Low back pain (LBP) with radiculopathy has a lifetime prevalence of ~5% but accounts for a disproportionately high proportion of expenditures for LBP. Appropriate treatment depends largely on proper diagnosis; however, the varying causes of radicular symptoms – somatic, neurogenic and visceral – can complicate diagnosis based on the description of radicular symptoms. Relating radiculopathy to dermatomal patterns is a common diagnostic approach, although it is also known that dermatomes have wide overlap and vary considerably among individuals, and there is additional evidence to indicate that radicular pain is not necessarily dermatomal.

The goals of this study were to identify L4, L5 and S1 radicular pain patterns and determine: 1) whether they were dermatomal; and 2) if the patterns were clinically indicative of the nerve root level involved…LOG IN OR SUBSCRIBE TO ACCESS THIS REVIEW!

THIS WEEK'S RESEARCH REVIEW:

“Clinical Utility of Lumbar Radicular Pain Patterns”

This paper was published in Chiropractic & Manual Therapies (2019) and this Review is posted in Recent Reviews, Lumbar Spine - Disc & Neurological, Clinical Testing & Procedures and the 2019 Archive.
 
Excerpt from Conclusion:
 
The authors conclude that radicular patterns in this cohort only approximate sensory dermatomes.  Prior knowledge of the patient-reported radicular pattern also did not improve the likelihood that clinicians could accurately identify the involved nerve root level.  As such, they conclude that pain distribution patterns alone do not provide anything more than minimal diagnostic information regarding the involved nerve root. Pain distribution can be interpreted as an indication of radiculopathy, but should not be considered an entirely accurate way to identify the specific level involved.

EDITOR’S NOTE: clinicians are often discouraged by studies like this, but I think in some ways these findings simplify our clinical approach a bit. What I mean by that is – stressing about the exact location of pain distribution likely does not result in a higher chance of identifying a specific level, so it remains more important to overtly recognize the symptomatology (ex. pain the low back AND leg), put together the pieces (corresponding reflex, motor or sensory deficiencies) and arrive at an accurate diagnosis (ex. lumbar disc herniation) regardless of the specific level. This doesn’t mean we can’t approximate or guess the level based on the totality of clinical information, but we must recognize that our ability to be reliably accurate in this regard is limited. Luckily, the exact level of disc herniation (for example), rarely changes the overall treatment approach in a meaningful way, right? 

lower limb dermatomes