Psychogenic paraplegia in a patient with normal electrophysiologic findings

Abstract

Study design: A case report of psychogenic paraplegia following a motor vehicle accident was clinically diagnosed using median (MN) and posterior tibial nerves (PTN) somatosensory evoked potentials (SSEPs). Objective: To report an unusual case of paraplegia in spite of normal electrophysiological and non-compromising radiographic spine findings. Summary of background data: Conversion disorder with motor system symptoms or deficit is a subtype which includes symptoms such as impaired motor coordination or balance, paraplegia, muscle weakness, difficulty in swallowing, and urinary retention. Methods: The SSEPs were performed by each PTN at the ankle region behind the medial malleolus or the MN at the wrist using square wave pulses in 15 mA intensity. The SSEPs revealed well-developed somatosensory peaks for all extremities. Results: Well-resolved MN-SSEPs were seen with stimulation of either arm. The principal peaks of N20 and P22 were 17 and 21 ms for both upper extremities. The principal peaks of P37 and N45 were 35 and 46 ms for both lower extremities. No side-to-side latency difference was noted. The MRI scan finding was a non-displaced L1 fracture without spinal canal compromise. Conclusions: In spite of an apparent paraplegia, contradictory clinical findings, normal neurophysiologic tests, and normal neuroradiologic findings are positive criteria for paraplegia/quadriplegia with psychogenic etiology.