[A 28-year-old woman with newly-onset urinary incontinence]

28 year-old woman developed sensory loss in the gluteal region and involuntary micturition during sleep. After two days she arrived at the Department of neurology. Examination disclosed absence of the right ancle reflex (S1), sensory loss in the saddle area including the dermatomes S1-S5, absence of the ano cutan (S3-S5) and bulbocavernous reflexes (S3-S4). She had sphincter disturbance and a sensory palsy of the bladder, but no retention. She experienced no vertebral, radicular or other pain at any time. Because of the lack of pain, the tentative diagnosis was acute myelitis, and a CT scan was not done. A further investigation with MRI vas postponed to the next day. The MRI scan showed a large herniation of the L5/S1 disc, with significant affection of the cauda equina. The patient went to surgery with laminectomia and extirpation of the hernia. This case illustrates that a disk herniation with a cauda equina syndrome is not necessarily painful.