THE CLINICAL FEATURES AND PROGNOSIS OF SCAN NEGATIVE URO-NEUROLOGICAL DISORDERS

BackgroundMore than 50% of patients presenting with cauda equina syndrome (CES) have normal imaging. These patients require phenotyping to ascertain symptom aetiology and mechanism.Prospective Study Results198 patients presented with suspected CES over 28 months. 47 were diagnosed with ‘scan-positive’ CES (mean age 48yrs, 43% female). 76 patients had evidence of nerve root compres- sion or displacement and were placed into a ‘mixed’ category (mean age 46yrs, 71% female) and 61 patients had normal scans ‘scan-negative’ CES (mean age 40yrs, 77% female). Fourteen patients had a neurological diagnosis explaining their clinical CES symptoms during admission.Patients with ‘scan-positive’ CES were more likely to have reduced or lost bilateral ankle jerks (78% vs. 30% and 12%, p≤0.0001). Patients with ‘scan-negative’ CES were found to have positive signs of a functional neurological disorder on examination (11% v. 34% and 68%, p≤0.0001) as well as high rates of panic, medication usage and psychopathology. Four patients out of 151 (4%, mixed group n=3, ‘scan-negative’ group n=1) had a neurological diagnosis after discharged which potentially explained their clinical CES presentation.ConclusionsThis is the first well phenotyped, prospective study of patients with ‘scan-negative’ CES dem- onstrating a pain, medication and functional mechanism of symptom production.ingrid.hoeritzauer@ed.ac.uk