Non-right Handedness Research Articles

Felt presence and its determinants in young adults: results from three independent samples.

Felt presence (FP) is a phenomenon that might appear in individuals with mental and neurological disorders as well as those without any specific morbidity. Some studies have indicated that FP is closely related to psychotic symptomatology. Yet, the mechanisms underlying its occurrence remain largely unknown. The present study aimed to disentangle as to whether FP is associated with widely known risk factors of psychosis. Data from three independent samples of non-clinical young adults were analyzed. Self-reports were administered to assess psychopathological symptoms (samples 1 - 3), neurodevelopmental risk factors for psychosis (sample 1), social defeat components (sample 2), childhood trauma and loneliness (sample 3). A total of 4782 individuals were surveyed across all three samples. Unadjusted analyses showed that the following factors are associated with higher odds of FP: obstetric complications, childhood trauma, non-right handedness, a lower education level, unemployment, minority status, humiliation, perceived constraints, and loneliness. However, only minority status and a lower level of education were associated with higher odds of FP after adjustment for other psychopathological symptoms, age, and gender. Importantly, hallucination-like experiences across all recorded modalities and paranoia were associated with higher odds of FP in all samples. Depressive symptoms were weakly associated with FP in two samples. Findings from the present study suggest that the majority of known risk factors for psychosis contribute to the emergence of FP through the effects on psychotic experiences. Low educational attainment and minority status might be the only risk factors independently contributing to the emergence of FP.

Handedness and 23 Early Life Characteristics in 37,495 Dutch Twins.

In studies of singletons, a range of early-life characteristics have been reported to be associated with handedness, but some of these associations have failed to replicate. We examined associations between 23 early life characteristics with handedness in a large sample of 37,495 5-year-old twins. We considered three definitions of handedness: left-handedness (LH), mixed-handedness (MH), and non-right-handedness (NRH). Our main aim was to test whether the associations with sex, birth weight, gestational age, and season of birth - as reported in singletons - replicate in twins, and to examine twin-specific variables, including zygosity, chorionicity, birth order, and intertwin delivery time. Compared to previously published data from adults born as singletons (7.23%), the prevalence of NRH was higher in both twins (16.19%) and their parents (15.09%). In the twins, LH and NRH were associated with parents' LH. Male sex and lower gestational age were associated with NRH, and LH was associated with not being breastfed. MH was related to neurodevelopmental delays and higher externalizing problems later in childhood. Other previously reported associations were not replicated, and no twin-specific characteristics were related to handedness. These results emphasize the importance of considering multiple definitions of handedness and indicate a small number of replicated associations across studies.

Language and reading impairments are associated with increased prevalence of non-right-handedness.

Handedness has been studied for association with language-related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non-right-handedness (NRH) frequency was assessed in N=2503 cases with reading and/or language impairment and N=4316 sex-matched controls identified from 10 distinct cohorts (age range 6-19 years old; European ethnicity) using a priori set criteria. A meta-analysis (Ncases =1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR=1.21, CI=1.06-1.39, p=.01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions.

Non-Right Handedness is Associated with More Time Awake After Sleep Onset and Higher Daytime Sleepiness Than Right Handedness: Objective (Actigraphic) and Subjective Data from a Large Community Sample.

