Slowly progressive pure word deafness.

Among the reports of primary progressive aphasia, there are few about patients who exhibited progressive pure word deafness with detailed auditory and radiological examination as well as neuropsychological assessment. We describe a 67-year-old right-handed man who exhibited slowly progressive pure word deafness over a period of 9 years without exhibiting any other cognitive or mental deterioration. Magnetic resonance imaging of his brain revealed generalized cortical atrophy, particularly in the left superior temporal region. Auditory examination revealed severe disability in discriminating each syllable or mora of Japanese words despite adequate auditory acuity. He also showed impairment in temporal auditory discrimination assessed by the click fusion test and the click counting test. His ability to discriminate meaningful environmental sounds was mildly impaired. We discuss the pathophysiology of slowly progressive pure word deafness over a period of many years which was not complicated by other language or cognitive dysfunctions.