[Delayed low back pain after spinal anesthesia].

A 50-year-old man had an inguinal hernia repair under spinal anaesthesia with bupivacaine. On the 2nd postoperative day, he complained of backache and paresis at the posterior part of the lower extremities, well relieved by non-steroidal anti-inflammatory drugs. On the 6th postoperative day, he came back to hospital, because of low back pain associated with a heavy feet sensation. The hypothesis of a neurological complication of the spinal anaesthesia was considered. The interview of the patient revealed a history of lumbar disk disease, not reported during the preoperative visit. After an in depth clinical examination, two causes seemed possible: subarachnoid haematoma and lumbar disk protusion. Against the first diagnosis were the initial clinical signs. However, in many cases, objective neurological deficit arise too late to allow efficient neurosurgical treatment. Thus, a MRI examination was performed which is non invasive in comparison with a computed tomography myelogram. In our patient, it did not detect a true lumbar disk protusion, but a simple degenerative disease of the L5-S1 disk. In suppressing the lumbar lordosis, spinal anaesthesia probably allowed a distension of spinal capsules and tendons, responsible for the troubles.