Chronic low back pain: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:32

Chronic low back pain is a common patient concern that can have many underlying causes including conditions that affect the nerves, joints, bones, muscles and other soft tissues.
Common causes of chronic low back pain include neuropathic pain due to nerve damage and nociceptive pain, due to myalgia, arthralgia, ostalgia, and referred visceral pain.

Focused H&P0:32–1:02

When a patient presents with chronic low back pain, first obtain a focused history and physical exam history typically reveals low back pain that has lasted three months or more.
While physical exam might reveal limited range of motion of the spine tenderness to palpation over the spine or paraspinal tissue.
And in some cases overlying edema or erythema. With these findings, you can diagnose chronic low back pain to find the cause of low back pain.

Neuropathic Chronic Low Back Pain1:02–3:47

You should first assess for neuropathic pain. This type of pain is described as lancinating electrical radiating, burning or cold in nature.
Let's first look at if neuropathic pain is present. In this case, the patient might report a history of numbness and tingling as well as radicular pain, which is pain radiating down one or both legs.
Physical exam may reveal allodynia which is when pain is elicited from a stimulus that doesn't usually cause pain like a feather.
They may also have a positive straight leg raise, test, decreased patellar or achilles reflexes, dermatomal sensory deficits and myotomal strength deficits.
With these findings diagnose neuropathic chronic low back pain. Here's a clinical pearl.
There are many possible causes of neuropathic chronic low back pain. For example, a herniated vertebral disc causing spinal nerve root impingement can lead to radicular pain.
Alternatively, lumbar spinal stenosis which occurs due to degenerative narrowing of the spinal canal can cause nerve root impingement and subsequent back pain, numbness and weakness of the lower extremities.
Finally, post herpetic neuralgia can cause neuropathic chronic low back pain. This type of back pain occurs initially when a patient develops a herpes zoster rash on their back and it may continue long term in the distribution of the rash.
All right, when it comes to treatment, start with lifestyle modifications, including continued activity is tolerated if needed.
Recommend physical therapy. Pharmacologic therapy includes nonsteroidal antiinflammatory drugs or nsaids.
Acetaminophen muscle relaxants or serotonin and norepinephrine inhibitors, also known as SNRI s anticonvulsants like gabapentin might be helpful to some patients with neuropathic pain as well.
You can also consider prescribing opiates, but only if other medications failed to control the pain. Moreover, if your patient's symptoms are not improving, you can obtain a surgical consult for minimally invasive interventions such as epidural spinal injections or spinal cord stimulation.
Surgery can also be an option if patients with severe symptoms, fail to have them resolve with less invasive therapy. All right.

Nociceptive Chronic Low Back Pain3:47–4:16

If neuropathic chronic, low back pain is not present, assess for no susceptive pain. This type of back pain is localized and usually described as dull or sharp.
It does not radiate has an identifiable pain source and usually involves joints, bones, muscles or soft tissues. If this is the case diagnose no susceptive chronic low back pain.

Arthralgia4:16–7:28

Next, assess the primary tissue involved to determine the source of the pain. Starting with arthralgia.
History typically reveals back stiffness and possibly fatigue, malaise and pain in multiple joints. The exam may show a limited range of motion of the spine or spinal deformity.
If this is the case, suspect arthralgia, labs like blood work are not typically indicated with suspected arthralgia. However, if you think there's an underlying inflammatory disease, you can order human leukocyte antigen B 27 or HLA B 27 as well as inflammatory markers such as ESR and CRP.
Additionally, you can order an X ray labs might be normal or your patient may have a positive HLA B 27 an elevated E SR and C RP, possibly indicating ankylosing spondylitis.
The X ray might demonstrate sacral ileitis characterized by small erosions and subchondral sclerosis. In either case diagnose arthralgia time for a clinical pearl.
Common causes of arthralgic low back pain include osteoarthritis, ankylosing spondylitis and psoriatic spondylitis. Osteoarthritis is the most common cause of back pain.
In primary care. This degenerative disease of the joints is characterized by mechanical wear and tear injury to articular cartilage, resulting in bony and synovial damage.
Ankylosing spondylitis is a chronic inflammatory illness. More common in biological males that can result in disabling spinal arthritis.
Some patients with this disease carry the HLA B 27 gene. Finally, psoriatic spondylitis is another inflammatory condition.
These patients often have additional symptoms such as psoriasis, uveitis, peripheral edema dactylitis, and pitting of the fingernails.
Ok. Let's talk about treatment for lower back arthralgia.
Lifestyle modifications include aerobic and strengthening exercises as well as hydrotherapy. Some patients may benefit from physical therapy.
Pharmacologic therapy includes nsaids with or without acetaminophen. In patients with ankylosing spondylitis.
You can consider disease modifying anti rheumatic drugs or dmards like sulfaSALAzine. You can prescribe corticosteroids like predniSONE but only for short term treatment.
Again, opiates are an option only if other medications fail to control the pain. Lastly, you might need to obtain a surgical consult for minimally invasive spinal interventions such as facet joint or sacroiliac joint injections or surgery for those with persisting symptoms.
Despite less invasive therapy. Next up is ostalgia also known as bone pain.

