Official websites use. Share sensitive information only on official, secure websites. They result from sensitization of the mesocorticolimbic pathway that arose in predisposed PD patients concomitantly with spreading of PD pathology, non-physiological dopaminergic and pulsatile administration of dopamine replacement therapy DRT.
Neuropsychiatric fluctuations NPF reflect the psychotropic effects of dopaminergic drugs and play a crucial role in the emergence of ICDs and behavioral addictions. Dopamine agonists DA which selectively target D2 and D3 receptors mostly expressed within the mesocorticolimbic pathway, are the main risk factor to develop ICDs.
Genetic predispositions are crucial for the responsiveness of the mesolimbic system and the development of ICDs with several genes having been identified. Early screening for neuropsychiatric fluctuations, reduction of DA, fractionating levodopa dosage, education of patients and their relatives, are the key strategies for diagnosis and management of ICDs and related disorders.
Although motor signs namely bradykinesia, rigidity and tremor are still considered as the core feature of diagnostic criteria for Parkinson disease PD [ 71 ], increasing recognition has been given over time to non-motor manifestations of PD including cognitive, autonomic, and neuropsychiatric signs [ 99 ].
Neuropsychiatric signs also encompass neuropsychiatric fluctuations NPF , Impulse control disorders ICDs and related disorders, and psychosis that are frequently observed along the progression of PD pathology and the concurrent pulsatile administration of increasing doses of DRT [ 25 , 46 , 52 ]. Therefore, behavioural disorders in PD have been conceptualized as a hypodopaminergic behavioural syndrome where apathy predominates, hyperdopaminergic behavioural syndrome which includes ICDs and other behavioural addictions, and non-motor fluctuations [ 2 , 75 ] that together, define two opposite sides of one behavioural spectrum [ 81 ].
