The Clinical Problem Solvers Episode 443: Schema Episode – Unilateral Leg Weakness
Feb 10, 2026
A 52-year-old with progressive left leg pain and weakness sparks a diagnostic puzzle. The team debates localization between spinal, cortical, vascular, and peripheral causes. Imaging, EMG, labs, and red flags guide a deep dive into lumbosacral plexopathy and systemic causes like malignancy, inflammatory disease, and metabolic disorders. The case evolves with bilateral progression and complex next-step reasoning.
AI Snips
Chapters
Transcript
Episode notes
Localize With Pain, Weakness And Tempo
- Progressive unilateral pain then weakness localizes to either nerve or vascular causes rather than primary muscle disease.
- Early focused exam and tempo help distinguish radicular, plexus, cortical, and peripheral causes.
Use Exam To Direct Tests
- Test focal neuro signs: strength, reflexes, atrophy, and allodynia to separate lower motor neuron from central causes.
- Order targeted labs and imaging (CBC, ESR/CRP, A1c, CT/MRI) guided by localization.
Atypical Neuropathy Flags
- Asymmetric, painful motor-predominant neuropathy with atrophy and areflexia suggests plexopathy or mononeuropathy rather than typical diabetic symmetric neuropathy.
- A high ESR and protein gap point to an inflammatory or paraneoplastic process to investigate.