Ostalgia7:28–11:02

These patients are usually over 50 years old and may report chronic steroid use or unintentional weight loss. The physical exam reveals spinal tenderness to palpation and there might be an obvious spinal deformity.
In this case, suspect ostalgia. Ok.
Let's follow up with labs and imaging. You can check alkaline phosphatase levels as well as a liver function test, which can help distinguish between liver or bone as the cause of an elevated alkaline phosphatase.
You should also order an X ray of the spine for all patients with bony spinal pain. In some cases, additional imaging might be needed.
A bone density scan can help diagnose spinal fragility due to decreased bone mass. While a spinal MRI may help detect signs of malignancy.
All right, lab results might be normal for patients with ostalgia or they may show elevated alkaline phosphatase with normal liver function tests.
As an additional note, elevated T and alkaline phosphatase would indicate underlying liver disease in ostalgia. One or more imaging studies are typically abnormal.
A bone density scan may show at score of negative 2.5 or less. The spine X ray may show bone enlargement with osteolytic lesions, a fragility fracture or a vertebral fracture.
Lastly, the MRI may show spinal cord lesions or interosseous tumors with any of these results diagnose ostalgia. Here's a clinical pearl, important causes of ostalgia include osteoporosis, Paget disease of the bone and metastatic carcinoma.
In osteoporosis, there is decreased bone mass resulting in skeletal fragility with increased fracture risks. This can occur in postmenopausal female individuals or patients with a history of long term steroid use.
On the other hand, Paget disease of the bone is a metabolic bone disorder that results in bone overgrowth that can cause pain fracture or bone deformity.
Lastly, ostalgia can be the result of metastasis such as breast or prostate cancer. All right, let's talk about treatment.
Lifestyle modifications include low intensity exercise as tolerated and fall precautions to reduce the risk of further bone injuries.
Some patients may benefit from supplements like calcium and Vitamin D as well as physical therapy. Pharmacologic therapy includes nsaids with or without acetaminophen as well as an SNRI I.
Other medication options depend on the underlying cause of ostalgia. In cases of osteoporosis, the patient might need bisphosphonates, selective estrogen receptor modulators or calcitonin.
However, for metastatic disease, chemotherapy or radiation might be indicated as before opioids for pain are needed. Only if other medications fail.
Lastly, obtain a surgical consult for patients with severe symptoms that are refractory to less invasive therapy. Let's move on to myalgia.

Myalgia11:02–12:23

Also known as muscle pain history usually reveals muscle aches in multiple areas and fatigue. Physical examination shows muscle tenderness to palpation and sometimes pain with activity.
If this is the case diagnose myalgia. Here's another clinical pearl.
Most common causes of chronic low back pain due to myalgia include fibromyalgia and chronic back strain. Fibromyalgia is a chronic pain condition that results in widespread muscle pain and fatigue.
Though the exact underlying cause is poorly understood. On the other hand, chronic back strain typically has a known cause such as recurrent heavy lifting or poor posture.
All right, let's go over treatment. Lifestyle modifications include low intensity exercise that should be increased as tolerated.
Additionally, your patient may benefit from physical therapy or cognitive behavioral therapy, especially in the setting of fibromyalgia.
As for pharmacologic therapy, you might offer a tricyclic antidepressant, also known as a TCA SNRI muscle relaxant or anticonvulsant.

Referred Visceral Pain12:23–15:01

Finally, let's discuss referred visceral pain. In which case, the low back pain is coming from an internal organ.
These patients may have a history of abdominal pain and known renal or pancreatic disease. Physical exam might reveal a normal exam of the lower back, possibly with abdominal tenderness with these findings suspect referred visceral pain.
Now, moving on to labs and imaging referred pain to the low back is typically pancreatic gastrointestinal or renal in origin.
So what is CBC amylase lipase total bilirubin alkaline phosphatase? Liver function tests renal function tests and urinalysis.
Imaging should include an X ray and a renal ultrasound with or without a CT scan. Labs typically reveal a normal CBC but may show an abnormal amylase or lipase.
Additionally, total bilirubin alkaline phosphatase, liver function tests and renal function tests might be elevated when it comes to urinalysis.
You might find blood or the presence of RBC S due to nephrolithiasis or urinary tract infection. The x-ray should show no visible spinal abnormalities but the renal ultrasound may show renal cysts or nephrolithiasis.
These findings might also be visible on a CT scan or there may be pancreatic atrophy with calcifications with any of these findings diagnose referred visceral pain.
Here's one more clinical pearl visceral pain that is referred to the lower back can have several underlying causes. One common cause is chronic pancreatitis which is typically caused by recurrent episodes of acute pancreatitis.
Other options include autosomal dominant polycystic kidney disease or stones in the kidneys or ureters. Ok.
Treatment focuses on the underlying illness. Pharmacologic therapy includes acetaminophen with or without an NSAID which may be helpful.
However, remember to avoid nsaids. If renal disease is suspected, you can also use TCA S or SNRI S.
Here. Finally, opiates are your last option to control the pain.

Review15:01–15:48

All right. As a quick recap, chronic low back pain is a common patient concern that can have many underlying causes when assessing a patient first characterized their pain as either neuropathic due to underlying neuropathy or nociceptive due to arthralgia, ostalgia, myalgia, or referred visceral pain for neuropathic pain, arthralgia, ostalgia and myalgia treatment options include lifestyle modifications, physical therapy, pharmacologic therapy and obtaining a surgical consult, referred visceral pain is primarily addressed by treating the underlying cause as well as pharmacologic therapy.
Chronic low back pain: Video, Causes, and Symptoms | Osmosis