2015 Volume 54 Issue 11 Pages 1415-1419
Post-radiation lower motor neuron syndrome (PRLMNS) is a rare neurological complication of radiation therapy and its pathogenesis is unclear. We herein report a patient with PRLMNS who developed leg weakness 17 years after craniospinal radiation as a treatment for suprasellar germinoma. The electrophysiological evaluation, via a novel magnetic stimulation method, indicated a prolonged cauda equina conduction time, suggesting focal demyelination of the nerve roots in the cauda equina. The distribution of the denervated muscles detected by magnetic resonance imaging was consistent with patchy motor nerve root lesions. These results support the hypothesis that PRLMNS originates from ischemic radiculopathy in the cauda equina.