Effects of head trauma and sport participation in young-onset Parkinson's disease.

Head trauma (HT) is emerging as an event anticipating onset of neurodegenerative disorders. However, the potential contribution of HT in young-onset cases (YOPD, age at onset < 50) of Parkinson's disease (PD) has not been examined yet. Here, we systematically assessed HT history in PD patients to estimate the risk associated, especially in terms of age of onset, and define the correlations with the clinical-biochemical profile. The Brain Injury Screening Questionnaire (BISQ) was administered to 94 PD patients (31 with YOPD, known monogenic forms excluded) and 70 controls. HT history was correlated with motor and non-motor scores in all patients, and to CSF biomarkers of neurodegeneration (α-synuclein, amyloid-β42, total and phosporiled-181 tau, lactate, CSF/serum albumin) into a subgroup. HT increased the risk for both PD and YOPD. In PD patients, but not in those with YOPD, the number of HTs directly correlated with CSF total-tau levels. No other correlations resulted between HT and clinical parameters. Sport-related HT was a specific risk factor for YOPD; conversely, the prolonged sporting life represented a protective factor. HTs can favor PD onset, even as YOPD. Sport-related HT resulted a risk factor for YOPD, although the longer sporting practice delayed PD onset, protecting from YOPD. Tauopathy may underlie the overall association between HT and PD. Additional mechanisms could be instead implicated in HT contribution to YOPD onset.