PubMed1999
A 57-year-old woman presented with a slowly progressive gait disturbance in 1992 (53 years of age). Over the next year, she gradually began to talk less, but her speech itself became more rapid than before. He speech was frequently too fast even for family members to understand. In 1997, she was admitted to our hospital. On admission, the patient was disoriented but able to follow simple verbal commands, to name things, and to write simple words. Neither apraxia, aphasia, hemispatial neglect, nor a corpus callosum disconnection syndrome was observed. There was no muscle weakness or atrophy. She showed a positive Babinski sign with mild spasticity in the legs and Gegenhalten, but no rigidity. Her speech was monotonous and abnormally fast (cluttering-like speech). Her speech became faster and faster toward the end of sentences, skipping several syllables or even words. She was unable to speak slowly and clearly, even when efforts were made to pace her speech to the speed set by the examiner. She was able to stand only with a wide base of support and body flexion. When standing, she was unable to place one foot directly beside the other; as she tried to have one foot near the other, the former repelled the latter. She had great difficulties in taking her first step forward, and showed rapid freezing of gait even when she managed to succeed in starting. She was able to imitate walking or bicycling with her legs unloaded, indicating that her gait disturbance was a kind of apraxia of gait. Her intelligence was somehow difficult to assess because of her peculiar speech disturbance. However, her family members had noticed her memory disturbance and personality change (offensiveness) since 3 to 4 years before the admission. Moreover, she was defective not only on Hasegawa Damentia Scale-Revised but also on Raven's Colored Progressive Matrices which estimates non-verbal intelligence. It was also noted that she was inattentive and lazy in thinking on questionnaires. Thus we considered that she was at least mildly demented and the type of dementia was of frontal pathology. Laboratory data were all normal except for the head MRI, which demonstrated prominent and thinness of the corpus callosum from the anterior part of the body to splenium without any other brain lesions that could cause the thinness secondarily. Our case resembles two cases reported by Sunohara et al in 1985, together comprising a unique clinical feature. Although Sunohara et al did not refer to the thinness of the corpus callosum in their cases, the clinical profiles in our case and theirs raise the possibility that they form a new disease entity. A further study in a large number of similar cases, including autopsies will provide a conclusion.