In October, I posted about a newer classification of painful conditions…read it here. Well in this months edition of Manual Therapy, the same authors published another article looking further at the discriminant validity of mechanisms-based classifications of low back (+-leg) pain. In this article, the authors looked at this system by evaluating the extent to which patients classified this way, differ from one another according to various dimensions of pain including self-reported pain severity, quality of life, functional disability, anxiety and depression. 464 subjects were included in this cross-sectional, between-subjects design and data collection was taken by 15 physical therapists in 4 hospital systems (3 in Ireland, 1 in the UK).
For review, this classification of pain has three subgroups: nociceptive, peripheral neuropathic or central sensitization. Below are the criteria of each:
—intermittant and sharp with movement or mechanical provocation.
—pain localized to the area of injury or dysfunction
—clear, proportionate mechanical/anatomical nature to aggrevating and easing factors
—pain described as shooting, burning, sharp, electric-like
—pain in association with other dysesthesias
—night pain/disturbed sleep
2. Peripheral Neuropathic
—history of nerve injury, pathology or mechanical compromise
—pain in a dermatomal or cutaneous distribution
—pain/symptoms provocation with movement tests that move or compress neural tissue (ex. SLR)
3. Central Sentization:
—pain is disproportionate to the nature or extent of injury/pathology
—Disproportionate, non-mechanical, unpredictable pattern of pain provocation in response to aggrevating/easing factors
—strong association with maladaptive psychological factors
—Diffuse/non-anatomic areas of pain/tenderness to palpation
Results: Patients who were classified as having central sensitization, reported significantly more pain, poorer quality of life, higher levels of disability, anxiety and depression as compared to the other groups. This pattern was also found in patients with peripheral neuropathic pain as compared to nociceptive. It appears that this classification demonstrates discriminant validity among PTs.
Smart KM, Blake C, Staines A, et al. Self-reported pain severity, quality of life, disability, anxiety and depression in patients classified with nociceptive, peripheral neuropathic and central sensitisation pain. The discriminant validity of mechanism-based classification of low back (+-leg) pain. Manual Therapy 2012: 17; 119-125.