Parkinsonism and dementia are negative prognostic factors for the outcome of subdural hematoma.

To determine, among a population with subdural hematoma (SH), whether patients affected by neurodegenerative disorders (parkinsonism and dementia) have a worse clinical outcome. We reviewed the data of patients diagnosed with fall-related SH discharged from the Departments of Neurology/Stroke unit, Neurosurgery, Intensive Care Unit at Brotzu General Hospital (Cagliari, Italy) between January 2010 and December 2013. Patients with severe traumatisms, evidence of spontaneous intracerebral bleeding or aged less than 50 were excluded. 332 patients were selected: 69 with a neurodegenerative parkinsonism or dementia (N-group), 217 with history of chronic non-neurological medical conditions with significant disability, previous falls and/or balance problems (NND-group) and 46 with a history of "minor" chronic non-neurological disorder. (NN-group). The clinical status at admission and discharge was assessed by modified Rankin Scale (mRS). The time-span between trauma and hospital admission was also calculated. At hospital admission we found a significantly longer delay in SH's diagnosis (χ (2) test p < 0.001) and a worse mRS score (Kruskal Wallis p < 0.001) in the N-group compared to both NN and NND-groups. During hospital stay we observed the lack of significant variation in mRS score in N-group (Wilcoxon test p = 0.86), in contrast with NN and NND-groups who significantly improved (Wilcoxon test p < 0.001). Our results demonstrate that the consequences of SH are more severe in the N-group compared to NN and NND-groups. The longer interval between trauma and hospital admittance plays a critical role in worsening the outcome of patients with parkinsonism and dementia compared to subjects without neurodegenerative disorders.