Do Patients Present With A Standard Textbook Pattern of Referred Pain While Having A Pinched Nerve?

Dermatomes- look at C4,5 compare below

One of the useful things I learnt while I was still in physiotherapy school, that I am still using daily, are dermatomes. A dermatome is the area of skin that sends signals to the brain through our spinal nerves. These signals help us sense temperature, pressure and pain. 

When a patient comes in to our clinic with radiculopathy, which means a range of symptoms caused by the irritation of a nerve root, we can gauge what levels of the spine are affected, knowing the dermatomes chart. 

These symptoms can include pain, numbness, tingling sensations, sensory changes, loss of strength and even a change in reflexes. These can occur in the cervical (neck), thoracic (upper back) and lumbar (low back) regions. It is often known as a 'pinched nerve'.

C4,5 check with earlier picture

For example, if a patient comes in complaining of pain in the shoulder it may mean that C4,5 may be implicated. This is especially so if treating the shoulder does not make the patient better.

So I was very interested when I read about the following study, where the researchers studied how often patients who had cervical radiculopathy presented with the standard textbook versus non standard patterns.

Only patients with single level cervical radiculopathy operated by six surgeons were included in this study. Their symptoms of radiculopathy were compared to a standard textbook pattern. 

239 patients' records met the inclusion criteria. Their age, weight, BMI, gender and symptom duration were not different between patients with a standard radicular pattern versus those with a non standard pattern.

Picture of referral pattern from article

Overall, 54% (129 patients) fit the standard textbook pattern while 46% (110 patients) differed from the standard pattern. C5-6 and C6-7 were the two most common levels operated on for radicular pain. Non standard patterns of presentation were found in 50.9% (C5-6) and 44.7% (C6-7) of the cases.

Same sided neck pain (81% of patients) was the most common presenting symptom. Shoulder pain was reported in 142 patients (59.4%). 19.2% of the subjects (46 out of 239) had pain/ symptoms at the neck level with no referred pain down the arm. 

When a non standard pattern was encountered, it differed by 1.68 dermatomal levels, either higher or lower.

The authors concluded that observed patterns of cervical radiculopathy in their study only followed the standard textbook pattern in 54% of patients studied. Non standard referral patterns were more common than thought. 

Now, that's a good reminder to doctors, surgeons and physiotherapists (note to self). Patients suspected of referred pain from the neck and back may not always have symptoms that fit the standard textbook pattern.

We need to do our due diligence to ensure each patient get treated appropriately.

Reference 

McAnany SJ, Rhee JM et al (2019). Observed Patterns Of Cervical Radiculopathy: How Often Do They Differ From A standard, "Netter diagram" distribution? Spine. 19(7): 1137-1142. DOI: 10.1016/j.spinee.2018.08.002.

Change The Arms, Change The Neck

First assessment

Here's another patient who came in to our clinic complaining of neck pain, tingling, and sensations of electric currents/ pins and needles, down his left arm.

This patient works as an electrician and often has to be in awkward positions running electrical wires. He feels worse after prolonged time spent looking upwards - mostly due to running ceiling electrical wires.

He was referred to our clinic by another friend who had seen us and gotten better without needing surgery as suggesting by his surgeon.

Just like the other lady who had neck pain, I didn't treat his neck. Just treated his arms and shoulder girdle.

Have a look at the picture after treatment.

After treatment

You can see quite an dramatic change not only in his neck but in his rib cage and hips too. Even his nephew who came with him was amazed at the change.

Before and after

Have a look when I put both pictures together above. Quite a big difference? All done in less than an hour.

What did I do? No mobilizations or manipulations of the thoracic and cervical spine at all. Just treating the arm lines as seen in the picture below except for levator scapulae. Left that out as I wanted to "exclude" the neck.

Superficial and deep back, front arm lines

Do You Really Need An MRI?

Picture by Cory Doctorow from Flickr

My patient had severe low back pain with some referred sensation of numbness, pins and needles down to the left buttock and hamstring area after her weight training in the gym recently. She went to see her doctor who referred her to a spine surgeon who then ordered a spine magnetic resonance imaging (MRI) to investigate further.

Results show she had a prolapsed disc (PID) or what is commonly as a slipped disc. The surgeon suggested surgical intervention to remove the disc but my patient refused and sought a second opinion.

Subsequently she came to our clinic after her friend with similar findings on MRI (but didn't have surgery) got better after seeing me.

I've encountered some patients who showed up in our clinics with "many problems" on their MRI but no pain while other patients showed no abnormality on their MRI but complain of severe pain. If you "believe" the MRI you may end up treating the MRI and not treating the patient (or trying to fix the problem on the MRI rather than addressing the actual issue causing your patients' symptoms/ pain).

Personally, I believe that nine times out of ten, a competent health care provider (doctor, physiotherapist etc) can pinpoint the cause of your pain/ injury without ordering an expensive MRI.

In our clinics, we ask many questions about the patients' symptoms, training regime (for a sports injury), much like a detective looking for clues. We then do a thorough physical assessment - comparing limbs, palpating the area that hurts, moving your limbs/ joints through different positions or have the patient perform the aggravating movement, checking alignment etc.

Done correctly and accurately, we can often pinpoint the root cause of the problem from the physical assessment and treat it.

It's also interesting to note that everyone is built a little differently and our structures change with age. As MRI's are very sensitive, they can reveal abnormalities that aren't the actual cause of your problems.

A recent review article found 37 percent of 20 year old subjects and 96 percent of 80 year old subjects have evidence of disc degeneration on MRI. The authors concluded imaging findings of spine degeneration are present in high proportions of individuals with no pain. These changes in the spine may be a sign of normal ageing rather than medical conditions/ acute injuries that require treatment.

Here's a common running related example. Another of my patients came to our clinic after seeing a Traditional Chinese Physician, physiotherapist and even saw a surgeon for medial (inside) heel pain and didn't get better. She had been walking more than normal and woke up having to hobble with pain upon setting her foot on the ground. That clearly to me would lead me to check her plantar fascia.

In fact, her surgeon did order an MRI and confirmed what I suspected. He proceeded to give her a cortisone injection (steroid injection) which didn't help. My patient endured the cost and hassle of doing the scan for no good reason.

I treated her twice and am happy to report she's well on her way to recovery.

Don't get me wrong. There are definitely times when a MRI scan is needed. If you've had a Physiotherapist /doctor etc assess you thoroughly, rested, had treatment and still not gotten better then it might be a good time to get an ultrasound scan, x-ray or MRI to investigate further.

What about the first patient who had a PID whom I wrote about at the start of this post? Well, she's back running, weight training like normal. Her doctor was surprised to say the least ......


Reference

Brinjkii W, Luetmer PH et al (2015). Systematic Literature Review Of Imaging Features Of Spinal Degeneration In Asymptomatic Populations. J Am Neuroradiol. 36(4): 811-816. DOI: 10.3174/ajnr.A4173.