AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisMedium
A 48-year-old male presents with worsening lower back pain radiating down his left leg to his foot, accompanied by numbness in his left great toe. He reports pain is exacerbated by sitting and relieved by standing or walking. On examination, a positive straight leg raise test is noted on the left at 45 degrees, and he has diminished sensation in the L5 dermatome. Which of the following is the most likely diagnosis?
- ALumbar strain
- BPiriformis syndrome
- CSpinal stenosis
- DSciatica due to herniated disc
Show answer & explanationAnswer & explanation
Correct answer: D. Sciatica due to herniated disc
The patient's symptoms of radicular pain (sciatica) radiating to the foot, L5 dermatomal numbness, and a positive straight leg raise test, exacerbated by sitting, are classic for a herniated lumbar disc causing nerve root compression.
Why the other options are wrong
- A. Lumbar strain typically causes localized back pain without radicular symptoms or neurological deficits.
- B. Piriformis syndrome causes sciatic-like pain but is due to compression of the sciatic nerve by the piriformis muscle, usually without dermatomal numbness or a positive straight leg raise at 45 degrees.
- C. Spinal stenosis typically causes neurogenic claudication, with pain relieved by sitting and exacerbated by standing or walking, the opposite of this patient's report.
Lumbar Disc Herniation
Protrusion of the nucleus pulposus through the annulus fibrosus, often compressing a spinal nerve root.
- Symptoms: localized back pain with radicular pain (sciatica) down leg.
- Exacerbating factors: sitting, coughing, straining.
- Physical exam: positive straight leg raise, neurological deficits (sensory, motor, reflex) corresponding to compressed nerve root.
Memory trick: Herniated disc is a 'Hot' nerve, 'Hurting' down the leg, 'Helped' by standing.