A RECENT development of interest to neurologists is the almost complete disappearance of a previously common diagnosis, namely, neuritis of the sciatic nerve. Although toxic and infectious neuritides of the sciatic nerve exist as extremely rare conditions, the common painful state formerly called chronic, or recurrent, sciatica is now known to be the result of compression of a nerve root within the spinal canal or its foramen. It is also known that such sciatic pain is due to compression of the root by a diseased intervertebral disk in at least 75 per cent of cases. In the rest, compression of the root is produced by such pathologic conditions as intraspinal tumor or cyst, primary or metastatic tumor of a vertebra, spondylolisthesis and arthropathy.
Although the discovery that most sciatic pain is due to an intraspinal lesion has proved a boon to mankind, several details of therapy are still in the