Causes and incidental neuroimaging findings in pharmacologically confirmed Horner syndrome: a retrospective cohort study of 134 cases

Structural causes of HS are more frequently identified in acute and subacute presentations, supporting early imaging, especially to rule out ICA dissection. In chronic HS, selective imaging may be appropriate due to lower diagnostic yield. The high rate of incidental findings underscores the need for careful interpretation to optimize resource use and avoid unnecessary investigations.