PurposeHandedness has been linked to various physiological and pathological phenomena including memory function and psychiatric disorders. Also for sleep, several studies have reported associations. However, large-scale studies including a broad age span of participants and studies analyzing women and men separately are lacking.MethodsTherefore, objective sleep data were determined using at-home actigraphy from 1764 healthy participants (18 to 80 years, 908 women), averaging five consecutive nights. In addition, subjective sleep-related data were captured by self-report diaries, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS) and the Morningness-Eveningness-Questionnaire (MEQ). Handedness was determined with the Edinburgh Handedness Inventory (EHI) providing information on the direction (left vs right) and the degree of handedness (strong vs weak). To address the potential endocrine effects, premenopausal women (≤45 years) and postmenopausal women (≥55 years) were analyzed separately. This was also done for men.ResultsThe degree and direction of handedness were correlated with “wake after sleep onset” (WASO) in the total sample and all women (the more right-handed/lateralized the shorter WASO). In postmenopausal women, additionally, time in bed (TIB) and total sleep time (TST) were correlated. There were no other significant associations between an objective sleep variable and handedness. In both premenopausal women and >55-year-old men subjective quality of sleep (PSQI) was correlated with direction and degree of handedness (the more right-handed/lateralized the better). In the total sample and postmenopausal women, the degree and direction of handedness were negatively correlated with daytime sleepiness. The chronotype was not associated with handedness in any group.ConclusionWhile associations were not consistent in all groups, overall, right-handedness tended to be associated with better sleep and less daytime sleepiness. Handedness and sleep seemed to be differentially associated in women and men, being in line with endocrine interactions.

Handedness as a neurodevelopmental marker in schizophrenia: Results from the FACE-SZ cohort

Objectives High rates of non-right-handedness (NRH) including mixed-handedness have been reported in neurodevelopmental disorders. In schizophrenia (SZ), atypical handedness has been inconsistently related to impaired features. We aimed to determine whether SZ subjects with NRH and mixed-handedness had poorer clinical and cognitive outcomes compared to their counterparts. Methods 667 participants were tested with a battery of neuropsychological tests, and assessed for laterality using the Edinburg Handedness Inventory. Clinical symptomatology was assessed. Learning disorders and obstetrical complications were recorded. Biological parameters were explored. Results The prevalence of NRH and mixed-handedness was high (respectively, 42.4% and 34.1%). In the multivariable analyses, NRH was associated with cannabis use disorder (p = 0.045). Mixed-handedness was associated with positive symptoms (p = 0.041), current depressive disorder (p = 0.005)), current cannabis use (p = 0.024) and less akathisia (p = 0.019). A history of learning disorder was associated with NRH. No association was found with cognition, trauma history, obstetrical complications, psychotic symptoms, peripheral inflammation. Conclusions Non-right and mixed-handedness are very high in patients with SZ, possibly reflecting a neurodevelopmental origin. NRH is associated with learning disorders and cannabis use. Mixed-handedness is associated with positive symptoms, current depressive disorder, cannabis use and less akathisia. However, this study did not confirm greater cognitive impairment in these patients.

Handedness in bipolar disorders is associated with specific neurodevelopmental features: results of the BD-FACE cohort.

High rates of non-right-handedness (NRH) and mixed-handedness exist in neurodevelopmental disorders. Dysfunctional neurodevelopmental pathways may be implicated in the underlying pathophysiology of bipolar disorders (BD), at least in some subgroups. Yet little is known about correlates of NRH and mixed-handedness in BD. The objectives of this national study are to determine (i) the prevalence of NRH and mixed-handedness in a well-stabilized sample of BD individuals; (ii) if NRH/mixed-handedness in BD is associated with a different clinical, biological and neurocognitive profile. We included 2174 stabilized individuals. Participants were tested with a comprehensive battery of neuropsychological tests. Handedness was assessed using a single oral question. Learning and/or language disorders and obstetrical complications were recorded using childhood records. Common environmental, clinical and biological parameters were assessed. The prevalence of NRH and mixed-handedness were, respectively, 11.6 and 2.4%. Learning/language disorders were found in 9.7% out of the total sample and were associated with atypical handedness (only dyslexia for mixed-handedness (p < 0.01), and dyslexia and dysphasia for NRH (p = 0.01 and p = 0.04, respectively). In multivariate analyses, NRH was associated with a younger age of BD onset (aOR 0.98 (95% CI 0.96-0.99) and lifetime substance use disorder (aOR 1.40 (95% CI 1.03-1.82) but not with any of the cognitive subtasks. Mixed-handedness was associated in univariate analyses with lifetime substance use disorder, lifetime cannabis use disorder (all p < 0.01) and less mood stabilizer prescription (p = 0.028). No association was found between NRH or mixed-handedness and the following parameters: trauma history, obstetrical complications, prior psychotic symptoms, bipolar subtype, attention deficit/hyperactivity disorder, peripheral inflammation or body mass index. Handedness may be associated with specific features in BD, possibly reflecting a specific subgroup with a neurodevelopmental load.

