Reliability of clinical examination and computed tomography in the diagnosis of extreme lateral disc herniation.

Twenty-eight cases of extreme lateral and foraminal disc herniation diagnosed by CT are reported. All cases have been surgically verified. In four cases (14%) CT diagnosis failed. The clinical pattern in these cases was not very different from that of typical disc herniation. The reliability of clinical diagnosis is 71%. EMG is seldom diagnostic. Myelography is uniformly of no value as a diagnostic measure.