Analysis of handedness by way of the Edinburgh Inventory: Correlation between neurological assessment and radiological investigation

Handedness is usually determined by genetics, but early trauma, prenatal events, or even an acquired tendency to use a hand may affect individual preference. With the advent of fMRI studies, diagnosis of language laterality has become easier. However, some cheaper and simpler instruments may be used for this same proposal, such as the Edinburgh Handedness Inventory.
We sought to verify how accurately this instrument can settle cerebral lateralization by correlating its results with a complete neurological assessment and neuroradiological investigation.
A total of 75 adult individuals were evaluated between May 2007 and April 2008 at the Hospital das Clínicas – UNICAMP; 37 of them were neurologically healthy individuals, 37 were acute phase post-stroke patients, and one was a patient who had a metastatic disease to the central nervous system. Evaluation consisted of a medical history with complete neurological exam, including tests for attention, visual perception, phonemic perception, spontaneous speech, fluency, comprehension, repetition, naming, praxis evaluation (ideomotor/constructional), and the Edinburgh Inventory for analysis of handedness (scores 10 to 50). The original 10 daily activity items of the Edinburgh Inventory could receive a score of 1 (stronger right-hand preference) to 5 (stronger left-hand preference). The 38 patients with brain diseases were submitted to neuroimaging exams for correlation between the brain injury site and the assessment of handedness or cerebral dominance for language; all of them underwent a CT scan, and 16 were also submitted for MR of the brain. Fisher’s exact test was employed for contingency tables regarding association between the injury site and the presence or absence of aphasia, with a threshold of significance set at ρ<0.05.

Right-handed subjects were more common in our sample, proportionally according to most studies. Overall scores of the Edinburgh Inventory tended to be very low in case of right-handed individuals, and very high in case of left-handed ones. By and large, this analysis of handedness was reliable for determination of cerebral language dominance in most brain injured patients evaluated.

Supported by CAPES – Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. No relevant conflicts of interest declared.