A-079 Hand Preference in Men and Women with Parkinson’s Disease: A Preliminary Investigation

Abstract Objective Research has identified common genetic influences on handedness and neurological/mental health phenotypes. It also has been shown there may be increased risk for development of neurological disorders/diseases among individuals naturally left-handed or demonstrating non-right-hand preference. This investigation examined prevalence of right-handed versus non-right-handed individuals with Parkinson’s disease (PD) compared to controls. Method Participants were 264 patients with PD (mean age = 69.83 years) and 256 control volunteers (mean age = 71.42 years). Mean Dementia Rating Scale composites for the groups were 123.68 and 136.00, respectively. Participants self-identified their dominant hand for writing and usage was confirmed during the session. Results Proportions of non-right- and right-handed controls (7.0% and 93.0%) versus individuals with PD (6.8% and 93.2%) did not differ. Changes in proportions of non-right- and right-handedness across age ranges were not significant for controls or patients. There was a trend for a larger proportion of women (55.9%) versus men among controls (44.1%), □ 2 (1) = 3.29, p &amp;lt; .10; whereas, the proportion of men (64.4%) with PD was larger than that of women. (35.6%), □ 2 (1) = 21.31, p &amp;lt; .001. For controls and patients, non-right and right handedness gender proportions were similar. Conclusions This study is the first to assess handedness prevalence rates in PD. Results suggest prevalence of non-right handedness is similar in PD and healthy individuals and does not appear to differ markedly by gender or with advancing age. The occurrence of a trend for a larger proportion of women than men among controls is consistent with census-based statistics.

Can cerebral lateralisation explain heterogeneity in language and increased non-right handedness in autism? A literature review

BackgroundAutism is characterised by phenotypic variability, particularly in the domains of language and handedness. However, the source of this heterogeneity is currently unclear. AimsTo synthesise findings regarding the relationship between language, handedness, and cerebral lateralisation in autistic people and consider how future research should be conducted in order to progress our understanding of phenotypic variability. Methods and ProceduresFollowing a literature search and selection process, 19 papers were included in this literature review. Studies using behavioural, structural, and functional measures of lateralisation are reviewed. Outcomes and ResultsThe studies reviewed provided consistent evidence of differential cerebral lateralisation in autistic people, and this appears to be related to between-group differences in language. Evidence relating this to handedness was less consistent. Many of the studies did not include heterogeneous samples, and/or did not specify the language process they investigated. Conclusions and ImplicationsThis review suggests that further research is needed to fully understand the relationship between cerebral lateralisation and phenotypic variability within autism. It is crucial that future studies in this area include heterogeneous samples, specify the language process they are investigating, and consider taking developmental trajectories into account.

Handedness of healthy elderly and patients with Alzheimer’s disease

Purpose/Aim of the study: Research has suggested decreasing proportions of non-right handers in older age groups and reduced incidence of non-right handedness among individuals with Alzheimer’s disease (AD). We hypothesized that healthy elderly individuals would have a higher proportion of non-right handers than individuals with AD and that the proportion of non-right handers would decrease with increasing age. Further, we investigated whether the proportions of non-right handers differed between those with early and late onset of AD.Materials and Methods: Two-hundred and fifty-six healthy elderly and 182 individuals with AD served as participants. Hand dominance was recorded based on side of writing during testing and self-report. We analyzed proportions of right handers and non-right handers for three age ranges (≤ 69, 70 – 79, and ≥ 80 years). A second analysis focused on the proportions of right and non-right handers among patients with AD classified as either early or late disease onset.Results: Handedness proportions did not differ between the controls and ADs. For AD but not for controls, there was a trend towards reduced proportions of non-right handers with increasing age. Early onset AD was associated with a larger proportion of non-right handers compared to those with late onset AD.Conclusions: Results did not support a trend of decreasing non-right handedness with increasing age in controls, but did provide support for such a trend in individuals with AD. The results provided support for the hypothesis of increased incidence of non-right handedness in early onset vs. late onset AD.

