Chronic Pain Consultation

Chief Complaint

54 yo M presents for evaluation and management of chronic axial LBP with R lower extremity radiculopathy, ongoing for 3 years.

Subjective

• Pt reports constant dull ache in the lower back (6/10 baseline, 8/10 with prolonged standing > 20 mins) with intermittent sharp, shooting pain radiating down the R posterior thigh to the calf. Pain began insidiously 3 years ago while lifting heavy equipment at work; no acute trauma. Exacerbated by flexion, lifting, and cold weather; mildly relieved by heat and recumbency. Previously trialled physiotherapy and NSAIDs with minimal sustained relief. Denies saddle anesthesia, bowel/bladder incontinence, or progressive lower extremity weakness. Expresses frustration regarding inability to work and poor sleep due to pain.

Past Medical History

• HTN, T2DM, mild depression, lumbar disc herniation (L4-L5). Past surgical hx: laparoscopic cholecystectomy (12/05/2018), R knee arthroscopy (04/11/2012).

Medications

• 1. pregabalin (Lyrica®) 75 mg PO BID
  2. naproxen (Aleve®) 500 mg PO BID PRN
  3. metformin (Glucophage®) 1,000 mg PO BID
  4. ramipril (Altace®) 5 mg PO daily
  5. turmeric extract 500 mg PO daily
  6. magnesium bisglycinate 200 mg PO QHS

Allergies

• Penicillin (hives), codeine (severe nausea/vomiting).

Social History

• Born in the Philippines, migrated to Canada in 2010. Married with 2 adult children. Previously worked as a warehouse supervisor, currently on long-term disability for the past 8 months; holds a college diploma. Non-smoker, rare EtOH (1–2 beers/month). Previously enjoyed recreational basketball and gardening, now limited to short 10-minute flat walks due to pain exacerbation.

Sleep History

• Goes to bed at 22:30, sleep latency ~60 mins due to positional back discomfort. Reports fragmented, non-restorative sleep, waking 3–4 times nightly. Wife reports loud snoring; no witnessed apneic episodes. Completed level 3 home sleep study (14/08/2023) showing mild OSA (AHI 11). Trialled CPAP 6 months ago but discontinued due to mask claustrophobia.

Objective

• Alert, oriented, NAD. Gait slightly antalgic favouring R leg. Lumbar spine shows decreased lordosis, tenderness to palpation over L4–S1 paraspinal muscles and R sciatic notch. ROM limited in flexion (45 degrees) and extension (10 degrees) by pain. SLR positive on the R at 40 degrees, negative on the L. Lower extremity strength 5/5 bilaterally except R EHL 4+/5. Patellar and Achilles reflexes 2+ symmetric. Decreased sensation to light touch over R lateral calf (L5 dermatome).
• BP 134/82 mmHg, HR 76 bpm, RR 14/min, Temp 36.7 °C, SpO2 98% RA, Wt 88 kg, Ht 172 cm, BMI 29.7 kg/m².
• Lumbar MRI (18/01/2024): Moderate-to-severe R paracentral disc protrusion at L4–L5 contacting the traversing R L5 nerve root, mild facet arthropathy at L4–L5 and L5–S1, no central canal stenosis. HbA1c (10/01/2024): 6.8%. Creatinine 78 umol/L, eGFR > 60 mL/min.

Assessment

• 1. Chronic axial LBP with R L5 radiculopathy secondary to L4–L5 disc protrusion, complicated by features of central sensitization.
  2. Differential diagnosis: Lumbar facet joint syndrome, piriformis syndrome, sacroiliac joint dysfunction, diabetic peripheral neuropathy.

Plan

1. Medications

• Increase pregabalin (Lyrica®) to 150 mg PO BID to optimize neuropathic pain control. Initiate duloxetine (Cymbalta®) 30 mg PO daily for 1 week, then increase to 60 mg PO daily to address both chronic musculoskeletal pain and comorbid mood symptoms. Discontinue naproxen due to limited efficacy and GI/renal risks with concurrent ramipril use. Discussed potential side effects including dizziness, somnolence, dry mouth, and nausea, advising slow titration and taking duloxetine with food.

2. Physical Activity

• Counselled on anti-inflammatory diet principles (Mediterranean diet) and gradual weight reduction to offload lumbar spine. Advised low-impact aquatic therapy and daily pacing of flat walking, avoiding boom-bust activity cycles.
• Referred to multidisciplinary pain program, kinesiologist for core stabilization, and sleep clinic for CPAP mask refitting/positional therapy.

3. Interventional Procedures

Referred to interventional pain clinic for R L4–L5 transforaminal epidural steroid injection and diagnostic medial branch blocks. Discussed how targeted peripheral nerve blocks can reduce nociceptive input to the dorsal horn, helping to wind down central sensitization. Treatment goals established: 30% reduction in baseline pain and ability to walk 30 mins continuously.

4. Mindfulness

Recommended cognitive behavioural therapy for chronic pain (CBT-P) and daily 15-minute guided mindfulness-based stress reduction (MBSR) via smartphone app to modulate pain perception and reduce catastrophizing.

5. Surgery

Reviewed MRI findings; given lack of progressive motor deficit or cauda equina symptoms, surgical decompression (microdiscectomy) is not urgently indicated. Will re-evaluate for neurosurgical referral if conservative and interventional measures fail after 6 months.

6: Patient Education

At today's visit, we discussed central sensitization. Central sensitization is a nervous system condition associated with the development and persistence of chronic pain. When it occurs, the nervous system undergoes a process known as wind-up and remains regulated in a persistently heightened state of reactivity. This ongoing, or regulated, reactivity lowers the threshold for stimuli that cause pain and can sustain pain even after the original injury has healed. We discussed how chronic pain interventions work toward reducing pain as assessed by pain scores and subjective reports. We also discussed evaluating improvement through sleep, mood, and physical functioning.