Investigations of alterations in brain asymmetry often focus on the planum
temporale of patients with schizophrenia. Data also suggest changes in laterality of
demented patients associated with a more marked impairment of the left hemisphere.
Our study was performed on autoptic brain tissue of 84 patients, out of which there
were 25 nondemented nonpsychotic controls, 50 demented patients (34 Alzheimer
disease, 9 multi - infarct dementia and 7 mixed-type dementia patients) and 9 people
with schizophrenia. The plana temporalia were evaluated via a new volumetric method
using dental resin matter. Areas, cortical thickness and volumes of the right and left
planum temporale were evaluated without normalization to brain weight in 60 patients
and with normalization in 24 people. In controls, a mild right/left laterality of areas,
cortical thickness and volumes was found. Moreover, in control women the areas of the
left planum temporale were smaller than those observed in control men. The shifts to
left/right laterality of areas and volumes were found in all demented groups. In the more
numerous Alzheimer group, the change in laterality of an area was associated with a
mild decrease on the right and a mild increase on the left side. In contrast, marked but
only bilateral area shrinkage as well as reduced cortical thickness and brain volumes
were observed in schizophrenic patients.
Keywords: Brain laterality, dementia, planum temporale, schizophrenia, volumetry.
