[Two cases of pure agraphia developed after thalamic hemorrhage]

We have observed two cases suffered from left thalamic hemorrhage, that showed pure agraphia. The first case was a 49 year-old, right handed male, who was educated through 11th grade. The CT scan revealed left thalamic hemorrhage with ventricular casting. The second case was a 48 year- old, right handed male, who was educated through 9th grade. The CT scan revealed left thalamic hemorrhage which is smaller than that of the first case, without intraventricular rupture. With a standard neuropsychological evaluation performed at chronic stage, neither cases showed oral language disorder, apraxia and agnosia. On the Wechsler Adult Intelligence Scale, total IQ of the first and second case were 71 and 80 respectively. Each case developed severe writing disorder. The first case showed severe neographism and scrawl, mild literal paragraphia, which were frequently accompanied with perseveration. The second case showed literal paragraphia and no response, but neographism was not detected. The common characteristics of both cases were; 1) intact copy writing. 2) discrepancy between difficulty in writing "Kana" and that in "Kanji". 3) anosognosia of agraphia. The cerebral blood flow study by 123I-IMP Single photon emission computed tomography revealed low perfusion of the left cerebral hemisphere in both cases. From these findings, we concluded that dysfunction of the left cerebral cortex is responsible for producing agraphia in these cases.