Spinal Cord Disease — Written Clinical Reasoning

SAQ 1 — Metastatic Spinal Cord Compression: Emergency Management (20 marks, 30 minutes)

Prompt: Outline your integrated assessment and management plan for this patient, covering the immediate recognition and stabilisation, the diagnostic pathway, the definitive treatment decision (surgery versus radiotherapy) with the evidence supporting it, the dose and rationale for corticosteroids, the supportive care bundle, and the prognostic communication with the patient and family. Justify each decision with reference to evidence and guideline recommendations. ^[1]

Model Answer

Diagnosis and problem list (3 marks): ^[1]

This is acute malignant spinal cord compression (MSCC) from prostate cancer metastasis at the thoracic level. The diagnosis is clinical: a known cancer patient with progressive nocturnal back pain (the earliest and most common symptom, present in over 95 percent of MSCC cases), a clear T10 sensory level, UMN weakness below the lesion (spastic paraparesis with hyperreflexia, clonus, and extensor plantars), and sphincter disturbance (urinary retention, reduced perianal sensation, lax anal tone). The sphincter involvement indicates advanced compression and a worse prognosis. The problems are: ^[1]

1. Acute thoracic MSCC from prostate cancer — emergency dexamethasone and MRI required.
2. Metastatic prostate cancer on androgen deprivation — oncology input for systemic disease control.
3. Urinary retention — catheterisation required to prevent bladder injury.
4. Severe nociceptive back pain and likely neuropathic pain — opioid-based analgesia required.
5. VTE risk from immobility and cancer — pharmacological prophylaxis.
6. Functional and psychological impact of a potentially life-changing diagnosis. ^[1]

Immediate stabilisation (4 marks): ^[1]

I would recognise this as a neurological emergency immediately. The single best predictor of ambulation after treatment is ambulation at presentation — and this patient has already lost ambulation — so every hour matters. My immediate actions: ^[1]

• Dexamethasone 16 mg IV immediately. This reduces cord oedema by suppressing the inflammatory response to compression, buying time for definitive imaging and treatment. The conventional regimen is 16 mg loading then 8 mg twice daily, tapered after definitive treatment. I would give it before the MRI because the clinical diagnosis is secure.
• Catheterisation for the 450 mL retention to prevent bladder overdistension and injury.
• Notify the spinal surgery, radiation oncology and oncology teams in parallel — the decision between surgery and radiotherapy is made once the MRI defines the compressive site(s).
• Analgesia — opioid-based (regular paracetamol plus an opioid such as oxycodone or morphine) for the nociceptive bone pain, and consider a gabapentinoid for the neuropathic component.
• DVT prophylaxis with low-molecular-weight heparin (enoxaparin 40 mg subcutaneously daily) plus intermittent pneumatic compression, as cancer and immobility confer a high VTE risk.
• Gastric protection with a PPI alongside the dexamethasone, and glucose monitoring for steroid-induced hyperglycaemia. ^[1]

Diagnostic pathway (3 marks): ^[1]

• Emergency MRI whole spine with gadolinium within 24 hours. This is the gold standard — it shows the cord, the compressive mass, the epidural space, and any other sites of compression or spinal metastasis. A plain CT or X-ray does NOT show the cord and cannot exclude compression.
• If MRI is contraindicated (pacemaker), CT myelography is the alternative.
• I would not perform a lumbar puncture — there is no indication for CSF analysis in MSCC, and an LP below a compressive lesion risks neurological deterioration.
• Bloods: FBC, coagulation, U&E, LFTs, bone profile, PSA, and group-and-save in case of surgery. ^[1]

Surgery versus radiotherapy — the Patchell decision (5 marks): ^[1]

The definitive treatment decision depends on the Patchell 2005 randomised trial criteria. The Patchell trial (PMID 16112300, published in the Lancet) compared direct decompressive surgery plus radiotherapy against radiotherapy alone in patients with a single area of MSCC. The trial was stopped early at interim analysis because surgery was clearly superior: 84 percent of the surgery group remained or became ambulatory versus 57 percent with radiotherapy alone; the median duration of ambulation was 122 days versus 13 days; among non-ambulatory at presentation, 62 percent with surgery versus 19 percent with radiotherapy regained walking; and survival was significantly longer with surgery (median 126 versus 100 days). ^[1]

The Patchell criteria for surgical candidacy are: (1) a single compressive site, (2) predicted survival greater than 3 months, (3) paraplegia for less than 48 hours, (4) a fit surgical candidate, and (5) consideration of tumour radiosensitivity (surgery preferred for radioresistant tumours like renal cell, melanoma, sarcoma). ^[1]

For this patient with prostate cancer: prostate cancer is moderately radiosensitive, and the decision depends on the MRI findings. If there is a single compressive site at the T10 level and he is fit for surgery with a predicted survival of more than 3 months (reasonable given the prognosis of metastatic prostate cancer), I would recommend direct decompressive surgery followed by radiotherapy — especially because he has already lost ambulation, and the Patchell data show surgery doubles the chance of regaining walking in non-ambulatory presenters. If the MRI shows multiple compressive sites, or if he is not a surgical candidate, I would give palliative radiotherapy (typically 8 Gy single fraction or 20 Gy in 5 fractions) plus continued dexamethasone, tapering after treatment. ^[1]

Dexamethasone dose and rationale (2 marks): ^[1]

The standard dose is 16 mg loading then 8 mg twice daily, tapered over 2 to 3 weeks after definitive treatment. I would NOT use high-dose regimens (96 to 100 mg per day) because the Vecht 1989 trial (PMID 2771077) showed no additional benefit over the conventional dose, with significantly more toxicity (psychosis, gastric perforation, infection). This is the most commonly tested pharmacology fact in MSCC. I would prescribe a PPI for gastric protection and monitor blood glucose. ^{[1] [2]}

Supportive care and complications (2 marks): ^[1]

• Bladder management: indwelling catheter initially, then trial of void once the neurological status improves.
• Bowel management: regular aperients to prevent constipation (compounded by opioids and immobility).
• Pressure area care: regular turning, pressure-relieving mattress — the patient has reduced sensation and cannot feel pressure damage.
• Rehabilitation: early physiotherapy and occupational therapy input for mobility, transfers, and activities of daily living.
• Psychological support: the diagnosis of MSCC and the threat of permanent paraplegia are devastating — I would involve the social work and psychology teams and ensure the family is supported. ^[1]

Prognostic communication (1 mark): ^[1]

I would speak to him and his family in plain language: "You have a condition where the cancer has spread to a bone in your spine and is pressing on your spinal cord — this is why your legs have become weak and you have lost the feeling of needing to pass urine. This is a serious complication, but we can treat it. I have given you a steroid medicine to reduce the swelling, and we are arranging an urgent scan to see exactly where the pressure is. Depending on the scan, you may need an operation to relieve the pressure, followed by radiotherapy. The aim is to keep you walking and to control your pain. The sooner we act, better chance of preserving your leg function. I cannot promise full recovery, but we will do everything we can to maximise your independence." I would set realistic expectations, involve the oncology and palliative care teams for systemic disease management, and arrange regular family updates. ^[1]