Progressive Supranuclear Palsy drives the Infratentorial Cerebrovascular Diseases-associated Hypertrophic Olivary Degeneration

Hypertrophic olivary degeneration (HOD) is a transsynaptic degeneration characterized by the disruption of dentato-rubro-olivary tract, a region also known as the Guillain-Mollaret triangle (GMT), which often occurs because of posterior fossa or brainstem lesions. Infratentorial cerebrovascular diseases (ICVD) has been linked to HOD in previous studies. The underlying mechanism of ICVD patients developed HOD, however, remains undetermined. In this study, we analyzed clinical features of 334 patients with ICVD and the results showed that brainstem hemorrhage was most likely to develop HOD (43.5%) among four types of ICVD. In addition, multivariate regression analysis revealed that PSP-RS was an independent risk factor (OR = 6.69, 95% CI: 1.58–28.32) for ICVD-HOD, and the presence of HOD was obviously higher in PSP-RS patients complicated by ICVD (43.5%) than that in PSP-RS patients uncomplicated by ICVD (4.2%). Furthermore, DTI study showed that the PSP-RS, HOD, PSP-RS with HOD, and PSP-RS with ICVD-HOD groups displayed the impaired microstructural integrity of the GMT compared to iPD and HCs groups. Moreover, some DTI parameters of the GMT showed correlation with the Progressive Supranuclear Palsy Rating Scale (PSPRS) score in PSP-RS patients. Taken together, our study demonstrated that PSP-RS was an independent etiological factor for ICVD-HOD which might due to impaired microstructural integrity of the GMT. More importantly, these findings suggest that PSP-RS patients should aim for the prevention of ICVD to reduce the occurrence of HOD.