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Hi, this is Dave Yousem

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from Johns Hopkins Medical Institution,

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coming to you live from Cincinnati,

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Ohio in the studios of MRI Online.

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Today's topic is the degenerative diseases of the spine.

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This is a great topic because it's shared with

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musculoskeletal radiology, as well as neuroradiology.

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And I'll give you my take on it

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as a neuroradiologist working predominantly

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with neurosurgeons.

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I will be discussing the nomenclature of disc

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pathology as it was established about 20 years ago

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by a combined task force of the

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North American Spine Society,

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the American Society of Spine Radiology,

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and the American Society of Neuroradiology.

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We wanted to have a joint commission that

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established a common language for the description

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of lumbar spine disc pathology.

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And it's been applied also to cervical disc pathology.

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So this was revised about ten years ago,

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and I will be providing you with that second

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revision of the common nomenclature,

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and credit goes to doctors Fardon and

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Millette for working on this topic.

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Let's talk a little bit about the background of back pain.

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So most of the time, back pain is self limited.

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It may be a very short duration event

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that lasts a couple of days.

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Some people have long standing back pain,

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and of those,

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over 60% will still recover in about one month.

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80% will feel better and have no further issues

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at two months. And if you wait long enough,

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even as long as three months,

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90% of people have relief of their back pain.

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Of all the people that have back pain,

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there's a relatively small percentage that have

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persistent back pain that go on to surgery and

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that surgery may be performed by orthopedic surgery

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professionals or neurosurgeons,

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or a combination of the two.

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With regard to the overall prevalence of disease,

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about by age 60,

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which I just recently celebrated my birthday,

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35% of people who are asymptomatic will have a herniated

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disc demonstrated on their lumbar spine MRI scan.

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Those discs herniations are typically found at the

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L4-L5 level or L5-S1.

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They may extend into the spinal canal,

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they may be foraminal, they may be far lateral.

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We'll be talking about the location

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of the disc herniation shortly.

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The natural evolution of a disc herniation is to shrink.

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And that is why with time, most patients do resolve

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their clinical symptomatology.

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This is usually treated with bedrest

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and nonsteroidal anti-inflammatory drugs.

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In those patients who are in severe discomfort,

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you may have a steroid pack that is given for

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approximately three to six days that also relieves

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the pain. And it's thought that with time,

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these herniations will shrink. That said,

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there's probably something like tachyphylaxis

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that occurs with a disc herniation.

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And that is that after a period of

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time of that disc herniation,

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irritating the nerve and the nerve

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sending impulses to the brain,

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eventually the brain probably stops reacting to it.

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And so we do see some patients who have persistent

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disc herniations against nerve roots.

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And the disc herniation doesn't change

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at all in a follow up MRI scanning,

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yet the patient has become asymptomatic.

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So, I think it that's probably what I refer to as

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sort of a tachyaphylaxis. As far as surgery goes,

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the larger the herniation,

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the more likely it is that it will be symptomatic,

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and the more likely that the surgeons

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will feel compelled to recommend

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surgical intervention for that.

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But it is hard to tell which patient is going to

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resolve completely over the course of

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time, versus have persistent pain.

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So when do we get MRI or when

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do we get advanced imaging?

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CMS, the Centers for Medicare Services,

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Medicare and Medicaid Services, generally states

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that they will not reimburse for advanced imaging

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such as MRI for lumbar spine pain until the

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patient has had six weeks of medical therapy.

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Those patients who do have weakness or a foot drop,

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or other symptoms that are referable to the

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nerve root may get imaging earlier,

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particularly if they have unremitting pain that

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is difficult to treat with nonsteroidal

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anti-inflammatory drugs or opioids.

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So, failure of conservative management with either a

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steroid pack or nonsteroidal anti-inflammatory

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drugs and other pain medication after six weeks is

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generally the most common indication

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for MRI being performed.

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However, some people say that the earlier

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you get to a herniation,

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the less likely the patient will have persistent

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pain or less likely to have neurologic deficits.