Cognition and cerebral blood flow in lateralised parkinsonism: lack of functional lateral asymmetries.

Cognitive and cerebral blood flow (CBF) lateral asymmetries have been quantified in 23 right handed patients with lateralised idiopathic Parkinson's disease. Thirteen patients who had predominant right-sided symptoms (RPD) were compared with ten who had predominant left-sided symptoms (LPD). The patient subgroups were matched for age, education, duration of illness, disease severity and medication. Normalised asymmetries scores were calculated from the data obtained with a test battery and SPECT. No correlation was found between laterality of motor Parkinsonian symptoms and cognitive or haemodynamic asymmetry scores.