Dynamics of cognitive impairments during L-dopa therapy in Parkinson's disease

Abstract

To assess the dynamics of cognitive impairments (CI) in patients with Parkinson's disease (PD) during L-dopa therapy. The randomized clinical study included 41 patients with a refined diagnosis of PD 2.5-3.5 stages by Hoehn-Yahr scale, mainly with akinetic-rigid and mixed forms, and with CI associated with PD. All patients were on levodopa therapy. The average duration of the disease was 5 years. The study participants were randomized into two groups according to the design. To assess the dynamics of CI, a neuropsychological study was carried out twice with an interval of 6 months: in group I - at the «peak and outcome» of L-DOPA therapy, and in group II - at the «outcome and peak» of levodopa therapy, respectively. Assessment of cognitive functions (CF) was carried out using Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB), Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-Cog), Geriatric Depression Scale (GDS). The statistically significant improvement of CF at the «peak» of levodopa drugs and the deterioration at the «outcome» of L-DOPA therapy in the form of an increase in CI (p<0.05) was revealed. CI in PD, in a certain extent, may be dependent on L-DOPA therapy as well as motor manifestations. The most dependent on L-DOPA therapy CF were attention, speech, executive and visual-spatial functions.