Non-right handed primary progressive apraxia of speech

In recent years a large and growing body of research has greatly advanced our understanding of primary progressive apraxia of speech. Handedness has emerged as one potential marker of selective vulnerability in degenerative diseases. This study evaluated the clinical and imaging findings in non-right handed compared to right handed participants in a prospective cohort diagnosed with primary progressive apraxia of speech. A total of 30 participants were included. Compared to the expected rate in the population, there was a higher prevalence of non-right handedness among those with primary progressive apraxia of speech (6/30, 20%). Small group numbers meant that these results did not reach statistical significance, although the effect sizes were moderate-to-large. There were no clinical differences between right handed and non-right handed participants. Bilateral hypometabolism was seen in primary progressive apraxia of speech compared to controls, with non-right handed participants showing more right hemispheric involvement. This is the first report of a higher rate of non-right handedness in participants with isolated apraxia of speech, which may point to an increased vulnerability for developing this disorder among non-right handed participants. This challenges prior hypotheses about a relative protective effect of non-right handedness for tau-related neurodegeneration. We discuss potential avenues for future research to investigate the relationship between handedness and motor disorders more generally.

What causes psychosis? An umbrella review of risk and protective factors.

Psychosis is a heterogeneous psychiatric condition for which a multitude of risk and protective factors have been suggested. This umbrella review aimed to classify the strength of evidence for the associations between each factor and psychotic disorders whilst controlling for several biases. The Web of Knowledge database was searched to identify systematic reviews and meta-analyses of observational studies which examined associations between socio-demographic, parental, perinatal, later factors or antecedents and psychotic disorders, and which included a comparison group of healthy controls, published from 1965 to January 31, 2017. The literature search and data extraction followed PRISMA and MOOSE guidelines. The association between each factor and ICD or DSM diagnoses of non-organic psychotic disorders was graded into convincing, highly suggestive, suggestive, weak, or non-significant according to a standardized classification based on: number of psychotic cases, random-effects p value, largest study 95% confidence interval, heterogeneity between studies, 95% prediction interval, small study effect, and excess significance bias. In order to assess evidence for temporality of association, we also conducted sensitivity analyses restricted to data from prospective studies. Fifty-five meta-analyses or systematic reviews were included in the umbrella review, corresponding to 683 individual studies and 170 putative risk or protective factors for psychotic disorders. Only the ultra-high-risk state for psychosis (odds ratio, OR=9.32, 95% CI: 4.91-17.72) and Black-Caribbean ethnicity in England (OR=4.87, 95% CI: 3.96-6.00) showed convincing evidence of association. Six factors were highly suggestive (ethnic minority in low ethnic density area, second generation immigrants, trait anhedonia, premorbid IQ, minor physical anomalies, and olfactory identification ability), and nine were suggestive (urbanicity, ethnic minority in high ethnic density area, first generation immigrants, North-African immigrants in Europe, winter/spring season of birth in Northern hemisphere, childhood social withdrawal, childhood trauma, Toxoplasma gondii IgG, and non-right handedness). When only prospective studies were considered, the evidence was convincing for ultra-high-risk state and suggestive for urbanicity only. In summary, this umbrella review found several factors to be associated with psychotic disorders with different levels of evidence. These risk or protective factors represent a starting point for further etiopathological research and for the improvement of the prediction of psychosis.

Left-Handedness Detection

abstract In this paper, a new left-handedness sensing and detection module, has been developed to classify the handedness of a person. Handedness of the person can be determined from the EEG data captured and further confirmed using a simple game as testing module. EEG signals were obtained from three locations namely A1, O1 and O2. The signals were then classified into four different frequency bands: Alpha, Beta, Delta and Theta before they were used to determine the Mean EEG Coherence. Generally the left handed person has higher Mean EEG Coherence which means that there are more connections between the left and right hemisphere of cerebrums through the corpus callosum. Based on research, personal non-right handedness has been associated with both increased corpus callosum size and increased functional interaction between cerebral hemispheres. To relate the former to the later, it is suggested that the increased size of corpus callosum, which somehow passes information between the two sides of the brain, allows greater inter-hemispheric communication. Handedness is determined based on this criterion. At the end of the research, the module developed enables the determination of handedness personnel.

