Lateral femoral cutaneous nerve conduction v somatosensory evoked potentials for electrodiagnosis of meralgia paresthetica.

The aim of this study is to compare sensory nerve conduction with somatosensory evoked potentials of the lateral femoral cutaneous nerve to determine which is the most reliable electrodiagnostic method to assess meralgia paresthetica. Thirty patients with unilateral clinically defined meralgia paresthetica and 30 controls were studied with both methods. The main outcome measures were sensory action potential side-to-side amplitude ratio, somatosensory evoked potentials side-to-side latency difference, and side-to-side amplitude ratio. Sensory nerve conduction was abnormal in all patients: only four participants had abnormal somatosensory evoked potentials with double derivation (Fz/Cz and Ci/Cc) recording, and eight participants had abnormal findings with Fz/Cz derivation. Overall, this study demonstrates that sensory nerve conduction is the more reliable method for meralgia paresthetica electrodiagnosis. In fact, only very serious nerve damage regularly induces abnormal somatosensory evoked potentials, which is not recommended for routine electrodiagnostic study of meralgia paresthetica.