Myoclonia continua in primary CNS natural killer/T-cell lymphoma, nasal type

A 58-year-old right-handed man presented with 3 months gradual worsening of twitching in his left hand. He had no remarkable medical or family history. Examination demonstrated continuous twitching in his left upper limb and dystonic posture of his left hand (videos 1 and 2 at [Neurology.org][1]). Superficial, deep, and cortical sensations were not disturbed in his left upper limb. Acknowledgment: The authors thank Drs. Shigeru Nishizawa and Mayu Takahashi from the Department of Neurosurgery, University of Occupational and Environmental Health School of Medicine, for performing open brain biopsy. [1]: http://neurology.org/lookup/doi/10.1212/WNL.0000000000003515