About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
Key points
- Saddle anaesthesia, urinary retention or new bowel/bladder dysfunction is cauda equina until proven otherwise.
- Cancer history plus new severe back pain or neurological deficit is malignant spinal cord compression until proven otherwise.
- Fever, IVDU, immunosuppression or recent spinal procedure raises concern for spinal epidural abscess.
- Progressive motor weakness is more urgent than pain severity alone.
- MRI is the key investigation for cord, cauda equina, infection and malignancy.
Approach to the Presentation
Start with red flags, not analgesic choice. Ask about bladder retention/incontinence, saddle sensory change, bilateral sciatica, progressive weakness, gait, fever, cancer, trauma, steroid use, anticoagulation and IVDU. Examine power, reflexes, sensation, perianal sensation, anal tone where appropriate, gait and post-void residual.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Cauda equina syndrome | must-not-miss | Saddle anaesthesia, urinary retention, overflow incontinence, bilateral sciatica, reduced anal tone, leg weakness | Urgent MRI lumbosacral spine; post-void residual supports |
| Malignant spinal cord compression | must-not-miss | Cancer history, night pain, thoracic pain, progressive weakness, sensory level, bladder/bowel symptoms | Urgent MRI whole spine |
| Spinal epidural abscess | must-not-miss | Back pain, fever, neurological deficit; IVDU, diabetes, immunosuppression, recent procedure | MRI with contrast, blood cultures, ESR/CRP |
| Spinal fracture | must-not-miss | Trauma, osteoporosis, steroid use, focal bony tenderness | X-ray/CT; MRI if neuro deficit |
| Cervical/thoracic myelopathy | must-not-miss | Spastic gait, hand clumsiness, hyperreflexia, sensory level | MRI spine |
| Lumbar radiculopathy | common | Dermatomal leg pain, positive straight leg raise, reflex/myotome change | Clinical; MRI if severe/progressive or persistent |
| Spinal stenosis | common | Neurogenic claudication worse walking/extension, relieved sitting/flexion | MRI if functionally significant |
| Mechanical low back pain | common | Pain without neurological deficit or red flags | Clinical; no routine imaging |
Red Flags & Key History
Symptoms
Urinary retention, saddle anaesthesia or new incontinence
Progressive leg weakness or bilateral sciatica
Fever, IVDU, immunosuppression
Cancer history, unexplained weight loss or night pain
Radicular pain without deficit
Signs
Reduced anal tone/perianal sensation
Post-void residual elevation
UMN signs/sensory level
Dermatomal sensory loss/reflex change
Approach to Investigation
First-line
Focused neurological examPower, reflexes, dermatomes, gait, saddle sensation and sphincter assessment when indicated.
Post-void residual bladder scanUrinary retention supports cauda equina but normal result does not fully exclude.
ESR/CRP, CBC, culturesIf infection or malignancy suspected.
Second-line
Urgent MRI spineCauda equina, cord compression, epidural abscess, progressive deficit or myelopathy.
CT spineTrauma/fracture assessment or when MRI temporarily unavailable.
Specialist
Neurosurgery/orthopaedic spineCauda equina, cord compression, progressive deficit.
Oncology/radiation oncologyMalignant spinal cord compression.
Management Principles
Canadian Association of Radiologists Spine Referral Guideline + CFPC low back pain guidance1
Cauda equina
- Urgent MRI and immediate spine surgery consultation
- Keep NPO and manage pain; do not delay for outpatient imaging
2
Malignant cord compression
- Urgent MRI whole spine
- Dexamethasone if suspected malignant cord compression unless contraindicated
- Spine surgery/radiation oncology urgently
3
Epidural abscess
- Blood cultures, MRI with contrast, broad-spectrum IV antibiotics after cultures if stable; immediate antibiotics if septic
- Surgical drainage if neurological deficit or instability
4
Non-red-flag radiculopathy
- Analgesia, activity, physiotherapy; imaging only if severe/progressive deficit or persistent symptoms
Complications & Pitfalls
- Asking only about incontinence: urinary retention often comes first.
- Missing thoracic pain: thoracic back pain is more concerning for malignancy/infection.
- Normal x-ray reassurance: cord/cauda/infection require MRI.
- Delaying referral: cauda equina and cord compression are time-sensitive.
MCCQE1 Exam Tips
- 1Saddle anaesthesia + urinary retention = urgent MRI.
- 2Cancer history + new neuro back pain = malignant cord compression.
- 3Epidural abscess triad is uncommon; do not require all three features.
- 4MRI is the investigation for cauda equina and cord compression.
- 5Routine mechanical low back pain does not need imaging.
- 6Progressive motor deficit is a red flag even without severe pain.
Put your reading into practice
Topic-specific question practice is not linked for this article yet.
Choose MCCQE Part I questions from the existing bank. General exam practice covers your selected topics; it is not filtered to this article. Your usual question-bank access applies.
Choose MCCQE Part I practiceAfter your session, return to this section to revisit the reading and choose your next review.
Verified Sources & References
related resources
Save your place and choose what comes next
Neurological · Article 17 of 39