Medically unexplained neurological symptoms

A 56-year-old woman with seronegative polyarthritis presented with a four-year history of lower back pain and right-sided sciatica. On examination she had reduced power and impaired sensation in her right leg. Magnetic resonance imaging (MRI) of the spine revealed anterior degenerative slip of L4 on L5 with moderate overall reduction in canal calibre and osteophyte encroachment in the right lateral recess at that level, causing compression of the right L5 nerve root. The facet joints were subluxed and there was prominent high T2 signal between the articular surfaces. She underwent an uncomplicated L4/5 posterior spinal decompression and instrumented fusion and initially made an uneventful postoperative recovery. Five days after surgery she woke up quadriplegic. Examination initially revealed absent power (0/5 by MRC power grading). However, it was noted that the patient was able to use her limbs to help turn in the bed. In addition, the patient was able to protect herself when her paralysed arm was dropped over her face. It was possible to demonstrate brief contractions of near-normal power with encouragement. Reflexes were all present and the plantar responses were down going. There was altered sensation in all four limbs but no clear sensory level. Sphincters function was intact. Computed tomography (CT) of her brain was normal and we suspected functional weakness. The patient’s symptoms improved gradually over the course of two weeks with simple reassurance and encouragement. By the time she was discharged she had made a complete recovery.