Clinical characteristics of hypertrophic olivary degeneration following brainstem or cerebellar hemorrhage.

Patients who have experienced bleeding in the posterior circulation of the brain often develop Hypertrophic Olivary Degeneration (HOD). This condition can lead to new neurological problems several months after the initial hemorrhage, potentially worsening the overall outcome for these patients. However, its pathogenesis and prognosis remain inconclusive. The research included 214 patients diagnosed with brainstem or cerebellar hemorrhage, of which 36 developed secondary HOD. The study aimed to analyze the clinical data of these patients, investigate the risk factors associated with HOD development, and evaluate the prognosis for those affected. (1) No significant differences in common cerebrovascular risk factors, such as hypertension and diabetes, were observed between the HOD and non-HOD groups among patients with lesions involving the Guillain-Mollaret triangle (GMT) (P > 0.05). (2) The site of hemorrhage was significantly correlated with the location of HOD (P < 0.05). (3) A significant association was found between the primary lesion's site and the interval before HOD onset (P < 0.05). (4) Patients in the HOD group showed poorer functional outcomes, reflected by higher mRS scores (Z =  -2.859, P = 0.004) and lower ADL scores (Z =  -2.859, P = 0.004). Among patients with brainstem or cerebellar hemorrhage, all individuals with HOD had lesions involving the GMT. A significant correlation was identified between the site of hemorrhage and the location of HOD. Cerebellar hemorrhage cases were associated with shorter intervals before HOD onset, and HOD was linked to significantly worse functional outcomes.