Pure alexia after damage to the right fusiform gyrus in a right-handed male.

Pure alexia refers to a rare acquired reading disorder commonly associated with damage to the posterior part of the left medial occipito-temporal (fusiform) gyrus, which is known as the visual word-form area (VWFA) and thought to be the neural basis for visual processing of letters and words. Right-sided lesions very rarely lead to pure alexia in right-handed individuals. We report a case of a 33-year-old right-handed man with isolated pure alexia resulting from a hemorrhagic lesion to the right fusiform gyrus. A limited recovery of reading skills was observed within six weeks post onset. During this period, the patient spontaneously developed a letter-by-letter reading strategy. Functional magnetic resonance imaging revealed right-hemisphere dominance for language as well as bilateral reading-related activity in the fusiform gyri. Our case indicates that pure alexia may arise as a consequence of damage to the right fusiform gyrus even in right-handed patients (who still may have right hemisphere dominance for language and reading skills), and may lead to a severe reading disorder, as in individuals with left-hemisphere dominance for language.

From single molecule to crystal: mapping out the conformations of tartaric acids and their derivatives.

Stereoisomers of one of the most important organic compounds, tartaric acid, optically active and meso as well as the ester or amide derivatives, can show diverse structures related to the rotation around the three carbon-carbon bonds. This study determines the controlling factors for conformational changes of these molecules in vacuo, in solution, and in the crystalline state using DFT calculations, spectroscopic measurements, and X-ray diffraction. All structural variations can be logically accounted for by the possibility of formation and breaking of hydrogen bonds between the hydroxy or amide donors and oxygen acceptors, among these the hydrogen bonds that close five-membered rings being the most stable. These findings are useful in designing molecular and crystal structures of highly polar, polyfunctional, chiral compounds.