musculoskeletal and connective tissue disorders
Lumbar Herniated Nucleus Pulposus
Diagnosis of Lumbar Herniated Nucleus Pulposus
MRI or CT Diagnosis is usually suspected during a history and physical examination and confirmed by MRI or CT. The physical examination should include the an evaluation of strength, sensation, and reflexes. Tests for dural tension should also be done. On examination, with the patient in supine with legs extended, raising the leg may cause pain to radiate down the posterior thigh to below the knee (straight leg-raising test). Pain can be bilateral with central disc herniation. Straightening the knee while sitting can produce similar pain (sitting straight-leg raising test). A variation of this test in which straightening the knee with the patient sitting and bending forward at the waist with the foot dorsiflexed is called the slump test. In upper lumbar disc herniation (L1-2, L2-3), extending the leg at the hip with the patient prone can cause pain radiating into the anterior thigh (femoral stretch test). Achilles tendon and patellar reflexes may be diminished or absent. MRI or CT can identify the cause and precise level of the lesion. Rarely (ie, when MRI is contraindicated and CT is inconclusive), CT myelography is necessary. Electrodiagnostic testing may help identify the involved root. Because an asymptomatic herniated disk is common, the clinician must carefully correlate symptoms with MRI abnormalities before invasive procedures are considered. 