Altered subthalamic alpha-beta oscillations in PRKN-associated early onset Parkinson's disease in relation to off-dystonia.

INTRODUCTION

Electrophysiological features of monogenic early onset Parkinson's disease (EOPD) are poorly studied. This lack of knowledge hinders the development of personalized therapy for patients suffering from these PD forms. In this work, we aimed to investigate the differences in STN activity in patients with PRKN mutation and idiopathic EOPD (iEOPD).

METHODS

All the patients underwent clinical evaluation assessing their disease phenotype. We utilized MLPA to test for the mutations in target genes and selected six patients with homozygous ex.8 deletion in PRKN gene. Seven patients without mutations were recruited to a control group. We recorded subthalamic activity intraoperatively, and analyzed single cell patterning and oscillations as well as LFPs.

RESULTS

PRKN patients without off-dystonia demonstrated less prominent alpha and low beta oscillations but had more pause-burst cells compared to iEOPD. Pause-burst neurons were predominant in patients with dystonia regardless of the mutation, while the proportion of alpha-oscillating cells in PRKN patients with dystonia was drastically increased. STN activity in PRKN-PD and iEOPD did not differ significantly when compared without accounting for dystonia.

CONCLUSIONS

PRKN mutation alters subthalamic activity both in single cell patterns and oscillations. Future research may benefit from accounting for dystonia when studying EOPD.