Frequency of non-right-handedness in bipolar disorder and schizophrenia

Increased non-right-handedness (NRH) probably reflects neurodevelopmental abnormalities in psychiatric disorders. Past studies of NRH have focused more on schizophrenia (SZ) than bipolar disorder (BPD). We report results on NRH in two large studies. In (1), NRH was compared among BPD patients with psychosis, SZ patients, and healthy controls (HC). NRH was elevated in BPD with psychosis and SZ patients relative to HC, but not SZ relative to BPD. In (2), NRH was compared between BPD patients with and without psychosis. NRH was similarly elevated in both. The findings suggest that NRH may reflect shared brain anomalies in SZ and BPD.

How to Keep Ultrasound Safe in Obstetrics? What have We Learned?

If asked, the vast majority of end users (and patients) will respond that ultrasound is not X-rays and is completely safe. In reality, there is a marked lack of knowledge on effects of ultrasound in tissues being examined (bioeffects) among the majority of these end-users. Being a form of energy, ultrasound has effects in all insonated tissues (bioeffects), secondary to two main mechanisms: thermal and non-thermal (or mechanical). On-screen indicators of these potential bioeffects are the Thermal and Mechanical indices (TI and MI). Biological effects have been reported in animals, mostly for exposure exceeding those usually applied in humans. In humans, autism, abnormal hearing, vision or language development, intrauterine growth restriction, childhood cancer and increase in non-right handedness have been associated with ultrasound but no cause-effect has been proven by science-based analysis (except, possibly for a slight increase in non-right handedness, specifically in males). Yet, essentially all epidemiological studies are based on information obtained with pre-1992 machines, when acoustic output of instruments was allowed to be increased, for fetal use, by a factor of almost 8. Increasingly, ultrasound is performed early in gestation, a time when the fetus is known to be particularly sensitive to external influences. Most examinations are performed with B-mode, but some studies employ Doppler technology, known to expose the fetus to much higher levels of acoustic energy, hence requiring special precautions. There should always be a medical indication and operators should follow the rule of the shortest time possible, at the lowest possible output, compatible with an adequate diagnosis (ALARA). Keeping the TI and MI below 1 will, almost certainly, not cause deleterious effects to the fetus. Education of the operators is vital to maintain the unblemished record of ultrasound in obstetrics. WFUMB. WFUMB Clinical Safety Statement for Diagnostic Ultrasound. Available from: http://www.wfumb.org/about/statements.aspx. Abramowicz JS, Sheiner E:Ultrasound Bioeffects and Safety: what the practitioner should know. In Fleischer a, Abramowicz JS, Gonsalves L, Manning F, Monteagudo A, Timor I, Toy E (eds): Sonography in Obstetrics and Gynecology-Principles and Practice. 8th edition, 2018.

Neurodevelopmental Outcomes and Neural Mechanisms Associated with Non-right Handedness in Children Born Very Preterm

