The discal hernia are unfrequent in dorsal localization and neurological appearances are deceptive. We report a case with amyotrophic and fasciculations developing a progressive spinal cord amyotrophy aspect. The complementary investigations (gaz myelography and spinal angiography) show the discal hernia in T11-T12 which was operated successfully. The vascular factor role is discussed about semiologic and pathogenic view.