Slowly progressive limb-kinetic apraxia.

The case of a 69-year-old female with slowly progressive limb-kinetic apraxia (LKA) of the right hand over 3.5 years is reported. She did not show any other neurological or neuropsychological symptoms except for a defect in two-point discrimination, and 3.5 years after onset she developed a slight cogwheel-like muscle tone in the right wrist. Brain MRI revealed atrophic changes in the left central region including the precentral and postcentral gyri and the superior parietal region, and among them, most strikingly at the postcentral gyrus. 123I-IMP SPECT revealed decreased 123I uptake in the atrophic lesion as revealed by MRI. We should suspect corticobasal degeneration as the etiology for this patient taking her symptoms and findings on MRI and SPECT into consideration. However, her symptoms and course were quite unique among the case reports of patients with slowly progressive LKA as she had only LKA and a defect in two-point discrimination for more than 3.5 years without any other symptoms. This characteristic also indicated that the simultaneous appearance of LKA and a defect in two-point discrimination may suggest a mechanism of LKA in the present patient.