Non-right handedness (NRH) is reportedly more common in very preterm (VPT; <32 weeks' gestation) children compared with term-born peers, but it is unclear whether neonatal brain injury or altered brain morphology and microstructure underpins NRH in this population. Given that NRH has been inconsistently reported to be associated with cognitive and motor difficulties, this study aimed to examine associations between handedness and neurodevelopmental outcomes in VPT 7-year-olds. Furthermore, the relationship between neonatal brain injury and integrity of motor tracts (corpus callosum and corticospinal tract) with handedness at age 7 years in VPT children was explored. One hundred seventy-five VPT and 69 term-born children completed neuropsychological and motor assessments and a measure of handedness at 7 years' corrected age. At term-equivalent age, brain injury on MRI was assessed and diffusion tensor measures were obtained for the corpus callosum and posterior limb of the internal capsule. There was little evidence of stronger NRH in the VPT group compared with term controls (regression coefficient [b] -1.95, 95% confidence interval [-5.67, 1.77]). Poorer academic and working memory outcomes were associated with stronger NRH in the VPT group. While there was little evidence that neonatal unilateral brain injury was associated with stronger NRH, increased area and fractional anisotropy of the corpus callosum splenium were predictive of stronger NRH in the VPT group. VPT birth may alter the relationship between handedness and academic outcomes, and neonatal corpus callosum integrity predicts hand preference in VPT children at school age. (JINS, 2015, 21, 610-621).

A parietal biomarker for ADHD liability: as predicted by the distributed effects perspective model of ADHD.

We previously hypothesized that poor task-directed sensory information processing should be indexed by increased weighting of right hemisphere (RH) biased attention and visuo-perceptual brain functions during task operations and have demonstrated this phenotype in ADHD across multiple studies, using multiple methodologies. However, in our recent distributed effects model of ADHD, we surmised that this phenotype is not ADHD specific, but rather more broadly reflective of any circumstance that disrupts the induction and maintenance of an emergent task-directed neural architecture. Under this view, increased weighting of RH-biased attention and visuo-perceptual brain functions is expected to generally index neurocognitive sets that are not optimized for task-directed thought and action, and when durable expressed, liability for ADHD. The current study tested this view by examining whether previously identified rightward parietal EEG asymmetry in ADHD was associated with common ADHD characteristics and comorbidities [i.e., ADHD risk factors (RFs)]. Barring one exception (non-right handedness), we found that it was. Rightward parietal asymmetry (RPA) was associated with carrying the DRD4-7R risk allele, being male, having mood disorder, and having anxiety disorder. However, differences in the specific expression of RPA were observed, which are discussed in relation to possible unique mechanisms underlying ADHD liability in different ADHD RFs. Rightward parietal asymmetry appears to be a durable feature of ADHD liability, as predicted by the Distributed Effects Perspective Model of ADHD. Moreover, variability in the expression of this phenotype may shed light on different sources of ADHD liability.

An EEG-based approach for left-handedness detection

This paper illustrates a left-handedness sensing and detection system to classify the handedness of a person. The recruited test subjects were required to rest or expose to graphical stimulus, the electroencephalogram (EEG) signals at the homologous occipital region were then captured. Using a simple game as a testing module, the handedness can be determined from the EEG data captured and recognized. In this work, the EEG signals were obtained from three locations namely A1, O1 and O2. The extracted signals from these locations were then classified into four different frequency bands: Alpha, Beta, Delta and Theta. The analyses and classification results were used to determine the Mean EEG Coherence of these signals. From our observation, the left handed person has higher Mean EEG Coherence which means that there are more connections between the left and right hemisphere of cerebrums through the corpus callosum. Based on the research, we realized that the non-right handedness personnel has been associated with both increased corpus callosum size and increased functional interaction between cerebral hemispheres. We also realized that the increased size of corpus callosum, which somehow passes information between the two sides of the brain, allows greater inter-hemispheric communication. Thus, the handedness is determined based on the above mentioned criterion. From all the experiments conducted, the developed handedness sensing and detection system could determine the handedness personnel efficiently.

Handedness in schizophrenia and schizoaffective disorder in an afrikaner founder population

