Transient involuntary mirror writing triggered by anxiety.

Mirror writing (MW) has mainly been observed in left-hemisphere-damaged patients writing with the left hand. This study evaluated the presence of MW in 24 patients with mild cognitive impairment (MCI). We found that MW is not a typical feature of MCI. However, one woman (FC), mislabeled initially with MCI but in fact affected by anxiety, showed florid MW when writing with her left hand, which resolved as her anxiety receded. This case study supports anecdotal reports of MW triggered by anxiety, and the features of FC's performance indicate a motor rather than a perceptual basis for the phenomenon.