This clinical mind map is organized based upon the duration of pain. As discussed in reference to the shoulder pain mind map, some patients with chronic conditions may present early in the disease process and some patients with acute conditions may continue to have pain for a long time period if left untreated. Therefore, a clinician should keep these situations in mind to avoid being misled. Generally, the onset of pain is sudden in acute causes and gradual in chronic causes.

Based upon the pathophysiologic processes, most differentials in this mind map are identified as Muscular/Mechanical, Originating from an Organ system, Neurological, Degenerative, and Systemic, and are denoted as such in parentheses in front of the diagnoses as M, O, N, D, and S, respectively.

Life-threatening conditions which give rise to urgent and emergent situations include spinal abscess, cauda equine, and Aortic Artery Aneurysm (AAA). Features associated with these diagnoses are color coded red and underlined. Features related to a vertebral fracture might also be considered an urgent/emergent situation, and may lead to significant morbidity, but most vertebral fractures are not life-threatening and can be managed conservatively. 

The first pathology on the list of differentials is somatic dysfunction, which is a set of conditions arising from various sources which cause muscular imbalance and are usually treatable with osteopathic manipulation and physical therapy. Although very common, these should be labelled as final diagnoses only after some of the other more serious pathologies have been ruled out. The diagnosis of somatic dysfunction relies upon a proper history and a physical exam. Three diagnoses which are chunked together (spondylosis, spondylolysis, and spondylolisthesis) present very similar to each other in terms of clinical features. However, they have structural differences which cannot be elicited at bedside, such that a clinician can reach the final diagnosis only after imaging. These differences between structural pathologies are:

1. Spondylosis – Degenerative disc disease or arthritis of the spine.

2.  Spondylolysis – Pars articularis defect in the vertebrae or a fracture in the pars articularis, which is different from a fracture of the vertebral spine, commonly known as a spine fracture, which causes acute pain.

3. Spondylolisthesis – Forward slippage of a vertebrae.

Unlike most clinical mind maps, due to space constraints, the medium yield questions are not listed in detail under the reference list of questions in this clinical mind map. Instead, information corresponding to the medium yield questions is noted in green font in front of differentials. To simplify, a list of reference questions is provided below.

Reference list of questions:

High yield questions – Duration, Location

Medium yield questions – the rest of the OLDCARTS (onset, characteristics, aggravating and relieving factors, radiation, timing, and severity), recurrence, trauma, fever, flank pain, urinary symptoms, numbness, tingling, pelvic pain, menstrual irregularities, fatigue, bone pain, and weight loss. Physical exam findings and lab/imaging features which aid in confirming the diagnoses are displayed in brown and purple font, respectively.

 

Back pain poses a unique challenge in terms of diagnostic reasoning due to the following,

1. Back pain is exceedingly common. Over 90% of the population has experienced back pain at some point in their lives, making it one of the most common reasons to seek medical care. The vast majority of back pain is caused by non-serious or non-life-threatening conditions. However, due to the high degree of variability in patient presentation, it may become very challenging for a clinician to differentiate between serious and non-serious morbidities.

2. There is a wide range of overlap of symptoms and signs among various pathologies. For example, a patient with acute abdominal aortic dissection, which is a life-threatening condition, presents with acute and unrelenting pain associated by nausea, diaphoresis, and distress. However, a patient with acute lumbar disc herniation, which is expected to resolve on its own in 80-90% of cases in less than six weeks, may also present with acute and unrelenting pain which causes nausea, diaphoresis, and distress due to its severity.

3. It is very common for patients living with chronic back pain to develop multiple pathologies. This is because one diagnosis of back pain can become a risk factor for another diagnosis. For example, patients who develop chronic back pain due to spondylolisthesis are at a higher than average risk to develop intervertebral disc herniation. Therefore, a clinician must evaluate each new complaint of back pain as a new problem, regardless of a pre-existing pathology.

4. Lumbar spine pathology is very common in the general population, regardless of the development of symptoms. According to some estimates, up to 80% of the population above the age of 40 has some degree of degenerative disc disease (DDD). A clinician needs to keep this in mind when an imaging study such as MRI is available showing lumbar DDD, and there seems to be a mismatch between a patient’s clinical features and a diagnosis arising from DDD. An example is an elderly female patient presenting with a new onset of acute low back pain which has caused a severe restriction in her mobility. Even if a recent MRI is available, which might have been done for any unrelated reason, and shows DDD, a clinician must consider additional acute diagnoses such as vertebral fracture, and acute lumbar disc herniation. Similarly, a patient with a history of DDD can develop multiple sclerosis as well, which causes similar chronic back pain but also produces additional findings. Therefore, a clinician must not prematurely close an investigation, and should try to avoid anchor bias.

A helpful mnemonic to remember causes of acute back pain is FIS - CURLS and to remember causes of chronic back pain is SSSSSAF – PUM