Bimanual mirror letter writing: a post-traumatic case

Mirror writing is inverse writing that can only be read with the help of a mirror. It is generally associated with dominant hemisphere lesions and affects only one hand. We describe the case of a patient who, after cranial injury, developed bimanual mirror writing for letters but no other focal neurological symptom. The only abnormal complementary finding was a zone of left parieto-occipital hypoperfusion visibly by SPECT. No signs of psychological disorder were present to which the dysgraphia could be attributed. Symptoms disappeared after three months. We conclude that isolated bimanual mirror letter writing may be an expression of reversible parieto-occipital dysfunction of the dominant hemisphere.