether or not sequentially presented words rhymed. ERPs from left-handed males with a family history of sinistrality were compared with those from 12 right-handers, none of whom had such a family history. As in previous work (e.g. Rugg, M. D. Neuropsychologia 22, 435–443, 1984) the slow negative wave developing during the interval in which subjects waited for the final word was more negative from left-hemisphere electrodes, and the rhyme/non-rhyme differences in the ERPs following this word were greater over the right hemisphere. Neither of these asymmetries differed between the left and right-handers. Possible reasons for the occurrence of these ERP asymmetries during rhyme-matching are discussed, and it is suggested that the aspect(s) of linguistic processing tapped by this task, and influencing concurrently recorded ERPs, may be similarly lateralised in the brains of left- and right-handers.

Asymmetry of the Face at Rest: Size, Area and Emotional Expression

In a sample of 53 right-handed, young adult males, asymmetry was examined in the size of 11 facial regions, in total area, and in emotional expression of the face at rest. In the complete sample no evidence was obtained of consistent asymmetry in size of facial regions, in facial area, or in emotional expression. There was, however, an interaction between family history of sinistrality and sighting dominance in facial asymmetry for the pleasantness/unpleasantness of facial expression. The findings suggest that previously established asymmetries in phasic emotional displays are not an outcome of expressive or morphological asymmetries of the face at rest.

Familial Sinistrality and Sex Differences in Cognitive Abilities

The performance of right-handed males and females, with and without a family history of sinistrality (FS+ and FS-, respectively) were examined for three cognitive abilities: spatial ability, verbal fluency, and perceptual speed. FS+ subjects, especially females, showed performance decrements in spatial ability. Also, FS+ subjects, especially males, showed performance decrements in perceptual speed, with no differences being observed in verbal fluency.

Spatial ability and handedness

The relationship between preferred handedness and spatial visualization was examined for 124 female and 229 male undergraduate students. Handedness and spatial ability were used in the design as continuous variables. Other variables examined were sex of subject and family history of sinistrality. Spatial ability was found to be systematically related to measured handedness, familial left-handedness, and sex of subject. Males outperformed females at all levels of handedness. The lowest performance was obtained by subjects who were either extremely left-handed or extremely right-handed. The highest scores were obtained by individuals with left-handed relatives and whose handedness scores were in the range considered mixed or slightly right-handed. The results suggest that decreased hemispheric specialization is associated with increased spatial ability.