When to consider “mixed pain”? The right questions can make a difference!

Figures & data

Table 1. Patient case details.

A 59-year old male travel agent presented with a 7-month history of therapy-resistant low back pain with radiation into the left buttock, groin and thigh (“like electric shocks”) He is 186 cm tall, weighs 68 kg, and has a BMI of 19.7 In the last 4 weeks, the pain has begun to radiate into his left leg and foot Ibuprofen provided some pain relief in the first 3 months of his condition but was associated with unacceptable side effects He was subsequently prescribed celecoxib which resulted in the same level of pain control with fewer side effects, but this was discontinued when his prescription ran out Several months prior to consultation, he received a steroid injection – this was associated with pain relief for 2 weeks only, after which pain was noted to recur. Physiotherapy instituted in the weeks following did not provide pain relief 4 weeks prior to consultation, he was prescribed tramadol which resulted in much better analgesia, but “afraid of getting addicted” he has only been taking this on an as-needed basis 3 week prior to consultation, he was prescribed pregabalin – this has resulted in better sleep and less electric shock–like pain

Table

Where exactly do you feel your pain? Please mark the painful areas in this pain drawing. What words would you use to describe your pain? How long have you been experiencing your pain? On a scale of 0–10, how intense is your pain at rest and during movement? Do you feel pain constantly, more on movement or more at rest? Is your pain related to any identifiable cause? How did it start and develop? What have you done to treat your pain? Has your pain caused you psychological distress? Have you experienced any other symptoms or changes which have worried you?

Table 2. Answers to key questions that may help identify mixed pain.

Our patient’s answers and their evaluation are depicted in rightmost.

Table 3. Patient case details (continued).

Physical examination findings No clinical signs of infection, either general or focused on the back No motor deficit in the lower limbs No neurological deficits except hypoesthesia to pricking in the left L5/S1 region All proprioceptive muscle reflexes positive Negative Babinski No vibration loss (6/8 both sides) Positive Lasegue sign (Straight Leg Raise test) left side >45° No allodynia (thermal/mechanical/dynamic) Movement of the lumbar spine painfully restricted while rotating to the left and bending forward (finger-floor distance 30 cm) Iliosacral joint blockade left side (positive forward flexion phenomenon, positive Mennell sign) Questionnaire assessments painDETECT questionnaire score: 21 (neuropathic component likely >90%) Patient Health Questionnaire (PHQ)-9 score: 5 (minimal depression) Medical Outcomes Study (MOS)-Sleep Scale: 60 (severe sleep disturbances) Laboratory findings Normal laboratory findings HLA-B27 negative Imaging findings Lumbar X-ray (Figure 2(A)): Multisegmental osteochondrosis with anterior spondylosis of the thoracic 11/12 and lumbar 1/2/3. Caudally emphasized facet joint arthrosis Lumbar magnetic resonance imaging (Figure 2(B,C)): Spondylarthrosis L3/4/5 and S1 (hypertrophic, destructive and activated as L4/5) with a synovial cyst L5/S1 left with relocation and compression of the nerve route S1 left. Synovial cyst L4/5 right without compression of the nerve route

Working diagnosis Lumbar facet joint degenerative osteoarthritis with synovial cyst L5/S1 left and compression of the nerve route S1 with radiculopathy (chronic mixed pain)