Sinistrad mirror writing and reading after brain concussion in a bi-systemic (oriento-occidental) polyglot.

The problem of mirror writing and reading is discussed in the light of a clinical case, where this disturbance appeared after an apparently minor head injury. Mirror writing and reading in this polyglot individual affected only the sinistrad (Hebrew) writing and reading system, leaving the dextrad (Latin) system unimpaired. This disturbance appeared together with dyscalculia, left-right disorientation and slight temporal confusion, suggestive of parieto-occipital lobe pathology. The clinical picture also showed apparently "conversional" traits, such as are sometimes seen in incomplete parietal lobe syndromes. The relevant literature is reviewed and patho-physiological mechanisms of mirror reversal are discussed.