Recognition and characterising non-motor profile in early onset Parkinson's disease (EOPD)

Early onset Parkinson's disease (EOPD) has been recently defined as a clinical entity with subjects presenting with Parkinson's disease (PD) between the ages of 21–50 and replaces the term Young Onset PD (YOPD). Presentations in this age group are somewhat different to the typical Late Onset sporadic PD (LOPD) and genetic basis may play an important role. The presentations are however, to be differentiated from other causes of juvenile onset or early onset parkinsonism, which are often driven by rare genetic, brain metal deposition, or metabolic progressive disorders with a levolevodopa unresponsive or poorly responsive phenotype. Specific genetic mutations can also underpin EOPD and include nonmotor symptoms of EOPD, which have not been studied extensively. However, some real-life comparator studies with LOPD suggest a nonmotor profile in EOPD dominated by neuropsychiatric symptoms (anxiety), pain, sexual dysfunction, and a higher risk of impulse control disorders and segregation to the recently described noradrenergic and Park-sleep nonmotor endophenotypes may occur. Awareness of the phenotypic variants and nonmotor expression will pave the way for future precision and personalised medicine.