Spinal segmental myoclonus associated with CASPR2 antibody confounded by tethered cord

Spinal segmental myoclonus is rhythmic or semirhythmic involuntary contractions of muscle groups supplied by one or several contiguous segments of the brainstem and/or spinal cord evident with surface electromyographic (EMG) discharges. The clinical spectrum of contactin‐associated protein‐2 (CASPR2) autoantibody‐associated disorders is more diverse and reports on unusual, sometimes isolated, and immunotherapy‐responsive movement disorders in CASPR2 autoantibody‐associated syndromes have been described. We describe a rare case of spinal segmental myoclonus associated with CASPR2 antibody.