Handedness and laterality of the viscera

Abstract

Neurology and general medicine: the neurological aspects of medical disorders. New York Churchill Livingstone, 1989431-447. 4. Headache Classification Committee of the International Headache Society. Classification and diagnostic criteria for headache disorders, cranial neuralgias and facial pain. Cephalalgia 1988;8(suppl 7): 1-96. 5. Newman LC, Lipton RB, Solomon S. The hypnic headache syndrome. In: Rose FC, ed. New advances in headache research. London: SmithGordon and Company LM., 1991:31-34. 6. Goadsby PJ, Lipton RB. A review of paroxysmal hemicranias, SUNCT syndrome and other short-lasting headaches with autonomic feature, including new cases [review article]. Brain 1977;120:192-209. 7. Newman LC, Lipton RB, Solomon S. The hypnic headache syndrome: a benign headache disorder of the elderly. Neurology 1990;401904-1905. 8. Mosek A, Dodick DW. The hypnic headache syndrome: the Mayo Clinic Experience.The biological basis of handedness remains to be determined in humans. Hepper et a1.l supported the genetic explanation of handedness by demonstrating a preference for thumb sucking before birth. However, Dryden2 rejected this hypothesis and proposed that handedness was related to neuromuscular development secondary to the oxygen level in the blood.We have now confirmed the independence of handedness and the asymmetric position of the viscera in humans. We assessed the relationship between the physical laterality of the internal organs and handedness in 16 healthy Japanese subjects with situs inversus universalis. We studied eight males and eight females (age range, 7 to 91 years; mean, 35 years). All subjects had dextrocardia without congenital heart disease.Subjects were not mentally retarded and they had no psyehiatric disorders, autoimmune disease, or the asplenic syndrome. One subject was blind, which excluded the determination of eyedness in this individual. Subjects were assigned to the right-handed group if they wrote, drew, and threw a ball with the right hand. Right-eyed meant the subject used the right eye when looking through a camera or telescope. Right-footed was defined as use of the right foot when kicking a ball. The subjects with left handedness, and those with mixed handedness, footedness, and eyedness were assigned to the "nonright" group. Statistical analysis was performed using the chi-squared test.About 90% of the population is right handed.3 We found that 15 of the 16 subjects (94%) with situs inversus universalis were right Table Behavioral preferences in subjects with situs inversus universalis Handedness Footedness Eyedness* (n = 16) (n = 16) (n = 15) ~~ Right 15 (93.8%) 15 (93.8%) 11 (73.3%) Nonright 1(6.3%) 1(6.3%) 4 (26.7%) Z t 3.5 3.5 1.8 Probability 0.0005 0.0005 0.0707 * Excluded one individual who was blind.t Right-handed bias.handed (table), consistent with the incidence of right handedness in normal people. In addition, 15 of the 16 subjects (94%) were right footed, again consistent with the incidence observed in normal people.' These data excluded a significant relationship betw...

The Functional Genetics of Handedness and Language Lateralization: Insights from Gene Ontology, Pathway and Disease Association Analyses

“…This finding has been supported by neuroimaging studies of patients with situs inversus, who displayed atypical patterns of frontal and occipital cerebral asymmetries ( Kennedy et al, 1999 ; Ihara et al, 2010 ). However, situs inversus patients display the standard pattern of handedness, which rather supports a dissociation between visceral and brain asymmetries ( Matsumoto et al, 1997 ; McManus et al, 2004 ; Afzelius and Stenram, 2006 ). It might be that genes associated with handedness are not necessarily involved in body asymmetry formation, but rather in anatomical structure development per se .…”

A School-based Twin Study of Handedness among Adolescents in Taiwan

“…Taken together, these studies provide some empirical basis for our findings in handedness. Nevertheless, a caveat to note is that some studies examining individuals with a mirror-image reversal of asymmetric visceral organs failed to support the link between visceral and cerebral asymmetries (Kennedy et al, 1999;Matsumoto et al, 1997). Second, the low heritability of handedness might be due to adaptive evolution as traits responding to selection would come to predominate in all individuals, leading in long time to genetic homogeneity (Corballis, 1997(Corballis, , 2003Palmer, 2004).…”

Callosal misconnectivity and the sex difference in psychosis

“…The two can be dissociated. The former is not detectably changed in schizophrenia but is reversed in individuals with situs inversus who show normal language dominance, normal asymmetry of the planum temporale and are mostly right-handed (Matsumoto et al, 1997). Thus the physical shift of the hemispheres is not related to the lateralization of language and this feature probably has an old evolutionary origin.…”