Visual working memory impairment in 30 patients with myasthenia gravis

Abstract

Objective To investigate the situation of visual memory impairment in patients with myasthenia gravis (MG).Methods Thirty MG patients and 28 normal control subjects were tested with a battery of computerized tests (modified Smith working memory software), which was designed to assess visual-spatial and visual-object working memory.Results There was no significant difference in the accuracy rate of visual-object working memory test between the MG group and normal controls (MG group 73.4% ±9.7%, normal controls 72.7% ±8.5%).The accuracy rate of the visual-spatial working memory test in the MG group (76.6% ± 16.5%) was significantly lower than that in the normal controls (86.6% ±7.5%, Z = -2.204, P = 0.028).Conclusion The visual-spatial working memory is probably impaired while the visual-object working memory is relatively spared in MG patients. Key words: Myasthenia gravis; Memory disorders; Space perception