Authors: Eric Ch Wolters Ysbrand D van der Werf Odile A van den Heuvel
Publish Date: 2008/09/12
Volume: 255, Issue: 5, Pages: 48-
Abstract
In Parkinson’s disease PD there is increasing evidence for disorders in the impulsivecompulsive spectrum related to the disease itself to the pharmacological management of this disease or to both These disorders comprise dopamine deficiency syndrome with immediate reward seeking behaviour dopamine dependency syndrome with addictive behaviour dopamine dysregulation syndrome with both addictive behaviour and stereotyped behaviour and impulse control disorders such as pathological gambling compulsive shopping binge eating and hypersexuality These disorders are especially seen in PD patients with young age of onset higher doses of antiparkinsonian drugs preexistent or current depression preexisting recreational drug or alcohol use and high novelty seeking personality traitsDopamine is not only implicated in voluntary movement control but also plays a significant role in the brain’s reward system and the modulation of behaviours Therefore most if not all drugnaïve PD patients will suffer dysphoria leading to mild immediate reward seeking behaviour as a consequence of the striatal dopaminergic denervation In some of these patients during treatment this may even lead to the intake of increasing quantities of levodopa above those required to adequately treat motor parkinsonism with all characteristics of a dopamine dependence syndrome These patients may develop plastic changes in the striatal matrix leading to hyperkinesia caused by extracellular striatal dopaminergic fluctuations due to pulsatile dopamine replacement therapy As soon as these changes are also seen in the striatal striosomes in the framework of a dopamine dysregulation syndrome stereotyped behaviours punding may occur supposedly due to dorsal versus ventral striatal overactivity Finally impulse control disorders are suggested as being pure adverse sideeffects of dopamine replacement therapy Obsessivecompulsive behaviour caused by ventral to dorsal overactivity so far has not been described in PD patientsTreatment of impulse control disorders is related to the underlying pathology In the case of an intrinsic dopamine deficiency syndrome treatment with dopamine replacement therapy especially levodopa will help In the multifactorial intrinsic and extrinsic dopamine dependency and dysregulation syndromes addictive behaviour might best be helped by psychosocial strategies and punding by continuous dopaminergic receptor stimulation or amantadine hypothesized to reduce the plastic changesinduced hypersensitization The extrinsic impulse control disorders might be best treated by reducing or replacing dopamine receptor agonists
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