Pimp Questions
โ What is the most important prognostic factor in malignant cord compression?
Pre-treatment neurologic status. Patients who are ambulatory at diagnosis have ~80% chance of remaining ambulatory. Patients who are paraplegic at diagnosis have < 10% chance of regaining ambulation. This is why immediate dexamethasone and urgent imaging matter -every hour counts. Patchell, 2005
โ Why do you NOT give prophylactic anticonvulsants for brain metastases?
Multiple RCTs show no benefit from prophylactic AEDs in brain mets without prior seizure, AND significant side effects (rash, drug interactions with chemo, sedation). AAN guidelines explicitly recommend against prophylaxis. Treat only if seizure has occurred. Levetiracetam preferred (fewer drug interactions than phenytoin).
โ Why should you avoid pRBC transfusion before plasmapheresis in hyperviscosity?
Transfusing pRBCs increases blood viscosity further by raising hematocrit. In a patient already symptomatic from hyperviscosity (IgM paraprotein causing sludging), this can precipitate stroke, retinal vein occlusion, or cardiac failure. Do plasmapheresis FIRST, then transfuse if needed afterward.
โ Name the classic triad of SVC syndrome.
Facial/upper extremity edema + dyspnea + distended neck/chest wall veins. Worse when leaning forward or lying flat. Pemberton sign: facial plethora + cyanosis when arms raised above head. Most common cause: lung cancer (especially right-sided). Second: lymphoma (more steroid-responsive).
โ What imaging do you order for suspected cord compression and why must you image the entire spine?
MRI entire spine with gadolinium contrast -gold standard. Must image the ENTIRE spine because 10-38% of patients have multiple levels of compression. Treating only the symptomatic level while missing another will lead to treatment failure. CT myelography is an alternative if MRI contraindicated.
โ When is surgery preferred over radiation for cord compression?
Surgery (decompressive laminectomy ยฑ stabilization) is preferred when: (1) unknown primary (need tissue for diagnosis), (2) radioresistant tumor (renal cell, melanoma), (3) mechanical spinal instability, (4) single level of disease with good overall prognosis, (5) progression during or after radiation. Patchell, 2005 showed surgery + RT was superior to RT alone for single-level compression.
Sample Presentation
Mr. Johnson is a 62-year-old man with known Stage IV NSCLC (right upper lobe, 3 cycles of pembrolizumab) presenting with 2 days of progressive lower extremity weakness and urinary retention. Exam: 4/5 hip flexors bilateral, absent ankle reflexes, T10 sensory level, post-void residual 400 mL. No saddle anesthesia. VS stable. MRI spine: T9-T10 epidural mass with cord compression.
Key Points: This is MSCC -give dexamethasone 10 mg IV STAT, consult radiation oncology AND spine surgery. Motor function at presentation is the strongest predictor of outcome. Ambulatory at diagnosis โ 80% remain ambulatory. Non-ambulatory โ only 10-20% regain walking.