DOPAMINE DYSREGULATION SYNDROME IN PARKINSON’S DISEASE AND APPROACHES TO ITS CORRECTION WITH DRUGS

Abstract

The objective is to describe a clinical case of dopamine dysregulation syndrome (DDS) with compulsive intake of large doses of levodopa in a patient with Parkinson’s disease (PD). Materials and methods. Male patient R., born in 1956, has had PD since 2004 when he noticed changes in his handwriting, difficulties to perform small movements with the right hand. Therapy with levodopa/benserazide was started at 300 mg/day. With time symptoms of the disease escalated: gait impairment and motor fluctuations started. Action duration after administration of levodopa/benserazide sin gle dose shortened to 2 hours, peak dose dyskinesia developed, as well as instability with frequent falls. In 2012, clinical picture of the disease included symptoms of DDS. The patient independently increased the drug dose, decreased time between doses, didn’t follow the doctor’s recommendations. Relatives noticed a state of euphoria in the patient after taking a dose of levodopa/benserazide. At the time of visiting the Department of Neurology of the Russian Medical Academy of Continuous Professional Education in the beginning of 2016, the daily equivalent levodopa dose was 2000 mg, and 800 mg of it were taken at night. Results. The patient was transferred to a three-component modern levodopa drug Stalevo (levodopa + carbidopa + entacapone) 150 mg + levodopa/benserazide 50 mg 6 times a day (daily dose 1200 mg). Decreased levodopa daily dose achieved by transferring the patient to a three-component drug with better bioavailability lead to significant reduction of motor and non-motor symptoms, significant increase in effect duration after a single dose of levodopa. In a year of follow-up, DDS symptoms gradually regressed, time between drug administration increased, the patient stopped taking the drug at night, fluctuations and drug-induced dyskinesias significantly decreased. Conclusion. In this clinical case, manifestations of DDS caused by long-term compulsive levodopa intake at doses significantly exceeding daily dose (necessary for control of motor symptoms) are described. One of the approaches to reduction of high doses of levodopa and control of motor fluctuations is prescription of Stalevo which stabilizes levodopa level in plasma and provides a more continuous stimulation of dopamine receptors in the striatum.