Early hyperdopaminergic state following sub-thalamic nucleus deep brain stimulation in Parkinson disease

Hyperdopaminergic state (HS), especially impulse control behaviors (ICBs), are not rare in Parkinson's disease (PD). Controversial data regarding HS prevalence one year following sub-thalamic nucleus deep brain stimulation (STN-DBS) are reported.

Our objectives were to describe early postoperative HS (PoOHS) including ICBs, hypomania and psychotic symptoms during the first 3 months following STN-DBS (V1) and their prognosis at 1 year (V2).

This descriptive study included 24 PD patients treated successively with bilateral STN-DBS between 2017 and 2019. The primary endpoint was prevalence of PoOHS at V1 according to the Ardouin Scale of Behaviour in Parkinson's Disease.

Prior to STN-DBS (V0), 25% patients had HS (only ICBs) whereas at V1 (during the 3 first months), 10 patients (41.7%) had one or several HS (P=0.22) (de novo in 29.2%): 7 (29.2%) ICBs, 4 (16.7%) hypomanic mood, 1 (4.7%) psychotic symptoms. At V2, all V0 and V1 HS had disappeared, while 1 patient (4.2%) presented de novo HS (P<0.01). No correlation was found between the occurrence of PoOHS at V1 and any V0 data. Higher levodopa equivalent dose of dopamine agonists at V1 was correlated with ICB at V1 (P=0.04).

We found that early PoOHS are frequent in PD after STN-DBS, mostly de novo, with ICBs and hypomania being the most frequent. Despite a good prognosis of PoOHS at one year, our work emphasizes the importance of both a cautious adjustment of dopamine agonist doses and a close non-motor monitoring pre- and post-STN-DBS in PD.