Elevated 14-3-3 protein and axonal loss in immunoglobulin-responsive, idiopathic acute transverse myelitis

Objectives: To report the elevation of the 14-3-3 protein and the complete denervation of hand muscles in idiopathic acute transverse myelitis (IATM) of the cervical cord. Case description: In a 29-year-old woman with a 2-week history of neck pain and repeated attenuated flus, subacute quadriplegia, hypaesthesia of both arms, a T3 sensory level, and urinary dysfunction occurred. Based upon the clinical findings, the cervical MRIs, and an elevated 14-3-3 protein in the CSF, IATM C4–C7 was diagnosed. Ten, 17, 28 and 61 days after onset, nerve conduction studies revealed complete denervation of the right abductor pollicis brevis and abductor digiti minimi muscles but gradual improvement of the compound muscle action potential of the left abductor pollicis brevis muscle. F-waves of the right median nerve were absent. Tibial somatosensory evoked potentials showed a prolonged central conduction time. Transcranial magnetic stimulation evoked a response in the left but not the right abductor digiti minimi muscle. Conclusion: IATM may cause elevation of the 14-3-3 protein and loss of motor axons originating from affected anterior horn cells.