Objective: An association between the Leucine-rich repeat trans membrane neuronal 1 gene (LRRTM1), schizophrenia/ schizoaffective disorder and handedness was recently claimed to be established. This study aimed to test the hypothesis that Afrikaner patients with schizophrenia/schizoaffective disorder are more non-right handed than their non-affected firstdegree relatives and that of two separate control groups. The association between handedness, gender and age at onset of illness in the patients group was also determined. Method: Two cross-sectional studies were carried out, which compared the handedness of a group of 100 (30 females and 70 males) Afrikaner patients with schizophrenia/schizoaffective disorder, their non-affected first-degree relatives, and two separate control groups. Handedness was determined by the Edinburg Handedness Inventory (EHI). Results: Patients were found to be more right-handed than expected with only 17 out of 100 being non-right-handed compared to 11 out of 100 non-affected relatives; 36 out of 100 students and 75 out of 500 nonaffected Afrikaner participants. The students were significantly more non-right handed than the patient and family groups but no difference in handedness was found when comparing the patients, family members and 500 participant control group. There was no significant difference between age at onset of illness and handedness. A significant association between female gender and non-right handedness in the patient group was found but no gender difference in the family and student groups. A highly significant association was found between the male gender of the patients and student control group regarding handedness. A significant difference was found between the median EHI raw scores of the patients and the family members. The median EHI raw scores of the patients were significantly lower than their paired family members. Conclusion: The study failed to prove a leftward shift of handedness in the patients with Schizophrenia and Schizoaffective disorder in the Afrikaner Founder population. Whether or not LRRTM1 is indeed the genetic basis of handedness, remains unclear.

Handedness in FTLD (P07.168)

Objective: To describe the prevalence of non-right handedness in Frontotemporal Lobar Degeneration. Background Non-right handedness - ambidexterity and left handedness - occurs in 8-10% of the population. 95% of right handed individuals have left lateralized language localization and associated structural asymmetry L>R, most notable in the temporal planum. Non-right handed individuals have greater variability in language distribution. Non-right handedness is also associated with an increased frequency of learning disability. Rogalski et al. reported increased rates of learning disability in patients with Primary Progressive Aphasia. We hypothesized that structural and functional differences in handedness might reveal themselves among various types of neurodegenerative disease. Design/Methods: We reviewed our entire PPA (LPA, n= 56; NFV-PPA, n=64; SV-PPA n=135) and PSP cohorts (n=89). Results: 9% of the LPA cohort (n=5 of 56) is non-right handed, consistent with handedness in the general population. 14% of the SV-PPA cohort is non-right handed (n=19 of 135) compared to 5% of the NFV-PPA/PSP cohort (n=7 of 151). Chi-square analysis of observed versus expected, reveals a statistically significant increase of non-right handedness in SV-PPA with an expected 8% rate of non-right handedness (p Conclusions: There appears to be a handedness bias among FTLD diagnoses. Given the high clinicopathological correlation between SV-PPA and NFV-PPA/PSP, with TDP-43 and Tau respectively, this analysis supports dichotomization of handedness among underlying pathologies. In the context of increased learning disability in non-right handed patients and PPA, this observation integrates both of these findings and may help with future diagnostic discrimination. Supported by: NIH/NIA P01 AG019724, P50 AG023501, T32 AG23481. Disclosure: Dr. Miller has nothing to disclose. Dr. Rankin has nothing to disclose. Dr. Gorno Tempini has nothing to disclose. Dr. Miller has received personal compensation for activities with Allon Therapeutics, Inc. and TauRx Therapeutics, Ltd. Dr. Miller has received research support from Novartis.

Ultrasound in pregnancy and non‐right handedness: meta‐analysis of randomized trials

To study the association between exposure to ultrasound in pregnancy and non-right handedness in children with available data from randomized trials. Follow-up data of 8865 children aged 8-14 years from three randomized trials on routine ultrasonography at 15-20 weeks' gestation were available. Handedness was assessed through questionnaires to the parents and classified according to five, 10 or 11 questions. Children not classified as right handed were regarded as non-right handed. There was a statistically significant increased prevalence of non-right handedness in ultrasonographically screened children compared with controls (odds ratio (OR) 1.15; 95% CI, 1.03-1.29). The results in subgroups according to gender are consistent with the overall results, with no significant differences between boys and girls. Among boys, the association became stronger when an exploratory analysis according to ultrasound exposure before 19-22 weeks' gestation was done (OR 1.30; 95% CI, 1.10-1.53). There is a statistically significant-albeit weak-association between ultrasound screening during pregnancy and being non-right handed later in life.