Mete Ozdikici*


Department of Radiology, Sultan 2. Abdulhamid Han Training and Research Hospital, Istanbul, Turkey


Introduction: Geschwind-Behan-Galaburda hypothesis states that the high intrauterine levels of testosterone impede the growth of certain regions of the left hemisphere, which leads to the right hemisphere language dominance and an increase of left-handedness. Simultaneously, the higher levels of testosterone suppress the development of the thymus. In that case, is there any difference in the incidence of Coronavirus (COVID-19) infection between right- and left-handed individuals?

Materials and methods: This retrospective study conducted in a public hospital in Istanbul consists of patients who have been diagnosed with COVID-19 disease because of positive laboratory findings and have been asked for a chest computerized tomography (CT) for the possibility of pneumonia. One hundred forty-three COVID-19 patients, aged between 19 and 89 years, were included in our study, 85 of them were males and 58 were females. The healthy control group consisted of 359 people (180 males and 179 females) and their ages ranged between 18 and 88 years. The determination of left-handedness was made by asking which hand was used when writing. The left-handedness rates in COVID-19 patients and the healthy control group were determined. The findings were evaluated statistically.

Results: The left-handedness rate of COVID-19 patients was 29% in males and 26% in females. In the healthy control group, these rates are 21% and 18%, respectively. The difference between the two groups is statistically very significant (p<0.001).

Conclusion: Our results support the Geschwind-Behan-Galaburda hypothesis, which expresses the negative effect of left-handedness on the immune system via the thymus.


Covid-19, handedness, incidence, Geschwind-Behan-Galaburda hypothesis.