scholarly journals Heritability of language laterality assessed by functional transcranial Doppler ultrasound: a twin study

2020 ◽  
Vol 4 ◽  
pp. 161
Author(s):  
Dorothy V.M. Bishop ◽  
Timothy C. Bates
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Structural Equation ◽  
Transcranial Doppler Ultrasound ◽  
Equation Modeling ◽  
Shared Environment ◽  
Functional Language ◽  
Laterality Index ◽  
Heritability Estimates ◽  
Language Laterality

Background: Prior studies have estimated heritability of around 0.25 for the trait of handedness, with studies of structural brain asymmetry giving estimates in a similar or lower range. Little is known about heritability of functional language lateralization. This report describes heritability estimates using functional language laterality and handedness phenotypes in a twin sample previously reported by Wilson and Bishop (2018). Methods: The total sample consisted of 194 twin pairs (49% monozygotic) aged from 6 to 11 years. A language laterality index was obtained for 141 twin pairs, who completed a protocol where relative blood flow through left and right middle cerebral arteries was measured using functional transcranial Doppler ultrasound (fTCD) while the child described animation sequences. Handedness data was available from the Edinburgh Handedness Inventory (EHI) and Quantification of Hand Preference (QHP) for all 194 pairs. Heritability was assessed using conventional structural equation modeling, assuming no effect of shared environment (AE model). Results: For the two handedness measures, heritability estimates (95% CI) were consistent with prior research: .25 (.03 - .34) and .18 (0 – .31) respectively for the EHI and QHP. For the language laterality index, however, the twin-cotwin correlations were close to zero for both MZ and DZ twins, and the heritability estimate was zero (0 - .15). Conclusions: A single study cannot rule out a genetic effect on language lateralisation. It is possible that the low twin-cotwin correlations were affected by noisy data: although the split-half reliability of the fTCD-based laterality index was high (0.85), we did not have information on test-retest reliability in children, which is likely to be lower. We cannot reject the hypothesis that there is low but nonzero heritability for this trait, but our data suggest that individual variation in language lateralisation is predominantly due to stochastic variation in neurodevelopment.

scholarly journals Heritability of language laterality assessed by functional transcranial Doppler ultrasound: a twin study

2020 ◽  
Vol 4 ◽  
pp. 161
Author(s):  
Dorothy V.M. Bishop ◽  
Timothy C. Bates
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Structural Equation ◽  
Transcranial Doppler Ultrasound ◽  
Equation Modeling ◽  
Shared Environment ◽  
Functional Language ◽  
Laterality Index ◽  
Heritability Estimates ◽  
Language Laterality

Background: Prior studies have estimated heritability of around 0.25 for the trait of handedness, with studies of structural brain asymmetry giving estimates in a similar or lower range. Little is known about heritability of functional language lateralization. This report describes heritability estimates using functional language laterality and handedness phenotypes in a twin sample previously reported by Wilson and Bishop (2018). Methods: The total sample consisted of 194 twin pairs (49% monozygotic) aged from 6 to 11 years. A language laterality index was obtained for 141 twin pairs, who completed a protocol where relative blood flow through left and right middle cerebral arteries was measured using functional transcranial Doppler ultrasound (fTCD) while the child described animation sequences. Handedness data was available from the Edinburgh Handedness Inventory (EHI) and Quantification of Hand Preference (QHP) for all 194 pairs. Heritability was assessed using conventional structural equation modeling, assuming no effect of shared environment (AE model). Results: For the two handedness measures, heritability estimates were consistent with prior research: 0.23 and 0.22 respectively for the EHI and QHP. For the language laterality index, however, the twin-cotwin correlations were close to zero for both MZ and DZ twins, and the heritability estimate was zero. Conclusions: A single study cannot rule out a genetic effect on language lateralisation. It is possible that the low twin-cotwin correlations were affected by noisy data: although the split-half reliability of the fTCD-based laterality index was high (0.85), we did not have information on test-retest reliability in children, which is likely to be lower. We cannot reject the hypothesis that there is low but nonzero heritability for this trait, but our data suggest that individual variation in language lateralisation is predominantly due to stochastic variation in neurodevelopment.

scholarly journals Negligible heritability of language laterality assessed by functional transcranial Doppler ultrasound: a twin study

2019 ◽  
Vol 4 ◽  
pp. 161 ◽  
Author(s):  
Dorothy V.M. Bishop ◽  
Timothy C. Bates
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Twin Study ◽  
Transcranial Doppler Ultrasound ◽  
Equation Modeling ◽  
Shared Environment ◽  
Laterality Index ◽  
Heritability Estimates ◽  
Language Laterality ◽  
Rule Out

