Supplementary Material for: Case Report: Absent F-waves in a case of spinal ischemia – a potential source of diagnostic error

Background Rapidly progressive para- or tetraparesis and early loss of F-waves on the electrodiagnostic studies usually indicate acute inflammatory demyelinating polyneuropathy. A less common alternative etiology is acute spinal cord pathology. Case Presentation We here describe a case of a 65-year-old woman with progressive motor deficits and absent F-waves early in the disease course due to anterior spinal artery syndrome. We provide serial electrodiagnostic findings with focus on the basic electrodiagnostic parameters as well as imaging correlates during the inpatient management. Conclusion Anterior spinal artery syndrome represents an uncommon cause of absent F-waves on the electrodiagnostic exam. Absent F-waves may precede any changes on the imaging and follow-up investigations are often warranted, as spinal cord ischemia can be a dynamic process.