Originally Posted by tennis_tater
Well, I think it depends on what the symptoms are that the patient is complaining of, but I think if an ortho or neuro is treating a patient for complaints of leg pain/leg weakness, then obtains an MRI that confirms the existance of a disc herniation and the probability of nerve impingment , and then does further neurological testing (i.e., EMG) that shows specific irregularities with the nerve whose nerve root is adjacent to the level where the disc herniated is located and where the nerve is believed to be impinged based upon a review of the MRI, then I think that individual can be fairly certain in opining that the disc herniation is the cause of the lower leg issues.
Makes sense, but given the high rate of MRI confirmed "disc herniation" in the general population, the presence of it is not highly correlated with causation.
From the groundbreaking (but by no means only) study of it's type that all show basically the same thing:
"We performed magnetic resonance imaging on sixty-seven individuals who had never
had low-back pain, sciatica, or neurogenic claudication. The scans were interpreted independently by three neuro-radiologists who had no knowledge about the presence or absence of clinical symptoms in the subjects. About one-third of the subjects were found to have a substantial abnormality
. Of those who were less than sixty years old, 20 per cent had a herniated nucleus pulposus and one had spinal stenosis. In the group that was sixty years old or older, the findings were abnormal on about 57 per cent of the scans: 36 per cent of the subjects had a herniated nucleus pulposus and 21 per cent had spinal stenosis. There was degeneration or bulging of a disc at at least one lumbar level in 35 per cent of the subjects between twenty and thirty-nine years old and in all but one of the sixty to eighty-year-old subjects. In view of these findings in asymptomatic subjects, we concluded that abnormalities on magnetic resonance images must be strictly correlated with age and any clinical signs and symptoms before operative treatment is contemplated."