Background: It is widely assumed that individual differences in language lateralisation have a strong genetic basis, yet prior studies show low heritability (around 0.25) for the related trait of handedness, and two twin studies of structural brain asymmetry obtained similarly low estimates. This report describes heritability estimates from a twin study of language laterality and handedness phenotypes. Methods: The total sample consisted of 194 twin pairs (49% monozygotic) aged from 6 to 11 years. A language laterality index was obtained for 141 twin pairs, who completed a protocol where relative blood flow through left and right middle cerebral arteries was measured using functional transcranial Doppler ultrasound (fTCD) while the child described animation sequences. Handedness data was available from the Edinburgh Handedness Inventory (EHI) and Quantification of Hand Preference (QHP) for all 194 pairs. Heritability was assessed using conventional structural equation modeling, assuming no effect of shared environment (AE model). Results: For the two handedness measures, heritability estimates were consistent with prior research: 0.23 and 0.22 respectively for the EHI and QHP. For the language laterality index, however, the twin-cotwin correlations were very close to zero for both MZ and DZ twins, and the heritability estimate was zero. Conclusions: A single study showing negligible heritability for language laterality cannot rule out a genetic effect on language lateralisation. It is possible that the low twin-cotwin correlations were affected by noisy data: although the split-half reliability of the fTCD-based laterality index was high (0.85), we did not have information on test-retest reliability in children, which is likely to be lower. We cannot rule out the possibility that true heritability of differences in language lateralization is non-zero, but results indicate that the heritability of this trait is low at best. Stochastic variation in neurodevelopment appears to play a major role in determining cerebral lateralisation.

scholarly journals Heritability of tic disorders: a twin-family study

2016 ◽  
Vol 47 (6) ◽  
pp. 1085-1096 ◽  
Author(s):  
N. R. Zilhão ◽  
M. C. Olthof ◽  
D. J. A. Smit ◽  
D. C. Cath ◽  
L. Ligthart ◽  
...  
Keyword(s):  
Structural Equation ◽  
Large Population ◽  
Epidemiological Studies ◽  
Population Based ◽  
Tic Disorders ◽  
Equation Modeling ◽  
Shared Environment ◽  
Tic Disorder ◽  
Heritability Estimates ◽  
Additive Genetic Effects

BackgroundGenetic–epidemiological studies that estimate the contributions of genetic factors to variation in tic symptoms are scarce. We estimated the extent to which genetic and environmental influences contribute to tics, employing various phenotypic definitions ranging between mild and severe symptomatology, in a large population-based adult twin-family sample.MethodIn an extended twin-family design, we analysed lifetime tic data reported by adult mono- and dizygotic twins (n = 8323) and their family members (n = 7164; parents and siblings) from 7311 families in the Netherlands Twin Register. We measured tics by the abbreviated version of the Schedule for Tourette and Other Behavioral Syndromes. Heritability was estimated by genetic structural equation modeling for four tic disorder definitions: three dichotomous and one trichotomous phenotype, characterized by increasingly strictly defined criteria.ResultsPrevalence rates of the different tic disorders in our sample varied between 0.3 and 4.5% depending on tic disorder definition. Tic frequencies decreased with increasing age. Heritability estimates varied between 0.25 and 0.37, depending on phenotypic definitions. None of the phenotypes showed evidence of assortative mating, effects of shared environment or non-additive genetic effects.ConclusionsHeritabilities of mild and severe tic phenotypes were estimated to be moderate. Overlapping confidence intervals of the heritability estimates suggest overlapping genetic liabilities between the various tic phenotypes. The most lenient phenotype (defined only by tic characteristics, excluding criteria B, C and D of DSM-IV) rendered sufficiently reliable heritability estimates. These findings have implications in phenotypic definitions for future genetic studies.

High-Grade Stenosis of a Traumatic Brachiocephalic Pseudoaneurysm and the Change in Cerebral Blood Flow Assessed With Transcranial Doppler Ultrasound

2021 ◽  
pp. 154431672110023
Author(s):  
Winnie Nguyen ◽  
Tammy Albanese ◽  
Vanessa Tran ◽  
Anne Moore ◽  
Laligam Sekhar
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Transcranial Doppler Ultrasound ◽  
Computed Tomographic Angiography ◽  
Computed Tomographic ◽  
Vertebral Arteries ◽  
Luminal Narrowing ◽  
Basilar Arteries ◽  
The Right ◽  
Tomographic Angiography

This is a case report of a 35-year-old female pedestrian struck by a semi-truck. computed tomographic angiography (CTA) revealed a pseudoaneurysm at the proximal brachiocephalic artery measuring 1.8 cm in cranio-caudal length and 1.2 × 0.6 cm transverse. Just distal to the pseudoaneurysm, there was severe luminal narrowing caused by either a dissection flap or mural thrombus. Due to profound left-sided weakness, transcranial Doppler ultrasound was performed which demonstrated “hesitant” waveforms in the right middle cerebral and right vertebral arteries secondary to proximal obstruction. Hesitant waveforms display mid-systolic velocity deceleration and may also be referred to as the “bunny” waveform. Emboli monitoring of the right middle cerebral and basilar arteries were positive for active embolization

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