[Acquired stuttering associated with callosal infarction: a case report].

A 66-year-old right-handed man with acquired stuttering was reported. He complained of paresis in his left leg and speech dysfluency. He was not aphasic in terms of comprehension and writing. His speech dysfluency was mainly characterized by initial syllable repetitions. He has apraxia with his left hand, but has neither agraphia with his left hand nor crossed optic ataxia. MRI showed cerebral infarction in the truncus of the corpus callosum, and angiography revealed occlusion of the right anterior cerebral artery. 99mTc HM-PAO SPECT showed decreased blood flow in the right frontal lobe. Within six months of its onset, the patient's speech dysfluency had diminished. As the causative lesion for acquired stuttering, we proposed a hemispheric lesion in addition to a callosal lesion.