Functional hemispheric specialization for verbal and visual perceptual processes in terms of blood flow velocity changes in unilateral brain lesions

Abstract

Objective: to comparatively analyze the patterns of functional hemispheric specialization in patients with local brain tumor lesions and in healthy participants.Patients and methods. 40 patients (20 men and 20 women) with local unilateral brain tumor lesions (astrocytomas, gliomas, metastases) aged 19–60 years (mean age, 33±9.2 years) were examined for functional hemispheric specialization for verbal and visual perceptual functions when performing cognitive tasks by functional transcranial Doppler ultrasonography. The findings were compared with those in 57 healthy individuals (mean age, 28±5.1 years). All the participants were right-handed.Results. There was a more pronounced increase in blood flow velocity (BFV) while performing verbal cognitive tasks in the vessels of the left hemisphere (LH) and a more marked rise in that when fulfilling non-verbal cognitive tasks in the vessels of the right hemisphere (RH). The trends in the ratio of LH/RH BFV amplification when performing cognitive tasks were observed to be the same as previously observed in the healthy participants.

Keywords

• functional specialization
• speech functions
• visual perceptual functions
• doppler ultrasound
• blood flow velocity
• cerebral arteries
• cognitive loads
• verbal stimulus material
• non-verbal stimulus material